2018
28.
Ossadtchi, A.; Altukhov, D.; Jerbi, K. (2018). Phase shift invariant imaging of coherent sources (PSIICOS) from MEG data. NeuroImage, 183, 950-971. https://doi.org/10.1016/j.neuroimage.2018.08.031
@article{Ossadtchi2018,
title = {Phase shift invariant imaging of coherent sources (PSIICOS) from MEG data},
author = {A. Ossadtchi and D. Altukhov and K. Jerbi},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1016_j.neuroimage.2018.08.031.pdf},
doi = {10.1016/j.neuroimage.2018.08.031},
issn = {1053-8119},
year = {2018},
date = {2018-12-00},
urldate = {2018-12-00},
journal = {NeuroImage},
volume = {183},
pages = {950-971},
publisher = {Elsevier BV},
abstract = {Increasing evidence suggests that neuronal communication is a defining property of functionally specialized brain networks and that it is implemented through synchronization between population activities of distinct brain areas. The detection of long-range coupling in electroencephalography (EEG) and magnetoencephalography (MEG) data using conventional metrics (such as coherence or phase-locking value) is by definition contaminated by spatial leakage. Methods such as imaginary coherence, phase-lag index or orthogonalized amplitude correlations tackle spatial leakage by ignoring zero-phase interactions. Although useful, these metrics will by construction lead to false negatives in cases where true zero-phase coupling exists in the data and will underestimate interactions with phase lags in the vicinity of zero. Yet, empirically observed neuronal synchrony in invasive recordings indicates that it is not uncommon to find zero or close-to-zero phase lag between the activity profiles of coupled neuronal assemblies.
Here, we introduce a novel method that allows us to mitigate the undesired spatial leakage effects and detect zero and near zero phase interactions. To this end, we propose a projection operation that operates on sensor-space cross-spectrum and suppresses the spatial leakage contribution but retains the true zero-phase interaction component. We then solve the network estimation task as a source estimation problem defined in the product space of interacting source topographies. We show how this framework provides reliable interaction detection for all phase-lag values and we thus refer to the method as Phase Shift Invariant Imaging of Coherent Sources (PSIICOS).
Realistic simulations demonstrate that PSIICOS has better detector characteristics than existing interaction metrics. Finally, we illustrate the performance of PSIICOS by applying it to real MEG dataset recorded during a standard mental rotation task. Taken together, using analytical derivations, data simulations and real brain data, this study presents a novel source-space MEG/EEG connectivity method that overcomes previous limitations and for the first time allows for the estimation of true zero-phase coupling via non-invasive electrophysiological recordings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Increasing evidence suggests that neuronal communication is a defining property of functionally specialized brain networks and that it is implemented through synchronization between population activities of distinct brain areas. The detection of long-range coupling in electroencephalography (EEG) and magnetoencephalography (MEG) data using conventional metrics (such as coherence or phase-locking value) is by definition contaminated by spatial leakage. Methods such as imaginary coherence, phase-lag index or orthogonalized amplitude correlations tackle spatial leakage by ignoring zero-phase interactions. Although useful, these metrics will by construction lead to false negatives in cases where true zero-phase coupling exists in the data and will underestimate interactions with phase lags in the vicinity of zero. Yet, empirically observed neuronal synchrony in invasive recordings indicates that it is not uncommon to find zero or close-to-zero phase lag between the activity profiles of coupled neuronal assemblies.
Here, we introduce a novel method that allows us to mitigate the undesired spatial leakage effects and detect zero and near zero phase interactions. To this end, we propose a projection operation that operates on sensor-space cross-spectrum and suppresses the spatial leakage contribution but retains the true zero-phase interaction component. We then solve the network estimation task as a source estimation problem defined in the product space of interacting source topographies. We show how this framework provides reliable interaction detection for all phase-lag values and we thus refer to the method as Phase Shift Invariant Imaging of Coherent Sources (PSIICOS).
Realistic simulations demonstrate that PSIICOS has better detector characteristics than existing interaction metrics. Finally, we illustrate the performance of PSIICOS by applying it to real MEG dataset recorded during a standard mental rotation task. Taken together, using analytical derivations, data simulations and real brain data, this study presents a novel source-space MEG/EEG connectivity method that overcomes previous limitations and for the first time allows for the estimation of true zero-phase coupling via non-invasive electrophysiological recordings.
Here, we introduce a novel method that allows us to mitigate the undesired spatial leakage effects and detect zero and near zero phase interactions. To this end, we propose a projection operation that operates on sensor-space cross-spectrum and suppresses the spatial leakage contribution but retains the true zero-phase interaction component. We then solve the network estimation task as a source estimation problem defined in the product space of interacting source topographies. We show how this framework provides reliable interaction detection for all phase-lag values and we thus refer to the method as Phase Shift Invariant Imaging of Coherent Sources (PSIICOS).
Realistic simulations demonstrate that PSIICOS has better detector characteristics than existing interaction metrics. Finally, we illustrate the performance of PSIICOS by applying it to real MEG dataset recorded during a standard mental rotation task. Taken together, using analytical derivations, data simulations and real brain data, this study presents a novel source-space MEG/EEG connectivity method that overcomes previous limitations and for the first time allows for the estimation of true zero-phase coupling via non-invasive electrophysiological recordings.
27.
Yaple, Zachary; Martinez-Saito, Mario; Novikov, Nikita; Altukhov, Dmitrii; Shestakova, Anna; Klucharev, Vasily (2018). Power of Feedback-Induced Beta Oscillations Reflect Omission of Rewards: Evidence From an EEG Gambling Study. Frontiers in Neuroscience, 12. https://doi.org/10.3389/fnins.2018.00776
@article{Yaple2018,
title = {Power of Feedback-Induced Beta Oscillations Reflect Omission of Rewards: Evidence From an EEG Gambling Study},
author = {Zachary Yaple and Mario Martinez-Saito and Nikita Novikov and Dmitrii Altukhov and Anna Shestakova and Vasily Klucharev},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnins.2018.00776.pdf},
doi = {10.3389/fnins.2018.00776},
issn = {1662-453X},
year = {2018},
date = {2018-10-30},
urldate = {2018-10-30},
journal = {Frontiers in Neuroscience},
volume = {12},
publisher = {Frontiers Media SA},
abstract = {The functional role of high beta oscillations (20–35 Hz) during feedback processing has been suggested to reflect unexpected gains. Using a novel gambling task that separates gains and losses across blocks and directly compares reception of monetary rewards to a ‘no-reward/punishment’ condition with equal probability we aimed to further investigate the role of beta oscillations. When contrasting different feedback conditions across rewards, we found that a late low beta component (12–20 Hz) had increased in power during the omission of rewards relative to the reception of rewards, while no differences were observed during the loss domain. These findings may indicate that late low beta oscillations in the context of feedback processing may respond to omission of gains relative to other potential outcomes. We speculate that late low beta oscillations may operate as a learning mechanism that signals the brain to make future adequate decisions. Overall, our study provides new insights for the role of late low beta oscillations in reward processing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The functional role of high beta oscillations (20–35 Hz) during feedback processing has been suggested to reflect unexpected gains. Using a novel gambling task that separates gains and losses across blocks and directly compares reception of monetary rewards to a ‘no-reward/punishment’ condition with equal probability we aimed to further investigate the role of beta oscillations. When contrasting different feedback conditions across rewards, we found that a late low beta component (12–20 Hz) had increased in power during the omission of rewards relative to the reception of rewards, while no differences were observed during the loss domain. These findings may indicate that late low beta oscillations in the context of feedback processing may respond to omission of gains relative to other potential outcomes. We speculate that late low beta oscillations may operate as a learning mechanism that signals the brain to make future adequate decisions. Overall, our study provides new insights for the role of late low beta oscillations in reward processing.
26.
Sysoeva, Olga V.; Constantino, John N.; Anokhin, Andrey P. (2018). Event-related potential (ERP) correlates of face processing in verbal children with autism spectrum disorders (ASD) and their first-degree relatives: a family study. Molecular Autism, 9(1), 41. https://doi.org/10.1186/s13229-018-0220-x
@article{Sysoeva2018,
title = {Event-related potential (ERP) correlates of face processing in verbal children with autism spectrum disorders (ASD) and their first-degree relatives: a family study},
author = {Olga V. Sysoeva and John N. Constantino and Andrey P. Anokhin},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1186_s13229-018-0220-x.pdf},
doi = {10.1186/s13229-018-0220-x},
issn = {2040-2392},
year = {2018},
date = {2018-07-05},
urldate = {2018-07-05},
journal = {Molecular Autism},
volume = {9},
number = {1},
pages = {41},
publisher = {Springer Science and Business Media LLC},
abstract = {Background
Inherited abnormalities of perception, recognition, and attention to faces have been implicated in the etiology of autism spectrum disorders (ASD) including abnormal components of event-related brain potentials (ERP) elicited by faces.
Methods
We examined familial aggregation of face processing ERP abnormalities previously implicated in ASD in 49 verbal individuals with ASD, 36 unaffected siblings (US), 18 unaffected fathers (UF), and 53 unrelated controls (UC). The ASD, US, and UC groups ranged in age from 12 to 21 years, the UF group ranged in age from 30 to 56 years. ERP responses to images of upright and inverted faces and houses were analyzed under disparate EEG reference schemes.
Results
Face-sensitive features of N170 and P1 were readily observed in all groups. Differences between ASD and control groups depended upon the EEG reference scheme. Notably, the superiority of face over object for N170 latency was attenuated in ASD subjects, but not their relatives; this occurred exclusively with the average reference. The difference in N170 amplitude between inverted and upright faces was reduced in both ASD and US groups relative to UC, but this effect was significant only with the vertex reference. Furthermore, similar group differences were observed for both inverted faces and inverted houses, suggesting a lack of face specificity for the attenuation of the N170 inversion effect in ASD.
Conclusion
The present findings refine understanding of face processing ERPs in ASD. These data provide only modest evidence for highly-selective ASD-sensitive ERP features, and underscore the sensitivity of these biomarkers to ERP reference scheme. These schemes have varied across published studies and must be accounted for in future studies of the relationship between these commonly acquired ERP characteristics, genotype, and ASD.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Inherited abnormalities of perception, recognition, and attention to faces have been implicated in the etiology of autism spectrum disorders (ASD) including abnormal components of event-related brain potentials (ERP) elicited by faces.
Methods
We examined familial aggregation of face processing ERP abnormalities previously implicated in ASD in 49 verbal individuals with ASD, 36 unaffected siblings (US), 18 unaffected fathers (UF), and 53 unrelated controls (UC). The ASD, US, and UC groups ranged in age from 12 to 21 years, the UF group ranged in age from 30 to 56 years. ERP responses to images of upright and inverted faces and houses were analyzed under disparate EEG reference schemes.
Results
Face-sensitive features of N170 and P1 were readily observed in all groups. Differences between ASD and control groups depended upon the EEG reference scheme. Notably, the superiority of face over object for N170 latency was attenuated in ASD subjects, but not their relatives; this occurred exclusively with the average reference. The difference in N170 amplitude between inverted and upright faces was reduced in both ASD and US groups relative to UC, but this effect was significant only with the vertex reference. Furthermore, similar group differences were observed for both inverted faces and inverted houses, suggesting a lack of face specificity for the attenuation of the N170 inversion effect in ASD.
Conclusion
The present findings refine understanding of face processing ERPs in ASD. These data provide only modest evidence for highly-selective ASD-sensitive ERP features, and underscore the sensitivity of these biomarkers to ERP reference scheme. These schemes have varied across published studies and must be accounted for in future studies of the relationship between these commonly acquired ERP characteristics, genotype, and ASD.
Inherited abnormalities of perception, recognition, and attention to faces have been implicated in the etiology of autism spectrum disorders (ASD) including abnormal components of event-related brain potentials (ERP) elicited by faces.
Methods
We examined familial aggregation of face processing ERP abnormalities previously implicated in ASD in 49 verbal individuals with ASD, 36 unaffected siblings (US), 18 unaffected fathers (UF), and 53 unrelated controls (UC). The ASD, US, and UC groups ranged in age from 12 to 21 years, the UF group ranged in age from 30 to 56 years. ERP responses to images of upright and inverted faces and houses were analyzed under disparate EEG reference schemes.
Results
Face-sensitive features of N170 and P1 were readily observed in all groups. Differences between ASD and control groups depended upon the EEG reference scheme. Notably, the superiority of face over object for N170 latency was attenuated in ASD subjects, but not their relatives; this occurred exclusively with the average reference. The difference in N170 amplitude between inverted and upright faces was reduced in both ASD and US groups relative to UC, but this effect was significant only with the vertex reference. Furthermore, similar group differences were observed for both inverted faces and inverted houses, suggesting a lack of face specificity for the attenuation of the N170 inversion effect in ASD.
Conclusion
The present findings refine understanding of face processing ERPs in ASD. These data provide only modest evidence for highly-selective ASD-sensitive ERP features, and underscore the sensitivity of these biomarkers to ERP reference scheme. These schemes have varied across published studies and must be accounted for in future studies of the relationship between these commonly acquired ERP characteristics, genotype, and ASD.
25.
Orekhova, Elena V.; Sysoeva, Olga V.; Schneiderman, Justin F.; Lundström, Sebastian; Galuta, Ilia A.; Goiaeva, Dzerasa E.; Prokofyev, Andrey O.; Riaz, Bushra; Keeler, Courtney; Hadjikhani, Nouchine; Gillberg, Christopher; Stroganova, Tatiana A. (2018). Input-dependent modulation of MEG gamma oscillations reflects gain control in the visual cortex. Scientific reports, 8(1), 8451. https://doi.org/10.1038/s41598-018-26779-6
@article{Orekhova2018c,
title = {Input-dependent modulation of MEG gamma oscillations reflects gain control in the visual cortex},
author = {Elena V. Orekhova and Olga V. Sysoeva and Justin F. Schneiderman and Sebastian Lundström and Ilia A. Galuta and Dzerasa E. Goiaeva and Andrey O. Prokofyev and Bushra Riaz and Courtney Keeler and Nouchine Hadjikhani and Christopher Gillberg and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1038_s41598-018-26779-6.pdf},
doi = {10.1038/s41598-018-26779-6},
issn = {2045-2322},
year = {2018},
date = {2018-05-31},
urldate = {2018-05-31},
journal = {Scientific reports},
volume = {8},
number = {1},
pages = {8451},
publisher = {Springer Science and Business Media LLC},
abstract = {Gamma-band oscillations arise from the interplay between neural excitation (E) and inhibition (I) and may provide a non-invasive window into the state of cortical circuitry. A bell-shaped modulation of gamma response power by increasing the intensity of sensory input was observed in animals and is thought to reflect neural gain control. Here we sought to find a similar input-output relationship in humans with MEG via modulating the intensity of a visual stimulation by changing the velocity/temporal-frequency of visual motion. In the first experiment, adult participants observed static and moving gratings. The frequency of the MEG gamma response monotonically increased with motion velocity whereas power followed a bell-shape. In the second experiment, on a large group of children and adults, we found that despite drastic developmental changes in frequency and power of gamma oscillations, the relative suppression at high motion velocities was scaled to the same range of values across the life-span. In light of animal and modeling studies, the modulation of gamma power and frequency at high stimulation intensities characterizes the capacity of inhibitory neurons to counterbalance increasing excitation in visual networks. Gamma suppression may thus provide a non-invasive measure of inhibitory-based gain control in the healthy and diseased brain.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gamma-band oscillations arise from the interplay between neural excitation (E) and inhibition (I) and may provide a non-invasive window into the state of cortical circuitry. A bell-shaped modulation of gamma response power by increasing the intensity of sensory input was observed in animals and is thought to reflect neural gain control. Here we sought to find a similar input-output relationship in humans with MEG via modulating the intensity of a visual stimulation by changing the velocity/temporal-frequency of visual motion. In the first experiment, adult participants observed static and moving gratings. The frequency of the MEG gamma response monotonically increased with motion velocity whereas power followed a bell-shape. In the second experiment, on a large group of children and adults, we found that despite drastic developmental changes in frequency and power of gamma oscillations, the relative suppression at high motion velocities was scaled to the same range of values across the life-span. In light of animal and modeling studies, the modulation of gamma power and frequency at high stimulation intensities characterizes the capacity of inhibitory neurons to counterbalance increasing excitation in visual networks. Gamma suppression may thus provide a non-invasive measure of inhibitory-based gain control in the healthy and diseased brain.
24.
Koptelova, A.; Bikmullina, R.; Medvedovsky, M.; Novikova, S.; Golovteev, A.; Grinenko, O.; Korsakova, M.; Kozlova, A.; Arkhipova, N.; Vorobyev, A.; Melikyan, A.; Paetau, R.; Stroganova, T.; Metsähonkala, L. (2018). Ictal and interictal MEG in pediatric patients with tuberous sclerosis and drug resistant epilepsy. Epilepsy Research, 140, 162-165. https://doi.org/10.1016/j.eplepsyres.2017.12.014
@article{Koptelova2018,
title = {Ictal and interictal MEG in pediatric patients with tuberous sclerosis and drug resistant epilepsy},
author = {A. Koptelova and R. Bikmullina and M. Medvedovsky and S. Novikova and A. Golovteev and O. Grinenko and M. Korsakova and A. Kozlova and N. Arkhipova and A. Vorobyev and A. Melikyan and R. Paetau and T. Stroganova and L. Metsähonkala},
doi = {10.1016/j.eplepsyres.2017.12.014},
issn = {0920-1211},
year = {2018},
date = {2018-02-00},
urldate = {2018-02-00},
journal = {Epilepsy Research},
volume = {140},
pages = {162-165},
publisher = {Elsevier BV},
abstract = {Purpose: Drug resistant epilepsy (DRE) is common in patients with tuberous sclerosis (TS). Interictal MEG has been shown as a valuable instrument in the presurgical workup. The goal of our study was to evaluate the role of ictal MEG in epileptogenic tuber selection, especially in patients with multiple irritative zones.
Methods: The clinical and MEG data of 23 patients with TS and DRE from two medical/research centers were reviewed. Seven pediatric patients, who had seizures during MEG recording and underwent resection or disconnection surgery, were included into the study. Cortical sources of ictal and interictal epileptiform MEG discharges were compared with epileptogenic zone location in six patients with favorable surgery outcome.
Results: In patients who improved substantially after surgery all resected and several other tubers demonstrated epileptiform activity on interictal MEG. Ictal MEG provided crucial information about lobar location of the seizure onset zone (SOZ) in two cases, and in the other four it confirmed the SOZ location derived from the interictal data. In one case, ictal MEG findings were unreliable. In one patient, who did not benefit from surgical treatment, the resected tubers did not overlap with interictal and ictal MEG sources.
Conclusion: The combination of interictal and ictal MEG is a valuable tool for identification of the epileptogenic tuber/tubers in presurgical work-up in patients with TS.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Purpose: Drug resistant epilepsy (DRE) is common in patients with tuberous sclerosis (TS). Interictal MEG has been shown as a valuable instrument in the presurgical workup. The goal of our study was to evaluate the role of ictal MEG in epileptogenic tuber selection, especially in patients with multiple irritative zones.
Methods: The clinical and MEG data of 23 patients with TS and DRE from two medical/research centers were reviewed. Seven pediatric patients, who had seizures during MEG recording and underwent resection or disconnection surgery, were included into the study. Cortical sources of ictal and interictal epileptiform MEG discharges were compared with epileptogenic zone location in six patients with favorable surgery outcome.
Results: In patients who improved substantially after surgery all resected and several other tubers demonstrated epileptiform activity on interictal MEG. Ictal MEG provided crucial information about lobar location of the seizure onset zone (SOZ) in two cases, and in the other four it confirmed the SOZ location derived from the interictal data. In one case, ictal MEG findings were unreliable. In one patient, who did not benefit from surgical treatment, the resected tubers did not overlap with interictal and ictal MEG sources.
Conclusion: The combination of interictal and ictal MEG is a valuable tool for identification of the epileptogenic tuber/tubers in presurgical work-up in patients with TS.
Methods: The clinical and MEG data of 23 patients with TS and DRE from two medical/research centers were reviewed. Seven pediatric patients, who had seizures during MEG recording and underwent resection or disconnection surgery, were included into the study. Cortical sources of ictal and interictal epileptiform MEG discharges were compared with epileptogenic zone location in six patients with favorable surgery outcome.
Results: In patients who improved substantially after surgery all resected and several other tubers demonstrated epileptiform activity on interictal MEG. Ictal MEG provided crucial information about lobar location of the seizure onset zone (SOZ) in two cases, and in the other four it confirmed the SOZ location derived from the interictal data. In one case, ictal MEG findings were unreliable. In one patient, who did not benefit from surgical treatment, the resected tubers did not overlap with interictal and ictal MEG sources.
Conclusion: The combination of interictal and ictal MEG is a valuable tool for identification of the epileptogenic tuber/tubers in presurgical work-up in patients with TS.
23.
Kozunov, Vladimir; Nikolaeva, Anastasia; Stroganova, Tatiana A. (2018). Categorization for Faces and Tools—Two Classes of Objects Shaped by Different Experience—Differs in Processing Timing, Brain Areas Involved, and Repetition Effects. Frontiers in Human Neuroscience, 11, 650. https://doi.org/10.3389/fnhum.2017.00650
@article{Kozunov2018,
title = {Categorization for Faces and Tools—Two Classes of Objects Shaped by Different Experience—Differs in Processing Timing, Brain Areas Involved, and Repetition Effects},
author = {Vladimir Kozunov and Anastasia Nikolaeva and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnhum.2017.00650.pdf},
doi = {10.3389/fnhum.2017.00650},
issn = {1662-5161},
year = {2018},
date = {2018-01-09},
urldate = {2018-01-09},
journal = {Frontiers in Human Neuroscience},
volume = {11},
pages = {650},
publisher = {Frontiers Media SA},
abstract = {The brain mechanisms that integrate the separate features of sensory input into a meaningful percept depend upon the prior experience of interaction with the object and differ between categories of objects. Recent studies using representational similarity analysis (RSA) have characterized either the spatial patterns of brain activity for different categories of objects or described how category structure in neuronal representations emerges in time, but never simultaneously. Here we applied a novel, region-based, multivariate pattern classification approach in combination with RSA to magnetoencephalography data to extract activity associated with qualitatively distinct processing stages of visual perception. We asked participants to name what they see whilst viewing bitonal visual stimuli of two categories predominantly shaped by either value-dependent or sensorimotor experience, namely faces and tools, and meaningless images. We aimed to disambiguate the spatiotemporal patterns of brain activity between the meaningful categories and determine which differences in their processing were attributable to either perceptual categorization per se, or later-stage mentalizing-related processes. We have extracted three stages of cortical activity corresponding to low-level processing, category-specific feature binding, and supra-categorical processing. All face-specific spatiotemporal patterns were associated with bilateral activation of ventral occipito-temporal areas during the feature binding stage at 140–170 ms. The tool-specific activity was found both within the categorization stage and in a later period not thought to be associated with binding processes. The tool-specific binding-related activity was detected within a 210–220 ms window and was located to the intraparietal sulcus of the left hemisphere. Brain activity common for both meaningful categories started at 250 ms and included widely distributed assemblies within parietal, temporal, and prefrontal regions. Furthermore, we hypothesized and tested whether activity within face and tool-specific binding-related patterns would demonstrate oppositely acting effects following procedural perceptual learning. We found that activity in the ventral, face-specific network increased following the stimuli repetition. In contrast, tool processing in the dorsal network adapted by reducing its activity over the repetition period. Altogether, we have demonstrated that activity associated with visual processing of faces and tools during the categorization stage differ in processing timing, brain areas involved, and in their dynamics underlying stimuli learning.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The brain mechanisms that integrate the separate features of sensory input into a meaningful percept depend upon the prior experience of interaction with the object and differ between categories of objects. Recent studies using representational similarity analysis (RSA) have characterized either the spatial patterns of brain activity for different categories of objects or described how category structure in neuronal representations emerges in time, but never simultaneously. Here we applied a novel, region-based, multivariate pattern classification approach in combination with RSA to magnetoencephalography data to extract activity associated with qualitatively distinct processing stages of visual perception. We asked participants to name what they see whilst viewing bitonal visual stimuli of two categories predominantly shaped by either value-dependent or sensorimotor experience, namely faces and tools, and meaningless images. We aimed to disambiguate the spatiotemporal patterns of brain activity between the meaningful categories and determine which differences in their processing were attributable to either perceptual categorization per se, or later-stage mentalizing-related processes. We have extracted three stages of cortical activity corresponding to low-level processing, category-specific feature binding, and supra-categorical processing. All face-specific spatiotemporal patterns were associated with bilateral activation of ventral occipito-temporal areas during the feature binding stage at 140–170 ms. The tool-specific activity was found both within the categorization stage and in a later period not thought to be associated with binding processes. The tool-specific binding-related activity was detected within a 210–220 ms window and was located to the intraparietal sulcus of the left hemisphere. Brain activity common for both meaningful categories started at 250 ms and included widely distributed assemblies within parietal, temporal, and prefrontal regions. Furthermore, we hypothesized and tested whether activity within face and tool-specific binding-related patterns would demonstrate oppositely acting effects following procedural perceptual learning. We found that activity in the ventral, face-specific network increased following the stimuli repetition. In contrast, tool processing in the dorsal network adapted by reducing its activity over the repetition period. Altogether, we have demonstrated that activity associated with visual processing of faces and tools during the categorization stage differ in processing timing, brain areas involved, and in their dynamics underlying stimuli learning.
22.
Козунова, Г. Л.; Воронин, Н. А.; Венидиктов, В. В.; Строганова, Т. А. (2018). Обучение с подкреплением: роль непосредственной обратной связи и внутренней модели ситуации. Журнал высшей нервной деятельности им. И.П. Павлова, 68(5), 602-613. https://doi.org/10.1134/s0044467718050076
@article{Козунова2018,
title = {Обучение с подкреплением: роль непосредственной обратной связи и внутренней модели ситуации},
author = {Г. Л. Козунова and Н. А. Воронин and В. В. Венидиктов and Т. А. Строганова},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1134_s0044467718050076.pdf},
doi = {10.1134/s0044467718050076},
issn = {0044-4677},
year = {2018},
date = {2018-01-00},
urldate = {2018-01-00},
journal = {Журнал высшей нервной деятельности им. И.П. Павлова},
volume = {68},
number = {5},
pages = {602-613},
publisher = {Российская академия наук},
abstract = {Поведение человека в условиях частичной неопределенности исхода характеризуется соответствием частоты выполняемых действий вероятности их подкрепления. Мы исследовали роль вероятностных сигналов награды и наказания в этом феномене. 29 взрослых испытуемых выполняли задачу на выбор из двух альтернатив, где один стимул из пары вознаграждался в 70% случаев, а другой – в 30% случаев. Перед появлением предпочтения выгодного стимула у испытуемых возникала парадоксальная восприимчивость к редким, нерепрезентативным сигналам награды и наказания. Это указывает на наличие имплицитной оценки вероятности награды при выборе каждого стимула. Расхождение актуального результата с моделью провоцировало у испытуемых смену стратегии. Этот механизм может лежать в основе феномена вероятностного соответствия.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Поведение человека в условиях частичной неопределенности исхода характеризуется соответствием частоты выполняемых действий вероятности их подкрепления. Мы исследовали роль вероятностных сигналов награды и наказания в этом феномене. 29 взрослых испытуемых выполняли задачу на выбор из двух альтернатив, где один стимул из пары вознаграждался в 70% случаев, а другой – в 30% случаев. Перед появлением предпочтения выгодного стимула у испытуемых возникала парадоксальная восприимчивость к редким, нерепрезентативным сигналам награды и наказания. Это указывает на наличие имплицитной оценки вероятности награды при выборе каждого стимула. Расхождение актуального результата с моделью провоцировало у испытуемых смену стратегии. Этот механизм может лежать в основе феномена вероятностного соответствия.
21.
Николаева, А. Ю.; Строганова, Т. А. (2018). Влияние лексико-семантической обработки глаголов движения рук и ног на указательные движения тех же конечностей. Журнал высшей нервной деятельности им. И.П.Павлова, 68(5), 627-636. https://doi.org/10.1134/s0044467718050118
@article{Николаева2018,
title = {Влияние лексико-семантической обработки глаголов движения рук и ног на указательные движения тех же конечностей},
author = {А. Ю. Николаева and Т. А. Строганова},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1134_s0044467718050118.pdf},
doi = {10.1134/s0044467718050118},
issn = {0044-4677},
year = {2018},
date = {2018-00-00},
urldate = {2018-00-00},
journal = {Журнал высшей нервной деятельности им. И.П.Павлова},
volume = {68},
number = {5},
pages = {627-636},
publisher = {Российская академия наук},
abstract = {Согласно теории ассоциативного обучения, при восприятии глаголов “ходить” или “писать” происходит реактивация моторных нейронных репрезентаций руки или ноги, вовлеченных в осуществление соответствующих действий. Общая активация моторных зон
должна приводить к эффектам интерференции, т.е. к замедлению движения определенной
конечности при семантической обработке глагола, обозначающего ее движения. Целью
работы был анализ избирательности эффектов интерференции семантической обработки
глаголов, обозначающих движения рук и ног, с движениями этих же конечностей. Перед
испытуемыми (14 женщин, 14 мужчин, средний возраст 28 лет) стояла семантическая задача – определить конкретность/абстрактность глаголов, включавших в том числе глаголы
движения рук и ног. Испытуемые отвечали либо рукой, либо ногой, как правой, так и левой в зависимости от серии эксперимента. Результаты исследования показали, что обработка семантической информации о глаголах движения интерферирует с одновременными произвольными движениями конечностей, но не по соматотопическому принципу.
Выявленная избирательная интерференция говорит о том, что структуры левого полушария, вовлеченные в восприятие глаголов, частично задействуют те же мозговые механизмы, что и инициация движений правых конечностей, в особенности движений правой руки. Наши результаты не опровергают теорию ассоциативного обучения речи, но показывают, что ее предсказания нельзя проверить с помощью предназначенных для этой цели
поведенческих экспериментов.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Согласно теории ассоциативного обучения, при восприятии глаголов “ходить” или “писать” происходит реактивация моторных нейронных репрезентаций руки или ноги, вовлеченных в осуществление соответствующих действий. Общая активация моторных зон
должна приводить к эффектам интерференции, т.е. к замедлению движения определенной
конечности при семантической обработке глагола, обозначающего ее движения. Целью
работы был анализ избирательности эффектов интерференции семантической обработки
глаголов, обозначающих движения рук и ног, с движениями этих же конечностей. Перед
испытуемыми (14 женщин, 14 мужчин, средний возраст 28 лет) стояла семантическая задача – определить конкретность/абстрактность глаголов, включавших в том числе глаголы
движения рук и ног. Испытуемые отвечали либо рукой, либо ногой, как правой, так и левой в зависимости от серии эксперимента. Результаты исследования показали, что обработка семантической информации о глаголах движения интерферирует с одновременными произвольными движениями конечностей, но не по соматотопическому принципу.
Выявленная избирательная интерференция говорит о том, что структуры левого полушария, вовлеченные в восприятие глаголов, частично задействуют те же мозговые механизмы, что и инициация движений правых конечностей, в особенности движений правой руки. Наши результаты не опровергают теорию ассоциативного обучения речи, но показывают, что ее предсказания нельзя проверить с помощью предназначенных для этой цели
поведенческих экспериментов.
должна приводить к эффектам интерференции, т.е. к замедлению движения определенной
конечности при семантической обработке глагола, обозначающего ее движения. Целью
работы был анализ избирательности эффектов интерференции семантической обработки
глаголов, обозначающих движения рук и ног, с движениями этих же конечностей. Перед
испытуемыми (14 женщин, 14 мужчин, средний возраст 28 лет) стояла семантическая задача – определить конкретность/абстрактность глаголов, включавших в том числе глаголы
движения рук и ног. Испытуемые отвечали либо рукой, либо ногой, как правой, так и левой в зависимости от серии эксперимента. Результаты исследования показали, что обработка семантической информации о глаголах движения интерферирует с одновременными произвольными движениями конечностей, но не по соматотопическому принципу.
Выявленная избирательная интерференция говорит о том, что структуры левого полушария, вовлеченные в восприятие глаголов, частично задействуют те же мозговые механизмы, что и инициация движений правых конечностей, в особенности движений правой руки. Наши результаты не опровергают теорию ассоциативного обучения речи, но показывают, что ее предсказания нельзя проверить с помощью предназначенных для этой цели
поведенческих экспериментов.
2017
20.
Pavlova, Anna A.; Butorina, Anna V.; Nikolaeva, Anastasia Y.; Prokofyev, Andrey O.; Ulanov, Maxim A.; Stroganova, Tatiana A. (2017). Not all reading is alike: task modulation of magnetic evoked response to visual word. Psychology in Russia: State of the art, 10(3), 190-205. https://doi.org/10.11621/pir.2017.0313
@article{nokey,
title = {Not all reading is alike: task modulation of magnetic evoked response to visual word},
author = {Pavlova, Anna A. and Butorina, Anna V. and Nikolaeva, Anastasia Y. and Prokofyev, Andrey O. and Ulanov, Maxim A. and Stroganova, Tatiana A.},
doi = {10.11621/pir.2017.0313},
year = {2017},
date = {2017-12-00},
journal = {Psychology in Russia: State of the art},
volume = {10},
number = {3},
pages = {190-205},
publisher = {Russian Psychology Society},
abstract = {Background.
Previous studies have shown that brain response to a written word depends on the task: whether the word is a target in a version of lexical decision task or should be read silently. Although this effect has been interpreted as an evidence for an interaction between word recognition processes and task demands, it also may be caused by greater attention allocation to the target word.
Objective.
We aimed to examine the task effect on brain response evoked by non-target written words.
Design.
Using MEG and magnetic source imaging, we compared spatial-temporal pattern of brain response elicited by a noun cue when it was read silently either without additional task (SR) or with a requirement to produce an associated verb (VG).
Results.
The task demands penetrated into early (200-300 ms) and late (500-800 ms) stages of a word processing by enhancing brain response under VG versus SR condition. The cortical sources of the early response were localized to bilateral inferior occipitotem-poral and anterior temporal cortex suggesting that more demanding VG task required elaborated lexical-semantic analysis. The late effect was observed in the associative auditory areas in middle and superior temporal gyri and in motor representation of articulators. Our results suggest that a remote goal plays a pivotal role in enhanced recruitment of cortical structures underlying orthographic, semantic and sensorimotor dimensions of written word perception from the early processing stages. Surprisingly, we found that to full a more challenging goal the brain progressively engaged resources of the right hemisphere throughout all stages of silent reading. Conclusion. Our study demonstrates that a deeper processing of linguistic input amplies activation of brain areas involved in integration of speech perception and pro-duction. This is consistent with theories that emphasize the role of sensorimotor integration in speech understanding.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background.
Previous studies have shown that brain response to a written word depends on the task: whether the word is a target in a version of lexical decision task or should be read silently. Although this effect has been interpreted as an evidence for an interaction between word recognition processes and task demands, it also may be caused by greater attention allocation to the target word.
Objective.
We aimed to examine the task effect on brain response evoked by non-target written words.
Design.
Using MEG and magnetic source imaging, we compared spatial-temporal pattern of brain response elicited by a noun cue when it was read silently either without additional task (SR) or with a requirement to produce an associated verb (VG).
Results.
The task demands penetrated into early (200-300 ms) and late (500-800 ms) stages of a word processing by enhancing brain response under VG versus SR condition. The cortical sources of the early response were localized to bilateral inferior occipitotem-poral and anterior temporal cortex suggesting that more demanding VG task required elaborated lexical-semantic analysis. The late effect was observed in the associative auditory areas in middle and superior temporal gyri and in motor representation of articulators. Our results suggest that a remote goal plays a pivotal role in enhanced recruitment of cortical structures underlying orthographic, semantic and sensorimotor dimensions of written word perception from the early processing stages. Surprisingly, we found that to full a more challenging goal the brain progressively engaged resources of the right hemisphere throughout all stages of silent reading. Conclusion. Our study demonstrates that a deeper processing of linguistic input amplies activation of brain areas involved in integration of speech perception and pro-duction. This is consistent with theories that emphasize the role of sensorimotor integration in speech understanding.
Previous studies have shown that brain response to a written word depends on the task: whether the word is a target in a version of lexical decision task or should be read silently. Although this effect has been interpreted as an evidence for an interaction between word recognition processes and task demands, it also may be caused by greater attention allocation to the target word.
Objective.
We aimed to examine the task effect on brain response evoked by non-target written words.
Design.
Using MEG and magnetic source imaging, we compared spatial-temporal pattern of brain response elicited by a noun cue when it was read silently either without additional task (SR) or with a requirement to produce an associated verb (VG).
Results.
The task demands penetrated into early (200-300 ms) and late (500-800 ms) stages of a word processing by enhancing brain response under VG versus SR condition. The cortical sources of the early response were localized to bilateral inferior occipitotem-poral and anterior temporal cortex suggesting that more demanding VG task required elaborated lexical-semantic analysis. The late effect was observed in the associative auditory areas in middle and superior temporal gyri and in motor representation of articulators. Our results suggest that a remote goal plays a pivotal role in enhanced recruitment of cortical structures underlying orthographic, semantic and sensorimotor dimensions of written word perception from the early processing stages. Surprisingly, we found that to full a more challenging goal the brain progressively engaged resources of the right hemisphere throughout all stages of silent reading. Conclusion. Our study demonstrates that a deeper processing of linguistic input amplies activation of brain areas involved in integration of speech perception and pro-duction. This is consistent with theories that emphasize the role of sensorimotor integration in speech understanding.
19.
Alamian, Golnoush; Hincapié, Ana-Sofía; Pascarella, Annalisa; Thiery, Thomas; Combrisson, Etienne; Saive, Anne-Lise; Martel, Véronique; Althukov, Dmitrii; Haesebaert, Frédéric; Jerbi, Karim (2017). Measuring alterations in oscillatory brain networks in schizophrenia with resting-state MEG: State-of-the-art and methodological challenges. Clinical Neurophysiology, 128(9), 1719-1736. https://doi.org/10.1016/j.clinph.2017.06.246
@article{Alamian2017b,
title = {Measuring alterations in oscillatory brain networks in schizophrenia with resting-state MEG: State-of-the-art and methodological challenges},
author = {Golnoush Alamian and Ana-Sofía Hincapié and Annalisa Pascarella and Thomas Thiery and Etienne Combrisson and Anne-Lise Saive and Véronique Martel and Dmitrii Althukov and Frédéric Haesebaert and Karim Jerbi},
doi = {10.1016/j.clinph.2017.06.246},
issn = {1388-2457},
year = {2017},
date = {2017-09-00},
urldate = {2017-09-00},
journal = {Clinical Neurophysiology},
volume = {128},
number = {9},
pages = {1719-1736},
publisher = {Elsevier BV},
abstract = {Objective: Neuroimaging studies provide evidence of disturbed resting-state brain networks in Schizophrenia (SZ). However, untangling the neuronal mechanisms that subserve these baseline alterations requires measurement of their electrophysiological underpinnings. This systematic review specifically investigates the contributions of resting-state Magnetoencephalography (MEG) in elucidating abnormal neural organization in SZ patients.
Method: A systematic literature review of resting-state MEG studies in SZ was conducted. This literature is discussed in relation to findings from resting-state fMRI and EEG, as well as to task-based MEG research in SZ population. Importantly, methodological limitations are considered and recommendations to overcome current limitations are proposed.
Results: Resting-state MEG literature in SZ points towards altered local and long-range oscillatory network dynamics in various frequency bands. Critical methodological challenges with respect to experiment design, and data collection and analysis need to be taken into consideration.
Conclusion: Spontaneous MEG data show that local and global neural organization is altered in SZ patients. MEG is a highly promising tool to fill in knowledge gaps about the neurophysiology of SZ. However, to reach its fullest potential, basic methodological challenges need to be overcome.
Significance: MEG-based resting-state power and connectivity findings could be great assets to clinical and translational research in psychiatry, and SZ in particular.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objective: Neuroimaging studies provide evidence of disturbed resting-state brain networks in Schizophrenia (SZ). However, untangling the neuronal mechanisms that subserve these baseline alterations requires measurement of their electrophysiological underpinnings. This systematic review specifically investigates the contributions of resting-state Magnetoencephalography (MEG) in elucidating abnormal neural organization in SZ patients.
Method: A systematic literature review of resting-state MEG studies in SZ was conducted. This literature is discussed in relation to findings from resting-state fMRI and EEG, as well as to task-based MEG research in SZ population. Importantly, methodological limitations are considered and recommendations to overcome current limitations are proposed.
Results: Resting-state MEG literature in SZ points towards altered local and long-range oscillatory network dynamics in various frequency bands. Critical methodological challenges with respect to experiment design, and data collection and analysis need to be taken into consideration.
Conclusion: Spontaneous MEG data show that local and global neural organization is altered in SZ patients. MEG is a highly promising tool to fill in knowledge gaps about the neurophysiology of SZ. However, to reach its fullest potential, basic methodological challenges need to be overcome.
Significance: MEG-based resting-state power and connectivity findings could be great assets to clinical and translational research in psychiatry, and SZ in particular.
Method: A systematic literature review of resting-state MEG studies in SZ was conducted. This literature is discussed in relation to findings from resting-state fMRI and EEG, as well as to task-based MEG research in SZ population. Importantly, methodological limitations are considered and recommendations to overcome current limitations are proposed.
Results: Resting-state MEG literature in SZ points towards altered local and long-range oscillatory network dynamics in various frequency bands. Critical methodological challenges with respect to experiment design, and data collection and analysis need to be taken into consideration.
Conclusion: Spontaneous MEG data show that local and global neural organization is altered in SZ patients. MEG is a highly promising tool to fill in knowledge gaps about the neurophysiology of SZ. However, to reach its fullest potential, basic methodological challenges need to be overcome.
Significance: MEG-based resting-state power and connectivity findings could be great assets to clinical and translational research in psychiatry, and SZ in particular.
18.
Butorina, Anna V.; Pavlova, Anna A.; Nikolaeva, Anastasia Y.; Prokofyev, Andrey O.; Bondarev, Denis P.; Stroganova, Tatiana A. (2017). Simultaneous Processing of Noun Cue and to-be-Produced Verb in Verb Generation Task: Electromagnetic Evidence. Frontiers in Human Neuroscience, 11, 279. https://doi.org/10.3389/fnhum.2017.00279
@article{Butorina2017,
title = {Simultaneous Processing of Noun Cue and to-be-Produced Verb in Verb Generation Task: Electromagnetic Evidence},
author = {Anna V. Butorina and Anna A. Pavlova and Anastasia Y. Nikolaeva and Andrey O. Prokofyev and Denis P. Bondarev and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnhum.2017.00279.pdf},
doi = {10.3389/fnhum.2017.00279},
issn = {1662-5161},
year = {2017},
date = {2017-05-30},
urldate = {2017-05-30},
journal = {Frontiers in Human Neuroscience},
volume = {11},
pages = {279},
publisher = {Frontiers Media SA},
abstract = {A long-standing but implicit assumption is that words strongly associated with a presented cue are automatically activated in the memory through rapid spread of activation within brain semantic networks. The current study was aimed to provide direct evidence of such rapid access to words’ semantic representations and to investigate its neural sources using magnetoencephalography (MEG) and distributed source localization technique. Thirty-three neurotypical subjects underwent the MEG recording during verb generation task, which was to produce verbs related to the presented noun cues. Brain responses evoked by the noun cues were examined while manipulating the strength of association between the noun and the potential verb responses. The strong vs. weak noun-verb association led to a greater noun-related neural response at 250–400 ms after cue onset, and faster verb production. The cortical sources of the differential response were localized in left temporal pole, previously implicated in semantic access, and left ventrolateral prefrontal cortex (VLPFC), thought to subserve controlled semantic retrieval. The strength of the left VLPFC’s response to the nouns with strong verb associates was positively correlated to the speed of verbs production. Our findings empirically validate the theoretical expectation that in case of a strongly connected noun-verb pair, successful access to target verb representation may occur already at the stage of lexico-semantic analysis of the presented noun. Moreover, the MEG results suggest that contrary to the previous conclusion derived from fMRI studies left VLPFC supports selection of the target verb representations, even if they were retrieved from semantic memory rapidly and effortlessly. The discordance between MEG and fMRI findings in verb generation task may stem from different modes of neural activation captured by phase-locked activity in MEG and slow changes of blood-oxygen-level-dependent (BOLD) signal in fMRI.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A long-standing but implicit assumption is that words strongly associated with a presented cue are automatically activated in the memory through rapid spread of activation within brain semantic networks. The current study was aimed to provide direct evidence of such rapid access to words’ semantic representations and to investigate its neural sources using magnetoencephalography (MEG) and distributed source localization technique. Thirty-three neurotypical subjects underwent the MEG recording during verb generation task, which was to produce verbs related to the presented noun cues. Brain responses evoked by the noun cues were examined while manipulating the strength of association between the noun and the potential verb responses. The strong vs. weak noun-verb association led to a greater noun-related neural response at 250–400 ms after cue onset, and faster verb production. The cortical sources of the differential response were localized in left temporal pole, previously implicated in semantic access, and left ventrolateral prefrontal cortex (VLPFC), thought to subserve controlled semantic retrieval. The strength of the left VLPFC’s response to the nouns with strong verb associates was positively correlated to the speed of verbs production. Our findings empirically validate the theoretical expectation that in case of a strongly connected noun-verb pair, successful access to target verb representation may occur already at the stage of lexico-semantic analysis of the presented noun. Moreover, the MEG results suggest that contrary to the previous conclusion derived from fMRI studies left VLPFC supports selection of the target verb representations, even if they were retrieved from semantic memory rapidly and effortlessly. The discordance between MEG and fMRI findings in verb generation task may stem from different modes of neural activation captured by phase-locked activity in MEG and slow changes of blood-oxygen-level-dependent (BOLD) signal in fMRI.
17.
Sysoeva, Olga V.; Galuta, Ilia A.; Davletshina, Maria S.; Orekhova, Elena V.; Stroganova, Tatiana A. (2017). Abnormal Size-Dependent Modulation of Motion Perception in Children with Autism Spectrum Disorder (ASD). Frontiers in Neuroscience, 11, 164. https://doi.org/10.3389/fnins.2017.00164
@article{Sysoeva2017,
title = {Abnormal Size-Dependent Modulation of Motion Perception in Children with Autism Spectrum Disorder (ASD)},
author = {Olga V. Sysoeva and Ilia A. Galuta and Maria S. Davletshina and Elena V. Orekhova and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnins.2017.00164.pdf},
doi = {10.3389/fnins.2017.00164},
issn = {1662-453X},
year = {2017},
date = {2017-03-29},
urldate = {2017-03-29},
journal = {Frontiers in Neuroscience},
volume = {11},
pages = {164},
publisher = {Frontiers Media SA},
abstract = {Excitation/Inhibition (E/I) imbalance in neural networks is now considered among the core neural underpinnings of autism psychopathology. In motion perception at least two phenomena critically depend on E/I balance in visual cortex: spatial suppression (SS), and spatial facilitation (SF) corresponding to impoverished or improved motion perception with increasing stimuli size, respectively. While SS is dominant at high contrast, SF is evident for low contrast stimuli, due to the prevalence of inhibitory contextual modulations in the former, and excitatory ones in the latter case. Only one previous study (Foss-Feig et al., 2013) investigated SS and SF in Autism Spectrum Disorder (ASD). Our study aimed to replicate previous findings, and to explore the putative contribution of deficient inhibitory influences into an enhanced SF index in ASD—a cornerstone for interpretation proposed by Foss-Feig et al. (2013). The SS and SF were examined in 40 boys with ASD, broad spectrum of intellectual abilities (63 < IQ < 127) and 44 typically developing (TD) boys, aged 6–15 years. The stimuli of small (1°) and large (12°) radius were presented under high (100%) and low (1%) contrast conditions. Social Responsiveness Scale and Sensory Profile Questionnaire were used to assess the autism severity and sensory processing abnormalities. We found that the SS index was atypically reduced, while SF index abnormally enhanced in children with ASD. The presence of abnormally enhanced SF in children with ASD was the only consistent finding between our study and that of Foss-Feig et al. While the SS and SF indexes were strongly interrelated in TD participants, this correlation was absent in their peers with ASD. In addition, the SF index but not the SS index correlated with the severity of autism and the poor registration abilities. The pattern of results is partially consistent with the idea of hypofunctional inhibitory transmission in visual areas in ASD. Nonetheless, the absence of correlation between SF and SS indexes paired with a strong direct link between abnormally enhanced SF and autism symptoms in our ASD sample emphasizes the role of the enhanced excitatory influences by themselves in the observed abnormalities in low-level visual phenomena found in ASD.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Excitation/Inhibition (E/I) imbalance in neural networks is now considered among the core neural underpinnings of autism psychopathology. In motion perception at least two phenomena critically depend on E/I balance in visual cortex: spatial suppression (SS), and spatial facilitation (SF) corresponding to impoverished or improved motion perception with increasing stimuli size, respectively. While SS is dominant at high contrast, SF is evident for low contrast stimuli, due to the prevalence of inhibitory contextual modulations in the former, and excitatory ones in the latter case. Only one previous study (Foss-Feig et al., 2013) investigated SS and SF in Autism Spectrum Disorder (ASD). Our study aimed to replicate previous findings, and to explore the putative contribution of deficient inhibitory influences into an enhanced SF index in ASD—a cornerstone for interpretation proposed by Foss-Feig et al. (2013). The SS and SF were examined in 40 boys with ASD, broad spectrum of intellectual abilities (63 < IQ < 127) and 44 typically developing (TD) boys, aged 6–15 years. The stimuli of small (1°) and large (12°) radius were presented under high (100%) and low (1%) contrast conditions. Social Responsiveness Scale and Sensory Profile Questionnaire were used to assess the autism severity and sensory processing abnormalities. We found that the SS index was atypically reduced, while SF index abnormally enhanced in children with ASD. The presence of abnormally enhanced SF in children with ASD was the only consistent finding between our study and that of Foss-Feig et al. While the SS and SF indexes were strongly interrelated in TD participants, this correlation was absent in their peers with ASD. In addition, the SF index but not the SS index correlated with the severity of autism and the poor registration abilities. The pattern of results is partially consistent with the idea of hypofunctional inhibitory transmission in visual areas in ASD. Nonetheless, the absence of correlation between SF and SS indexes paired with a strong direct link between abnormally enhanced SF and autism symptoms in our ASD sample emphasizes the role of the enhanced excitatory influences by themselves in the observed abnormalities in low-level visual phenomena found in ASD.
16.
Alamian, Golnoush; Hincapié, Ana-Sofía; Combrisson, Etienne; Thiery, Thomas; Martel, Véronique; Althukov, Dmitrii; Jerbi, Karim (2017). Alterations of Intrinsic Brain Connectivity Patterns in Depression and Bipolar Disorders: A Critical Assessment of Magnetoencephalography-Based Evidence. Frontiers in Psychiatry, 8, 41. https://doi.org/10.3389/fpsyt.2017.00041
@article{Alamian2017,
title = {Alterations of Intrinsic Brain Connectivity Patterns in Depression and Bipolar Disorders: A Critical Assessment of Magnetoencephalography-Based Evidence},
author = {Golnoush Alamian and Ana-Sofía Hincapié and Etienne Combrisson and Thomas Thiery and Véronique Martel and Dmitrii Althukov and Karim Jerbi},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fpsyt.2017.00041.pdf},
doi = {10.3389/fpsyt.2017.00041},
issn = {1664-0640},
year = {2017},
date = {2017-03-17},
urldate = {2017-03-17},
journal = {Frontiers in Psychiatry},
volume = {8},
pages = {41},
publisher = {Frontiers Media SA},
abstract = {Despite being the object of a thriving field of clinical research, the investigation of intrinsic brain network alterations in psychiatric illnesses is still in its early days. Because the pathological alterations are predominantly probed using functional magnetic resonance imaging (fMRI), many questions about the electrophysiological bases of resting-state alterations in psychiatric disorders, particularly among mood disorder patients, remain unanswered. Alongside important research using electroencephalography (EEG), the specific recent contributions and future promise of magnetoencephalography (MEG) in this field are not fully recognized and valued. Here, we provide a critical review of recent findings from MEG resting-state connectivity within major depressive disorder (MDD) and bipolar disorder (BD). The clinical MEG resting-state results are compared with those previously reported with fMRI and EEG. Taken together, MEG appears to be a promising but still critically underexploited technique to unravel the neurophysiological mechanisms that mediate abnormal (both hyper- and hypo-) connectivity patterns involved in MDD and BD. In particular, a major strength of MEG is its ability to provide source-space estimations of neuromagnetic long-range rhythmic synchronization at various frequencies (i.e., oscillatory coupling). The reviewed literature highlights the relevance of probing local and interregional rhythmic synchronization to explore the pathophysiological underpinnings of each disorder. However, before we can fully take advantage of MEG connectivity analyses in psychiatry, several limitations inherent to MEG connectivity analyses need to be understood and taken into account. Thus, we also discuss current methodological challenges and outline paths for future research. MEG resting-state studies provide an important window onto perturbed spontaneous oscillatory brain networks and hence supply an important complement to fMRI-based resting-state measurements in psychiatric populations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Despite being the object of a thriving field of clinical research, the investigation of intrinsic brain network alterations in psychiatric illnesses is still in its early days. Because the pathological alterations are predominantly probed using functional magnetic resonance imaging (fMRI), many questions about the electrophysiological bases of resting-state alterations in psychiatric disorders, particularly among mood disorder patients, remain unanswered. Alongside important research using electroencephalography (EEG), the specific recent contributions and future promise of magnetoencephalography (MEG) in this field are not fully recognized and valued. Here, we provide a critical review of recent findings from MEG resting-state connectivity within major depressive disorder (MDD) and bipolar disorder (BD). The clinical MEG resting-state results are compared with those previously reported with fMRI and EEG. Taken together, MEG appears to be a promising but still critically underexploited technique to unravel the neurophysiological mechanisms that mediate abnormal (both hyper- and hypo-) connectivity patterns involved in MDD and BD. In particular, a major strength of MEG is its ability to provide source-space estimations of neuromagnetic long-range rhythmic synchronization at various frequencies (i.e., oscillatory coupling). The reviewed literature highlights the relevance of probing local and interregional rhythmic synchronization to explore the pathophysiological underpinnings of each disorder. However, before we can fully take advantage of MEG connectivity analyses in psychiatry, several limitations inherent to MEG connectivity analyses need to be understood and taken into account. Thus, we also discuss current methodological challenges and outline paths for future research. MEG resting-state studies provide an important window onto perturbed spontaneous oscillatory brain networks and hence supply an important complement to fMRI-based resting-state measurements in psychiatric populations.
2016
15.
Chernyshev, Boris V.; Pronko, Platon K.; Stroganova, Tatiana A. (2016). Early suppression effect in human primary visual cortex during Kanizsa illusion processing: A magnetoencephalographic evidence. Visual Neuroscience, 33, E007. https://doi.org/10.1017/s0952523816000031
@article{CHERNYSHEV2016,
title = {Early suppression effect in human primary visual cortex during Kanizsa illusion processing: A magnetoencephalographic evidence},
author = {Boris V. Chernyshev and Platon K. Pronko and Tatiana A. Stroganova},
doi = {10.1017/s0952523816000031},
issn = {1469-8714},
year = {2016},
date = {2016-03-16},
urldate = {2016-00-00},
journal = {Visual Neuroscience},
volume = {33},
pages = {E007},
publisher = {Maximum Academic Press},
abstract = {Detection of illusory contours (ICs) such as Kanizsa figures is known to depend primarily upon the lateral occipital complex. Yet there is no universal agreement on the role of the primary visual cortex in this process; some existing evidence hints that an early stage of the visual response in V1 may involve relative suppression to Kanizsa figures compared with controls. Iso-oriented luminance borders, which are responsible for Kanizsa illusion, may evoke surround suppression in V1 and adjacent areas leading to the reduction in the initial response to Kanizsa figures. We attempted to test the existence, as well as to find localization and timing of the early suppression effect produced by Kanizsa figures in adult nonclinical human participants. We used two sizes of visual stimuli (4.5 and 9.0°) in order to probe the effect at two different levels of eccentricity; the stimuli were presented centrally in passive viewing conditions. We recorded magnetoencephalogram, which is more sensitive than electroencephalogram to activity originating from V1 and V2 areas. We restricted our analysis to the medial occipital area and the occipital pole, and to a 40–120 ms time window after the stimulus onset. By applying threshold-free cluster enhancement technique in combination with permutation statistics, we were able to detect the inverted IC effect—a relative suppression of the response to the Kanizsa figures compared with the control stimuli. The current finding is highly compatible with the explanation involving surround suppression evoked by iso-oriented collinear borders. The effect may be related to the principle of sparse coding, according to which V1 suppresses representations of inner parts of collinear assemblies as being informationally redundant. Such a mechanism is likely to be an important preliminary step preceding object contour detection.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Detection of illusory contours (ICs) such as Kanizsa figures is known to depend primarily upon the lateral occipital complex. Yet there is no universal agreement on the role of the primary visual cortex in this process; some existing evidence hints that an early stage of the visual response in V1 may involve relative suppression to Kanizsa figures compared with controls. Iso-oriented luminance borders, which are responsible for Kanizsa illusion, may evoke surround suppression in V1 and adjacent areas leading to the reduction in the initial response to Kanizsa figures. We attempted to test the existence, as well as to find localization and timing of the early suppression effect produced by Kanizsa figures in adult nonclinical human participants. We used two sizes of visual stimuli (4.5 and 9.0°) in order to probe the effect at two different levels of eccentricity; the stimuli were presented centrally in passive viewing conditions. We recorded magnetoencephalogram, which is more sensitive than electroencephalogram to activity originating from V1 and V2 areas. We restricted our analysis to the medial occipital area and the occipital pole, and to a 40–120 ms time window after the stimulus onset. By applying threshold-free cluster enhancement technique in combination with permutation statistics, we were able to detect the inverted IC effect—a relative suppression of the response to the Kanizsa figures compared with the control stimuli. The current finding is highly compatible with the explanation involving surround suppression evoked by iso-oriented collinear borders. The effect may be related to the principle of sparse coding, according to which V1 suppresses representations of inner parts of collinear assemblies as being informationally redundant. Such a mechanism is likely to be an important preliminary step preceding object contour detection.
14.
Medvedovsky, Mordekhay; Nenonen, Jukka; Koptelova, Alexandra; Butorina, Anna; Paetau, Ritva; Makela, Jyrki P.; Ahonen, Antti; Simola, Juha; Gazit, Tomer; Taulu, Samu (2016). Virtual MEG Helmet: Computer Simulation of an Approach to Neuromagnetic Field Sampling. IEEE Journal of Biomedical and Health Informatics, 20(2), 539-548. https://doi.org/10.1109/jbhi.2015.2392785
@article{Medvedovsky2016,
title = {Virtual MEG Helmet: Computer Simulation of an Approach to Neuromagnetic Field Sampling},
author = {Mordekhay Medvedovsky and Jukka Nenonen and Alexandra Koptelova and Anna Butorina and Ritva Paetau and Jyrki P. Makela and Antti Ahonen and Juha Simola and Tomer Gazit and Samu Taulu},
doi = {10.1109/jbhi.2015.2392785},
issn = {2168-2208},
year = {2016},
date = {2016-03-00},
urldate = {2016-03-00},
journal = {IEEE Journal of Biomedical and Health Informatics},
volume = {20},
number = {2},
pages = {539-548},
abstract = {Head movements during an MEG recording are commonly considered an obstacle. In this computer simulation study, we introduce an approach, the virtual MEG helmet (VMH), which employs the head movements for data quality improvement. With a VMH, a denser MEG helmet is constructed by adding new sensors corresponding to different head positions. Based on the Shannon's theory of communication, we calculated the total information as a figure of merit for comparing the actual 306-sensor Elekta Neuromag helmet to several types of the VMH. As source models, we used simulated randomly distributed source current (RDSC), simulated auditory and somatosensory evoked fields. Using the RDSC model with the simulation of 360 recorded events, the total information (bits/sample) was 989 for the most informative single head position and up to 1272 for the VMH (addition of 28.6%). Using simulated AEFs, the additional contribution of a VMH was 12.6% and using simulated SEF only 1.1%. For the distributed and bilateral sources, a VMH can provide a more informative sampling of the neuromagnetic field during the same recording time than measuring the MEG from one head position. VMH can, in some situations, improve source localization of the neuromagnetic fields related to the normal and pathological brain activity. This should be investigated further employing real MEG recordings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Head movements during an MEG recording are commonly considered an obstacle. In this computer simulation study, we introduce an approach, the virtual MEG helmet (VMH), which employs the head movements for data quality improvement. With a VMH, a denser MEG helmet is constructed by adding new sensors corresponding to different head positions. Based on the Shannon's theory of communication, we calculated the total information as a figure of merit for comparing the actual 306-sensor Elekta Neuromag helmet to several types of the VMH. As source models, we used simulated randomly distributed source current (RDSC), simulated auditory and somatosensory evoked fields. Using the RDSC model with the simulation of 360 recorded events, the total information (bits/sample) was 989 for the most informative single head position and up to 1272 for the VMH (addition of 28.6%). Using simulated AEFs, the additional contribution of a VMH was 12.6% and using simulated SEF only 1.1%. For the distributed and bilateral sources, a VMH can provide a more informative sampling of the neuromagnetic field during the same recording time than measuring the MEG from one head position. VMH can, in some situations, improve source localization of the neuromagnetic fields related to the normal and pathological brain activity. This should be investigated further employing real MEG recordings.
13.
Vvedensky, Victor L.; Prokofyev, Andrey O. (2016). Timing of Cortical Events Preceding Voluntary Movement. Neural Computation, 28(2), 286-304. https://doi.org/10.1162/neco_a_00802
@article{Vvedensky2016,
title = {Timing of Cortical Events Preceding Voluntary Movement},
author = {Victor L. Vvedensky and Andrey O. Prokofyev},
doi = {10.1162/neco_a_00802},
issn = {1530-888X},
year = {2016},
date = {2016-02-00},
urldate = {2016-02-00},
journal = {Neural Computation},
volume = {28},
number = {2},
pages = {286-304},
publisher = {MIT Press - Journals},
abstract = {We studied magnetic signals from the human brain recorded during a second before a self-paced finger movement. Sharp triangular peaks were observed in the averaged signals about 0.7 second before the finger movement. The amplitude of the peaks varied considerably from trial to trial, which indicated that the peaks were concurrent with much longer oscillatory processes. One can cluster trials into distinct groups with characteristic sequences of events. Prominent short trains of pulses in the beta frequency band were identified in the premovement period. This observation suggests that during preparation of the intended movement, cortical activity is well organized in time but differs from trial to trial. Magnetoencephalography can capture these processes with high temporal resolution and allows their study in fine detail.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We studied magnetic signals from the human brain recorded during a second before a self-paced finger movement. Sharp triangular peaks were observed in the averaged signals about 0.7 second before the finger movement. The amplitude of the peaks varied considerably from trial to trial, which indicated that the peaks were concurrent with much longer oscillatory processes. One can cluster trials into distinct groups with characteristic sequences of events. Prominent short trains of pulses in the beta frequency band were identified in the premovement period. This observation suggests that during preparation of the intended movement, cortical activity is well organized in time but differs from trial to trial. Magnetoencephalography can capture these processes with high temporal resolution and allows their study in fine detail.
12.
Sysoeva, Olga V.; Davletshina, Maria A.; Orekhova, Elena V.; Galuta, Ilia A.; Stroganova, Tatiana A. (2016). Reduced Oblique Effect in Children with Autism Spectrum Disorders (ASD). Frontiers in Neuroscience, 9, 512. https://doi.org/10.3389/fnins.2015.00512
@article{Sysoeva2016,
title = {Reduced Oblique Effect in Children with Autism Spectrum Disorders (ASD)},
author = {Olga V. Sysoeva and Maria A. Davletshina and Elena V. Orekhova and Ilia A. Galuta and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnins.2015.00512.pdf},
doi = {10.3389/fnins.2015.00512},
issn = {1662-453X},
year = {2016},
date = {2016-01-21},
urldate = {2016-01-21},
journal = {Frontiers in Neuroscience},
volume = {9},
pages = {512},
publisher = {Frontiers Media SA},
abstract = {People are very precise in the discrimination of a line orientation relative to the cardinal (vertical and horizontal) axes, while their orientation discrimination sensitivity along the oblique axes is less refined. This difference in discrimination sensitivity along cardinal and oblique axes is called the “oblique effect.” Given that the oblique effect is a basic feature of visual processing with an early developmental origin, its investigation in children with Autism Spectrum Disorder (ASD) may shed light on the nature of visual sensory abnormalities frequently reported in this population. We examined line orientation sensitivity along oblique and vertical axes in a sample of 26 boys with ASD (IQ > 68) and 38 typically developing (TD) boys aged 7–15 years, as well as in a subsample of carefully IQ-matched ASD and TD participants. Children were asked to detect the direction of tilt of a high-contrast black-and-white grating relative to vertical (90°) or oblique (45°) templates. The oblique effect was reduced in children with ASD as compared to TD participants, irrespective of their IQ. This reduction was due to poor orientation sensitivity along the vertical axis in ASD children, while their ability to discriminate line orientation along the oblique axis was unaffected. We speculate that this deficit in sensitivity to vertical orientation may reflect disrupted mechanisms of early experience-dependent learning that takes place during the critical period for orientation selectivity.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
People are very precise in the discrimination of a line orientation relative to the cardinal (vertical and horizontal) axes, while their orientation discrimination sensitivity along the oblique axes is less refined. This difference in discrimination sensitivity along cardinal and oblique axes is called the “oblique effect.” Given that the oblique effect is a basic feature of visual processing with an early developmental origin, its investigation in children with Autism Spectrum Disorder (ASD) may shed light on the nature of visual sensory abnormalities frequently reported in this population. We examined line orientation sensitivity along oblique and vertical axes in a sample of 26 boys with ASD (IQ > 68) and 38 typically developing (TD) boys aged 7–15 years, as well as in a subsample of carefully IQ-matched ASD and TD participants. Children were asked to detect the direction of tilt of a high-contrast black-and-white grating relative to vertical (90°) or oblique (45°) templates. The oblique effect was reduced in children with ASD as compared to TD participants, irrespective of their IQ. This reduction was due to poor orientation sensitivity along the vertical axis in ASD children, while their ability to discriminate line orientation along the oblique axis was unaffected. We speculate that this deficit in sensitivity to vertical orientation may reflect disrupted mechanisms of early experience-dependent learning that takes place during the critical period for orientation selectivity.
11.
Величковский, Б. М.; Нуждин, Ю. О.; Свирин, Е. П.; Строганова, Т. А.; Федорова, А. А.; Шишкин, С. Л. (2016). Управление «силой мысли»: На пути к новым формам взаимодействия человека с техническими устройствами. Вопросы психологии, 62(1), 78-88.
@bachelorthesis{nokey,
title = {Управление «силой мысли»: На пути к новым формам взаимодействия человека с техническими устройствами},
author = {Величковский, Б.М. and Нуждин, Ю.О. and Свирин, Е.П. and Строганова, Т.А. and Федорова, А.А. and Шишкин, С.Л.},
year = {2016},
date = {2016-01-00},
journal = {Вопросы психологии},
volume = {62},
number = {1},
pages = {78-88},
abstract = {Рассмотрены две группы перспективных интерфейсов, создаваемых сегодня для улучшения взаимодействия человека с техническими системами. Интерфейсы первой группы опираются на использование данных, получаемых с помощью методов нейрофизиологии и психофизиологии, прежде всего путем регистрации ЭЭГ/магнитоэнцефалограммы. Интерфейсы второй группы используют данные о микроповедении глаза человека, опираясь на методы айтрекинга, популярные в психологии и эргономике. Продемонстрирована полезность совмещения этих подходов для создания высокоскоростных гибридных интерфейсов, пригодных не только для обеспечения коммуникации лиц с тяжелыми нарушениями речи и моторики, но и для повышения эффективности работы здоровых пользователей операторских профессий. Критическую роль в таком развитии имеет решение ряда фундаментальных проблем психологической науки, таких как поддержка зон совместного внимания в процессах опосредствованного техникой общения и выявление намерений пользователя по характеристикам движений глаз и мозговой активности.},
keywords = {},
pubstate = {published},
tppubtype = {bachelorthesis}
}
Рассмотрены две группы перспективных интерфейсов, создаваемых сегодня для улучшения взаимодействия человека с техническими системами. Интерфейсы первой группы опираются на использование данных, получаемых с помощью методов нейрофизиологии и психофизиологии, прежде всего путем регистрации ЭЭГ/магнитоэнцефалограммы. Интерфейсы второй группы используют данные о микроповедении глаза человека, опираясь на методы айтрекинга, популярные в психологии и эргономике. Продемонстрирована полезность совмещения этих подходов для создания высокоскоростных гибридных интерфейсов, пригодных не только для обеспечения коммуникации лиц с тяжелыми нарушениями речи и моторики, но и для повышения эффективности работы здоровых пользователей операторских профессий. Критическую роль в таком развитии имеет решение ряда фундаментальных проблем психологической науки, таких как поддержка зон совместного внимания в процессах опосредствованного техникой общения и выявление намерений пользователя по характеристикам движений глаз и мозговой активности.
2015
10.
Stroganova, Tatiana A.; Butorina, Anna V.; Sysoeva, Olga V.; Prokofyev, Andrey O.; Nikolaeva, Anastasia Yu.; Tsetlin, Marina M.; Orekhova, Elena V. (2015). Altered modulation of gamma oscillation frequency by speed of visual motion in children with autism spectrum disorders. Journal of Neurodevelopmental Disorders, 7(1), 21. https://doi.org/10.1186/s11689-015-9121-x
@article{Stroganova2015,
title = {Altered modulation of gamma oscillation frequency by speed of visual motion in children with autism spectrum disorders},
author = {Tatiana A. Stroganova and Anna V. Butorina and Olga V. Sysoeva and Andrey O. Prokofyev and Anastasia Yu. Nikolaeva and Marina M. Tsetlin and Elena V. Orekhova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1186_s11689-015-9121-x.pdf},
doi = {10.1186/s11689-015-9121-x},
issn = {1866-1955},
year = {2015},
date = {2015-12-00},
urldate = {2015-12-00},
journal = {Journal of Neurodevelopmental Disorders},
volume = {7},
number = {1},
pages = {21},
publisher = {Springer Science and Business Media LLC},
abstract = {Background
Recent studies link autism spectrum disorders (ASD) with an altered balance between excitation and inhibition (E/I balance) in cortical networks. The brain oscillations in high gamma-band (50–120 Hz) are sensitive to the E/I balance and may appear useful biomarkers of certain ASD subtypes. The frequency of gamma oscillations is mediated by level of excitation of the fast-spiking inhibitory basket cells recruited by increasing strength of excitatory input. Therefore, the experimental manipulations affecting gamma frequency may throw light on inhibitory networks dysfunction in ASD.
Methods
Here, we used magnetoencephalography (MEG) to investigate modulation of visual gamma oscillation frequency by speed of drifting annular gratings (1.2, 3.6, 6.0 °/s) in 21 boys with ASD and 26 typically developing boys aged 7–15 years. Multitaper method was used for analysis of spectra of gamma power change upon stimulus presentation and permutation test was applied for statistical comparisons. We also assessed in our participants visual orientation discrimination thresholds, which are thought to depend on excitability of inhibitory networks in the visual cortex.
Results
Although frequency of the oscillatory gamma response increased with increasing velocity of visual motion in both groups of participants, the velocity effect was reduced in a substantial proportion of children with ASD. The range of velocity-related gamma frequency modulation correlated inversely with the ability to discriminate oblique line orientation in the ASD group, while no such correlation has been observed in the group of typically developing participants.
Conclusions
Our findings suggest that abnormal velocity-related gamma frequency modulation in ASD may constitute a potential biomarker for reduced excitability of fast-spiking inhibitory neurons in a subset of children with ASD.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Recent studies link autism spectrum disorders (ASD) with an altered balance between excitation and inhibition (E/I balance) in cortical networks. The brain oscillations in high gamma-band (50–120 Hz) are sensitive to the E/I balance and may appear useful biomarkers of certain ASD subtypes. The frequency of gamma oscillations is mediated by level of excitation of the fast-spiking inhibitory basket cells recruited by increasing strength of excitatory input. Therefore, the experimental manipulations affecting gamma frequency may throw light on inhibitory networks dysfunction in ASD.
Methods
Here, we used magnetoencephalography (MEG) to investigate modulation of visual gamma oscillation frequency by speed of drifting annular gratings (1.2, 3.6, 6.0 °/s) in 21 boys with ASD and 26 typically developing boys aged 7–15 years. Multitaper method was used for analysis of spectra of gamma power change upon stimulus presentation and permutation test was applied for statistical comparisons. We also assessed in our participants visual orientation discrimination thresholds, which are thought to depend on excitability of inhibitory networks in the visual cortex.
Results
Although frequency of the oscillatory gamma response increased with increasing velocity of visual motion in both groups of participants, the velocity effect was reduced in a substantial proportion of children with ASD. The range of velocity-related gamma frequency modulation correlated inversely with the ability to discriminate oblique line orientation in the ASD group, while no such correlation has been observed in the group of typically developing participants.
Conclusions
Our findings suggest that abnormal velocity-related gamma frequency modulation in ASD may constitute a potential biomarker for reduced excitability of fast-spiking inhibitory neurons in a subset of children with ASD.
Recent studies link autism spectrum disorders (ASD) with an altered balance between excitation and inhibition (E/I balance) in cortical networks. The brain oscillations in high gamma-band (50–120 Hz) are sensitive to the E/I balance and may appear useful biomarkers of certain ASD subtypes. The frequency of gamma oscillations is mediated by level of excitation of the fast-spiking inhibitory basket cells recruited by increasing strength of excitatory input. Therefore, the experimental manipulations affecting gamma frequency may throw light on inhibitory networks dysfunction in ASD.
Methods
Here, we used magnetoencephalography (MEG) to investigate modulation of visual gamma oscillation frequency by speed of drifting annular gratings (1.2, 3.6, 6.0 °/s) in 21 boys with ASD and 26 typically developing boys aged 7–15 years. Multitaper method was used for analysis of spectra of gamma power change upon stimulus presentation and permutation test was applied for statistical comparisons. We also assessed in our participants visual orientation discrimination thresholds, which are thought to depend on excitability of inhibitory networks in the visual cortex.
Results
Although frequency of the oscillatory gamma response increased with increasing velocity of visual motion in both groups of participants, the velocity effect was reduced in a substantial proportion of children with ASD. The range of velocity-related gamma frequency modulation correlated inversely with the ability to discriminate oblique line orientation in the ASD group, while no such correlation has been observed in the group of typically developing participants.
Conclusions
Our findings suggest that abnormal velocity-related gamma frequency modulation in ASD may constitute a potential biomarker for reduced excitability of fast-spiking inhibitory neurons in a subset of children with ASD.
9.
Shtyrov, Yury Y.; Stroganova, Tatyana A. (2015). When ultrarapid is ultrarapid: on importance of temporal precision in neuroscience of language. Frontiers in Human Neuroscience, 9, 576. https://doi.org/10.3389/fnhum.2015.00576
@article{Shtyrov2015,
title = {When ultrarapid is ultrarapid: on importance of temporal precision in neuroscience of language},
author = {Yury Y. Shtyrov and Tatyana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnhum.2015.00576.pdf},
doi = {10.3389/fnhum.2015.00576},
issn = {1662-5161},
year = {2015},
date = {2015-10-21},
urldate = {2015-10-21},
journal = {Frontiers in Human Neuroscience},
volume = {9},
pages = {576},
publisher = {Frontiers Media SA},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
8.
Orekhova, Elena V.; Butorina, Anna V.; Sysoeva, Olga V.; Prokofyev, Andrey O.; Nikolaeva, Anastasia Yu.; Stroganova, Tatiana A. (2015). Frequency of gamma oscillations in humans is modulated by velocity of visual motion. Journal of Neurophysiology, 114(1), 244-255. https://doi.org/10.1152/jn.00232.2015
@article{Orekhova2015,
title = {Frequency of gamma oscillations in humans is modulated by velocity of visual motion},
author = {Elena V. Orekhova and Anna V. Butorina and Olga V. Sysoeva and Andrey O. Prokofyev and Anastasia Yu. Nikolaeva and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1152_jn.00232.2015.pdf},
doi = {10.1152/jn.00232.2015},
issn = {1522-1598},
year = {2015},
date = {2015-07-00},
urldate = {2015-07-00},
journal = {Journal of Neurophysiology},
volume = {114},
number = {1},
pages = {244-255},
publisher = {American Physiological Society},
abstract = {Gamma oscillations are generated in networks of inhibitory fast-spiking (FS) parvalbumin-positive (PV) interneurons and pyramidal cells. In animals, gamma frequency is modulated by the velocity of visual motion; the effect of velocity has not been evaluated in humans. In this work, we have studied velocity-related modulations of gamma frequency in children using MEG/EEG. We also investigated whether such modulations predict the prominence of the "spatial suppression" effect (Tadin D, Lappin JS, Gilroy LA, Blake R. Nature 424: 312-315, 2003) that is thought to depend on cortical center-surround inhibitory mechanisms. MEG/EEG was recorded in 27 normal boys aged 8-15 yr while they watched high-contrast black-and-white annular gratings drifting with velocities of 1.2, 3.6, and 6.0°/s and performed a simple detection task. The spatial suppression effect was assessed in a separate psychophysical experiment. MEG gamma oscillation frequency increased while power decreased with increasing velocity of visual motion. In EEG, the effects were less reliable. The frequencies of the velocity-specific gamma peaks were 64.9, 74.8, and 87.1 Hz for the slow, medium, and fast motions, respectively. The frequency of the gamma response elicited during slow and medium velocity of visual motion decreased with subject age, whereas the range of gamma frequency modulation by velocity increased with age. The frequency modulation range predicted spatial suppression even after controlling for the effect of age. We suggest that the modulation of the MEG gamma frequency by velocity of visual motion reflects excitability of cortical inhibitory circuits and can be used to investigate their normal and pathological development in the human brain.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gamma oscillations are generated in networks of inhibitory fast-spiking (FS) parvalbumin-positive (PV) interneurons and pyramidal cells. In animals, gamma frequency is modulated by the velocity of visual motion; the effect of velocity has not been evaluated in humans. In this work, we have studied velocity-related modulations of gamma frequency in children using MEG/EEG. We also investigated whether such modulations predict the prominence of the "spatial suppression" effect (Tadin D, Lappin JS, Gilroy LA, Blake R. Nature 424: 312-315, 2003) that is thought to depend on cortical center-surround inhibitory mechanisms. MEG/EEG was recorded in 27 normal boys aged 8-15 yr while they watched high-contrast black-and-white annular gratings drifting with velocities of 1.2, 3.6, and 6.0°/s and performed a simple detection task. The spatial suppression effect was assessed in a separate psychophysical experiment. MEG gamma oscillation frequency increased while power decreased with increasing velocity of visual motion. In EEG, the effects were less reliable. The frequencies of the velocity-specific gamma peaks were 64.9, 74.8, and 87.1 Hz for the slow, medium, and fast motions, respectively. The frequency of the gamma response elicited during slow and medium velocity of visual motion decreased with subject age, whereas the range of gamma frequency modulation by velocity increased with age. The frequency modulation range predicted spatial suppression even after controlling for the effect of age. We suggest that the modulation of the MEG gamma frequency by velocity of visual motion reflects excitability of cortical inhibitory circuits and can be used to investigate their normal and pathological development in the human brain.
7.
Kozunov, Vladimir V.; Ossadtchi, Alexei (2015). GALA: group analysis leads to accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings. Frontiers in Neuroscience, 9, 107. https://doi.org/10.3389/fnins.2015.00107
@article{Kozunov2015,
title = {GALA: group analysis leads to accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings},
author = {Vladimir V. Kozunov and Alexei Ossadtchi},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnins.2015.00107.pdf},
doi = {10.3389/fnins.2015.00107},
issn = {1662-453X},
year = {2015},
date = {2015-04-21},
urldate = {2015-04-21},
journal = {Frontiers in Neuroscience},
volume = {9},
pages = {107},
publisher = {Frontiers Media SA},
abstract = {Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis. We propose Group Analysis Leads to Accuracy (GALA)—a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects. A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face-specific evoked responses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis. We propose Group Analysis Leads to Accuracy (GALA)—a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects. A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face-specific evoked responses.
6.
Sysoeva, Olga V.; Lange, Elke B.; Sorokin, Alexander B.; Campbell, Tom (2015). From pre-attentive processes to durable representation: An ERP index of visual distraction. International Journal of Psychophysiology, 95(3), 310-321. https://doi.org/10.1016/j.ijpsycho.2014.12.007
@article{Sysoeva2015,
title = {From pre-attentive processes to durable representation: An ERP index of visual distraction},
author = {Olga V. Sysoeva and Elke B. Lange and Alexander B. Sorokin and Tom Campbell},
doi = {10.1016/j.ijpsycho.2014.12.007},
issn = {0167-8760},
year = {2015},
date = {2015-03-00},
urldate = {2015-03-00},
journal = {International Journal of Psychophysiology},
volume = {95},
number = {3},
pages = {310-321},
publisher = {Elsevier BV},
abstract = {Visual search and oddball paradigms were combined to investigate memory for to-be-ignored color changes in a group of 12 healthy participants. The onset of unexpected color change of an irrelevant stimulus evoked two reliable ERP effects: a component of the event-related potential (ERP), similar to the visual mismatch negativity response (vMMN), with a latency of 120-160 ms and a posterior distribution over the left hemisphere and Late Fronto-Central Negativity (LFCN) with a latency of 320-400 ms, apparent at fronto-central electrodes and some posterior sites. Color change of that irrelevant stimulus also slowed identification of a visual target, indicating distraction. The amplitude of this color-change vMMN, but not LFCN, indexed this distraction effect. That is, electrophysiological and behavioral measures were correlated. The interval between visual scenes approximated 1s (611-1629 ms), indicating that the brain's sensory memory for the color of the preceding visual scenes must persist for at least 600 ms. Therefore, in the case of the neural code for color, durable memory representations are formed in an obligatory manner.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Visual search and oddball paradigms were combined to investigate memory for to-be-ignored color changes in a group of 12 healthy participants. The onset of unexpected color change of an irrelevant stimulus evoked two reliable ERP effects: a component of the event-related potential (ERP), similar to the visual mismatch negativity response (vMMN), with a latency of 120-160 ms and a posterior distribution over the left hemisphere and Late Fronto-Central Negativity (LFCN) with a latency of 320-400 ms, apparent at fronto-central electrodes and some posterior sites. Color change of that irrelevant stimulus also slowed identification of a visual target, indicating distraction. The amplitude of this color-change vMMN, but not LFCN, indexed this distraction effect. That is, electrophysiological and behavioral measures were correlated. The interval between visual scenes approximated 1s (611-1629 ms), indicating that the brain's sensory memory for the color of the preceding visual scenes must persist for at least 600 ms. Therefore, in the case of the neural code for color, durable memory representations are formed in an obligatory manner.
5.
Nikolaeva, A. Y.; Butorina, A. V.; Prokofyev, A. O.; Stroganova, T. A. (2015). [Lateralized brain language semantic network demonstrated by word repetition suppression effect in MEG]. Zh Vyssh Nerv Deiat Im I P Pavlova, 65, 82-91.
@article{nokey,
title = {[Lateralized brain language semantic network demonstrated by word repetition suppression effect in MEG]},
author = {Nikolaeva, A.Y. and Butorina, A.V. and Prokofyev, A.O. and Stroganova, T.A.},
year = {2015},
date = {2015-01-00},
urldate = {2015-01-00},
journal = {Zh Vyssh Nerv Deiat Im I P Pavlova},
volume = {65},
pages = {82-91},
abstract = {We studied auditory word repetition suppression effect using magnetoencephalography while subjects listened to "new" and "old" words whose familiarity they had to judge upon presentation. The lateralization of brain magnetic activity during processing of "new" and "old" words were estimated by computing RMS measure of whole-brain magnetic response within time window of semantic N400 (350-450 ms). A magnetic N400 was significantly stronger in the left than in the right hemisphere for the "new" words only. Repetition of "new" words led to sharp decrease of N400 response RMS in the left hemisphere but did not change right-hemispheric N400 RMS. The asymmetry index of this repetition suppression effect was lateralized to the left hemisphere for the majority of the participants and its magnitude was related to memory task performance. The findings point to a strong left-hemispheric dominance of word repetition suppression effect within the brain semantic networks at the level of whole-network response.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We studied auditory word repetition suppression effect using magnetoencephalography while subjects listened to "new" and "old" words whose familiarity they had to judge upon presentation. The lateralization of brain magnetic activity during processing of "new" and "old" words were estimated by computing RMS measure of whole-brain magnetic response within time window of semantic N400 (350-450 ms). A magnetic N400 was significantly stronger in the left than in the right hemisphere for the "new" words only. Repetition of "new" words led to sharp decrease of N400 response RMS in the left hemisphere but did not change right-hemispheric N400 RMS. The asymmetry index of this repetition suppression effect was lateralized to the left hemisphere for the majority of the participants and its magnitude was related to memory task performance. The findings point to a strong left-hemispheric dominance of word repetition suppression effect within the brain semantic networks at the level of whole-network response.
2014
4.
Orekhova, Elena V; Elsabbagh, Mayada; Jones, Emily JH; Dawson, Geraldine; Charman, Tony; Johnson, Mark H (2014). EEG hyper-connectivity in high-risk infants is associated with later autism. Journal of Neurodevelopmental Disorders, 6(1), 40. https://doi.org/10.1186/1866-1955-6-40
@article{2014,
title = {EEG hyper-connectivity in high-risk infants is associated with later autism},
author = { Elena V Orekhova and Mayada Elsabbagh and Emily JH Jones and Geraldine Dawson and Tony Charman and Mark H Johnson},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1186_1866-1955-6-40.pdf},
doi = {10.1186/1866-1955-6-40},
issn = {1866-1955},
year = {2014},
date = {2014-11-07},
urldate = {2014-11-07},
journal = {Journal of Neurodevelopmental Disorders},
volume = {6},
number = {1},
pages = {40},
publisher = {Springer Science and Business Media LLC},
abstract = {Background
It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis.
Methods
In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD.
Results
As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.
Conclusions
The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis.
Methods
In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD.
Results
As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.
Conclusions
The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.
It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis.
Methods
In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD.
Results
As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power.
Conclusions
The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype.
3.
Shtyrov, Yury; Butorina, Anna; Nikolaeva, Anastasia; Stroganova, Tatiana (2014). Automatic ultrarapid activation and inhibition of cortical motor systems in spoken word comprehension. Proceedings of the National Academy of Sciences. USA, 111(18), E1918-E1923. https://doi.org/10.1073/pnas.1323158111
@article{Shtyrov2014,
title = {Automatic ultrarapid activation and inhibition of cortical motor systems in spoken word comprehension},
author = {Yury Shtyrov and Anna Butorina and Anastasia Nikolaeva and Tatiana Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.1073_pnas.1323158111.pdf},
doi = {10.1073/pnas.1323158111},
issn = {1091-6490},
year = {2014},
date = {2014-05-06},
urldate = {2014-05-06},
journal = {Proceedings of the National Academy of Sciences},
volume = {111},
number = {18},
pages = {E1918-E1923},
address = {USA},
abstract = {Significance
The mechanisms through which our brain generates complex cognitive percepts from simple sensory and motor events remain unknown. An important question is whether the basic brain structures controlling movements and perceptions directly participate in higher-order cognitive processes such as language comprehension. Using neurophysiology, we found ultrarapid (starting at ∼80 ms) activations in the human motor cortex in response to unattended action-related verbs and nouns, with words related to different body parts activating corresponding body representations. Accompanying this category-specific activity was activation suppression by words with area-incompatible meaning, demonstrating operation of the neurophysiological principles of lateral/surround inhibition in language processing. These instant activations and deactivations emerging for words of different types in the absence of attention advocate automatic involvement of neural sensorimotor circuits in language comprehension.
Abstract
To address the hotly debated question of motor system involvement in language comprehension, we recorded neuromagnetic responses elicited in the human brain by unattended action-related spoken verbs and nouns and scrutinized their timecourse and neuroanatomical substrates. We found that already very early on, from ∼80 ms after disambiguation point when the words could be identified from the available acoustic information, both verbs and nouns produced characteristic somatotopic activations in the motor strip, with words related to different body parts activating the corresponding body representations. Strikingly, along with this category-specific activation, we observed suppression of motor-cortex activation by competitor words with incompatible semantics, documenting operation of the neurophysiological principles of lateral/surround inhibition in neural word processing. The extremely early onset of these activations and deactivations, their emergence in the absence of attention, and their similar presence for words of different lexical classes strongly suggest automatic involvement of motor-specific circuits in the perception of action-related language.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Significance
The mechanisms through which our brain generates complex cognitive percepts from simple sensory and motor events remain unknown. An important question is whether the basic brain structures controlling movements and perceptions directly participate in higher-order cognitive processes such as language comprehension. Using neurophysiology, we found ultrarapid (starting at ∼80 ms) activations in the human motor cortex in response to unattended action-related verbs and nouns, with words related to different body parts activating corresponding body representations. Accompanying this category-specific activity was activation suppression by words with area-incompatible meaning, demonstrating operation of the neurophysiological principles of lateral/surround inhibition in language processing. These instant activations and deactivations emerging for words of different types in the absence of attention advocate automatic involvement of neural sensorimotor circuits in language comprehension.
Abstract
To address the hotly debated question of motor system involvement in language comprehension, we recorded neuromagnetic responses elicited in the human brain by unattended action-related spoken verbs and nouns and scrutinized their timecourse and neuroanatomical substrates. We found that already very early on, from ∼80 ms after disambiguation point when the words could be identified from the available acoustic information, both verbs and nouns produced characteristic somatotopic activations in the motor strip, with words related to different body parts activating the corresponding body representations. Strikingly, along with this category-specific activation, we observed suppression of motor-cortex activation by competitor words with incompatible semantics, documenting operation of the neurophysiological principles of lateral/surround inhibition in neural word processing. The extremely early onset of these activations and deactivations, their emergence in the absence of attention, and their similar presence for words of different lexical classes strongly suggest automatic involvement of motor-specific circuits in the perception of action-related language.
The mechanisms through which our brain generates complex cognitive percepts from simple sensory and motor events remain unknown. An important question is whether the basic brain structures controlling movements and perceptions directly participate in higher-order cognitive processes such as language comprehension. Using neurophysiology, we found ultrarapid (starting at ∼80 ms) activations in the human motor cortex in response to unattended action-related verbs and nouns, with words related to different body parts activating corresponding body representations. Accompanying this category-specific activity was activation suppression by words with area-incompatible meaning, demonstrating operation of the neurophysiological principles of lateral/surround inhibition in language processing. These instant activations and deactivations emerging for words of different types in the absence of attention advocate automatic involvement of neural sensorimotor circuits in language comprehension.
Abstract
To address the hotly debated question of motor system involvement in language comprehension, we recorded neuromagnetic responses elicited in the human brain by unattended action-related spoken verbs and nouns and scrutinized their timecourse and neuroanatomical substrates. We found that already very early on, from ∼80 ms after disambiguation point when the words could be identified from the available acoustic information, both verbs and nouns produced characteristic somatotopic activations in the motor strip, with words related to different body parts activating the corresponding body representations. Strikingly, along with this category-specific activation, we observed suppression of motor-cortex activation by competitor words with incompatible semantics, documenting operation of the neurophysiological principles of lateral/surround inhibition in neural word processing. The extremely early onset of these activations and deactivations, their emergence in the absence of attention, and their similar presence for words of different lexical classes strongly suggest automatic involvement of motor-specific circuits in the perception of action-related language.
2.
Vvedensky, V. L. (2014). Individual trial-to-trial variability of different components of neuromagnetic signals associated with self-paced finger movements. Neuroscience Letters, 569, 94-98. https://doi.org/10.1016/j.neulet.2014.03.058
@article{Vvedensky2014,
title = {Individual trial-to-trial variability of different components of neuromagnetic signals associated with self-paced finger movements},
author = {V.L. Vvedensky},
doi = {10.1016/j.neulet.2014.03.058},
issn = {0304-3940},
year = {2014},
date = {2014-05-00},
urldate = {2014-05-00},
journal = {Neuroscience Letters},
volume = {569},
pages = {94-98},
publisher = {Elsevier BV},
abstract = {We measured magnetic cortical responses to self-paced finger movements. Wide frequency band measurements revealed sharp elements of the response wave-shape, and allowed analysis of individual trials. The signal time course was decomposed into three components in the time window from 600ms before to 600ms after the movement. Each component had its own wave-shape and highly individual behavior. Two components displayed large trial-to-trial amplitude variations, whereas the amplitude of the third, high-frequency component remained stable. The frequency spectrum of the high-frequency component decayed exponentially, which indicates deterministic dynamics for the processes generating this magnetic signal. In spite of the large variations in the movement-related cortical signals, the movement itself, as measured by accelerometer attached to the finger tip, remained stable from trial to trial. The magnetic measurements are well-suited to reveal fine details of the process of movement initiation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We measured magnetic cortical responses to self-paced finger movements. Wide frequency band measurements revealed sharp elements of the response wave-shape, and allowed analysis of individual trials. The signal time course was decomposed into three components in the time window from 600ms before to 600ms after the movement. Each component had its own wave-shape and highly individual behavior. Two components displayed large trial-to-trial amplitude variations, whereas the amplitude of the third, high-frequency component remained stable. The frequency spectrum of the high-frequency component decayed exponentially, which indicates deterministic dynamics for the processes generating this magnetic signal. In spite of the large variations in the movement-related cortical signals, the movement itself, as measured by accelerometer attached to the finger tip, remained stable from trial to trial. The magnetic measurements are well-suited to reveal fine details of the process of movement initiation.
1.
Orekhova, Elena V.; Stroganova, Tatiana A. (2014). Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials. Frontiers in Human Neuroscience, 8, 34. https://doi.org/10.3389/fnhum.2014.00034
@article{Orekhova2014,
title = {Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials},
author = {Elena V. Orekhova and Tatiana A. Stroganova},
url = {https://megmoscow.ru/wp-content/uploads/pubs/10.3389_fnhum.2014.00034.pdf},
doi = {10.3389/fnhum.2014.00034},
issn = {1662-5161},
year = {2014},
date = {2014-02-06},
urldate = {2014-02-06},
journal = {Frontiers in Human Neuroscience},
volume = {8},
pages = {34},
publisher = {Frontiers Media SA},
abstract = {The extended phenotype of autism spectrum disorders (ASD) includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs) and magnetic fields (ERFs) may help to reveal which processing stages underlying brain response to unattended but salient sensory event are affected in individuals with ASD. Previous research focusing on two sequential stages of the brain response—automatic detection of physical changes in auditory stream, indexed by mismatch negativity (MMN), and evaluation of stimulus novelty, indexed by P3a component,—found in individuals with ASD either increased, decreased, or normal processing of deviance and novelty. The review examines these apparently conflicting results, notes gaps in previous findings, and suggests a potentially unifying hypothesis relating the dampened responses to unattended sensory events to the deficit in rapid arousal process. Specifically, “sensory gating” studies focused on pre-attentive arousal consistently demonstrated that brain response to unattended and temporally novel sound in ASD is already affected at around 100 ms after stimulus onset. We hypothesize that abnormalities in nicotinic cholinergic arousal pathways, previously reported in individuals with ASD, may contribute to these ERP/ERF aberrations and result in attention re-orienting deficit. Such cholinergic dysfunction may be present in individuals with ASD early in life and can influence both sensory processing and attention re-orienting behavior. Identification of early neurophysiological biomarkers for cholinergic deficit would help to detect infants “at risk” who can potentially benefit from particular types of therapies or interventions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The extended phenotype of autism spectrum disorders (ASD) includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs) and magnetic fields (ERFs) may help to reveal which processing stages underlying brain response to unattended but salient sensory event are affected in individuals with ASD. Previous research focusing on two sequential stages of the brain response—automatic detection of physical changes in auditory stream, indexed by mismatch negativity (MMN), and evaluation of stimulus novelty, indexed by P3a component,—found in individuals with ASD either increased, decreased, or normal processing of deviance and novelty. The review examines these apparently conflicting results, notes gaps in previous findings, and suggests a potentially unifying hypothesis relating the dampened responses to unattended sensory events to the deficit in rapid arousal process. Specifically, “sensory gating” studies focused on pre-attentive arousal consistently demonstrated that brain response to unattended and temporally novel sound in ASD is already affected at around 100 ms after stimulus onset. We hypothesize that abnormalities in nicotinic cholinergic arousal pathways, previously reported in individuals with ASD, may contribute to these ERP/ERF aberrations and result in attention re-orienting deficit. Such cholinergic dysfunction may be present in individuals with ASD early in life and can influence both sensory processing and attention re-orienting behavior. Identification of early neurophysiological biomarkers for cholinergic deficit would help to detect infants “at risk” who can potentially benefit from particular types of therapies or interventions.