@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}