Olga Sysoeva

• PhD
• Leading Researcher at Russian Academy of Sciences

Background/Objectives:: The link between serotonergic modulation and depression is under debate; however, serotonin reuptake inhibitors (SRIs) are still the first-choice medicine in this condition. Disturbances in time perception are also reported in depression with one of the behavioral schedules used to study interval timing, differential-reinfor...

Introduction Time perception is a fundamental cognitive function, the brain mechanisms of which are not fully understood. Recent electroencephalography (EEG) studies have shown that neural oscillations in specific frequency bands may play a role in this process. In the current study, we sought to investigate how neurophysiological activity of corti...

Behavioral copying is a key process in group actions, but it is challenging for individuals with autism spectrum disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n = 16), a new potential rodent model for ASD, compared to control Wistar rats (n = 15). A randomly chosen h...

Time perception is a fundamental cognitive function essential for adaptive behavior and shared across species. The neural mechanisms underlying time perception, particularly its neuromodulation, remain debated. In this review, we examined the role of the serotonergic system in time perception (at the scale of seconds and minutes), building a transl...

Research has shown that semantic analysis occurs at early stages of word processing (less than 200 ms). While traditional studies have focused on isolated words/sentences, our research explores rapid semantic processing during reading stories using event-related potentials and magnetoencephalography. We employed the rapid serial visual presentation...

Recent advances in cognitive neuroscience have expanded the tools available to study language processing beyond traditional event-related potentials (ERPs), to methods like the Temporal Response Function (TRF). TRF allows for a nuanced investigation of brain dynamics by modeling neural responses as a convolution of stimuli with self- optimized TRF...

The paper is devoted to presentation and assessment of the algorithm for extraction of heartbeat evoked potential (HEP) using the independent component analysis (ICA). The algorithm includes simultaneous recording of electroencephalogram (EEG) and photoplethysmogram (PPG), selection the EEG-epochs, related to the peak of the PPG pulse wave, separat...

Neural tracking is the ability of the cerebral cortex to track changes in various components of stimuli. In our study, we examine the features of neural tracking of acoustic characteristics and features of syllable processing under conditions of listening to natural speech and syllable sequences in children aged 3 to 9 years. During the experimenta...

Behavioral copying is a key process in group actions, but it is challenging for individuals with Autism Spectrum Disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n=16), a new rodent model for ASD, compared to control Wistar rats (n=15). A randomly chosen healthy Wistar...

Behavioral copying is a key process in group actions, but it is challenging for individuals with Autism Spectrum Disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n=16), a new rodent model for ASD, compared to control Wistar rats (n=15). A randomly chosen healthy Wistar...

Numerous behavioral studies have demonstrated a rhythmic priming effect (RPE) on grammatical processing using grammaticality judgment tasks (GJT), where participants performed better following regular rhythmic sequences compared to baseline conditions or irregular rhythmic sequences (i.e. auditory rhythmic sequences with violated metrical structure...

Major depressive disorder (MDD) and obsessive-compulsive disorder (OCD) are psychiatric disorders that often co-occur. We aimed to investigate whether their high comorbidity could be traced not only by clinical manifestations, but also at the level of functional brain activity. In this paper, we examined the differences in functional connectivity (...

Функция временного отклика — новый метод, который позволяет исследовать мозговые механизмы восприятия естественной, натуралистической речи. В отличие от других методов изучения мозговой активности (например, вызванных потенциалов), функция временного отклика не требует предъявления большого количества однотипных стимулов для получения устойчивого м...

Receptive speech is the ability to understand speech addressed to a person. It is a crucial process for a child’s cognitive development. We examine the relationship between receptive speech and neural tracking of natural speech in 52 children aged 3 to 8 years to infer the neurophysiological mechanisms underlying speech development. We registered a...

Introduction Mental disorders are a significant concern in contemporary society, with a pressing need to identify biological markers. Long-range temporal correlations (LRTC) of brain rhythms have been widespread in clinical cohort studies, especially in major depressive disorder (MDD). However, research on LRTC in obsessive-compulsive disorder (OCD...

Aim The current study aimed to infer neurophysiological mechanisms of auditory processing in children with Rett syndrome (RTT)—rare neurodevelopmental disorders caused by MECP2 mutations. We examined two brain responses elicited by 40‐Hz click trains: auditory steady‐state response (ASSR), which reflects fine temporal analysis of auditory input, an...

This study addresses the dynamics of the parieto-occipital α rhythm of the brain in relation to the process of comparing stimulus durations. An EEG study was conducted in which participants (n = 48) were asked to compare pairs of visual stimuli with durations in the range 3.2–6.4 sec. Time-frequency analysis of EEG recordings was run in the range 8...

Speech development is crucial for a child’s mental growth. Moreover, speech development significantly impacts a child’s educational and professional achievements. It enables the child to interact with the external environment and develop self-awareness and behavioral skills. Thus, the study of the mechanisms of speech development disorders and the...

Background Rett syndrome (RS) is a rare neurodevelopmental disorder characterized by mutations in the MECP2 gene. Patients with RS have severe motor abnormalities and are often unable to walk, use hands and speak. The preservation of perceptual and cognitive functions is hard to assess, while clinicians and care-givers point out that these patients...

Our study describes the effects of sensory tetanization on neurophysiological and behavioral measures in humans linking cellular studies of long-term potentiation with high-level brain processes. Rapid (every 75ms) presentation of pure tone (1020 Hz, 50ms) for 2 minutes was preceded and followed by oddball blocks that contained the same stimulus pr...

Spontaneous EEG contains important information about neuronal network properties that is valuable for understanding different neurological and psychiatric conditions. Rett syndrome (RTT) is a rare neurodevelopmental disorder, caused by mutation in the MECP2 gene. RTT is characterized by severe motor impairments that prevent adequate assessment of c...

Major depressive disorder (MDD) is characterized by dramatic and persistent worsening of mood, as well as a subjective feeling of time slowing. However, experimental data on time perception are inconsistent. As serotonergic dysfunction implicated in MDD etiology, we aim to examine time perception in MDD through the framework of lossy temporal integ...

This research is aimed at studying the dynamics of the parietal-occipital alpha rhythm in its connection with the process of stimuli duration comparison. EEG study was conducted in which participants (n = 48) were asked to compare pairs of visual stimuli of different durations ranging from 3.2 to 6.4 s. The time-frequency analysis of the EEG was ca...

Studying mu-rhythm in developmental disorders is crucial for identifying the origin of motor and social malfunctioning. However, the commonly used mu-rhythm experimental protocol, that requires following instructions, is challenging for children with motor and cognitive deficits. Here we present an inclusive experimental procedure that contains pas...

Potocki–Lupski Syndrome (PTLS) is a rare condition associated with a duplication of 17p11.2 that may underlie a wide range of congenital abnormalities and heterogeneous behavioral phenotypes. Along with developmental delay and intellectual disability, autism-specific traits are often reported to be the most common among patients with PTLS. To contr...

Background. Interoception can serve as the basis for time perception. This assumption is supported with a considerable overlap between the brain structures that are involved in processing of interoceptive information and estimation of time duration. However, the psychophysiological mechanisms of interoceptive information integration during time per...

Potocki-Lupski Syndrome (PTLS) is a rare condition associated with a duplication of 17p11.2 that may underlie a wide range of congenital abnormalities and heterogeneous behavioral phenotypes. Along with developmental delay and intellectual disability, autism-specific traits are often reported to be the most common among patients with PTLS. To contr...

In clinical practice, epilepsy is often comorbid with the autism spectrum disorders (ASDs). This warrants a search of animal models to uncover putative overlapping neuronal mechanisms. The Krushinsky-Molodkina (KM) rat strain is one of the oldest inbred animal models for human convulsive epilepsies. We analyzed the behavioral response of adult seiz...

Rett syndrome (RTT), a severe neurodevelopmental disorder caused by MECP2 gene abnormalities, is characterized by atypical EEG activity, and its detailed examination is lacking. We combined the comparison of one-time eyes open EEG resting state activity from 32 girls with RTT and their 41 typically developing peers (age 2–16 years old) with longitu...

Rett Syndrome (RS) is a rare neurodevelopmeтtal disorder characterized by mutations in the MECP2 gene. Patients with RS have severe motor abnormalities and are often unable to walk, use hands and speak. The preservation of perceptual and cognitive functions is hard to assess, while clinicians and care-givers point out that these patients need more...

Spontaneous EEG contains important information about neuronal network properties that is valuable for understanding different neurological and psychiatric conditions. Rett syndrome (RTT) is a rare neurodevelopmental disorder, caused by mutation in the MECP2 gene. RTT is characterized by severe motor impairments that prevent adequate assessment of c...

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Our study reviewed abnormalities in spontaneous, as well as event-related, brain activity in syndromes with a known genetic underpinning that are associated with autistic symptomatology. Based on behavioral and neurophysiological evidence, we tentatively subdivided the syndromes on primarily hyper-sensitive (Fragile X, Angelman) and hypo-sensitive...

Independent Component Analysis (ICA) is a conventional approach to exclude non-brain signals such as eye movements and muscle artifacts from electroencephalography (EEG). A rejection of independent components (ICs) is usually performed in semiautomatic mode and requires experts’ involvement. As also revealed by our study, experts’ opinions about th...

High-frequency electrical stimulation induces increases in synchronous transmission between pairs of neurons which persists for prolonged periods (long-term potentiation, LTP). Recent studies showed that sensory (so-called LTP-like, with a frequency of over 9 Hz) stimulation can induce effects analogous to those seen after electrical stimulation an...

Выявлена отрицательная корреляция между индивидуальными частотами пика альфа-ритма в теменных отведениях при выполнении задачи «субъективная минута» и длительностью субъективной минуты. Результаты позволяют сделать вывод о связи частоты индивидуального пика альфа-ритма со скоростью течения внутренних часов.

A fuller understanding of the effects of auditory tetanization in humans would inform better language and sensory learning paradigms, however, there are still unanswered questions. Here, we probe sustained changes in the event‐related potentials (ERPs) to 1020Hz and 980Hz tones following a rapid presentation of 1020Hz tone (every 75 ms, 13.3Hz, tet...

Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliab...

Independent Component Analysis (ICA) is a conventional approach to exclude non-brain signals such as eye-movements and muscle artifacts from electroencephalography (EEG). Due to other possible EEG contaminations, a rejection of independent components (ICs) is usually performed in semiautomatic mode and requires experts’ involvement. Noteworthy, as...

SHANK3 encodes a scaffold protein involved in postsynaptic receptor density in glutamatergic synapses, including those in the parvalbumin (PV)+ inhibitory neurons—the key players in the generation of sensory gamma oscillations, such as 40-Hz auditory steady-state response (ASSR). However, 40-Hz ASSR was not studied in relation to SHANK3 functioning...

Background Deficits in perception and production of vocal pitch are often observed in people with autism spectrum disorder (ASD), but the neural basis of these deficits is unknown. In magnetoencephalogram (MEG), spectrally complex periodic sounds trigger two continuous neural responses—the auditory steady state response (ASSR) and the sustained fie...

SHANK3 encodes scaffold protein involved in postsynaptic receptor density in glutamatergic synapses, including those in the parvalbumin (PV)+inhibitory neurons – the key players in generation of sensory gamma oscillations, such as 40-Hz auditory steady-state response(ASSR). Here we describe a clinical and neurophysiological phenotype of a 15-years...

Background: Deficits in perception and production of vocal pitch are often observed in people with autism spectrum disorder (ASD), but the neural basis of these abnormalities is unknown. In magnetoencephalogram (MEG), spectrally complex periodic sounds trigger two continuous neural responses – the auditory steady state response (ASSR) and the susta...

Background: Deficits in perception and production of vocal pitch are often observed in people with autism spectrum disorder (ASD), but the neural basis of these abnormalities is unknown. In magnetoencephalogram (MEG), spectrally complex periodic sounds trigger two continuous neural responses – the auditory steady state response (ASSR) and the susta...

Background: Deficits in perception and production of vocal pitch are often observed in people with autism spectrum disorder (ASD), but the neural basis of these deficits is unknown. In magnetoencephalogram (MEG), spectrally complex periodic sounds trigger two continuous neural responses – the auditory steady state response (ASSR) and the sustained...

Perceptual learning is defined by increased effectiveness of completing perceptual tasks as a result of experience or training. This review presents the analysis of changes in the components of event-related potentials (ERPs) after visual and auditory perceptual learning in humans. The use of the EEG method, which has a high temporal resolution, ma...

Due to severe motor impairments and the lack of expressive language abilities seen in most patients with Rett Syndrome (RTT), it has proven extremely difficult to obtain accurate measures of auditory processing capabilities in this population. Here, we examined early auditory cortical processing of pure tones and more complex phonemes in females wi...

Objective: Systematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations). Methods: Pubmed, ISI Web of Knowledge and BIORXIV were searche...

Due to severe motor impairments and the lack of expressive language abilities seen in most patients with Rett Syndrome (RTT), it has proven extremely difficult to obtain accurate measures of auditory processing capabilities in this population. Here, we examined early auditory cortical processing of pure tones and more complex phonemes females with...

Rett syndrome (RTT), a rare neurodevelopmental disorder caused by mutations in the MECP2 gene, is typified by profound cognitive impairment and severe language impairment, rendering it very difficult to accurately measure auditory processing capabilities behaviorally in this population. Here we leverage the mismatch negativity (MMN) component of th...

Rett syndrome (RTT), a rare neurodevelopmental disorder caused by mutations in the MECP2 gene, is typified by profound cognitive impairment and severe language impairment, rendering it very difficult to accurately measure auditory processing capabilities behaviorally in this population. Here we leverage the mismatch negativity (MMN) component of th...

Gamma oscillations facilitate information processing by shaping the excitatory input/output of neuronal populations. Recent studies in humans and nonhuman primates have shown that strong excitatory drive to the visual cortex leads to suppression of induced gamma oscillations, which may reflect inhibitory‐based gain control of network excitation. Th...

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 implicate...

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 sou...

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 sou...

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 w...

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 e...

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...

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...

THIS STUDY AIMED TO EXAMINE EFFECT OF PHYSICAL EXERCISE ON MOTOR TIMING: personal, maximum and "once per second" tapping. The acute effect was examined by comparing the baseline tapping with that after acute exercise in 9 amateur athletes, 8 elite synchronous swimmers and 9 elite biathletes. Then the baseline tapping was compared among athletes of...

Establishing links between experimental data, their models, and the neural substrates presents a permanent challenge for research in timing and time perception. This applies particularly to the problem of internal repre-sentation of temporal duration and its neural implementation. In this short communica-tion we will report on progress achieved wit...

Background: The present study investigates neurobiological underpinnings of individual differences in time perception.

Association of brain processes presumably underlying aggression with serotonin transporter gene polymorphism in men was studied. Carriers of more active gene variant are characterized by higher aggression index, increased component of brain potential mismatch negativity responsible for automatic difference detection, and decreased P300 component ch...

Aggression is a heterogeneous heritable psychological trait, also influenced by environmental factors. Previous studies, mostly conducted on male population, have found some associations of the aggression with the polymorphisms of genes, regulating the activity of serotonin (5-HT) in the brain. However, psychological as well as biochemical manifest...

Previous studies have repeatedly found that late (300–800 ms) components of event-related potentials (ERP) reflected semantic analysis, i.e. the differentiation between abstract and concrete words. However, the human brain may detect the meaning of the words much earlier. This study investigated the brain mechanisms of the processing of abstract an...