Volume 73, Nº 2 (2023)
ОБЗОРЫ И ТЕОРЕТИЧЕСКИЕ СТАТЬИ
NEUROBIOLOGICAL FACTORS OF EXECUTIVE DYSFUNCTION IN AUTISM SPECTRUM DISORDERS
Resumo
Autism is a pervasive neurodevelopmental disorder that is defined by difficulties in social interaction and abnormal preoccupation in repetitive and stereotypic activities. Deficit of basic executive functions, such as cognitive flexibility, inhibitory control, working memory may strongly contribute to these symptoms. Prefrontal and cingulate cortices play a crucial role in the executive functions. These brain structures are regulated by neuromodulatory systems of the brain: cholinergic, noradrenergic, serotonergic, and dopaminergic. During the early brain development these neuromodulators act as neurotrophic factors, and they regulate excitation-inhibition balance in the brain. Pathogenesis of autism is hypothesized to be linked to impairment in metabolism of one or more of these neuromodulators. The aim of this review is to consider the functional role of these neuromodulators and the significance of their imbalance in mature and developing brain, as an important factor in the development of autistic symptoms in children and adults.
METHODS OF BRAIN RESEARCH IN THE CERVICAL DYSTONIA
Resumo
The review is based on 149 foreign and Russian articles. The features of the brain functioning in cervical dystonia (CD) through the prism of modern technologies are reviewed. CD is hard to diagnose currently. CD is one of the promising areas not only in the clinical paradigm. In the future, CD can become an interesting model for studying the features of the balance of excitation/inhibition in brain neurons with the use of modern technologies. Using CD as a model of specific changes in function connections of brain regions, it would be possible to extrapolate the results to a healthy population and to the patients with other neurological or mental diseases.
FORMATION OF PROSOCIAL BEHAVIOR AND ITS NEUROPHYSIOLOGICAL MECHANISMS IN EARLY CHILDHOOD
Resumo
From a very early age children are capable on prosocial acts: giving objects, comforting and sharing with other people. This review considers modern research on the patterns and neurophysiological mechanisms of helping behavior (HB) formation in early childhood, including the results of the authors’ own work. Methods for HB researching in infants and young children are presented. The factors of development and neurophysiological mechanisms of instrumental, empathic and altruistic HB, and the role of empathy in these kinds of behaviors are analyzed. We also described data about involvement of various brain structures (for example, the mirror system as extended part of sensorimotor and emotional neural networks) in implementation of HB. The importance of research into the mechanisms of prosocial behavior for the full-fledged upbringing and education of children in the conditions of modern society is emphasized.
ФИЗИОЛОГИЯ ВЫСШЕЙ НЕРВНОЙ (КОГНИТИВНОЙ) ДЕЯТЕЛЬНОСТИ ЧЕЛОВЕКА
COHERENCE OF THE TETA1-BAND EEG IN A STATE OF RELATIVE REST AND DURING ATTENTION TESTING IN SUBJECTS WITH DIFFERENT LEVELS OF TRAIT ANXIETY
Resumo
Anxiety has a significant impact on the effectiveness of cognitive activity, which may be due to the peculiarities of the organization of voluntary and involuntary attention in individuals with different anxiety. Aim: to examine functional cortical connections in subjects with different levels of trait anxiety in a state of relative rest and when performing an attention test with usage of the coherent analysis of the teta1-band EEG (4–6 Hz). Coherence of teta1-band of EEG was analyzed in subjects (43 people, men aged 19–21 years) with low, medium and high level of trait anxiety (TA, according to C.D. Spielberger) in three experimental situations: the state of relative rest with closed eyes, the initial state before performing the test (with eyes opened) and during the test (red-black tables of F.D. Gorbov). Subjects with high TA in the state of relative rest with their eyes closed had a lower right-hemisphere coherence of the teta1-band EEG in the system of interrelations with focus in the temporal lead. In the initial state, with eyes opened and during test performing, individuals with high TA showed high level of interhemispheric coherence of the teta1-band of EEG. The highest lability of the structure of coherent relationships in the teta1-range of the EEG was observed in subjects with medium TA, who demonstrated an increase mainly in the interhemispheric coherence of most areas of the cortex during the test compared to the initial state. Individuals with high TA were characterized by relative inertia of the structure of coherent relationships in the teta1-range of the EEG at the stages of examination. The results of the study indicate that trait anxiety is one of the factors modulating the organization of neurocognitive networks both in a state of relative rest and during attention testing.
ACTIVITY OF THE MIRROR NEURON SYSTEM IN PEOPLE WITH DEPRESSIVE SYMPTOMS
Resumo
The global events of the last few years have led to the fact that more and more people are beginning to experience depressive symptoms. Developing depression significantly affects the emotional state of a person and his perception of the world around him. The purpose of this study was to analyze the reactions of mu- and alpha-rhythms reflecting the work of the mirror and visual systems of the brain, when perceiving and repeating emotionally colored social stimuli in people with different levels of depression. The study involved 32 healthy subjects who were divided into two groups – with high and low levels of depression on the Beck scale. A 32-channel EEG was recorded in two experimental blocks activating the emotional and motor components of the mirror neuron system (MNS): 1) when perceiving emotional faces expressing joy or grief; 2) when observing and repeating motor hand gestures. The desynchronization levels of the mu- and alpha-rhythm components in each of the tasks identified by the independent component method (ICA) were analyzed. It was found that the mu- desynchronization was significantly higher in people with depression when repeating motor hand movements, as well as when perceiving negative emotional facial expressions. Desynchronization of the alpha rhythm did not differ in the two groups of volunteers. Thus, the development of a depressive state increases MNS activation, and its sensitivity to negative emotional stimuli. This effect does not apply to the visual cortex and visual attention.
MULTI-VOXEL PATTERN ANALYSIS OF fMRI DATA DURING SELF- AND OTHER-REFERENTIAL PROCESSING
Resumo
The study of brain activity in the processing of self-referential information, as compared to the processing of information related to other people, is based on the application of mass-univariate analysis, based on the assumption that activity in one region is independent of activity in other regions. Recently, there has been a growing interest in neuroimaging to investigate spatially distributed information using multivariate approaches such as multivoxel pattern analysis (MVPA). In this paper, we used MVPA to analyze fMRI data recorded during self-evaluation and evaluation of other people of varying proximity. In all pairwise classifications tested, the number of correct identifications was significantly higher than the level of random matches. Predictively significant structures were widely distributed over different brain regions and included areas of the visual, lateral prefrontal, and many other cortical areas in addition to the cortical midline structures that contributed the most. In the self-other classification, ventral areas of the medial prefrontal and cingulate cortex were the most informative for the self condition, whereas parietal and occipital medial areas were the most informative for the other condition. The combination of brain structures, which included the anterior cingulate cortex and both amygdalae, revealed by principal component analysis, correlated positively with the psychometric scale of sensitivity to reward, and negatively with neuroticism scales. Overall, the results show the fruitfulness of using machine learning methods to analyze data from such kinds of experiments.
AUDITORY AFTER-EFFECT: STATIONARY ADAPTER CHANGES THE PERCEIVED TRAJECTORIES OF MOVING SOUNDS
Resumo
Perceived trajectories of dichotically presented sound stimuli with different spatial patterns were investigated in silence and after listening to stationary adapters. The spatial position of all stimuli was determined by the interaural level differences. The subjects indicated the perceived position of the beginning and end of the stimulus trajectory. Lateralized stationary adapters had no effect on the perceived position of the neighboring (ipsilateral) stimuli, but “pushed away” the stimuli located on the opposite side of the acoustic space. After exposure to the central adapter, the lateral points of the perceived trajectories were pushed away from the adapter, regardless of the motion direction. The motion starting points located near the central adapter shifted in the direction of the stimulus motion, but the perceived position of the central endpoints was not affected by the central adapter. The effect of stationary adapters on the perceived trajectories of moving sounds can be best explained by a three-channel model of the neural coding of auditory space.
ЭКСПЕРИМЕНТАЛЬНАЯ ПАТОЛОГИЯ ВЫСШЕЙ НЕРВНОЙ ДЕЯТЕЛЬНОСТИ
STUDYING THE ABILITY FOR RESEARCH ACTIVITY IN MONKEYS
Resumo
The level of research ability in four species of lower monkeys was studied: green monkeys (Chlorocebus aethiops), Javanese macaques (Macaca fascicularis), rhesus monkeys (Macaca mulatta) and hamadryas baboons (Papio hamadryas). The assessment was made according to such indicators as the level of research activity, the dynamics of research activity, the diversity of research activities. The results found indicate a higher level of the studied parameters in Javan macaques and hamadryas baboons in comparison with rhesus macaques and green monkeys.