The role of risk subcortical brain regions in the formation alalie

Complex children examination with alalia was based the analysis by the role of subcortical brain structures for the formation of speech was investigated. Alalia is systemic speech underdevelopment in children, which violated all the components of speech. Evaluation of the functional state of brain structures on the EEG has allowed to distinguish the two groups, which depend on the nature of changes in bioelectric activity (BEA). The first group is one with the changes of alpha rhythm and/or local changes in BEA predominantly in the left hemisphere, the second group with violations ofbrainstem origin, mainly generalized EEG changes. A comprehensive analysis of clinical data has allowed to suggest the basis of the formation alalia lies subcortical structures lesion of the left hemisphere of the brain and stem departments of one. The analysis of perinatal risk factors has allowed to hypothesize about the connection of subcortical structures lesion with antenatal complications in the first half of pregnancy.     

The role of damage to the cerebral subcortical divisions in the formation of alalia

The role of the cerebral subcortical structures in speech formation was studied by analyzing the data on the comprehensive examination of children with alalia. Alalia is a systemic underdevelopment of speech in which all the speech components are disordered. The assessment of the functional state of the brain structures by means of EEG allowed us to identify two groups differing in the pattern of changes in bioelectrical activity (BEA): group 1 with α rhythm changes and/or local BEA changes, predominantly in the left hemisphere, and group 2 with predominantly generalized EEG changes of brainstem origin. Integrated analysis of clinical data allowed us to suggest that a lesion of the left hemisphere subcortical structures and the brainstem divisions underlies the formation of alalia. The analysis of the perinatal risk factors allowed us to advance the hypothesis that damage to the subcortical structures was linked to antenatal complications in the first half of pregnancy.     

Structural and functional organization of a developing brain and formation of cognitive functions in child ontogeny

Results of multidisciplinary studies, including neuromorphological, neurophysiological, neuropsychological, and psychphysiological studies, are reviewed. They allow the brain mechanisms of cognition formation and development during maturation to be identified. The role of regulatory (modulatory) brain systems in forming the cognitive function in the child is demonstrated. Data on considerable changes in the brain systems responsible for the development of cognitive functions in children between the ages of five to six and seven to eight years are presented. At this age, the morphological and functional maturations of the frontal cortical areas and their descending connections with other cerebral structures increase the efficiencies of arbitrary selective attention, learning the activity program, inhibition of spontaneous responses, and regulation and organization of activity, i.e., the functions that are important for successful schooling.     

The effect of the level of consciousness on the spatial organization of cortical activity in mental processes

In the present study the influence of the level of consciousness on spatial organization of the cortical functional activity in human psychic processes was investigated. For regulation of the level of consciousness models were used of hypnotic analgesia, automatization of intellectual actions and mental activity in hypnotic state. Evaluation of the mosaic of the cortical activity was made by parameters of spatial synchronization of the potentials with topographic mapping of crosscorrelation, spectral and coherent-phasic EEG characteristics. The obtained data allow to conclude about special role of the frontal areas of the left hemisphere in the process of realization of information. It has been shown that one of the main functions in neurophysiological structure of consciousness is the selection of signals according to dominating motivation. The frontal areas of the left hemisphere control the degree of inclusion of foci of increased activity, specific and non-specific for each type of activity, and possibly, regulate the way of transformation of the information.     

参与不同难度数字计算的脑区——脑功能磁共振成像研究

本研究用功能磁共振成像技术观察了人脑进行不同难度数字加减计算时的脑区激活情况,并探讨大脑皮层和皮层下结构在数字计算中的作用.用Siemens 1.5 Tesla磁共振机对16名右利手健康志愿者进行简单及复杂数字加减任务的fMRI扫描.实验采用组块设计.刺激任务分为简单加减计算任务、复杂加减计算任务和基线任务.用SPM99软件进行数据分析和脑功能区定位.分别比较同一任务各个脑区平均激活强度和同一脑区在两种任务中的激活强度.结果显示,简单及复杂加减计算激活的被试者的脑区基本相同,激活的皮层区主要见于额叶、顶叶、枕叶、扣带回、丘脑及小脑;简单及复杂加减计算激活的皮层下结构包括两侧尾状核、左纹状体边缘区等基底核结构和丘脑.在简单及复杂计算中,纹状体与皮质结构(额叶、顶叶)间激活强度均无显著性差异.简单计算与复杂计算比较,右顶叶,在复杂任务时出现激活,在简单任务时未出现激活.上述结果提示,完成数字计算任务的脑区除了额叶、顶叶、扣带回等皮层结构外,大脑皮层下的一些结构如纹状体、纹状体边缘区,也是参与数字计算的重要部位.皮层下结构纹状体和优势半球的纹状体边缘区参与了数字工作记忆,可能是进行数字计算神经环路的重要组成部位.右项叶(缘上回)只在复杂任务出现激活,该区可能是视空间记忆和加工的重要部位.     

Formation of the functional organization of the cerebral cortex at rest in young schoolchildren varying in the maturity of cerebral regulatory systems: I. Analysis of EEG spectral characteristics in the state of rest

Spectral correlation analysis of the EEG was used to study the organization of the rhythmic electrical activity (EA) of the cerebral cortex in normal children aged seven to eight and nine to ten years and children with the two types of functional immaturity of cerebral regulatory systems most common at this age, namely, fronto-thalamic regulatory system immaturity (IFTS) and brainstem nonspecific activation system immaturity (deficiency) (DNA). Statistical comparison (ANOVA) of these groups of children with respect to the absolute and relative α-and ?-band spectral powers of the background EEGs of 12 cortical areas showed the specific features of the effects of functional immaturity of regulatory systems at different levels on the cortical rhythmic EA pattern at rest. DNA led to a significant increase in the absolute spectral power of α and ? waves recorded in all derivations in both age groups, which indicated a generalized decrease in cortex activation in these children. IFTS caused a significant decrease in the relative strength of α waves and an increase in the strength of ? waves. Taking into account the results of ontogenetic studies, this may be regarded as evidence for a relative underdevelopment of cortical rhythm-generating networks. The absolute spectral powers of both α and ? waves were decreased in all groups of children by nine to ten years of age, which indicated that nonspecific activation was enhanced in the age interval studied. Significant changes were observed in children with functional immaturity of regulatory systems. In children with DNA, the age-related increase in cortex activation was expressed as a significant increase in the α-rhythm peak frequency. In children with IFTS, by nine to ten years of age, both the absolute and relative strengths of ? waves were decreased in most cortical areas studied, which may be regarded as the progressive formation of cortical rhythm-generating mechanisms.     

Neurophysiological Markers of Abnormal Development in Children with Mental Disorders

Longitudinal analysis of the spectral power of the main EEG bands was performed in the wakeful state with the eyes open and the eyes closed in children with mental disorders at various stages of correction by transcranial direct current stimulation (tDCS). A significant increase in the power of α-rhythm in the parietal-occipital areas and a significant decrease in the slow wave activity in the left frontotemporal areas were observed in the course of the correction process. The data obtained can be considered as the neurophysiological markers of the tDCS effects (formation of age-related EEG parameters in children with mental disorders). The data also prove the relations between the described phenomena and the cortical mechanisms of speech disorders and other psychic processes caused by perinatal CNS disorders.     

Continuity and prospects of development of researches in area system-integrativity of psychophysiology of functional state and cognitive activity

In the review one of actual problems of psychophysiology in studying a phenomenon of integration of mechanisms of regulation of state of a brain and features of the organization is discussed by a brain of cognitive activity. Basic value of results of long-term researches of academician N.P. Bechterevoj and of her school is opened in the field of neurophysiology of functional states as bases of the organization of mental activity in conditions of direct, long and sparing contact to a cortical and subcortical structures of a brain, with the help long-term intracerebral electrodes. Arguments about a commensurability and complementary value similar on amplitud-time parameters slow and superslow gradual changes of neurophysiological processes registered simultaneously in identified zones of subcortical structures of a brain and with removal from a surface of a head in cortical projections of basic integrativity of the centres are submitted. Representations about a brain as difficultly organized "swimming" many-contour, neurodinamic informational-controlling suprasystem with hierarchically, probability a principle of the organization different on speeds and intensity of processes of the ability to live participating in maintenance of a condition of rest, mental conditions and cognitive activity are formulated and argued. At the limited set universal neurodinamic "languages", the brain has the multiregister mechanism of regulation of conditions and selectivity of mechanisms of the integration providing the contribution differing on information maintenance gradual neurophysiological of processes of different levels of the structurally functional organization in formation of brain systems of maintenance of concrete kinds of cognitive activity.     

Multiform wave organization of neurophysiological processes-universal “language” of human brain in realization of informational-controlling functions

The paper summarizes literature data and results of many-year Laboratory studies disclosing principles of the multiform spatial-time organization of differing by rates of neurophysiologic brain processes as the universal “language” of its informational-controlling functions. There are considered current concepts of electrogenesis and physiological significance of ratios of gradual changes of biopotentials and impulse activity of neurons considered in studies of cerebral mechanisms of regulation of normal and pathological states, and organization of human psychic activity. Put forward and argumented are concepts of the probability principle of hierarchical organization of differing by rates of neurophysiologic processes brain zones, structures, and areas in formation of the brain systems participating in provision of the higher psychic functions and states. It is proposed to discuss the concept of the brain as the “swimming,” many-contour, neurodynamic informational-controlling suprasystem with universal, hierarchically organized neurodynamic structures—”functional organs” by A.A. Ukhtomskii (1978), of which formation provides large informational brain capacity and a wide specter of adaptive possibilities of the human organism.     

EEG Spectral Characteristics in Junior Schoolchildren with Learning Problems

EEG spectral characteristics were studied in two age groups (7–8.5 and 8.5–10 years) of mentally healthy children and children with learning problems at rest and during performance of a Raven test. It was shown that slow frequencies are more pronounced in the EEG of 7- to 8.5-year-old children with learning problems than in EEG of healthy children of the same age group. An immature form of EEG activation, i.e., an increase not only in the but also in the frequencies during activity, was characteristic of these children. The reaction of the activation of the definitive type develops between the 8.5–10 years of age. This reaction is correlated with an increase in the efficiency of the sensory perceptive and sensorimotor activity. The distinctive feature of children with learning problems between 8.5–10 years of age is a greater expression of slow frequencies in the baseline EEG of the frontal (in particular, left frontal) areas of the cortex. The obtained results are considered as a reflection of a retardation of the functional maturation of the brain structures responsible for the deficit of involuntary and voluntary attention and the disorder of a systemic organization of perception and analytical–synthetic brain activity as compared to the normal age characteristics. Possible neurophysiological mechanisms responsible for learning problems in junior schoolchildren are discussed on the basis of the obtained results and evidence from the literature.     

Longitudinal Study of the Development of Higher Mental Functions in Primary School Children

This article presents the results of a longitudinal population-based neuropsychological study of the development of higher mental functions (HMFs) in primary school children from grades 1 through 3 at a Moscow public school (n = 84). We monitored changes in HMFs in the total sample and in groups of children with different baseline HMFs (high, medium, low), as measured in the first grade, using seven indexes that reflect individual HMF components such as executive functions (voluntary regulation of activity), serial organization of movements and actions, processing of kinesthetic, auditory, visual, and visual-spatial information, and regulation of activation, at three time points (first, second, and third grades). The study found a generally positive trend in the structural and functional components of HMFs in the children who were tested. Groups of children with different baseline levels of HMFs steadily maintained their differences in the degree of development of the HMFs at each evaluation time point, although the greatest change in HMF components was found in children with initially low scores, and the least change was in children with initially high HMF scores. Among the components with the least change was voluntary regulation—that is, the programming, regulation, and control of one's activity. The fact that children with high baseline functioning did not change significantly in a given function from first to third grades may be related to a decline in learning motivation, insofar as their learning is then occurring in the zone of actual and not proximal development.     

The dynamics of intracortical interaction during thinking activities

A new method is described of the brain mapping, based on determination of the probability of appearance of isofrequency components in the EEG derivations allowing to evaluate functional interaction of the brain structures in the process of psychic activity. The process of mental construction of visual image from separate elements includes three stages. At the stage of image search the focus of activity is in the occipital cortical area; in the stage of construction it moves to the frontal cortical areas; completion of the task and verbalization of the image are accompanied by joining of the cortical connections in common system. Alongside with the main focus of activity secondary focuses in the temporal cortex are also revealed during the search of the visual image. The topography of interaction at the frequencies of alpha-range in mainly determined by the stage of image construction. In case of prevalence of the image and abstract thinking shift is marked of the activity focuses at the frequencies of theta-range respectively to the right and left hemispheres.     

Peculiarity of brain mechanisms of regulation of level of wakefulness and of cognitive activity in children with retardation of psychic development and in healthy children of the same AGF

The work opens possibilities of the of modifications of the developed at the Laboratory systemic-integrative psychophysiological approach to study of the age-related organization or of deviation from norm in formation of superslow informational-controlling brain systems participating in mechanisms of regulation of the wakefulness level and of cognitive activity in the 5-7-year old healthy children and in children of the same age group with retardation of psychic and speech development of the cerebral-organic genesis. There are disclosed peculiarities of organization of: (a) cortical-brainstem and limbic-reticular mechanisms of regulation of the level of wakefulness; (b) suprasegmentary mechanisms of autonomic, hemodynamic, and oxygen-dependent energy supply of the wakefulness level in the examined children's contingent. There are substantiated concepts about interrelations of peculiarities of the level of actual development of emotional and cognitive spheres with age-related peculiarities or disturbances of formation of mechanisms of regulation of the wakefulness level, its autonomic and hemodynamic provision as well as of the oxygen-dependent energetic potential.     

Peculiarities of brain mechanisms of regulation of level of wakefulness and of cognitive activity in children with retardation of psychic development and in healthy children of the same age

The work opens possibilities of the of modifications of the developed at the Laboratory systemic-integrative psychophysiological approach to study of the age-related organization or of deviation from norm in formation of superslow informational-controlling brain systems participating in mechanisms of regulation of the wakefulness level and of cognitive activity in the 5–7-year old healthy children and in children of the same age group with retardation of psychic and speech development of the cerebral-organic genesis. There are disclosed peculiarities of organization of: (a) cortical-brainstem and limbic-reticular mechanisms of regulation of the level of wakefulness; (b) suprasegmentary mechanisms of autonomic, hemodynamic, and oxygen-dependent energy supply of the wakefulness level in the examined children’s contingent. There are substantiated concepts about interrelations of peculiarities of the level of actual development of emotional and cognitive spheres with age-related peculiarities or disturbances of formation of mechanisms of regulation of the wakefulness level, its autonomic and hemodynamic provision as well as of the oxygen-dependent energetic potential.     

Global and regional differences in brain anatomy of young children born small for gestational age

In children who are born small for gestational age (SGA), an adverse intrauterine environment has led to underdevelopment of both the body and the brain. The delay in body growth is (partially) restored during the first two years in a majority of these children. In addition to a negative influence on these physical parameters, decreased levels of intelligence and cognitive impairments have been described in children born SGA. In this study, we used magnetic resonance imaging to examine brain anatomy in 4- to 7-year-old SGA children with and without complete bodily catch-up growth and compared them to healthy children born appropriate for gestational age. Our findings demonstrate that these children strongly differ on brain organisation when compared with healthy controls relating to both global and regional anatomical differences. Children born SGA displayed reduced cerebral and cerebellar grey and white matter volumes, smaller volumes of subcortical structures and reduced cortical surface area. Regional differences in prefrontal cortical thickness suggest a different development of the cerebral cortex. SGA children with bodily catch-up growth constitute an intermediate between those children without catch-up growth and healthy controls. Therefore, bodily catch-up growth in children born SGA does not implicate full catch-up growth of the brain.     

Continuity and prospects of research in systemic integrative psychophysiology of functional states and cognitive activity

An important problem of psychophysiology related to the study of the integration of the mechanisms controlling the state of the brain and characteristics of the cerebral organization of cognitive activity is discussed. The fundamental role of the results of long-term research in the neurophysiology of functional states as the basis of the organization of mental activity under conditions of direct, long-term, sparing contact with the cortex and subcortical structures by means of long-term intracerebral electrodes carried out by Academician Bechtereva and her scientific school is demonstrated. The commensurability and complementarity of slow and ultraslow gradual neurophysiological processes with similar amplitude-time parameters recorded in intravitally identified zones of deep cerebral structures and from scalp sites corresponding to the cortical projections of the main integrative centers are substantiated. The notion of the brain as a complexly organized, “floating,” multicircuit neurodynamic suprasystem with hierarchically, probabilistically organized vital processes varying in rate and intensity that are involved in maintaining the state of rest, mental states, and cognitive activity are formulated and substantiated. While the set of universal neurodynamic languages is limited, the brain employs a multiregister mechanism controlling the state and selective mechanisms of integration, ensuring the contribution of gradual neurophysiological processes at different levels of the structural and functional organization that vary in terms of information content in the formation of the cerebral systems underlying specific cognitive activities.     

EEG Effects of Therapeutic Electric Stimulation of the Human Brain in the Posttraumatic Unconscious State

The effects of therapeutic SCS and transcranial electric stimulation on the functional activity of the brain in seven patients in the posttraumatic unconscious state were compared. The therapeutic transcranial stimulation was shown to exert a positive effect on the EEG and the characteristics of its spatial–temporal organization in most cases, which corresponds with positive shifts in the mental and motor sphere. The phasic character of changes in the bioelectric activity reflecting the sequence of involvement of the cerebral structures (primary activation of the deep frontal lobe divisions, activation of the subcortical-diencephalic structures, activation of the cortex) in the developing adaptive reactions, which helps understand their neurophysiological mechanisms, was described. It was established that the formation of the foci of persistent pathological activity with dominant characteristics in the brain is one of the possible complications of both SCS and transcranial electric stimulation. The mechanisms of their neurogenesis and the electrographic equivalents require further study. The data may serve as the basis for further clinical study of the influence of transcranial electric stimulation on the recovery of patients in postcomatose unconscious states.     

Formation of the System of Visual Perception in Ontogeny

Structural, electrophysiological, and behavioral evidence characterizing the specific features of the visual perception at different stages of ontogeny is considered. The main tendency of the formation of the mature type of the brain organization of the visual system is traced from local sensory reactions to active cognitive perception. The formation of the mature type of the organization of the visual perception is largely determined by the involvement of gradually maturing frontal areas. These areas, involved in the processing of sensory-specific information via pathways descending to deep regulatory structures and other cortical areas, provide for a selective dynamic organization of the visual perception system, which functions depending on the specific perceptive task.     

Face Patch Resting State Networks Link Face Processing to Social Cognition

Faces transmit a wealth of social information. How this information is exchanged between face-processing centers and brain areas supporting social cognition remains largely unclear. Here we identify these routes using resting state functional magnetic resonance imaging in macaque monkeys. We find that face areas functionally connect to specific regions within frontal, temporal, and parietal cortices, as well as subcortical structures supporting emotive, mnemonic, and cognitive functions. This establishes the existence of an extended face-recognition system in the macaque. Furthermore, the face patch resting state networks and the default mode network in monkeys show a pattern of overlap akin to that between the social brain and the default mode network in humans: this overlap specifically includes the posterior superior temporal sulcus, medial parietal, and dorsomedial prefrontal cortex, areas supporting high-level social cognition in humans. Together, these results reveal the embedding of face areas into larger brain networks and suggest that the resting state networks of the face patch system offer a new, easily accessible venue into the functional organization of the social brain and into the evolution of possibly uniquely human social skills.     

Disorders of System Brain Activity in Children with Motor (Expressive) Alalia

Motor alalia refers to a number of disorders of expressive speech that are caused by the dysfunction of cerebral structures in the period when the formation of the speech system is not complete. This form of speech disorder is considered as a language disorder characterized by a persistent disturbance of the assimilation of a system of linguistic units. The possible cause of deviations in the development of speech function in children is a disproportion in the levels of development of speech structures in the left and right hemispheres, and this temporary dominance is often associated with an increased activity in the right hemisphere. According to the results of electroencephalographic studies, in children aged five to six years, there are two types of changes of the bioelectric potential system interaction of the brain cortex. The disorders of the spatial organization of interregional EEG correlations are more pronounced in either the left or right hemispheres of the brain. Thus, motor alalia can be accompanied either by disturbances in the interaction between Broca’s and Wernicke’s areas of the left hemisphere, or between symmetrical areas of the right hemisphere.