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.     

Psychophysiological study of the effects of adaptation to tactile interaction with dolphins in six- to seven-year-old children

The possibility of the use of an integrative psychophysiological approach to the investigation of the role of ultraslow information-controlling brain systems in the mechanisms regulating the wakefulness level and the actual development of cognitive functions in six- to seven-year-old children was estimated. For the studied children, with different types of psychological adaptation to an unfamiliar emotional situation (tactile interaction with dolphins), we found the features of the development of (a) corticosubcortical and limbic-reticular mechanisms of regulation of the wakefulness level and (b) suprasegmental mechanisms of autonomic, hemodynamic, and oxygen-dependent energy supply of the wakefulness level. The idea of a correlation between (1) the level of actual emotional and cognitive development and the type of adaptation to psychoemotional stress and (2) age-specific features of the formation of reflex and neurohumoral mechanisms of regulation of the wakefulness level in six- to seven-year-old children is substantiated.     

Features of brain mechanisms of regulation of the level of wakefulness, organization of cognitive functions and adaptive reactions in children with attention deficit with hyperactivity syndrome and healthy children

In work results of research of features of infringement superslow cortical-truncal, limbic-reticular and upsegmentary mechanisms of regulation of a level of wakefulness at children of 6-7 years with a syndrome of deficiency of attention and hyperactivity and healthy children, pupils of 1 class of a comprehensive school with different type of psychological adaptation are generalized. At use system-integrativity psychophysiology the approach features are established: a) organization emotional-motivational and cognitive spheres; b) psychophysiology mechanisms of formation of adaptive reactions at tactile interaction about earlier unknown alive object--a dolphin at the surveyed contingent of healthy and ill children.     

Peculiarities of interrelations of activation levels of frontal,temporal, and parietal cortex by parameters of ultraslow biopotentials in the 4–5-year-old children with the age norm and delayed speech development

Possibilities were considered of the integrative approach with use of parameters of the ultraslow informational-control brain and organism system in studying physiological grounds of the rest state, which determine structure and quality of the adaptive behavior. By using the proposal approach there were analyzed results of comparative studies of peculiarities of the wakefulness level, of its autonomous, hemodynamic, and oxygen-depended energy maintenance, and of activation levels and their interrelations in neocortical outputs of the brain systems of the frontal, temporal-parietal, and parietal cortex participating in organization of the higher integrative functions and speech in the 4–7-year-old children with the age norm of the general psychic and verbal development and with delay of the neuropsychic development, including development of speech.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 40, No. 5, 2004, pp. 455–468.Original Russian Text Copyright © 2004 by Ilyukhina, Krivoshchapova, Matveev, Ponomareva, Shaptilei.To the 100-Anniversary of N. N. Traugott     

Characteristics of the cerebral mechanisms controlling the level of wakefulness,maturity of cognitive functions,and adaptive responses in children with attention deficit hyperactivity disorder and healthy children of the same age

Data on the characteristics of the disturbance of ultraslow cortical-brainstem, limbic-reticular, and suprasegmental mechanisms controlling the wakefulness level (WL) in six- to seven-year-old children with attention deficit hyperactivity disorder (ADHD) and age-matched healthy children (first-year comprehensive primary school pupils) with different types of psychological adaptation have been summarized. An integrated systemic psychophysiological approach has been used to determine the characteristics of (a) the emotional-motivational and cognitive maturities and (b) the psychophysiological mechanisms of the formation of adaptive responses upon tactile interaction with an unfamiliar live object (a dolphin) in the examined groups of healthy and ADHD children.     

Autonomic tone in branches of the respiratory-hemodynamic system of junior schoolchildren

Periodic variations in the cardiac, vascular, and respiratory branches of the respiratory-hemodynamic system (RHDS) were studied in children 8–11 years of age at rest using spectral analysis. By analogy with studying the autonomous regulation of the cardiac rhythm, the averaged pattern of the autonomic tone (BAT) was determined in all RHDS branches. We aimed at studying various combinations of the autonomic balance (AB) in the same pattern and identifying individual typological peculiarities of the BAT patterns of the RHDS. Groups of children with different autonomic RHDS patterns were determined using cluster analysis; these groups differed significantly in many spectral and hemodynamic parameters.     

Problem of the structural and functional organization of the immature motor center

A hypothetical structural and functional scheme of organization of the immature spinal motor center is proposed, based on our own studies carried out on rat pups of the first month of postnatal development as well as on the analysis of data from literature. Taking into account peculiarities of functioning of various chains of the segmental reflex apparatus (high excitability of the motor center, heterochrony in the development of interneurons of the spinal cord dorsal horns as well as of excitatory and inhibitory mechanisms, possibility of generation of rhythmic activity by one of the half-centers of the motor generator regardless of the activity of the other one) and the mechanisms of its cholinergic and catecholaminergic regulation, age-related changes are considered, which are connected with the organization of interrelations of elements both within the motor center and from the descending regulatory systems.     

Peculiarities of brain mechanisms of compensation of oxygen-dependent energy deficit,organization of emotions and cognitive activity at delayed consequences of perinatal lesion of CNS of the hypoxic-ischemic genesis in the 3–6-year-old children with delay of psychic development

There are summarized results of studies on peculiarities of the compensatory-adaptive mechanisms of brain circulation and respiration at oxygen-dependent energy deficit in the 3–6-yearold children with delayed consequences of perinatal CNS lesion of hypoxic-ischemic genesis and delay of psychic development (DPD), with use of the systemic-integrative psychophysiological approach and of parameters of superslow information-controlled systems of the brain and of organism. In the examined contingent of children, differences have been revealed in development of emotional sphere and the higher psychic functions, depending on the character of disorganization of regulatory CNS functions and of the type of the formed compensatory-adaptive mechanisms of autoregulation of cerebral circulation and of the system of outer respiration.     

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.     

Factor structure of the functional state of five- and six-year-old children

The following factors determining the functional state (FS) of the body of five- and six-year-old children (n = 155) have been identified during the research: parasympathetic regulation of FS (factor I); hemodynamic support of cognitive activity (factor II); efficiency of cognitive activity (factor III); nonspecific stability of the body (factor IV); sympathetic regulation of FS (factor V); general work capacity (factor VI). The systematic approach implemented in this study allowed consideration of the psychophysiological content of these factors. In general, the results of research demonstrate the existence of rather stable, qualitatively peculiar groups of variables characterizing different aspects of preschool children’s FS. There is a set of stable relationships between various elements of FS ensuring its integrity. The significant relationship between physical performance and FS aspects, such as productivity and efficiency of cognitive activity, sympathetic and parasympathetic regulation of physiological functions, and nonspecific stability of body to cold-related illnesses, suggests the possibility of purposeful influence on children’s FS during intense activity using adequate programs of physical exercise.     

Specific Features of Sexual Dimorphism of Human Cognitive Functions under Conditions of Age-Related Involution

Specific features of certain cognitive functions were studied under conditions of age-related involution. A total of 66 women and 45 men in three age groups (30–39, 40–49, and 50–60 years old) were examined. An automated method of testing of a number of cognitive functions was used. It was found that different rates of formation of a more deterministic system of information processing are a specific psychophysiological feature of sexual dimorphism under conditions of age-related involution. This explains the fact that, during aging, cognitive functions in men deteriorate earlier than in women. Involution processes of these functions can be prevented as a result of adaptive compensatory brain mechanisms, which are manifested as an enhanced level of stochastic organization of the system of information processing.     

Catecholaminergic regulation of autorhythmical viscero- and somatomotor activity in early rat ontogenesis

Ontogenetic peculiarities of catecholaminergic regulation of three vitally important physiological processes are described: heart beating, respiration, and early somatomotor activity. They are subordinated to the autorhythmical regime and are submitted to modulating effects of noradrenergic and dopaminergic mechanisms. There are considered age-related changes of this effect whose peculiarity is polar changes of reactions in the process of their maturation from the predominantly excitatory reactions at early stages to the predominantly inhibitory ones.     

Voluntary regulation of the functional state and its influence on the effectiveness of cognitive activity during adolescence

We have analyzed the impact of voluntary relaxation on the functional organization and the effectiveness of the voluntary prestimulus attention in performing cognitive tasks in adolescents at the ages of 12–13 and 13–14 years. The effectiveness of cognitive task performance (audio-verbal short-term memory) was estimated on the basis of the number of correctly remembered words. We have found that both age groups are characterized by reduced capacity for voluntary relaxation and its impact on the effectiveness of cognitive task performance. The analysis of the coherence function of EEG rhythmic components in a situation of voluntary attention focused on the performance of cognitive tasks showed no significant change in the interaction of the prefrontal cortex with other cortical areas during the switch from quiet wakefulness or post-relaxation state to the preparation to perform the task, which is typical of adults and young children. Our findings can be a result of sub-optimal functioning of voluntary regulation mechanisms and organization of activities during adolescence.     

Peculiarities of formation of the cognitive functions in junior school children with different maturity of regulatory brain systems

To reveal the specific role of maturation of modulating, regulatory brain systems in formation of cognitive processes at the junior school age, was performed a complex electroencephalographic and neuropsychological examination of the 7–8-year-old children with different degrees of functional maturity of the regulatory systems. It has been shown that an essential factor determining formation of the higher psychic functions (HPF) at the junior school age is maturation of the fronto-thalamic system. Immaturity of this system in the 7–8-year-old children leads to a deficiency of functions of programming, regulation, and control of the activity. The most substantial changes were revealed for the components of the voluntary organization of the activity, which are connected with its selectivity both in realization of current tasks and in creation of the activity strategy. The deficiency of processes of voluntary regulation in the 7–8-year-old children with immaturity of the fronto-thalamic system is combined with a delay of development of the meaning-forming speech function. Comparison of data of the neuropsychological and electroencephalographic examination has permitted suggesting that the basis of the revealed changes in the HPF formation in the 7–8-year-old children is immaturity of the main neurophysiological mechanisms that provide a selective involvement of different cortical regions in providing their activity both in the course of its realization and during preparation to it as well as an under-development of differentiated intracortical connections in the left hemisphere.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 40, No. 5, 2004, pp. 427–435.Original Russian Text Copyright © 2004 by Machinskaya, Semenova.To the 100-Anniversary of N. N. Traugott     

Adaptation to Teaching Loads in New Educational Institutions

The authors analyzed physical development and training, nonspecific immunity, free-radical oxidation, hemodynamic indices, and autonomic regulation in pupils from the first to ninth grade levels of a new educational institution (gymnasium). All of these indices were influenced by the motor activity level. The children with hypokinesia had disadaptive changes in hemodynamics, weakened immunity, and lower antioxidant protection. The authors suggest principles for the pathogenetic correction of these disorders.     

About a possible role of parasomnias as a factor of stabilization of sleep cycles

Cyclical organization of sleep is one of necessary conditions of normal human and animal life activity and one of basic manifestations of the circadian cycle. Transition from the slowwave to the paradoxical sleep is often accompanied by brief, sometimes rhythmical motor and autonomic reactions that do not cause awakening, but seem to promote activation of the mechanisms providing the “switch” of the sleep phases. Immaturity (or a lesion) of the neurophysiologic mechanisms responsible for the “switch” of the sleep stages leads to hindering of alternation of the sleep phases, which disturbs their normal sequence and leads to deficit of reparative and homeostatic processes. This is manifested as deterioration of the neuropsychical state during wakefulness. The data are presented which allow suggesting that the stereotypical motor or autonomic reactionspathological parasomnias, for instance enuresis, can appear as a compensatory mechanism promoting the sleep phase switch. Episodes of the pathological parasomnias promote normalization of the sleep stage alternation and thereby affect positively recovery of its cyclical organization.     

Age-related features of the organization of motor activity in 6- to 16-year-old children

The use of the KID-3 diagnostic set for a large-scale examination of 6- to 16-year-old children helped reveal substantial age-related differences in the mechanisms of the regulation of motor activity on the basis of correlation of the specified parameters: velocity, precision, smoothness, velocity of readjustment of motor tasks, etc. The study confirmed the leading role of visual control in the realization of the motor function in 6- to 9-year olds. The mechanisms of movement regulation, i.e., a transition from a primarily monitoring mechanism of control to one based on a preliminarily formed motor program, is changed substantially by nine–ten years. These changes are possible only at this age, since it is in this period that substantial shifts take place in the morphofunctional development of the frontal cortical areas, and they become more important in the control of the activation processes, which determine and regulate motor activity. The age of nine-ten years is transitional in the formation of the mechanisms of central commands. This efficient movement control mechanism only begins to form at this age, and its formation is completed at age 14.     

Age-related specificity of the frontal and temporoparietal cortex activation levels in three-to seven-year-old children

The results of studies on the specificity of formation of the frontal and temporoparietal cortex activation levels in children aged three, four to five, and six to seven years with a normal development of higher mental functions and speech are summarized. The parameters of the stable millivolt-range potential recorded from the head surface were used for this purpose. The results obtained are compared with published data on the specificity of the morphological and functional organization of the brain and the level of development of the slow information control system estimated on the basis of EEG parameters at the same ages. The estimation of the contribution of the brain superslow information control system by one of the basic parameters of state makes it possible to determine, in quantitative terms, (1) the characteristics of the formation of activation levels of cerebral systems involved in the regulation of the resting state, higher mental functions, and speech at different stages of ontogeny; (2) (on the basis of the stable-potential variance) the degrees of freedom of the activation levels of the cerebral systems studied, which determine their regulatory capacity at different ages; and (3) the degree of development of the system-forming mechanisms combining all these systems into an integrated whole at a certain stage of ontogeny (from six to seven years of age).     

Effectiveness of physical exercises for regulation of the functional state of six- to eight-year-old anxious children

The study aimed at optimizing the functional state (FS) of anxious six- to eight-year-old children showed that integrated use of physical exercises of a mainly aerobic character, relaxation training, respiratory exercises, and functional music is more effective in the long-term aspect than selective use of these means. Only physical exercises exert a marked influence in the FS of six- to eight-year-old anxious children under a stressful informational load. The use of other means of optimizing the FS appears to be less effective. The high effectiveness of physical exercises is determined by adaptive changes in the mechanisms of FS regulation in anxious children. Apparently, long-term adaptation to an adequate muscular activity ensures improved functioning of, and a better interaction between, the activating and inactivating structures of the modulating brain system located at different levels of the CNS, in particular, in the frontal cortical areas. It is emphasized that the peculiarities of the influence of different means of regulation of the FS on the body of anxious elementary school children are, largely determined by the immaturity of the frontothalamic regulatory system and the specifics of the functional organization of the limbic brain structures.     

Shift work and inter-individual differences in sleep and sleepiness

Inter-individual differences in tolerance for shift work have been studied primarily in terms of external factors affecting alertness on the job or the ability to rest and sleep while at home. However, there is increasing evidence that neurobiological factors play a role as well, particularly the major processes involved in the regulation of sleep and wakefulness. These include a sleep homeostatic process seeking to balance wakefulness and sleep and a circadian process seeking to promote wakefulness during the day and sleep during the night. Shift work is associated with a temporal misalignment of these two endogenous processes. During nightwork, this misalignment makes it difficult to stay awake during the nightshift and sleep during the day. However, inter-individual variability in the processes involved in sleep/wake regulation is substantial. Recent studies have demonstrated the existence of inter-individual differences in vulnerability to cognitive deficits from sleep loss. Moreover, these inter-individual differences were shown to constitute a trait. Interestingly, self-evaluations of sleepiness did not correspond well with the trait inter-individual variability in objective levels of performance impairment during sleep deprivation. Perhaps because of this discrepancy, in operational settings, the inter-individual differences in vulnerability to sleep loss do not appear to be limited due to self-selection mechanisms. Indeed, even among a highly select group of active-duty jet fighter pilots flying a series of simulated night missions, systematic inter-individual differences in performance impairment from sleep loss were still observed. There are significant personal and economic consequences to human error and accidents caused by performance deficits due to sleep loss. It is important, therefore, to study the inter-individual differences in the regulation of sleep and wakefulness in the work environment so that cognitive impairment during shift work may be better anticipated and prevented.