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The paper presents data on the vertical distribution of 137Cs of Chernobyl origin in arable and meadow soils to a depth of 40 cm in typical catenary junctions of predpolessie, predopolje, and opolje landscapes with a different density of 137Cs contamination 30 years after the accident at the Chernobyl nuclear power plant. Newly obtained data on the removal of 137Cs beyond the arable horizon presented in the paper indicate that this parameter varies depending on the landscape conditions: it varies in the range of 2.7–17.7% in predpolessie landscapes and in the range of 0.5 to 9% in opolje landscapes. In opolje landscapes, the coefficient of 137Cs removal from the arable horizon was proved to systematically decrease depending on the landscape catenary position: it amounts to 8.5% in the transit zone and is 1.4% in the accumulation zone. The vertical distribution of 137Cs and 210Pbex (excess) in the sod and floodplain soils in the basin of the Kostitsa River was studied to determine the sedimentation rate. Based on the analysis of the distribution of 137Cs in the soil, the sedimentation rate over the past 30 years in various parts of the floodplain was estimated at 0.42 ± 0.08 to 0.58 ± 0.11 cm/year. The average estimated sedimentation rate in the floodplain during approximately 50 past years was, according to the 210Pbex dating was equal to 0.7 ± 0.18 cm/year. The sedimentation rate in the bottom of a ravine was evaluated for sod soils based on the distribution of 210Pbex according to the CRS model for 1961–2016 y. It was revealed that the minimum sedimentation rate of 0.24 cm/year occurred in 1961–1988, and the maximal (0.7 cm/year) in 2000 to 2007.

Our research aims to study the difference in resting-state during EEG and fMRI experimental conditions, each of which has its own peculiarities. Therefore, we conducted EEG and fMRI experiments very close in terms of conditions, during which 108 and 109 healthy participants, respectively, were recorded at rest for ten minutes. Subjective content of conscious during resting-state was assessed using the Amsterdam Resting-State Questionnaire (ARSQ) 2.0. To approve the 10-factor structure of the questionnaire in both groups we used the method of confirmatory factor analysis, the differences between groups were assessed using the Mann-Whitney U test. In general, it was found that responses towards the Amsterdam Resting-State Questionnaire 2.0. were similar in both groups. However, during resting-state the EEG group had larger scores for Comfort, Sleepiness and Visual Thought, while the fMRI group had larger scores for Health Concerns. The gender differences were similar in both groups for the dimension of Verbal Thoughts, which was significantly higher in females. Thus, our findings imply a substantial effect of the experimental environment difference for fMRI and EEG on subjective thoughts and feelings during resting-state experience, even when the experimental conditions are similar. That should be taken into account when planning a research experiment and analyzing data.

Altered functional connectivity of the amygdala has been observed in a resting state immediately after fear learning, even one day after aversive exposure. The persistence of increased resting-state functional connectivity (rsFC) of the amygdala has been a critical finding in patients with stress and anxiety disorders. However, longitudinal changes in amygdala rsFC have rarely been explored in healthy participants. To address this issue, we studied the rsFC of the amygdala in two groups of healthy volunteers. The control group participated in three fMRI scanning sessions of their resting state at the first visit, one day, and one week later. The experimental group participated in three fMRI sessions on the first day: a resting state before fear conditioning, a fear extinction session, and a resting state immediately after fear extinction. Furthermore, this group experienced scanning after one day and week. The fear-conditioning paradigm consisted of visual stimuli with a distinct rate of partial reinforcement by electric shock. During the extinction, we presented the same stimuli in another sequence without aversive pairing. In the control group, rsFC maps were statistically similar between sessions for the left and right amygdala. However, in the experimental group, the increased rsFC mainly of the left amygdala was observed after extinction, one day, and one week. The between-group comparison also demonstrated an increase in the left amygdala rsFC in the experimental group. Our results indicate that functional connections of the left amygdala influenced by fear learning may persist for several hours and days in the human brain.

Previous studies showed differences in brain dynamics during rest and different tasks. We aimed to find changes of variance and scale-free properties of blood oxygenation level-dependent (BOLD) signal between resting-state sessions before and after fear learning and fear memory extinction in twenty-three healthy right-handed volunteers. During a 1-hour break between MRI-scanning, subjects passed through fear extinction procedure, followed by Pavlovian fear conditioning with weak electrical stimulation. After preprocessing, we extracted the average time course of BOLD signal from 245 regions of interest (ROI) taken from the resting-state functional atlas. The variance of the BOLD signal in and Hurst exponent (H), which reflects the scale-free dynamic, were compared in resting states before after fear learning. Six ROIs showed a significant difference in H after fear extinction, including areas from the fear and memory networks. In consistency with the previous results, H decreased during fear extinction but then increased higher than before, specifically in areas related to fear extinction network, whereas the other ROIs restored H to the initial level. The BOLD signal variance showed distinct behavior: the variance in subcortical regions increased permanently, while cortical areas demonstrated a decreasing variance during fear extinction and the reverse growth in resting state after fear extinction. A limited number of ROIs showed both changes in H and the variance. Our results suggest that the variability and scale-free properties of the BOLD signal are sensitive indicators of the residual brain activity related to the recent experience.

Lateral asymmetry is one of the fundamental properties of the functional anatomy of the human brain. Amygdala (AMYG) asymmetry was also reported in clinical studies of resting-state functional connectivity (rsFC) but rarely in healthy groups. To explore this issue, we investigated the reproducibility of the data on rsFC of the left and right AMYG using functional MRI twice a week in 20 healthy volunteers with mild-to-moderate anxiety. We found a resting-state network of the AMYG, which included regions involved in emotional processing and several other brain areas associated with memory and motor inhibition. The AMYG network was stable in time and within subjects, but the right AMYG had more significant connections with anatomical brain regions. The rsFC values of the right AMYG were also more sustained across the week than the left AMYG rsFC. Subjective ratings of anxiety did not correlate significantly with the patterns of seed-based AMYG connectivity. Our findings indicate that, for healthy subjects, rsFC may differ for the right and left AMYG. Moreover, the AMYG functional connectivity is variable in short-term observations, which may also influence the results of longitude studies.

Altered functional connectivity of the amygdala has been observed in a resting state immediately after fear learning, even one day after aversive exposure. The persistence of increased resting-state functional connectivity (rsFC) of the amygdala has been a critical finding in patients with stress and anxiety disorders. However, longitudinal changes in amygdala rsFC have rarely been explored in healthy participants. To address this issue, we studied the rsFC of the amygdala in two groups of healthy volunteers. The control group participated in three fMRI scanning sessions of their resting state at the first visit, one day, and one week later. The experimental group participated in three fMRI sessions on the first day: a resting state before fear conditioning, a fear extinction session, and a resting state immediately after fear extinction. Furthermore, this group experienced scanning after one day and week. The fear-conditioning paradigm consisted of visual stimuli with a distinct rate of partial reinforcement by electric shock. During the extinction, we presented the same stimuli in another sequence without aversive pairing. In the control group, rsFC maps were statistically similar between sessions for the left and right amygdala. However, in the experimental group, the increased rsFC mainly of the left amygdala was observed after extinction, one day, and one week. The between-group comparison also demonstrated an increase in the left amygdala rsFC in the experimental group. Our results indicate that functional connections of the left amygdala influenced by fear learning may persist for several hours and days in the human brain.

It has been shown in the previously performed experiments that it is possible to "recognize" by the EEG data the type of thinking and to know what kind of task (spatial or verbal-logical) is solving currently. This article describes the application of this technology to the study of schizophrenia patients..We obtained data about the essential difficulty of such recognition in schizophrenia patients, correlation of these difficulties with the severity of negative symptoms. It is shown that the'difficulty of recognition is associated with higher variability of rhythmic EEG patterns, intrinsic for particular type of thinking.

We analyzed the specific brain activity, measured by fMRI in spatial and verbal tasks, in 15 healthy sub- jects and in 9 patients with dysarthria or mild sensorimotor aphasia. In healthy participants, verbal thinking was characterized by activation in Brodmann area 19 and Broca area while specific activation for spatial thinking was observed in bilateral temporal-occipital-parietal areas, left insula, left visual fields 17 and 18. In patients with impaired speech, this distribution of networks specific to a particular type of task underwent significant changes with deactivation of the brain areas, as compared to healthy subjects. Despite the absence of clinical manifestations of cognitive impairment, the average time .to solve verbal tasks was significantly higher, and the percentage of correct answers was less in patients as compared to these values for a group of healthy subjects.

A new type of brain-computer interface was elaborated. It considers a variety of brain activity parameters to determine the type of mental operation being performed at the moment. The corresponding algorithm previously developed in the lab was modified for real-time application. The possibility of interface application for cognitive skills training was investigated. In the proposed paradigm, as soon as the EEG spectral pattern was adequate for the current task, some clue to the solution was presented. As we supposed, such positive biofeedback should facilitate memorization of the current brain state. After just one learning session, the differences in EEG spectra, corresponding two types of tasks, were concentrated in more narrow frequency ranges. It indicates the decrease of mental effort. Moreover, the majority of subjects succeeded to solve the tasks faster, that's an evidence of efficiency increased. The developed interface could be used for the new type of training, based on objective features of brain activity.

Abnormal functional connectivity of the amygdala with several other brain regions has been observed in patients with higher anxiety or post-traumatic stress disorder, both in a resting state and threatening conditions. However, findings on the specific connections of the amygdala might be varied due to temporal and individual fluctuations in the resting state functional connectivity (rsFC) of the amygdala and its lateral asymmetry, as well as possible variability in anxiety among healthy subjects. We studied reproducibility of rsFC data for the right and left amygdala, obtained by functional magnetic resonance imaging twice in a one-week interval in 20 healthy volunteers with low to moderate anxiety. We found resting-state amygdala network, which included not only areas involved in the emotion circuit, but regions of the default mode network (DMN) associated with memory and other brain areas involved in motor inhibition and emotion suppression. The amygdala network was stable in time and within subjects, but between-session reproducibility was asymmetrical for the right and left amygdala rsFC. The right amygdala had more significant connections with DMN regions and the right ventrolateral prefrontal cortex. The rsFC values of the right amygdala were more sustained across the week than the left amygdala rsFC. Our results support a hypothesis of functional lateralization of the amygdala. The left amygdala is more responsible for the conscious processing of threats, which may produce more variable rsFC; the right amygdala rsFC is more stable due to its greater engagement in continuous automatic evaluation of stimuli.HighlightsAmygdala resting state network included areas of emotion circuit and motor controlDuring rest amygdala was functionally connected with areas of default mode networkFunctional connectivity of the right amygdala was more sustained across the weekFunctional connections of amygdala network were more stable in the right hemisphere

Concurrent EEG and fMRI acquisitions in resting state showed a correlation between EEG power in various bands and spontaneous BOLD fluctuations. However, there is a lack of data on how changes in the complexity of brain dynamics derived from EEG reflect variations in the BOLD signal. The purpose of our study was to correlate both spectral patterns, as linear features of EEG rhythms, and nonlinear EEG dynamic complexity with neuronal activity obtained by fMRI. We examined the relationships between EEG patterns and brain activation obtained by simultaneous EEG-fMRI during the resting state condition in 25 healthy right-handed adult volunteers. Using EEG-derived regressors, we demonstrated a substantial correlation of BOLD signal changes with linear and nonlinear features of EEG. We found the most significant positive correlation of fMRI signal with delta spectral power. Beta and alpha spectral features had no reliable effect on BOLD fluctuation. However, dynamic changes of alpha peak frequency exhibited a significant association with BOLD signal increase in right-hemisphere areas. Additionally, EEG dynamic complexity as measured by the HFD of the 2-20 Hz EEG frequency range significantly correlated with the activation of cortical and subcortical limbic system areas. Our results indicate that both spectral features of EEG frequency bands and nonlinear dynamic properties of spontaneous EEG are strongly associated with fluctuations of the BOLD signal during the resting state condition.

This paper develops the thought that the possibility that mental processes control physiological processes makes it possible to effectively monitor the search for options and decision-taking, which is subjectively perceived as free will.

Background Fear conditioning allows modeling mechanisms of emotional learning and better understanding the emotional impairment. Neuroimaging of fear learning and extinction shows an altered activation of prefrontal cortex in different stress and anxiety disorders. Resting-state functional connectivity (rsFC) of amygdala also demonstrates changes after stressful events. We aimed to test whether the brain activity in fear extinction and rsFC of amygdala would show a correlation with scores of anxiety questionnaires in participants without explicit complain about health issues. Material and methods Twenty-four healthy volunteers participated in 3 fMRI-scanning sessions: the first resting state before fear conditioning and fear extinction, followed by the second resting state session. All participants filled Spielberger State and Trait Anxiety Inventory. The anxiety scores were used in the general regression analysis of the event-related BOLD response to conditioned stimuli and amygdala rsFC (pFWE Results State and trait anxiety varied from low to relatively higher scores (33.7 ± 10.54 and 41.3 ± 11.74 correspondingly). The BOLD response during fear extinction showed a significant negative correlation with trait anxiety scores in bilateral middle frontal gyri. Trait anxiety scores correlated positively with rsFC of the right amygdala and the right medial frontal gyrus only in the first resting-state session. Conclusions Our results confirm that personal anxiety can influence the prefrontal cortex activity during fear extinction and also can be associated with rsFC between the amygdala and specific areas of prefrontal cortex even in healthy participants. This work was supported by the Russian Scientific Foundation (Grant No. 16-15-00300 ).

Introduction Resting-state functional connectivity (rsFC) may indicate abnormalities in the brain physiology as it was shown at the example of altered rsFC within fear-processing brain circuit in patients with posttraumatic stress disorder. However, little is known about whether resting state networks vary their functional connections after experimental fear learning (FL). Here, we studied brain network changes in the resting state immediately, in one day and a week after FL using graph theory metrics. Methods We collected resting state fMRI data from 19 healthy controls and 24 healthy participants of FL protocol. Control group underwent three fMRI sessions: the second and the third sessions took place in one day and a week after the first respectively. FL group underwent five sessions: before FL, with fear memory retrieval, after FL, one day after, and a week after the first. We calculated paired FC of 94 anatomical regions of interest and analyze graph theory metrics of reconstructed networks for each session. Results The network during fear memory retrieval showed greater global efficiency than other resting state networks. Bilateral middle frontal gyri and parietal lobes became and remained network hubs after FL as well as in one day and one week afterward. No significant network changes were observed in the control group. Discussion and conclusions Our findings highlight the temporary effect of FL at resting state networks, which implies the functional readjustment of neural connections even after mild aversive exposure. This study was funded by the Grant No. 16-15-00300 of the Russian Scientific Foundation .

The history of study of schizophrenia has more than 100 years. During all this period there was collected a lot of data on clinical picture of the disease, psychological peculiarities of patients, biochemical and electrophysiological phenomena. In this respect it becomes actual nowadays to look for a concept that could combine different levels of schizophrenia research (clinical, biochemical, social, etc.) and explain relationships with various symptoms of the disease. In this article we analyze experimental psychological data on thinking of patients, instrumental studies (ERP fMRI, rhythmic patterns of thinking, dopamine theory) and their relationship with clinical implications. It is shown that all these data complement each other and allow us to tell about a basic violation in schizophrenia--the difficulty of patients to differentiate between more and less salient information. We can observe the violation on different levels of schizophrenia investigation and explain different symptoms of the disease as manifestations of that basic violation.

Changes in the functional status under the effect of intense mental exercise were studied in carriers of different variants of DAT1, DRD2, and COMT genes. The volunteers (n=140) performed 3-h monotonous mental work (information processing and logical problem solving). The degree of fatigue was evaluated before and after exercise by the HAM (Health status– Activity–Moods) and AMF (Acute Mental Fatigue) questionnaires. A signifi cant relationship between the DAT1, DRD2, and COMT gene polymorphism and changes in the mental sphere status were revealed. The effects of these polymorphisms were the most pronounced in girls. The results are discussed within the framework of hypothesis on the effects of changes in the phasic/tonic dopamine proportion on the studied functions.

Four issues are discussed: the possible mechanism of subjective events, conscious versus unconscious brain functions, the rhythmic coding of mental operations and the possible brain basis of understanding. i. Several approaches have been developed to explain how subjective experience emerges from brain activity. One of them is the return of the nervous impulses to the sites of their primary projections, providing a synthesis of sensory information with memory and motivation [Ivanitsky, A.M., 1976. Brain Mechanisms of the Signal Evaluation. Medicina, Moscow 264 pp. (in Russian)]. Support for the existence of such a mechanism stems from studies upon the brain activity that subserves perception (visual and somato-sensory) and thought (verbal and imaginative). The cortical centres for information synthesis have been found. For perception, these are located in projection areas; for thinking — in frontal and temporal-parietal associative cortex. Closely related ideas were also developed by G. Edelman [Edelman, G.M., 1978. Group selection and phasic reentrant signaling: A theory of higher brain function. In: Eds. Edelman, G.M., Mountcastle, V.B. The Mindful Brain. Cortical Organization and the Group-selective Theory of Higher Brain Function. Cambridge, MA, MIT Press, pp 51–100.] in his re-entry theory of consciousness. Both theories emphasize the key role of memory and motivation in the origin of conscious function. ii. Conscious experience elucidates not all, but only salient brain functions. As a rule, voluntary control is switched on when additional cognitive resources are needed. Even a rather complicated mental operation, such as the discrimination between concrete and abstract words, could be executed very rapidly and implicitly; explicit analysis being engaged only in more difficult tasks. Furthermore, these two different kinds of mental operations, i.e., automatic and conscious, are predominantly associated with two different kinds of memory: a recognition memory for implicit analysis, and an episodic memory for explicit functions. iii. Rearrangements of EEG rhythms underlie mental functions. Certain rhythmical patterns are related with definite types of mental activity. The dependence of one upon the other is rather pronounced and expressive, so it becomes possible to recognize the type of mental operation being performed in mind with few seconds of the ongoing EEG, provided that the analysis of rhythms is accomplished using an artificial neural network. iv. It is commonly recognized that the computer, in contrast to the living brain, can calculate, yet cannot understand [Penrose, R., 1996. Shadows of the Mind: A Search for the Missing Science of Consciousness New York, Oxford, Oxford University Press 480 pp.]. Comprehension implies the comparison of new and old information that requires the ability to search for associations, grouping similar objects together, and distinguishing different objects from one another. However, these functions may also be implemented on a computer. Still, it is believed that computers perform these complicated operations without genuine understanding. Evidently, comprehension additionally has to be based upon some biologically significant ground. It is hypothesized that the subjective feeling of understanding appears when current information is attributed to a definite need, which is scaled in sign (+/−) coordinates. This coordinate system ceases the brain calculations, when “comprehension” is reached, i.e., the acceptable level of need satisfaction is attained.

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 manifestations of the aggression are different in males and females. Our study aimed to investigate the association of 5-HTT gene polymorphism with different facets of aggression (BDHI) in females. Two groups: the synchronized swimming and non-athlete control, - were examined to study the possible modulation effect of sport on the association between 5-HTT gene polymorphism and aggression. It was found that in both groups the low-active 5-HTT polymorphism (SS) was associated with increased scores on Indirect Hostility scale and decreased scores on Negativism scale, compared to LL genotype. No interaction effect between sport and 5-HTT polymorphism was found. The higher percentage of LL-carriers and lower of LS-carriers in the synchronized swimming group compared to the control one was observed. This may be the sign of the importance of LL polymorphism of 5-HTT gene, previously associated with higher resistance to stress factors, for being an athlete, although this result has to be taken cautiously keeping in mind the stratification problem. Synchronized swimmers had lower scores on Assault, Negativism, Irritability and Verbal Hostility compared to age-matched control girls (in general and for each 5-HTT genotype separately), suggesting that they may have more matured emotional system (older control group has also lower scores on these scales).

The problem is considered whether the brain response is completely determined by the stimulus and the personal experience or in some cases the brain is free to choose its behavioral response to achieve the desired goal. The attempt is made to approach to this important philosophical problem basing on modern knowledge about the brain. The paper consists of four parts. In the first part the theoretical views about the free choice problem solving are considered, including views about the freedom of choice as a useful illusion, the hypothesis on appliance of quantum mechanics laws to the brain functioning and the theory of mentalism. In other tree parts consequently the more complicated brain functions such as choice reaction, thinking and creation are analyzed. The general conclusion is that the possibility of quite unpredictable, but sometimes very effective decisions increases when the brain functions are more and more complicated. This fact can be explained with two factors: increasing stochasticity of the brain processes and the role of top-down determinations from mental to neural levels, according to the theory of mentalism.

The synchronization of the rhythmical components of evoked potentials (EP) was studied during verbal-task solving. A novel method of the calculation of Wavelet curve correlation was used to reveal synchronization between the evoked rhythmical components in short time intervals. This method was applied to earlier EP records, which were conducted during the search for verbal associations and revealed the successive activation of the frontal and left parietal cortical areas. Two stages of task solving were identified. Independently of the task type, the first stage was characterized by a diffuse synchronization in a broad frequency band below 22 Hz immediately after the stimulus presentation. This stage results in a realization of the verbal stimulus. The second stage was manifested in a localized synchronization between the frontal and left temporal (Wernicke's) areas in the narrow frequency band about 17 Hz only during search for associations. This specific and local synchronization took place earlier than the diffuse activation of the left temporal cortex. This stage appears to reflect the information transmission from the frontal cortex to the left parietotemporal area.

Objectives Concurrent EEG and fMRI acquisitions in resting state showed a correlation between EEG power in various bands and spontaneous BOLD fluctuations. However, there is a lack of data how the EEG complexity of brain dynamic, such as instability or entropy of EEG rhythmic structure, may reflect variations in the BOLD signal. Methods We aimed to find the relationships between EEG dynamics and brain activation obtained by simultaneous EEG-fMRI during resting state condition in 25 healthy right-handed adult voluntaries. We applied nonlinear analysis in order to obtain chaotic features of EEG, which we used as regressors in GLM relating to changes in the BOLD signal. Results Fluctuations in beta rhythm were associated with the BOLD signal increase in basal ganglia and thalamic structures ( p 0.05 , FDR-corrected). Moreover, our data showed that Higuchi fractal dimension correlated with activation of cortical areas and limbic system regions. Offset of alpha-peak frequency and envelope frequency coincided with activation of thalamus, insula, hippocampus and temporal cortex predominantly in the right hemisphere. Conclusions Previously, nonlinear EEG analysis in clinical neurophysiology pointed that decreased complexity of brain dynamics might implicate increased neuronal interaction. Our results indicate that dynamic properties of spontaneous EEG have a significant association with resting state BOLD fluctuations reflecting possible sources of rhythmic neuronal activity. In particular, the observed increase in the BOLD signal significantly correlated with deviation of beta rhythm power that supports the hypothesis of basal-thalamic origin of beta rhythm. The study was supported by a grant of the Russian Science Foundation 116-15-00300.

Cortical connectivity was studied in tasks of generating the use of words in comparison with reading aloud the same words. These tasks were used earlier in PET and high density ERP recordings studies (Posner and Raichle, 1997; Abdullaev and Posner, 1998), in which both the functional anatomy and the time course of cortical areas involved in word processing were described. The wavelet transforms of ERP records and the calculation of correlations between wavelet curves were used to reveal connections between cortical areas. Three stages of intracortical communications while task performance were found. These were: (1) the connections between right and left frontal and central areas which preceded stimulus delivery and persisted up to 180 ms after it; (2) the network connecting right and left frontal with left posterior temporal-parietal junction at 280-450 ms; and (3) communications between left and right temporal zones in 550-800 ms. The data are in good agreement with results of previous PET and ERP studies and supply the earlier findings with circuitry of cortical information transfer.

The aim of this study was to investigate an interaction between frontal and left temporo-parietal cortices in tasks requiring word association. A new method was used to examine averaged event-related potentials in different frequency bands by calculating correlation coefficients between wavelet curves in distant cortical areas. This method was applied to previous event-related potentials recordings which found successive activation of frontal and left posterior areas [1]. Correlated activity at 17 Hz was observed between frontal and left temporal (Wernicke's) areas prior to full activation of Wernicke's area.

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 characterizing involuntary attention and cognitive control.

Genetic and psychological analysis of the relationships between catechol-O-methyltransferase Val158Met polymorphism and various types of aggressiveness was performed in 114 women. Dispersion analysis revealed significant association of ValVal genotype with elevated physical aggression.

Unique in its breadth and detail, this encyclopedia offers a comprehensive and highly readable guide to a complex and fast-expanding field. The five-volume reference work gathers more than 10,000 entries, including in-depth essays by internationally known experts, and short keynotes explaining essential terms and phrases. In addition, expert editors contribute detailed introductory chapters to each of 43 topic fields ranging from the fundamentals of neuroscience to fascinating developments in the new, inter-disciplinary fields of Computational Neuroscience and Neurophilosophy. Some 1,000 multi-color illustrations enhance and expand the writings. This user-friendly reference will be indispensable to basic and clinical scientists and practitioners in academia, hospitals, private practice, and industry, as a source of reliable information on the structure and function of the nervous system. The Encyclopedia of Neuroscience opens the topic to health care professionals, students, teachers and informed laypersons who require relevant information on this rapidly evolving field.

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 and concrete written words in four experimental conditions: i) Simple Reading, during which volunteers were required to silently read words; ii) Simple Classification, during which volunteers were required to classify the presented word into the abstract and concrete categories; and iii) Cued and iv) Uncued Selective Classification conditions, during which subjects had to classify only the words typed in a particular colour. 19-channel EEG was recorded during the experiment from 13 subjects. The ERP to abstract and concrete words differed not only at the late but also at early (40-100 ms) latencies in the Simple Reading and Classification conditions, as well as for the words that should not be explicitly classified in the Cued Selective Classification condition. This means that semantic analysis can occur in a manner which is both very rapid and implicit. Moreover, increasing task demands can even suppress this rapid semantic analysis. The functional microstate analysis revealed a topographical difference in response to abstract and concrete words, which indicated that at least partly distinct brain networks are involved in the processing of words during both early (implicit differentiation) and late (explicit classification) latencies.

1. Volume Transmission in the Striatum as Constituting Information Processing 2. Unitary Postsynaptic Mechanisms of LTP and LTD in the Neocortex 3. Memory Consolidation: Narrowing the Gap Between Systems and Molecular Genetics Neurosciences 4. Informational Synthesis in Crucial Cortical Areas, as the Brain Basis of Subjective Experience 5. Nature of Sensory Awareness: the Hypothesis of Self-identification 6. Brain Mechanisms of Emotions 7. The Functional Significance of High-frequency Components of Brain Electrical Activity 8. EEG Mapping in Emotional and Cognitive Pathology 9. Brain Organization of Selective Tasks Preceding Attention: Ontogenetic Aspects 10. Formation and Realization of Individual Experience in Humans and Animals: a Psychological Approach 11. Applicability of the Reinforcement Concept to Studies in Simple Nervous Systems 12. Sensory Factors in the Ontogenetic Reorganization of Behaviour 13. Colour Spaces of Animal-trichromats (Rhesus Monkeys and Carp), Revealed by Instrumental Discrimination Learning 14. Neurobiology of Gestalts 15. The Striatal Cholinergic System and Instrumental Behaviour 16. The Motor Cortex Inhibits Synergies Interfering With a Learned Movement: Reorganization of Postural Co-ordination in Dogs 17. Biochemical Correlates of Individual Behaviour 18. Brain Serotonin in Genetically Defined Defensive Behaviour

There are two sorts of criteria of consciousness — objective and subjective ones. They are the ability for operating with the knowledge which could be addressed to other people in the abstract form and the feeling of ‘ego’ as a ‘host’ of these actions, respectively. These two signs of consciousness are provided with the mechanism based on the synthesis in the brain structures of different kinds of information: sensory information, the data extracted from the memory and the signals from the centers of emotions and motivation. As a result of this synthesis, the sense of ‘ego’ arises and the message designated for others is determined. A significant role in the informational synthesis is played by dynamic cortical structures — foci of interaction. In perception they are localized predominantly in the projectional cortex, in thinking and in the associative areas. Realization is closely connected with communication and appearance of the interaction foci in the verbal zones of the left hemisphere. Pavlov (1951), in his program lecture in Madrid early in the present century, said that he saw the final aim of his study in the revealing of the mechanism and the inner vital sense of human consciousness. It is important, that Pavlov placed the words ‘mechanism’ and ‘vital sense’ near each other, i.e., he considered that the sense of consciousness would be realized through revealing its mechanism. This insight attracts our attention now, when the problem on consciousness mechanism is in scientific plans and the search for the meaning of life by the end of the twentieth centry, one full of dramatic events, acquires a special value.

A new method for recognition of mental activity type with EEG is elaborated. The recognition is based on the analysis of EEG rhythms. Few (three-five) seconds of multi-channel EEG record is enough to accomplish the recognition since an artificial neural network (ANN) is utilized for the purpose. Best results are attained when using the smoothed power spectra of single EEG trials as an input to ANN, i.e. when the classification is based on the analysis of the frequency and the topography of rhythms. At the first stage, the ANN learns to detect mental activity types correctly using the learning set of data, for which the activity type is assumed to be known for every portion of EEG. Later, the network recognizes the unknown EEG data. To induce the thoughts of certain kinds, the appropriate tasks were prepared and presented to subjects on a computer monitor. The tasks belonged to two principally different cognitive styles, i.e. verbal and spatial. For each of these two, four different task types were designed, and for each of those 100 actual tasks were prepared. So, a total of 800 tasks were presented to every subject. There were an overall of twenty adult healthy subjects. Our results show that reliable discrimination between principal cognitive styles can be easily done on base of short EEG trials. For instance, when teaching the ANN to distinguish between basic thinking modes (verbal vs. spatial) with four task types (two verbal and two spatial), the other four are ascribed to the appropriate basic classes correctly. The average (over all subjects and task types) recognition score is about 90% in this case. The discrimination of particular task types within one basic class is possible but with lower scores (66%). Basing on literature data, we hypothesize that brain processes such as directional attention, memory load, and motivational trend may underlay the appearance of distinctive rhythmical patterns. A mu-rhythm may also play a significant role since execution of tasks might be accompanied by involuntary subtle movements and virtual speech production or, vice-versa, their suppression. The observed rhythmical patterns reveal to be highly specific, both to a subject and to a certain mental activity type. At the same time, they are surprisingly stable in time and are preserved for at least several months. Thus, a set of characteristic EEG rhythms pertinent to certain mental activity types forms an individual subject's ‘EEG portrait’.

To explore the mechanism of sensation correlations between EP (evoked potential) component amplitude and signal detection indices (d' and criterion) were studied. The time of sensation coincided with the peak latency of those EP components that showed a correlation with both indices. The components presumably reflected information synthesis in projection cortical neurons. A mechanism providing the synthesis process is proposed.

Within the Hebbian paradigm the mechanism for integrating cell assemblies oscillating with different frequencies remains unclear. We hypothesize that such an integration may occur in cortical “interaction foci” that unite synchronously oscillated assemblies through hard-wired connections, synthesizing the information from various functional systems of the brain.

To study the cortical regulation of emotions, event-related potentials (ERP) were recorded in the situation of a television tennis game. Winning the ball was used as a model of a positive and losing it was that of a negative emotional reaction.