Individual differences in the neural representation of cooperation and competition.

Much evidence links the Big Five's agreeableness to a propensity for cooperation and aggressiveness to a propensity for competition. However, the neural basis for these associations is unknown. In this functional magnetic resonance imaging study, using multivariate pattern analysis of data recorded during a computer game in which participants were required to construct target patterns either in cooperation or in competition with another person, we sought to determine how individual differences in neural representations of cooperative and competitive behavior relate to individual differences in agreeableness and aggressiveness. During cooperation, agreeableness was positively correlated with the consistency of spatial patterns of neural activation in the left temporoparietal junction (TPJ) and showed positive correlations with inter-subject similarity in the dynamics of neural responses in the posterior default mode network hub and areas involved in the regulation of attention, movement planning, and visual perception. During competition, aggressiveness was positively correlated with the consistency of spatial patterns in the left and right TPJ and showed positive correlations with neural dynamics in visual processing and movement regulation areas. These results are consistent with the assumption that agreeable individuals are more involved in cooperative interactions with others, whereas aggression-prone individuals are more involved in competitive interactions.

[Severity of depressive symptoms and oscillatory responses to emotional facial expressions].

We studies the differences in oscillatory responses to emotional facial expressions in 40 subjects with different severity of depressive symptoms (19 men and 21 women) aged 18-30 years. In subjects with low severity of depressive symptoms (group 2), the perception of happy facial expressions was marked by lower delta synchronization as compared with angry and neutral expressions; in subjects with high severity of depressive chronization as compared with angry and neutral expression; in subjects with high severity of depressive symptoms (group 1), the perception of happy faces was marked by higher delta synchronization. Since an increase in delta oscillations is usually observed in aversive conditions, we suggest that happy facial expressions are perceived as negative stimuli by the subjects of group 1. The perception of angry facial expressions was accompanied by alpha band desynchronization in Group 2 and by alpha synchronization in Group 1. Basing on Klimesch's theory, this effect suggests that the subjects of group 1 are initially set up for the perception of negative emotional information. The effect of emotional stimulus category was significant in group 2, but not significant in group 1, which is an evidence of disorders in the recognition of emotional information in depression-prone individuals.

[A role of personality and stress in the development of depressive symptoms in students]. / Rol' lichnosti i stressa v razvitii depressivnykh rasstroistv u studentov.

AIM: To study a role of personality and stress as a mediator between personality and depression in university first-year students. MATERIAL AND METHODS: Sixty-four students (76.6% female, mean age 18.7±1.02 years), including 30 first year- and 34 second-year students, were studied. RESULTS AND CONCLUSION: The first-year students experienced more stress and more frequently had depressive symptoms compared to second-year students. Neuroticism mainly contributed to depression in the first-year students and extroversion was a protective factor against all depressive symptoms, whereas extraversion and conscientiousness were significant unique predictors for depression in the second-year students. Neuroticism was strongly associated with somatic symptoms, while consciousness was linked to cognitive-affective symptoms. The role of stress as a mediator of the relationship between personality and depression was confirmed for consciousness in the first-year students; other personality traits and stress contributed directly to depressive symptoms.

[Vulnerability to Depression and Oscillatory Resting-State Networks].

Depression is the most commonly observed mood disorder, which is accompanied by changes in emotional processes and the default mode network (DMN) activity. In this study, we aimed to investigate how predisposition to depression shows up in the emotional coloring of spontaneous thoughts and the activity of oscillatory resting-state networks, as revealed by source localization and independent component analysis techniques. Depressive symptoms correlated positively with the prevalence of negative emotion during EEG registration and with delta and theta activity in the orbitofrontal cortex and negatively with theta activity in the DMN. Since an increase of low-frequency oscillations in the orbitofrontal cortex is observed in aversive states, whereas their decrease in the DMN reflects an activation of this network, which is related to self-referenced processing, our results are consistent with the notion that vulnerability to depression is associated with general negative emotional disposition and excessive focus on the self.

Gender differences in association between serotonin transporter gene polymorphism and resting-state EEG activity.

Human brain oscillations represent important features of information processing and are highly heritable. Gender has been observed to affect association between the 5-HTTLPR (serotonin-transporter-linked polymorphic region) polymorphism and various endophenotypes. This study aimed to investigate the effects of 5-HTTLPR on the spontaneous electroencephalography (EEG) activity in healthy male and female subjects. DNA samples extracted from buccal swabs and resting EEG recorded at 60 standard leads were collected from 210 (101 men and 109 women) volunteers. Spectral EEG power estimates and cortical sources of EEG activity were investigated. It was shown that effects of 5-HTTLPR polymorphism on electrical activity of the brain vary as a function of gender. Women with the S/L genotype had greater global EEG power compared to men with the same genotype. In men, current source density was markedly different among genotype groups in only alpha 2 and alpha 3 frequency ranges: S/S allele carriers had higher current source density estimates in the left inferior parietal lobule in comparison with the L/L group. In women, genotype difference in global power asymmetry was found in the central-temporal region. Contrasting L/L and S/L genotype carriers also yielded significant effects in the right hemisphere inferior parietal lobule and the right postcentral gyrus with L/L genotype carriers showing lower current source density estimates than S/L genotype carriers in all but gamma bands. So, in women, the effects of 5-HTTLPR polymorphism were associated with modulation of the EEG activity in a wide range of EEG frequencies. The significance of the results lies in the demonstration of gene by sex interaction with resting EEG that has implications for understanding sex-related differences in affective states, emotion and cognition.

Reciprocal relationships between the oscillatory systems of the brain.

Resting EEG recordings were made from cohorts of 146 children aged 7-17 years and 132 adults aged 18-32 years and the levels of personality features and psychopathology were assessed using the Eysenck, Spilberger, Gray-Wilson, and Goodman questionnaires. Factor analysis was used to discriminate covariance of measures of the spectral power of EEG rhythms into positive and negative components. The latter were interpreted as a measure of inhibitory interactions between oscillatory systems. In children, positive covariance of rhythms was stronger than in adults, while reciprocal relationships between oscillatory systems were weaker. In adults, trait anxiety correlated positively with the strength of the reciprocal relationship between the alpha and delta oscillatory systems. In children, an analogous relationship was seen between anxiety and the strength of the reciprocal relationship between the theta and delta systems. The data are discussed in the light of the evolutionary interpretation of EEG rhythms.

Event-related delta and theta synchronization during explicit and implicit emotion processing.

Emotion information processing may occur in two modes which are differently represented in conscious awareness. Fast online processing involves coarse-grained analysis of salient features, and is not represented in conscious awareness; offline processing takes hundreds of milliseconds to generate fine-grained analysis, and is represented in conscious awareness. These processing modes may be studied using event-related electroencephalogram theta and delta synchronization as a marker of emotion processing. Two experiments were conducted, which differed on the mode of emotional information presentation. In the explicit mode subjects were explicitly instructed to evaluate the emotional content of presented stimuli; in the implicit mode they performed a gender discrimination task. Firstly, we show that in both experiments theta and delta synchronization is stronger upon presentation of "emotional" than "neutral" stimuli, and in subjects who are more sensitive, or experience higher emotional involvement than in less sensitive or detached subjects. Secondly, we show that in the implicit mode theta and delta synchronization is more pronounced in an early (before 250 ms post-stimulus) processing stage, whereas in the explicit mode it is more pronounced in a later processing stage. Source localization analysis showed that implicit processing of angry and happy (relative to neutral) faces is associated with higher early (before 250 ms) theta synchronization in the right parietal cortex and the right insula, respectively. Explicit processing of angry and happy faces is associated with higher late (after 250 ms) theta synchronization in the left temporal lobe and bilateral prefrontal cortex, respectively.

Substance use underlying behavior: investigation of theta and high frequency oscillations in emotionally relevant situations.

High sensitivity of the Behavioral Approach System (BAS) was shown to be one of the strongest predictors of substance use (SU). It was hypothesized that individuals with high BAS sensitivity would experience higher emotional arousal in the reward expectancy situation and lower in the punishment expectancy situation than individuals with low BAS activity. The level of emotional arousal indicated by theta spectral power, and general cortical excitability indicated by high frequency oscillations (HFO), were measured in a sample of young people who filled out Carver and White's Behavioral Inhibition System/Behavioral Approach System (BIS/BAS) scales. Frontal theta and HFO increased in high BAS scorers during expectation of reward and decreased during expectation of punishment. In low BAS scorers spectral powers of theta and HFO increased, contrary to those for the punishment cue, and decreased for reward cue. Theta-gamma coupling increased in high Drive scorers (those above the median) in reward and in low Drive scorers (those who appeared to be below the median split on this scale) in punishment situation.

Socio-economic and school factors of psychological and physical health in Siberian schoolchildren.

Cultural influences on psychological and physical health were examined in a sample of Russian schoolchildren in Novosibirsk. To evaluate the children's behaviour the translated short form of the Child Behaviour Checklist was given out to mothers. A School Adjustment Scale and the Rutter Teacher Questionnaire were completed by teachers and one total score was derived from the Rutter Health Questionnaire for children. Children from disturbed families had worse school adjustment and more behavioural problems. Acute respiratory diseases were more frequent in children from large families, while the mother's education level was a protective factor. Academic attainment was positively related to parents' education, CBCL Somatic Complaints and the occurrence of psychosomatic and inflammatory diseases, and negatively related to Externalising Problems. The CBCL Somatic complaints score was the key variable in the prediction of most physical health variables. Overall, the findings show the significance of academic attainment for a child's physical and psychological health. Low academic attainment tends to be connected with Externalising Problems, while higher attainment could be connected with somatisation and physical illness.

Trophic functions of primary sensory neurons: are they really local?

The results of the present study, in the rat and cat, indicate that not only a lesion of peripheral nerve or capsaicin pretreatment but also pharmacological deafferentation with local anaesthetic or disruption of the connections between primary sensory neurons and the central nervous system are effective in producing dystrophic changes in tissues. These effects of deafferentation do not seem to depend on the sympathetic or parasympathetic efferents. Dystrophic changes are connected with microcirculation disturbances: slow down of local blood flow, elevation of the vascular permeability, oedema and leucocyte infiltration. The findings indicate that capsaicin-sensitive primary sensory neurons are the afferent part of some reflex arrangement which participates in the regulation of microcirculation and the maintenance of trophic processes in peripheral tissues. The efferent part of this arrangement is unknown.

Neuroparalytic keratitis and capsaicin.

Subcutaneous injection of 50 mg/kg capsaicin to newborn rats resulted in a marked decrease of heat pain sensitivity and neurogenic inflammation. There was, however, no significant difference between capsaicin-pretreated and control rats in the severity of neuroparalytic keratitis after surgical deafferentation of the eye. Retrobulbar injection of 100 microliters of 0.5% capsaicin produced keratitis-like corneal changes. These changes were not prevented by previous pretreatment with a total subcutaneous dose of 200 mg/kg capsaicin. The findings indicate that corneal changes after deafferentation are not due to excessive release of substance P and other neuropeptides from the degenerating afferent fibres.

Analysis of the role of central noradrenergic structures in memory trace recall.

During the reproduction of a conditioned passive avoidance response by albino rats and also during the action of a conditioning stimulus in animals trained by invariable reinforcement of the conditioning stimulus, a significant decrease was found in the noradrenalin content in nuclei of the limbic system and anterior hypothalamus compared with the control. In untrained animals, and also in trained animals subjected to repeated testing in the course of 4 days, the decrease in the noradrenalin content was less marked. Reproduction of the conditioned active avoidence response in a shuttle box did not induce changes in the noradrenalin content.