Electroencephalographic Correlates of Mental Performance of Emotional Autobiographic and Scenic Situations: II. Characteristics of Spatial Synchronization

The EEG spatial synchronization in the frequency bands , , ₁, ₂, ₁, and ₂ was studied on the basis of estimations of corresponding mean values of the coherence function in two groups of subjects (students actors and nonactors) during internal induction of emotional states by means of recall of autobiographic experience and mental performance of given scenic situations as a known character. Emotion-induced changes in the state of the cortex were reflected in statistically significant heterogeneous changes in the EEG spatial synchronization in many cortical areas and different frequency bands. The results obtained are discussed in combination with data presented earlier on changes in EEG local synchronization obtained in the course of the same experiments. The EEG bands stand out against the background of extensive changes in the local and spatial EEG synchronization: the EEG changes in these bands are most prominent. Also, the changes in the prefrontal and temporal cortical areas, most involved in actualization of emotional states, are noteworthy. Some of the findings can be interpreted as confirming the hypothesis about neurophysiological mechanisms of brain defense from functionally excessive emotions.     

Electroencephalographic Correlates of Brain States during Verbal Learning: I. Characteristics of EEG Local Synchronization

Electroencephalograms (EEGs) were recorded by 19 standard derivations in 57 subjects in a resting state with the eyes opened, during memorization of verbal bilingual semantic pairs (Latin and Russian), and during retrieval (monitoring) of the learned information. Statistical comparison of the EEG spectral power in the frequency bands θ, α₁, α₂, β₁, β₂, and γ showed that induction of the states of memorization (encoding) and retrieval of the verbal information led to multiple significant changes in the EEG absolute power (local synchronization) as compared to the state of rest. Such changes took place simultaneously in different frequency bands over the entire cortex. The relative values and significance of changes in different cortical regions varied. The main features of the EEG power-difference patterns were an increase in the power of the γ band over the entire cortex, a bilateral increase in the power of the β₂ band in the temporal areas, and a decrease in the power of the α₂ and α₁ bands over a large part of the cortical surface. In the state of retrieval, synchronization in the γ- and β₂ bands and desynchronization in the α₂ band were significantly stronger than in the state of encoding. In the α₁ band, desynchronization was more pronounced in the state of encoding than in the state of retrieval. The results are discussed in combination with the available data of the EEG studies of different types of memory.     

Electroencephalographic Correlates of Brain States during Verbal Learning: II. Characteristics of EEG Spatial Synchronization

Spatial EEG synchronization was studied using mean EEG coherences in 57 subjects in a resting state with the eyes open, during memorization of verbal bilingual semantic pairs (Latin and Russian), and during retrieval (monitoring) of the learned information. Statistical comparison of the EEG spectral power in the frequency bands θ, α ₁, α₂, β₁, β₂, and γ showed that induction of the states of memorization and retrieval of the verbal information resulted in multiple significant increases in the mean coherence (spatial synchronization) as compared to the state of rest. These increases were significantly higher in the state of retrieval than in the state of memorization. Such changes simultaneously occurred in different frequency bands and over the entire cortex. The highest relative augmentations of coherence with the highest significance estimates were observed in long-distance derivation pairs involving the temporal areas or combining the anterofrontal and frontal derivations with the parietal and occipital ones. The results are discussed in combination with data obtained in the same study for changes in EEG local synchronization and reported earlier. The intense rearrangements of the bioelectrical activity of the cortex may be determined both by the effect of cognitively specific mechanisms of encoding-decoding of information in the memory system and by a cognitively nonspecific modulating system of the brain.     

Some Neurophysiological Correlates of Changed Mental States after Delivery: I. EEG Characteristics

A group of parturient women was divided on the basis of a special psychological poll into subgroups with a high (changed mental state, CMS) and low (unchanged mental state, UMS) number of signs of changes in the mental state during and after delivery. The background EEG was recorded in 16 monopolar leads before and after delivery. EEG processing included the calculation of indices of the basic rhythms, the parameters of auto- and cross-correlation functions, and the conditional probabilities of the mutual transitions of the EEG wave components that belong to the basic rhythm components according to their duration. Statistical comparison of the EEG characteristics of the subgroups, as well as their comparison with similar characteristics of the reference group of healthy nulliparous women, showed that the subgroups differed significantly in some parameters; the difference were generalized by lead zones. As a rule, the EEG characteristics of the CMS subgroup differed from those of the reference group more than those of the UMS subgroup. The differences between the CMS and UMS subgroups testify to some imbalance of the regulatory mechanisms in the former with the predominance of excitation at the predelivery stage and a more manifest physiological cerebral reaction to the delivery.     

Influence of the Emotional Perception of a Signal on the Electroencephalographic Correlates of Creative Activity

Subjects were asked to invent as many definitions (ideas of a definition) of emotionally positive, emotionally negative, or neutral notions as possible using notions of other semantic fields. In the control task, the notions to be defined and to be used in definition were of the same or close semantic fields. The EEG was recorded during task performance. Significant differences in EEG local power (LS) and spatial synchronization (SS) were established in comparison of EEGs recorded during performance of creative tasks differing in complexity, complex creative tasks differing in emotional background (positive and negative), and tasks performed with or without emotional induction. Differences in LS and SS were most distinct in the medio- and posterotemporal areas of both hemispheres. Positive emotions increased LS and differently affected SS. Negative emotions predominantly increased SS. Analysis of self-reports of the subjects showed that both positive and negative induced emotions increased the fluency of association of notions from different semantic fields but decreased the originality of the ideas produced by a subject to define a notion.     

Electroencephalographic characteristics of cognitive-specific alerting attention in verbal learning: I. Characteristics of EEG local synchronization

The EEG was recorded in 19 standard derivations in 88 students in the following states: rest with the eyes open, memorization (learning) of bilingual verbal semantic pairs (Latin and Russian), and retrieval (check) of the learned information. In order to calculate the mean heart rate (HR) in each state, the electrocardiogram was recorded. The subjective difficulty of task performance was assessed. Statistical comparison of the spectral power estimates in these states for frequency bands θ (4–7 Hz), α₁ (7–10 Hz), α₂ (10–13 Hz), β₁ (13–18 Hz), β₂ (18–30 Hz), and γ (30–40 Hz) demonstrated a number of significant differences in the EEG absolute power (local synchronization) between the states reproducible in subgroups. Comparison of the states of memorization and retrieval showed that, in the state of memorization, the EEG power in the γ, β₂, and θ bands was significantly lower throughout the cortical surface. Comparison of the active states with the reference state of rest showed that, in both active states, changes in the EEG power were of the same direction in the majority of the frequency bands (an increase in the θ, β₂, and γ bands and a decrease in the α₂ band) except α₁, in which memorization was predominantly accompanied by a decrease in the power, whereas retrieval was associated with an increase. No significant differences were found between the states of memorization and retrieval in the HR or the subjective estimate of task difficulty. The results can be interpreted as a reflection of cognitive-specific forms of general preparatory attention.     

Neuroelectric Correlates of Pragmatic Emotional Incongruence Processing: Empathy Matters

The emotions people feel can be simulated internally based on emotional situational contexts. In the present study, we assessed the behavioral and neuroelectric effects of seeing an unexpected emotional facial expression. We investigated the correct answer rate, response times and Event-Related Potential (ERP) effects during an incongruence paradigm between emotional faces and sentential contexts allowing emotional inferences. Most of the 36 healthy participants were recruited from a larger population (1 463 subjects), based on their scores on the Empathy Questionnaire (EQ). Regression analyses were conducted on these ratings using EQ factors as predictors (cognitive empathy, emotional reactivity and social skills). Recognition of pragmatic emotional incongruence was less accurate (P < .05) and slower (P < .05) than recognition of congruence. The incongruence effect on response times was inversely predicted by social skills. A significant N400 incongruence effect was found at the centro-parietal (P < .001) and centro-posterior midline (P < .01) electrodes. Cognitive empathy predicted the incongruence effect in the left occipital region, in the N400 time window. Finally, incongruence effects were also found on the LPP wave, in frontal midline and dorso-frontal regions, (P < .05), with no modulation by empathy. Processing pragmatic emotional incongruence is more cognitively demanding than congruence (as reflected by both behavioral and ERP data). This processing shows modulation by personality factors at the behavioral (through self-reported social skills) and neuroelectric levels (through self-reported cognitive empathy).     

EEG Correlates of Emotional Problems and Conduct Disorder in Schoolchildren

The relationships between EEG and the teachers' and parents' ratings of conduct disorder and emotional problems were studied in 20 schoolchildren between the ages of 9 to 13 years. For the assessment of behavioral and emotional problems, we used the Rutter questionnaire for teachers and the Achenbach questionnaire for parents. The intelligence was determined with the Wechsler test. The electroencephalogram was recorded at rest with eyes open and closed, from 16 derivations, using the international 10–20 system. Correlation analysis, controlling the effects of age and sex, and stepwise multiple regression analysis revealed a positive relationship between the ₁ relative spectral power and parental ratings of delinquent behavior and teachers' ratings of hyperactivity and conduct disorder. The relative spectral power of the band positively correlated with the intelligence and negatively, with the teachers' ratings of conduct disorder and hyperactivity. Children with high parental ratings of anxiety and depression and low teachers' ratings of hyperactivity had higher spectral power of the band in the left occipital region than in the right region. The average difference between the spectral power of the band in the derivations P ₃ and P ₄ with eyes open and closed correlated negatively with the parents' ratings of attention deficit. The discussion of the results involves the relationship between impulsiveness and arousal and the role of the right hemisphere in the generation of emotions.     

Neural Correlates of Emotional Personality: A Structural and Functional Magnetic Resonance Imaging Study

Studies addressing brain correlates of emotional personality have remained sparse, despite the involvement of emotional personality in health and well-being. This study investigates structural and functional brain correlates of psychological and physiological measures related to emotional personality. Psychological measures included neuroticism, extraversion, and agreeableness scores, as assessed using a standard personality questionnaire. As a physiological measure we used a cardiac amplitude signature, the so-called E_κ value (computed from the electrocardiogram) which has previously been related to tender emotionality. Questionnaire scores and E_κ values were related to both functional (eigenvector centrality mapping, ECM) and structural (voxel-based morphometry, VBM) neuroimaging data. Functional magnetic resonance imaging (fMRI) data were obtained from 22 individuals (12 females) while listening to music (joy, fear, or neutral music). ECM results showed that agreeableness scores correlated with centrality values in the dorsolateral prefrontal cortex, the anterior cingulate cortex, and the ventral striatum (nucleus accumbens). Individuals with higher E_κ values (indexing higher tender emotionality) showed higher centrality values in the subiculum of the right hippocampal formation. Structural MRI data from an independent sample of 59 individuals (34 females) showed that neuroticism scores correlated with volume of the left amygdaloid complex. In addition, individuals with higher E_κ showed larger gray matter volume in the same portion of the subiculum in which individuals with higher E_κ showed higher centrality values. Our results highlight a role of the amygdala in neuroticism. Moreover, they indicate that a cardiac signature related to emotionality (E_κ) correlates with both function (increased network centrality) and structure (grey matter volume) of the subiculum of the hippocampal formation, suggesting a role of the hippocampal formation for emotional personality. Results are the first to show personality-related differences using eigenvector centrality mapping, and the first to show structural brain differences for a physiological measure associated with personality.     

EEG Correlates of Anxiety and Emotional Stability in Adult Healthy Subjects

We studied peculiarities of the spectral characteristics of EEG in 111 healthy adult subjects of both sexes. The levels of situative anxiety (anxiety state) and personal anxiety were estimated using the Spielberger–Khanin test system. To estimate anxiety-related properties of the personality, Cattel’s technique 16 PF (form А) was used. Estimates of situative anxiety demonstrated only two cases of positive correlation with the spectral power density (SPD) of EEG rhythms (SPDs of the beta2 rhythm in the right-hemisphere temporal and occipital regions; recording with the eyes open). Estimates of personal anxiety positively correlated with the SPDs of the beta1 and (especially) beta2 EEG rhythms. Under conditions with the eyes open, the number of significant correlations was greater, and correlations themselves were tighter than with the eyes closed. The closest correlations of the estimates of personal anxiety with the SPDs of the beta rhythm were found in frontal and central leads of both hemispheres and in parietal and occipital loci of the right hemisphere. Only a single case of correlation of the alpha rhythm SPD with personal anxiety (negative correlation, a parietal lead in the left hemisphere) was found. At the same time, rather numerous correlations of the alpha rhythm expression with an index congeneric to anxiety, the C factor by the Cattel’s questionnaire (emotional stability/instability), were found. Thus, the intense beta EEG rhythm can be considered an electrographic correlate of high situative and personal anxieties. At the same time, the alpha rhythm power correlates with the emotional stability of the individual. We suppose that persons with a well-developed alpha rhythm are characterized by active and stable functioning of the cerebral dopaminergic system; this simultaneously serves as a pre-requisite of high emotional stability and social adaptability.     

Personal Meaning and the Transformation of a Mental Image

It is generally accepted that the reflection of reality in human consciousness is by no means an exact photographic reproduction of reality. "An image is the reflection of an object, and an object is reflected in an image in just the same guise as it exists in the real life relation between it and the subject" (Rubinshtein, 1957. P. 230). Thus, an element of personal, subjective partiality, the reflection of not only phenomena or objective relations themselves but also of their meaning for the person and their relation to his needs (Rubinshtein, 1959. P. 124; Leont'ev, 1977; Vilyunas, 1983; etc.), is necessarily present in a mental image. Personal meaning is also a component of individual consciousness; in it the partiality of that consciousness finds expression, a partiality conditioned by the link between that consciousness and the subject's need and motivational sphere and the reality of his life in the world (Leont'ev, 1977. Pp. 152-53). The objects and phenomena of reality are presented to us in direct perception and in our imagination in a form that is "colored" by the personal meaning they have for us as a result of their objective place in our life activity and their relation to the realization of our needs. It is not always possible to differentiate between objective content and personal relation even in reflection. Often, the meaning of an object cannot be separated from the object itself and examined impartially, from the sidelines, so to speak. This is most patently in evidence in the example of one's perception of other people, especially those who are very familiar.     

Prediction of Successful Personal Cognitive Performance Based on Integrated Characteristics of Multichannel EEG

The present study aimed to assess the possible relationship between psychometric and electroencephalographic (EEG) parameters in humans. Normalized parameters of the integrated spatial (p _S ) and integrated temporal (p _T ) regularities of real resting EEG with the eyes closed were calculated. The algorithm of estimation of these parameters was based on the calculation of empirical multivariate temporal structure function of the first order. It was revealed that p _S and p _T parameters varied in a specific range, which was characterized by well-defined individual configuration reflecting the variability type (spatial, temporal, or mixed) of resting EEG. Obtained p _S and p _T parameters were compared to the speed of performed cognitive activity. The cognitive tasks included nonverbal subtests of the Wechsler Adult Intelligence Scale (WAIS) including block design according to a given template and construction of an object without any template, and motor probe. The successful performance on cognitive tasks was detected to be achieved with different combinations of p _S and p _T parameters in different subjects. Thus, the same intelligence resource can probably be organized with nonlinear principle in different subjects.     

Self-Orientation Modulates the Neural Correlates of Global and Local Processing

Differences in self-orientation (or “self-construal”) may affect how the visual environment is attended, but the neural and cultural mechanisms that drive this remain unclear. Behavioral studies have demonstrated that people from Western backgrounds with predominant individualistic values are perceptually biased towards local-level information; whereas people from non-Western backgrounds that support collectivist values are preferentially focused on contextual and global-level information. In this study, we compared two groups differing in predominant individualistic (N = 15) vs collectivistic (N = 15) self-orientation. Participants completed a global/local perceptual conflict task whilst undergoing functional Magnetic Resonance Imaging (fMRI) scanning. When participants high in individualistic values attended to the global level (ignoring the local level), greater activity was observed in the frontoparietal and cingulo-opercular networks that underpin attentional control, compared to the match (congruent) baseline. Participants high in collectivistic values activated similar attentional control networks o only when directly compared with global processing. This suggests that global interference was stronger than local interference in the conflict task in the collectivistic group. Both groups showed increased activity in dorsolateral prefrontal regions involved in resolving perceptual conflict during heightened distractor interference. The findings suggest that self-orientation may play an important role in driving attention networks to facilitate interaction with the visual environment.