Representational similarity analysis of self- versus other-processing: Effect of trait aggressiveness.

In this study, using the self/other adjective judgment task, we aimed to explore how people perceive themselves in comparison to various other people, including friends, strangers, and those they dislike. Next, using representational similarity analysis, we sought to elucidate how these perceptual similarities and differences are represented in brain activity and how aggressiveness is related to these representations. Behavioral ratings show that, on average, people tend to consider themselves more like their friends than neutral strangers, and least like people they dislike. This pattern of similarity is positively correlated with neural representation in social and cognitive circuits of the brain and negatively correlated with neural representation in emotional centers that may represent emotional arousal associated with various social objects. Aggressiveness seems to predispose a person to a pattern of behavior that is the opposite of the average pattern, that is, a tendency to think of oneself as less like one's friends and more like one's enemies. This corresponds to an increase in the similarity of the behavioral representation with the representation in the emotional centers and a decrease in its similarity with the representation in the social and cognitive centers. This can be seen as evidence that in individuals prone to aggression, behavior in the social environment may depend to a greater extent on the representation of social objects in the emotional rather than social and cognitive brain circuits.

Fast changes in default and control network activity underlying intraindividual response time variability in childhood: Does age and sex matter?

Intraindividual response time variability (RTV) is considered as a general marker of neurological health. In adults, the central executive and salience networks (task-positive networks, TPN) and the default mode network (DMN) are critical for RTV. Given that RTV decreases with growing up, and that boys are likely somewhat behind girls with respect to the network development, we aimed to clarify age and sex effects. Electroencephalogram was recorded during Stroop-like test performance in 124 typically developing children aged 5-12 years. Network fluctuations were calculated as changes of current source density (CSD) in regions of interest (ROIs) from pretest to 1-s test interval. In boys, TPN activation (CSD increase in ROIs included in the TPN) was associated with lower RTV, suggesting a greater engagement of attentional control. In children younger than 9.5 years, higher response stability was associated with the predominance of TPN activation over DMN activation (CSD increase in ROIs included in the TPN > that in the DMN); this predominance increased with age, suggesting that variability among younger children may be due to network immaturity. These findings suggest that the TPN and DMN may play different roles within the network mechanisms of RTV in boys and girls and at different developmental stages.

Electrophysiological signatures of resting state networks under new environmental conditions.

It is assumed that cognitive processes are provided by the regulatory interactions of different brain networks. The three most stable resting state networks, among which the default mode network (DMN), the central executive network (CEN) and the salience network (SN) are considered to be the key neurocognitive networks for understanding higher cognitive functions. Peculiarities of changes in the connectivity of resting state networks of an individual entering a new environment and after a year of adaptation in this environment remain poorly studied. The aim of this study was to investigate the peculiarities of the connectivity of resting state networks calculated in EEG data in students right after moving to an unfamiliar environment and one year after moving. 128-channel EEGs were recorded in the resting state in 45 students (all men) aged from 18 to 29 years, who moved to the North region of Russia (Yakutsk, Republic of Sakha (Yakutia)). Resting state networks were calculated by the seed-based method. The subjects had increased SN connectivity with the sensorimotor cortex and the posterior node of DMN (posterior cingulate cortex and precuneus) in the condition when they were exposed to a new unfamiliar environment, compared to the condition after a year in the same environment. In general, the obtained data are consistent with the notion of increased SN functioning when encountering new significant stimuli and tasks, i.e. new environmental conditions, and the representation of SN as closely related to the function of homeostasis regulation according to organism's internal goals and environmental requirements.

Harmonized-Multinational qEEG norms (HarMNqEEG).

This paper extends frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. (i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG "batch effects" and provide methods to calculate harmonized z-scores. (ii) We also show that harmonized Riemannian norms produce z-scores with increased diagnostic accuracy predicting brain dysfunction produced by malnutrition in the first year of life and detecting COVID induced brain dysfunction. (iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings.

Associations of Hyperactivity and Inattention Scores with Theta and Beta Oscillatory Dynamics of EEG in Stop-Signal Task in Healthy Children 7-10 Years Old.

In the current study, we aimed to investigate the associations between the natural variability in hyperactivity and inattention scores, as well as their combination with EEG oscillatory responses in the Stop-Signal task in a sample of healthy children. During performance, the Stop-Signal task EEGs were recorded in 94 Caucasian children (40 girls) from 7 to 10 years. Hyperactivity/inattention and inattention scores positively correlated with RT variability. Hyperactivity/inattention and inattention scores negatively correlated with an increase in beta spectral power in the first 200 ms after presentation of the Go stimulus. Such results are in line with the lack of arousal model in ADHD children and can be associated with less sensory arousal in the early stages of perception in children with symptoms of inattention. The subsequent greater increase in theta rhythm at about 300 ms after presentation of the Go stimulus in children with higher inattention scores may be associated with increased attention processes and compensation for insufficient vigilance in the early stages of perception.

How Self-Appraisal Is Mediated by the Brain.

Self-appraisal is a process that leads to the formation of self-esteem, which contributes to subjective well-being and mental health. Neuroimaging studies link self-esteem with the activity of the medial prefrontal cortex (MPFC), right temporoparietal junction (rTPJ), posterior cingulate cortex (PCC), anterior insula (AIns), and dorsolateral prefrontal cortex. It is not known, however, how the process of self-appraisal itself is mediated by the brain and how different nodes of the self-appraisal network interact with each other. In this study, we used multilevel mediation analysis of functional MRI data recorded during the trait adjective judgment task, treating the emotional valence of adjectives as the predictor, behavioral response as the dependent variable, and brain activity as the mediator. The mediation effect was revealed in the rTPJ. Dynamic causal modeling showed that positive self-descriptions trigger communication within the network, with the rTPJ exerting the strongest excitatory output and MPFC receiving the strongest excitatory input. rAIns receives the strongest inhibitory input and sends exclusively inhibitory connections to other regions pointing out to its role in the processing of negative self-descriptions. Analysis of individual differences showed that in some individuals, self-appraisal is mostly driven by the endorsement of positive self-descriptions and is accompanied by increased activation and communication between rTPJ, MPFC, and PCC. In others, self-appraisal is driven by the rejection of negative self-descriptions and is accompanied by increased activation of rAIns and inhibition of PCC and MPFC. Membership of these groups was predicted by different personality variables. This evidence uncovers different mechanisms of positive self-bias, which may contribute to different facets of self-esteem and are associated with different personality profiles.

Intrinsic Connectivity Networks in the Self- and Other-Referential Processing.

Neuroimaging studies have revealed a multitude of brain regions associated with self- and other-referential processing, but the question how the distinction between self, close other, and distant other is processed in the brain still remains unanswered. The default mode network (DMN) is the primary network associated with the processing of self, whereas task-positive networks (TPN) are indispensable for the processing of external objects. We hypothesize that self- and close-other-processing would engage DMN more than TPN, whereas distant-other-processing would engage TPN to a greater extent. To test this hypothesis, we used functional magnetic resonance imaging (fMRI) functional connectivity data obtained in the course of a trait adjective judgment task while subjects evaluated themselves, the best friend, a neutral stranger, and an unpleasant person. A positive association between the degree of self-relatedness and the degree of DMN dominance was revealed in cortical midline structures (CMS) and the left lateral prefrontal cortex. Relative to TPN, DMN showed greater connectivity in me than in friend, in friend than in stranger, and in stranger than in unpleasant conditions. These results show that the less the evaluated person is perceived as self-related, the more the balance of activity in the brain shifts from the DMN to the TPN.

Oscillatory dynamics of perception of emotional sentences in healthy subjects with different severity of depressive symptoms.

The aim of the study was to investigate the characteristics of the oscillatory dynamics of brain activity during the perception of negative, positive, and neutral sentences in healthy individuals with differing severity of depressive symptoms at the preclinical stage. The study involved 34 healthy people (22 women). The severity of the symptoms of depression was assessed using Beck's Depression Inventory (BDI II). Using independent component analysis and the function of dipfit in the EEGlab software, the EEG was divided into components and their localizations were calculated. To assess the induced responses, event-related spectral perturbations were calculated. The perception of emotional sentences was accompanied by a more pronounced increase in theta rhythm in the group with lower severity of depressive symptoms. The perception of all types of sentences was accompanied by a decrease in beta rhythm in the group with lower severity of depressive symptoms. The effects were localized to the precuneus. The decrease of oscillatory responses in the theta and beta ranges in individuals with a high severity of depressive symptoms suggests a reduction of attention to the emotional content and meaning of the sentences.

Stroop-like animal size test: Links with child effortful control, personality and problem behavior.

This study examined children's performance on the Stroop-like animal size test and its relations to parent-reported temperamental effortful control, personality, and common emotional and behavioral problems in a Russian sample of 5-12-year-olds (N = 202). The animal size test demonstrated a Stroop-like effect for accuracy and response time (RT) in both genders and across all ages. Children's performance on the animal size test considerably improved with age such that older children performed more accurately, were faster and their responses were less variable than younger children's responses. The findings indicated that RT was negatively related to temperamental trait of effortful control and its key components, attention focusing and inhibitory control, whereas RT variability was negatively related to both regulatory traits, effortful control and conscientiousness, and their components. Children's performance on the AST was meaningfully related to hyperactivity-inattention, externalizing behavior and overall level of childhood psychopathology. These findings provide support for the usefulness of the animal size test in the neuropsychological assessment of preschool and school-age children.

EEG cross-frequency correlations as a marker of predisposition to affective disorders.

EEG cross-frequency amplitude-amplitude correlation (CF-AAC) has been considered as a potential marker of social anxiety and other affective disturbances. Functional significance of this phenomenon remains unclear, partly because the majority of studies used channel-level analysis, which precluded the spatial localization of observed effects. It is not also clear whether CF-AAC may serve as a marker of specific pathological conditions and specific states, or a more general predisposition to affective disturbances. We used source-level analysis of EEG data obtained in resting conditions in a nonclinical sample and patients with major depressive disorder (MDD) and investigated associations of CF-AAC measures with a broad range of known risk factors for affective disorders, including age, gender, genotype, stress exposure, personality, and self-reported 'neurotic' symptomatology. A consistent pattern of associations showed that all investigated risk factors were associated with an enhancement of CF-AAC in cortical regions associated with emotional and self-referential processing. It could be concluded that CF-AAC is a promising candidate marker of a general predisposition to affective disorders at preclinical stages.

Impact of Polymorphisms in the Serotonin Transporter Gene on Oscillatory Dynamics during Inhibition of Planned Movement in Children.

The serotonin transporter plays an important role in serotonergic neuromodulation. It is known that polymorphisms in the serotonin transporter gene are linked to the dysregulation of emotions. In the current study, we aimed to investigate the impact of variation in the gene encoding serotonin transporter polymorphism on oscillatory dynamics during inhibition of planned movement in the stop signal paradigm. During performance the stop signal paradigm, electroencephalograms (EEGs) were recorded in 90 healthy Caucasian children (39 girls) from 7 to 12 years. Buccal epithelium probes were taken from all participants. The La, Lg, and S alleles of serotonin transporter-linked polymorphic region (5-HTTLPR) polymorphism were detected in the DNA samples using PCR. LaLa genotype carriers did not differ from LaS\LgS and LgS\LgLg\SS carriers in a number of successful inhibitions of a prepotent response. Carriers of LaLa exhibit higher alpha and beta event-related spectral perturbations (ERSP) in parietal and occipital cortices after the presentation of signal of inhibition of movement than LaS\LgS and LgS\LgLg\SS carriers. Results are consistent with current literature and confirm that S allele carriers are more predisposed to disturbances in cognitive control.

Cross-Frequency Coupling in Developmental Perspective.

It is generally assumed that different electroencephalogram (EEG) frequency bands are somehow related to different computational modes in the brain. Integration of these computational modes is reflected in the phenomenon of cross-frequency coupling (CFC). On slow temporal scales, CFC may reflect trait-like properties, which posits a question of its developmental trends. This is the first study that explored source-level CFC measures in a developmental perspective using both cross-sectional and longitudinal designs. CFC measures demonstrated good test-retest stability and proved to be higher in adults in cortical areas participating in sensory-motor integration, response inhibition, and attentional control. In children, greater CFC was observed in parietal regions involved in self-centered cognition. Over the period from 7 to 10 years, CFC demonstrated nonlinear growth trajectories. Introversion was associated with higher CFC in cortical areas related to emotion, attention, and social cognition, implying that the association between introversion and CFC appears early in the development.

EEG dynamics of spontaneous stimulus-independent thoughts.

In this study, we aimed to compare the oscillatory dynamics accompanying self-referential and non-self-referential stimulus-independent thoughts. Electroencephalograms were recorded in 30 healthy participants who were asked to press buttons classifying their spontaneous thoughts as self-referential or non-self-referential. EEG data were analyzed using independent component analysis in conjunction with dipole localization. Self-referential thoughts, as compared to non-self-referential thoughts, were accompanied by more pronounced decreases of theta, alpha, and beta spectral power in the anterior hub of the default-mode network, in the left lateral prefrontal, motor/somatosensory, and temporal cortices. These oscillatory dynamics are interpreted as a reflection of autobiographical memory retrieval intrinsic to self-referential thoughts. Abbreviations: BA: Brodmann area; BOLD: blood oxygenation level-dependent; DMN: default mode network; EEG: electroencephalogram; ERSP: event-related spectral perturbations; fMRI: functional magnetic resonance imaging; PCC: posterior cingulate cortex; PET: positron emission tomography; PFC: prefrontal cortex; SIT: stimulus-independent thought; WM: working memory.

Effect of Cultural Priming on Social Behavior and EEG Correlates of Self-Processing.

Humans are social beings and the self is inevitably conceptualized in terms of social environment. The degree to which the self is perceived as fundamentally similar or fundamentally different from other people is modulated by cultural stereotypes, such as collectivism and individualism. These stereotypes are not hardwired in our brains and individuals differ in the degree to which they adopt the attitudes that define their culture. Moreover, individuals can acquire multiple sets of cultural knowledge and, depending on the context, either individualistic or collectivistic cultural mindset could be activated. In this study, we used cultural priming techniques to activate either individualistic or collectivistic mindset and investigated the association between source-level EEG connectivity in the default mode network (DMN) and spontaneous self-related thoughts in the subsequent resting state. Afterward, participants performed a social interaction task, in which they were allowed to choose between friendly, avoidant, or aggressive behavior. After collectivism priming, self-related thoughts were associated with increased connectivity of DMN with the right temporoparietal junction (TPJ), which is involved in taking the perspective of others and is more active in representatives of collectivistic cultures, whereas after individualism priming they were associated with increased connectivity with the temporal pole, which is involved in self/other discrimination and is more active in representatives of individualistic cultures. Individual differences in the intensity of post-priming self-related thoughts and the strength of DMN-temporal pole connectivity predicted individual differences in behavior during the social interaction task, with individualistic mindset predisposing to more friendly and trustful social behavior.

Resting heart rate variability in young women is a predictor of EEG reactions to linguistic ambiguity in sentences.

Recent research has found a relationship between heart rate variability (HRV) and cognitive control mechanisms underlying various experimental tasks. This study explored the interaction between gender and resting-state HRV in brain oscillatory activity during visual recognition of linguistic ambiguity while taking state and trait anxiety scores into account. It is well known that stress or anxiety increases arousal levels, particularly under uncertainty situations. We tasked 50 young Mandarin speakers (26 women; average age 26.00 ±â€¯4.449) with the recognition of linguistic ambiguity in English (foreign) sentences with the purpose of imposing a sense of uncertainty in decision-making. Our results revealed a dependency between resting-state HRV and theta/alpha power in individual women. Low HRV women showed stronger theta/alpha desynchronization compared with their high HRV counterparts, independent of topographic localization. However, low and high HRV men exhibited comparable theta/alpha activity. Trait anxiety scores affected alpha power in the parieto-occipital regions, whereas men with higher scores and women with lower scores showed stronger alpha desynchronization. We posit that stress-provoking situations may impose additional effects on theta/alpha desynchronization in the frontal and temporal regions, a condition in which the interdependency between brain oscillatory activity and resting-state HRV could interact with cognitive control differently in men and women.

Effect of 5-HTTLPR on current source density, connectivity, and topological properties of resting state EEG networks.

The S allele of serotonin transporter gene (5-HTTLPR) has been found to increase the risk of depression and other mental health problems, but some evidence suggests that S-allele carriers outperform subjects carrying the long allele in an array of cognitive tasks. Evidence linking this polymorphism with individual variation in electrophysiological properties of resting state brain networks is very limited. This study investigated the effect of 5-HTTLPR polymorphism on EEG current source density, connectivity, and topological properties of resting state networks. We collected genetic and resting state EEG data in 113 Caucasians. As compared to L-homozygotes, S-allele carriers showed lower current source density and connectivity in most frequency bands in areas overlapping with the default mode and emotion regulation regions. The analysis of graph-theoretical measures showed that S-allele carriers, as compared to L-homozygotes, have less optimal topological properties of brain networks in theta, but more optimal in alpha band. This dissociation may reflect the predisposition to emotional disorders, which is inherent to S-allele carriers, and, on the other hand, their superior functioning in some cognitive domains.

Task-positive and task-negative networks in major depressive disorder: A combined fMRI and EEG study.

BACKGROUND: The study of intrinsic connectivity networks, i.e., sets of brain regions that show a high degree of interconnectedness even in the absence of a task, showed that major depressive disorder (MDD) patients demonstrate an increased connectivity within the default mode network (DMN), which is active in a resting state and is implicated in self-referential processing, and a decreased connectivity in task-positive networks (TPNs), which increase their activity in attention tasks. Cortical localization of this 'dominance' of the DMN over the TPN in MDD patients is not fully understood. Besides, this effect has been investigated using fMRI and its electrophysiological underpinning is not known. METHOD: In this study, we tested the dominance hypothesis using seed-based connectivity analysis of resting-state fMRI and EEG data obtained in 41 MDD patients and 23 controls. RESULTS: In MDD patients, as compared to controls, insula, pallidum/putamen, amygdala, and left dorso- and ventrolateral prefrontal cortex are more strongly connected with DMN than with TPN seeds. In EEG, all significant effects were obtained in the delta frequency band. LIMITATIONS: fMRI and EEG data were not obtained simultaneously during the same session. CONCLUSIONS: In MDD patients, major emotion and attention regulation circuits are more strongly connected with DMN than with TPN implying they are more prepared to respond to internally generated self-related thoughts than to environmental challenges.

Resting state connectivity mediates the relationship between collectivism and social cognition.

Humans are intrinsically social beings and it is natural that self-processing is associated with social cognition. The degree to which the self is perceived as a part of social environment is modulated by cultural stereotypes, such as collectivism and individualism. Here, we tested the hypothesis that individuals who endorse collectivist values would spontaneously think more about their relationships with other people and this association would be mediated by connectivity between the medial prefrontal cortex (MPFC) and the rest of the brain. Connectivity was evaluated based on resting state EEG data using the recently developed methods, which combine beamformer spatial filtering with seed based connectivity estimation. The formal mediation analysis revealed that collectivism is associated with an enhanced connectivity of MPFC with a set of cortical regions that are frequently co-activated in moral reasoning, empathy, and theory of mind tasks and with diminished connectivity with the precuneus\posterior cingulate cortex, which is involved in self-centered cognition. The relationship between collectivism and social cognition was mediated by MPFC connectivity with the left middle temporal gyrus implying that in participants with collectivistic attitude, thinking about relationships with other people may be associated with semantic memory retrieval and reasoning on moral issues and others' intentions.

Resting State Networks Mediate the Effect of Genotype by Environment Interaction on Mental Health.

A number of studies have shown that the presence of short (S) allele of the serotonin transporter-linked polymorphic region (5-HTTLPR) is associated with a higher risk for depression following exposure to stressful life events. These findings are in line with neuroimaging studies showing that 5-HTTLPR polymorphism has an effect on the connectivity among key areas involved in emotion regulation. Here using mediated moderation analysis, we show that electrophysiological manifestations of resting state networks in the alpha frequency band mediate the effect of 5-HTTLPR by stress interaction on depression/anxiety symptoms in a nonclinical sample. Specifically, at the brain level, both L-allele homozygotes and S-allele carriers are similarly responsive to stress exposure. However, these brain responses seem to act as triggers of psychopathological symptoms in S-allele carriers, but as suppressors in L-allele homozygotes. This finding implies that the interpretation of the effect of gene by environment interaction on psychopathology seems more complicated than behavioral results alone would imply. It is not just differential sensitivity to stress, but rather different ways of coping with stress, which distinguish S-allele carriers and L-allele homozygotes.

Suppression mediates the effect of 5-HTTLPR by stress interaction on depression.

A number of studies have shown that the presence of short (S), as opposed to long (L), allele of the serotonin transporter-linked polymorphic region (5-HTTLPR) is associated with a higher risk for depression following exposure to stressful life events. However, many other studies failed to confirm this association. One reason for this inconsistency might be the fact that the interaction of the 5-HTTLPR polymorphism with stress may relate not to depression per se, but rather to adaptive or maladaptive emotion regulation strategies. Here we show that individuals homozygous for the long allele respond to stressful events by reappraising their emotional meaning, which may hamper the harmful effect of stress on mental health. In S genotype carriers, on the other hand, stress triggers the appearance of intrusive thoughts and vain attempts to suppress them, which in this group acts as a mediator between stress and depressive symptoms. These findings are in line with neuroimaging studies showing that 5-HTTLPR polymorphism has an effect on the connectivity among key areas involved in emotion regulation.