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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. [ABSTRACT FROM AUTHOR]

The universally conserved protein YidC aids in the insertion and folding of transmembrane polypeptides. Supposedly, a charged arginine faces its hydrophobic lipid core, facilitating polypeptide sliding along YidC's surface. How the membrane barrier to other molecules may be maintained is unclear. Here, we show that the purified and reconstituted E. coli YidC forms an ion-conducting transmembrane pore upon ribosome or ribosome-nascent chain complex (RNC) binding. In contrast to monomeric YidC structures, an AlphaFold parallel YidC dimer model harbors a pore. Experimental evidence for a dimeric assembly comes from our BN-PAGE analysis of native vesicles, fluorescence correlation spectroscopy studies, single-molecule fluorescence photobleaching observations, and crosslinking experiments. In the dimeric model, the conserved arginine and other residues interacting with nascent chains point into the putative pore. This result suggests the possibility of a YidC-assisted insertion mode alternative to the insertase mechanism. [ABSTRACT FROM AUTHOR]

The grounds for identifying the Eboraciceras subordinarium Zone in the Upper Callovian of Siberia are critically discussed. The key sections of this zone and the ammonite assemblage that characterizes it are examined in detail. It is concluded that it is impossible to recognize the Eboraciceras subordinarium Zone and its further use in stratigraphic schemes is not suggested. North Siberian taxa, previously identified as Late Callovian Eboraciceras, are mostly assigned to Rondiceras and indicate a Middle Callovian age of the host rocks. Beds with Cadoquenstedtoceras begichevi have been proposed as an approximate equivalent of the European Q. lamberti Zone in the Upper Callovian of Siberia. [ABSTRACT FROM AUTHOR]

The high propensity of protons to stay at interfaces has attracted much attention over the decades. It enables long-range interfacial proton diffusion without relying on titratable residues or electrostatic attraction. As a result, various phenomena manifest themselves, ranging from spillover in material sciences to local proton circuits between proton pumps and ATP synthases in bioenergetics. In an attempt to replace all existing theoretical and experimental insight into the origin of protons' preference for interfaces, TELP, the "Transmembrane Electrostatically-Localized Protons" hypothesis, has been proposed. The TELP hypothesis envisions static H+ and OH− layers on opposite sides of interfaces that are up to 75 µm thick. Yet, the separation at which the electrostatic interaction between two elementary charges is comparable in magnitude to the thermal energy is more than two orders of magnitude smaller and, as a result, the H+ and OH− layers cannot mutually stabilize each other, rendering proton accumulation at the interface energetically unfavorable. We show that (i) the law of electroneutrality, (ii) Fick's law of diffusion, and (iii) Coulomb's law prevail. Using them does not hinder but helps to interpret previously published experimental results, and also helps us understand the high entropy release barrier enabling long-range proton diffusion along the membrane surface. [ABSTRACT FROM AUTHOR]

The taxonomic composition of the ammonite family Cardioceratidae is studied in the Bathonian of northern Siberia in the range of distribution of the last representatives of the genus Arcticoceras and the first representatives of the genus Catacadoceras, aiming to solve the problem of the Middle-Upper Bathonian boundary. It is shown that all previous identifications of northern Siberian material as the Middle Bathonian species Arcticoceras cranocephaloide Callomon et Birkelund, 1985, were incorrect. The misidentified specimens were mainly the Late Bathonian ammonite species Catacadoceras barnstoni (Meek, 1859) or the form with a narrow umbilicus referred to herein as Cat. aff. barnstoni. An updated ammonite zonal scale of the Middle–Upper Bathonian of Siberia is proposed, which is recommended for use both in the regional stratigraphic schemes of the Jurassic deposits of Eastern (Middle) Siberia and in the Boreal (Siberian) zonal standard of the Bathonian Stage. The extreme importance of preserving an auxiliary biostratigraphic subdivision in this scale, the Cat. barnstoni Beds, is emphasized, because of the wide distribution and abundance of the index species in Siberian sections, as well as its significance for the correlation of the lower part of the Upper Bathonian of northern Canada, northern Siberia, Franz Josef Land, and East Greenland. In addition, two intervals, i.e., the interval with Cat. aff. barnstoni and interval with Cat. perrarum, are fixed as marker levels, which are useful for rapid age determination and correlation of the Upper Bathonian deposits in Arctic sections within the upper part of the Cat. barnstoni Beds. [ABSTRACT FROM AUTHOR]

The aim of the research was to study the effect of depression, anxiety, and rumination scores on the balance of activity of the default mode network and attention networks revealed in the resting state EEG records. Forty-five healthy volunteers (24 men aged from 18 to 25 years) participated in the resting state EEG recording. The participants filled in the Beck Depression Inventory-II (BDI II), Ruminative Responses Scale, and Eysenck Personality Profiler. The connectivity measures of resting state networks were calculated in EEG data. The networks were detected by the "seed" method. The effects of depressive symptoms, anxiety, and rumination on the connectivity of the networks were analyzed by the regression method. The depressive symptom scores and the rumination scores were correlated with the dominance of the default mode network over attention networks in the right temporal cortex. The depression scores and the anxiety scores were correlated with the dominance of attention networks over the default mode network in the anterior cingulate cortex. It could be suggested that rumination processes are specific for depressive symptoms and are reflected in the dominance of the default mode network in brain structures associated with the processing of emotional introspection. Common to depressive and anxious symptoms is a state of alertness, which is reflected in the dominance of attention networks in brain structures associated with decision-making. [ABSTRACT FROM AUTHOR]

The study of Callovian ammonites Longaeviceras and closely related taxa from the east coast of Anabar Bay (section 109, northern Siberia) is presented. Genera and species previously unknown here, such as Rondiceras milaschevici, Pseudolongaeviceras densicostatum gen. et sp. nov., Platylongoceras holtedahli, and Pseudocadoceras laminatum, are identified. The presence of the Eboraciceras subordinarium Zone in the studied section is not confirmed. The division of genus Longaeviceras into Longoceras and Longaeviceras (including subgenus Soaniceras) is discussed. According to Cardioceras maltonense found in the upper part of the section studied, the age of the Oxfordian beds is defined more accurately. [ABSTRACT FROM AUTHOR]

A list and short description of the middle Callovian cardioceratid genera from Northern Siberia are given. These are Rondiceras and Stenocadoceras with specified diagnosis and also Bryocadoceras and Streptocadoceras, which were described earlier as subgenera of Cadoceras Fischer. The middle Callovian of Northern Siberia (section 503 at Bolshoy Begichev Island) is divided into the lower Rondiceras milaschevici, Protolongaeviceras arcticoides Zone (as the equivalent of the Kosmoceras jason Zone) and the upper Rondiceras nikolaevi, Stenocadoceras stenoloboide Zone (as the equivalent of the Erymnoceras coronatum Zone). [ABSTRACT FROM AUTHOR]

The bacterial channel SecYEG effciently translocates both hydrophobic and hydrophilic proteins across the plasma membrane. Translocating polypeptide chains may dislodge the plug, a half helix that blocks the permeation of small molecules, from its position in the middle of the aqueous translocation channel. Instead of the plug, six isoleucines in the middle of the membrane supposedly seal the channel, by forming a gasket around the translocating polypeptide. However, this hypothesis does not explain how the tightness of the gasket may depend on membrane potential. Here, we demonstrate voltage-dependent closings of the purified and reconstituted channel in the presence of ligands, suggesting that voltage sensitivity may be conferred by motor protein SecA, ribosomes, signal peptides, and/or translocating peptides. Yet, the presence of a voltage sensor intrinsic to SecYEG was indicated by voltage driven closure of pores that were forced-open either by crosslinking the plug to SecE or by plug deletion. We tested the involvement of SecY's half-helix 2b (TM2b) in voltage sensing, since clearly identifiable gating charges are missing. The mutation L80D accelerated voltage driven closings by reversing TM2b's dipolar orientation. In contrast, the L80K mutation decelerated voltage induced closings by increasing TM2b's dipole moment. The observations suggest that TM2b is part of a larger voltage sensor. By partly aligning the combined dipole of this sensor with the orientation of the membrane-spanning electric field, voltage may drive channel closure. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This review focusses on the energetics of protein translocation via the Sec translocation machinery. First we complement structural data about SecYEG's conformational rearrangements by insight obtained from functional assays. These include measurements of SecYEG permeability that allow assessment of channel gating by ligand binding and membrane voltage. Second we will discuss the power stroke and Brownian ratcheting models of substrate translocation and the role that the two models assign to the putative driving forces: (i) ATP (SecA) and GTP (ribosome) hydrolysis, (ii) interaction with accessory proteins, (iii) membrane partitioning and folding, (iv) proton motive force (PMF), and (v) entropic contributions. Our analysis underlines how important energized membranes are for unravelling the translocation mechanism in future experiments. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The association of personality with resting state networks has been investigated in the mature brain, but its development has not been investigated, particularly in longitudinal design. Besides, all existing evidence is obtained using functional magnetic resonance imaging and there are no data on electrophysiological underpinning of these associations. We have acquired three yearly recordings of resting state EEG data in primary school children. Parental ratings of child's personality were obtained in the third wave. Seed-based oscillatory power envelope correlation analysis in conjunction with beamformer spatial filtering were used to obtain electrophysiological signatures of the default mode network (DMN) associated with self-referential processing and the central executive network (CEN) related to the control of attention. Analysis showed that in alpha frequency band, developmental changes in the balance between DMN and CEN in frontal cortical regions involved in the representation of affective value of primary reinforcers predict parental ratings of positive personality traits captured by the general factor of personality. Latent growth curve modeling showed that relative increase of outward directed attention associated with CEN in the first school year underlies the development of positive personality traits during this developmental stage. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Summary Objectives Depression is one of the most prevalent mental illnesses and is associated with changes in emotion processing. The aim of this study was to determine the influence of depressive symptoms on EEG oscillatory dynamics accompanying implicit processing of angry and happy facial expressions in 46 healthy subjects. Methods The Beck Depression Inventory was used to assess the presence of depressive symptoms in normal subjects. During the experiment, they were told to categorize the gender of angry, neutral, or happy faces presented to them, while high-resolution EEG was recorded. Analysis of the event-related spectral perturbations and the analysis of dipoles were carried out on EEG recordings using the EEGLAB toolbox. Results High depression (HD) and low depression (LD) groups did not differ on error rate and reaction time during categorization of gender. The perception of happy faces was accompanied by higher theta synchronization in the LD than the HD group. In contrast, theta synchronization was higher in the HD than the LD group during perception of angry faces. Conclusion These findings imply that even at preclinical stages, HD scorers evidence increased emotional arousal to negative and decreased emotional arousal to positive stimuli during implicit emotion processing. [ABSTRACT FROM AUTHOR]

Some studies show that effects of risk factors for depression, such as neuroticism, stress, and maladaptive emotion regulation, are less pronounced in collectivistic Eastern than in individualistic Western cultures. The effect of individual patterns of endorsement of individualist and collectivist attitudes on mental health outcomes is more difficult to predict in diverse cultures, such as Russia, which traditionally combines Western and Eastern values. In this study, data on depressive symptoms, personality, stress level, emotion regulation strategies, and individualist/collectivist orientation were collected in a nonclinical Russian sample and structural equation modeling was used to assess the impact of cultural attitudes on the association between depression and the vulnerability factors. In sharp contrast with effects reported in collectivist East Asian cultures, collectivistic orientation appeared to increase the impact of stress and neuroticism on depression. This evidence highlights the necessity of a more nuanced approach to the study of cultural dimensions, such as individualism/collectivism, taking into account substantial between-culture differences in the nature of these constructs. [ABSTRACT FROM AUTHOR]

Introduction: Functional magnetic resonance imaging studies have shown changes in the activity of medial prefrontal, medial temporal, and occipital regions in major depressive disorder patients during recall of autobiographical memories. Electrophysiological underpinning of these changes is not known. It is also not clear whether they are a part of the clinical picture or appear at preclinical stages in individuals predisposed to depression. Method: In this study, the effect of depressive symptoms, as measured by the Beck Depression Inventory (BDI–II), on oscillatory dynamics accompanying retrieval of emotionally positive and negative autobiographical memories was investigated in a nonclinical sample using electroencephalographic event-related spectral power and connectivity measures. Results: Psychometric results showed that BDI scores correlated positively with the strength of negative emotion, vividness of negative memories, and their importance for participant’s life. In high BDI scorers, low-frequency synchronization, which is frequently used as a marker of emotional arousal, prevailed in negative episodes, whereas in low BDI scorers it prevailed in positive episodes. sLORETA localized sources of this synchronization in the medial prefrontal cortex. In negative episodes, depressive symptoms were associated with a diminished event-related connectivity in the alpha band in posterior regions and increased connectivity in beta and gamma bands in frontal regions. Conclusions: Overall, these results show that even at preclinical stages, depressive symptoms are associated with changes in electrophysiological processes accompanying retrieval of autobiographical memories. [ABSTRACT FROM PUBLISHER]

Resting state networks’ (RSNs) architecture is well delineated in mature brain, but our understanding of their development remains limited. Particularly, there are few longitudinal studies. Besides, all existing evidence is obtained using functional magnetic resonance imaging (fMRI) and there are no data on electrophysiological correlates of RSN maturation. We acquired three yearly waves of resting state EEG data in 80 children between 7 and 9 years and in 55 adults. Children’s parents filled in the Effortful Control (EC) scale. Seed-based oscillatory power envelope correlation in conjunction with beamformer spatial filtering was used to obtain electrophysiological signatures of the default mode network (DMN) and two task-positive networks (TPN). In line with existing fMRI evidence, both cross-sectional comparison with adults and longitudinal analysis showed that the general pattern of maturation consisted in an increase in long-distance connections with posterior cortical regions and a decrease in short connections within prefrontal cortical areas. Latent growth curve analysis showed that EC scores were predicted by a linear increase over time in DMN integrity in alpha band and an increase in the segregation between DMN and TPN in beta band. These data confirm the neural basis of observed in fMRI research maturation-related changes and show that integrity of the DMN and sufficient level of segregation between DMN and TPN is a prerequisite for appropriate attentional and behavioral control. [ABSTRACT FROM AUTHOR]

Although anxiety and depression frequently co-occur and share a substantial part of genetic vulnerability and other risk factors, they are distinct disorders and their effect on social functioning and accompanying cognitive and emotional processing could be different. In this study, in a nonclinical sample, we compared effects of trait anxiety and depressive symptoms on oscillatory dynamics accompanying perception of emotional facial expressions in the context of social interactions. Anxiety was associated with a longer reaction time, with preference of avoidance behavior, and with enhanced event-related alpha desynchronization and diminished theta synchronization. Depression did not show significant behavioral effects and was associated with diminished alpha desynchronization and augmented delta and theta synchronization in prefrontal cortical regions. Thus, in spite of frequent comorbidity, anxiety and depression show opposite patterns of associations with oscillatory dynamics accompanying social interactions. These patterns imply that anxiety is associated with hyper-reactive attentional system, whereas depression show signs of diminished cognitive reactivity. Depression-related enhancement of low-frequency synchronization in prefrontal cortex may reflect a compensatory mechanism of cognitive and emotional upregulation, which depression-prone individuals engage in the process of social interactions. [ABSTRACT FROM AUTHOR]

Major Depressive Disorder (MDD) has been associated with predominance of the default-mode network (DMN) over the task-positive network (TPN), which is considered a neurobiological base for ruminative responding. It is not known whether this predominance is a signature of the full-blown MDD or it already exists at preclinical stages. Besides, all relevant evidence has been obtained using fMRI, which allows for a precise spatial characterization of resting state networks (RSNs), but their neural correlates remain elusive. Here we show that after leakage correction of beamformer-projected resting EEG time series, seed-based oscillatory-power envelope correlation analysis allows revealing RSNs with significant similarity to respective fMRI RSNs. In a non-clinical sample, depressive symptoms, as measured by the Beck Depression Inventory, are associated with predominance of DMN over TPN connectivity in the right insula and the right temporal lobe in the delta frequency band. These findings imply that in individuals with heightened level of depressive symptoms, emotional circuits are stronger connected with DMN than TPN and should be more easily engaged in self-referential rumination than in responding to environmental challenges. The study’s findings are in agreement with fMRI evidence, thus confirming the neural base of the observed in fMRI research effects and showing that implicated in depression neural mechanism may already be in action even at preclinical stages. [ABSTRACT FROM AUTHOR]

The role of emotion in moral decision-making is still a matter of debate. Greene, Sommerville, Nystrom, Darley, and Cohen (2001) argue that ‘personal’ moral judgments are driven by emotional responses, while ‘impersonal’ judgments are largely driven by cognitive processes. In this study, oscillatory correlates of decision-making were compared in moral personal, moral impersonal, and nonmoral conditions, as well as in trials associated with utilitarian (i.e., favoring the ‘greater good’ over individual rights) and non-utilitarian choices. Event-related synchronization in delta and theta bands was greater in the right temporal lobe in personal than in both nonmoral and impersonal moral condition. Graph-theoretical analysis of connectivity patterns showed the prominent role of the orbitofrontal and cingulate cortices in personal moral decision-making, implying greater emotional and self-processing. Higher conscientiousness and intellect and lower behavioral activation were associated with greater difference in oscillatory responses between utilitarian and non-utilitarian choices in personal than in impersonal condition, indicating that sensitivity to moral issues and the ability to grasp the nuances of moral situation are essential for understanding the implications of utilitarian choices in personal and impersonal conditions. [ABSTRACT FROM PUBLISHER]

The neural efficiency theory was formulated in the field of intelligence research and it posits that better performers require less brain activity to successfully perform a task of a given difficulty level. Here we suggest that in the field of personality research, the neural efficiency concept could be reformulated so that habitual behavior requires less brain activity. To test this hypothesis, 46 participants were presented with a social interactions task, in which they had to choose one out of three ways of interaction with a virtual ‘person’: ‘attack’, ‘avoid’, or ‘make friends’, while EEG was recorded simultaneously. Personality was assessed using the Eysenck Personality Profiler. Extraverts made more friendly choices and these choices were accompanied by smaller event-related theta synchronization in the left prefrontal cortex. Neuroticism did not show significant behavioral effects, but in high neuroticism scorers, the choice of avoidance was accompanied by smaller theta synchronization in the right prefrontal cortex. Psychoticism was positively associated with the number of aggressive choices and in high psychoticism scorers, these choices were accompanied by smaller theta synchronization in the left precentral cortex. These results are consistent with the extension of the neural efficiency concept for personality. [ABSTRACT FROM AUTHOR]

Depression, one of the most widespread mental disorders, is associated with considerable alterations in emotional functioning. It is unclear whether these alterations are associated with clinical depression or exist already at preclinical stages. Here, in clinically healthy individuals, a combination of neuroticism and introversion was used as a predisposition to depression (PD) scale. Participants were presented with pictures of emotional facial expressions and performed the gender discrimination task, while their electroencephalogram (EEG) was recorded. The affective processing bias (i.e., longer reaction time and higher error rate for angry faces) was found in low, but not in high PD scorers. High PD scorers also showed reduced theta synchronization and enhanced alpha desynchronization in the test interval and higher delta and theta power in the interstimuli interval. The latter effect implies that activity of emotional circuits, which is mirrored in low-frequency oscillations, is tonically increased in predisposed-to-depression individuals, thus precluding an adequate response to external emotional cues. This results in unspecific general activation reflected in enhanced alpha desynchronization and in disrupted ability to differentiate incoming emotional information. [ABSTRACT FROM AUTHOR]

To better understand age-related differences in brain function and behavior, connectivity between brain regions was estimated from electroencephalogram source time series in eyes closed versus eyes open resting condition. In beta band, decrease of connectivity upon eyes opening was more pronounced in younger than in older participants. The extent of this decrease was associated with reaction time in attention tasks, and this relationship was fully mediated by participants' age, implying that physiological processes, which lead to age-related slowing, include changes in beta reactivity. Graph-theoretical analysis showed a decrease of modularity and clustering in beta and gamma band networks in older adults, implying that age makes brain networks more random. The overall number of nodes identified as hubs in posterior cortical regions decreased in older participants. At the same time, increase of connectedness of anterior nodes, probably reflecting compensatory activation of the anterior attentional system, was observed in beta-band network of older adults. These findings show that normal aging mostly affects interactions in beta band, which are probably involved in attentional processes. [ABSTRACT FROM AUTHOR]

Recollection of events from one's own life is referred to as autobiographical memory. Autobiographical memory is an important part of our self. Neuroimaging findings link self-referential processes with the default mode network (DMN). Much evidence coming primarily from functional magnetic resonance imaging studies shows that autobiographical memory and DMN have a common neural base. In this study, electroencephalographic data collected in 47 participants during recollection of autobiographical episodes were analyzed using temporal and spatial independent component analyses in combination with source localization. Autobiographical remembering was associated with an increase of spectral power in alpha and beta and a decrease in delta band. The increase of alpha power, as estimated by sLORETA, was most prominent in the posterior DMN, but was also observed in visual and motor cortices, prompting an assumption that it is associated with activation of DMN and inhibition of irrelevant sensory and motor areas. In line with data linking delta oscillations with aversive states, decrease of delta power was more pronounced in episodes associated with positive emotions, whereas episodes associated with negative emotions were accompanied by an increase of delta power. Vividness of recollection correlated positively with theta oscillations. These results highlight the leading role of alpha oscillations and the DMN in the processes accompanying autobiographical remembering. [ABSTRACT FROM AUTHOR]

While engaged in protein transport, the bacterial translocon SecYEG must maintain the membrane barrier to small ions. The preservation of the proton motif force was attributed to (i) cation exclusion, (ii) engulfment of the nascent chain by the hydrophobic pore ring, and (iii) a half-helix partly plugging the channel. In contrast, we show here that preservation of the proton motif force is due to a voltage-driven conformational change. Preprotein or signal peptide binding to the purified and reconstituted SecYEG results in large cation and anion conductivities only when the membrane potential is small. Physiological values of membrane potential close the activated channel. This voltage- dependent closure is not dependent on the presence of the plug domain and is not affected by mutation of 3 of the 6 constriction residues to glycines. Cellular ion homeostasis is not challenged by the small remaining leak conductance. [ABSTRACT FROM AUTHOR]

Highlights: [•] Spatial independent component analysis (ICA) of back-reconstructed EEG data correctly finds localization of sources. [•] This method is straightforward for comparison of EEG and fMRI data. [•] For temporally correlated sources this method performs better than temporal ICA. [ABSTRACT FROM AUTHOR]

In co-translational translocation, the ribosome funnel and the channel of the protein translocation complex SecYEG are aligned. For the nascent chain to enter the channel immediately after synthesis, a yet unidentified signal triggers displacement of the SecYEG sealing plug from the pore. Here, we show that ribosome binding to the resting SecYEG channel triggers this conformational transition. The purified and reconstituted SecYEG channel opens to form a large ion-conducting channel, which has the conductivity of the plug deletion mutant. The number of ion-conducting channels inserted into the planar bilayer per fusion event roughly equals the number of SecYEG channels counted by fluorescence correlation spectroscopy in a single proteoliposome. Thus, the open probability of the channel must be close to unity. To prevent the otherwise lethal proton leak, a closed post-translational conformation of the SecYEG complex bound to a ribosome must exist. [ABSTRACT FROM AUTHOR]

Abstract: In this study we sought to investigate cortical oscillatory dynamics accompanying three major kinds of social behavior: aggressive, friendly, and avoidant. Behavioral and EEG data were collected in 48 participants during a computer game modeling social interactions with virtual ‘persons’. 3D source reconstruction and independent component analysis were applied to EEG data. Results showed that social behavior was partly reactive and partly proactive with subject''s personality playing an important role in shaping this behavior. Most salient differences were found between avoidance and approach behaviors, whereas the two kinds of approach behavior (i.e., aggression and friendship) did not differ from each other. Comparative to avoidance, approach behaviors were associated with higher induced responses in most frequency bands which were mostly observed in cortical areas overlapping with the default mode network. The difference between approach- and avoidance-related oscillatory dynamics was more salient in subjects predisposed to approach behaviors (i.e., in aggressive or sociable subjects) and was less pronounced in subjects predisposed to avoidance behavior (i.e., in high trait anxiety scorers). There was a trend to higher low frequency phase-locking in motor area in approach than in avoid condition. Results are discussed in light of the concept linking induced responses with top-down and evoked responses with bottom-up processes. [Copyright &y& Elsevier]

Abstract: The default mode network (DMN) has been mostly investigated using positron emission tomography and functional magnetic resonance imaging (fMRI) and has received mixed support in electroencephalographic (EEG) studies. In this study, after sLORETA transformation of EEG data, we applied group spatial independent component analysis which is routinely used in fMRI research. In three large and diverse samples coming from two different cultures (Russian and Taiwanese), spontaneous EEG data and retrospective questionnaire measures of subject''s state, thoughts, and feelings during the EEG registration were collected. Regression analyses showed that appearance of spontaneous self-referential thoughts was best predicted by enhanced alpha activity within the DMN. Diminished theta and delta activity in the superior frontal gyrus and enhanced beta activity in the postcentral gyrus added to the prediction. The enhanced alpha activity prevailed in the posterior DMN hub in Russian, but in the anterior DMN hub in Taiwanese participants. Possible cross-cultural differences in personality and attitudes underlying this difference are discussed. [Copyright &y& Elsevier]

Fast lateral proton migration along membranes is of vital importance for cellular energy homeostasis and various proton-coupled transport processes. It can only occur if attractive forces keep the proton at the interface. How to reconcile this high affinity to the membrane surface with high proton mobility is unclear. Here, we tested whether a minimalistic model interface between an apolar hydrophobic phase (n-decane) and an aqueous phase mimics the biological pathway for lateral proton migration. The observed diffusion span, on the order of tens of micrometers, and the high proton mobility were both similar to the values previously reported for lipid bilayers. Extensive ab initio simulations on the same water/n-decane interface reproduced the experimentally derived free energy barrier for the excess proton. The free energy profile GH+ adopts the shape of a well at the interface, having a width of two water molecules and a depth of 6 ± 2RT. The hydroniums in direct contact with n-decane have a reduced mobility. However, the hydroniums in the second layer of water molecules are mobile. Their in silico diffusion coefficient matches that derived from our in vitro experiments, (5.7 ±0.7) x 10-5 cm2 s-1. Conceivably, these are the protons that allow for fast diffusion along biological membranes. [ABSTRACT FROM AUTHOR]

Knyazev, G. G., Barchard, K. A., Razumnikova, O. M. & Mitrofanova, L.G. (2012). The relationship of positive and negative expressiveness to the processing of emotion information. Scandinavian Journal of Psychology 53, 206-215. The tendency to express emotions non-verbally is positively related to perception of emotions in oneself. This study examined its relationship to perception of emotions in others. In 40 healthy adults, EEG theta synchronization was used to indicate emotion processing following presentation of happy, angry, and neutral faces. Both positive and negative expressiveness were associated with higher emotional sensitivity, as shown by cortical responses to facial expressions during the early, unconscious processing stage. At the late, conscious processing stage, positive expressiveness was associated with higher sensitivity to happy faces but lower sensitivity to angry faces. Thus, positive expressiveness predisposes people to allocate fewer attentional resources for conscious perception of angry faces. In contrast, negative expressiveness was consistently associated with higher sensitivity. The effects of positive expressiveness occurred in cortical areas that deal with emotions, but the effects of negative expressiveness occurred in areas engaged in self-referential processes in the context of social relationships. [ABSTRACT FROM AUTHOR]

Abstract: Several studies show that the fronto-posterior EEG spectral power gradient is a stable individual characteristic related to personality. Whether this characteristic is specifically related to agentic extraversion and theta band of frequencies or is associated with a broader set of personality traits and frequency bands is a matter of debate, as well as the specific cortical regions contributing to this effect. To clarify these questions, we used group independent component analysis (ICA) and source localization techniques. Agentic extraversion was associated with higher theta activity in the default mode network''s (DMN) posterior hub and lower theta activity in the orbitofrontal cortex (OFC). Regression analyses showed that theta activity predicted agentic extraversion better than other frequency bands and agentic extraversion predicted posterior versus frontal activity better than other personality dimensions. These results are taken to indicate higher tonic activity in OFC and lower activity in DMN in extraverts as compared to introverts. [Copyright &y& Elsevier]

Abstract: Functional significance of delta oscillations is not fully understood. One way to approach this question would be from an evolutionary perspective. Delta oscillations dominate the EEG of waking reptiles. In humans, they are prominent only in early developmental stages and during slow-wave sleep. Increase of delta power has been documented in a wide array of developmental disorders and pathological conditions. Considerable evidence on the association between delta waves and autonomic and metabolic processes hints that they may be involved in integration of cerebral activity with homeostatic processes. Much evidence suggests the involvement of delta oscillations in motivation. They increase during hunger, sexual arousal, and in substance users. They also increase during panic attacks and sustained pain. In cognitive domain, they are implicated in attention, salience detection, and subliminal perception. This evidence shows that delta oscillations are associated with evolutionary old basic processes, which in waking adults are overshadowed by more advanced processes associated with higher frequency oscillations. The former processes rise in activity, however, when the latter are dysfunctional. [Copyright &y& Elsevier]

Abstract: The default mode network (DMN) has been principally investigated using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) and has received mixed support in electroencephalographic (EEG) studies. In particular, the existing evidence is too inconsistent to allow formulation of specific hypotheses linking DMN activity to traditional EEG frequency bands. In this study, we aimed to test whether blind decomposition methods are able to identify in EEG data spatial patterns resembling the DMN as it is described in PET and fMRI studies. Further we aimed to test a degree of task-relatedness of DMN patterns identified in the traditional EEG frequency bands. To answer these questions we collected data both in a resting state and during performance of two experimental tasks: an explicit judgment of facial affect and a social game task. Individual differences in amount of self-referential thoughts during the resting state were measured by a short self-report scale. Only alpha band spatial patterns simultaneously showed a considerable overlap with the DMN and high correlations with presumptive DMN function-related outcomes both in the resting state and during the social game task. Spontaneous self-referential thoughts were associated with enhanced alpha activity in the posterior DMN hub, whereas processing of DMN function-related external stimuli disrupted this activity and simultaneously caused partial alpha phase-locking to external events. This evidence implies that synchronization of internal mental processes, as opposed to the processing of external stimuli, might be the primary function of alpha oscillations which is bound to be related to activity of the DMN. [Copyright &y& Elsevier]

Abstract: In recent studies, statistical relations among activities in different frequency EEG bands have been reported. Most of these studies investigate within-subject cross-frequency relations, such as amplitude–amplitude, phase–amplitude and phase–phase coupling between different frequencies. All these cross-frequency interactions are considered to be transient correlates of information processing. However, some authors suggested that a particular pattern of amplitude–amplitude relations among different frequencies may be associated with relatively stable states or even traits. Particularly delta–beta amplitude–amplitude correlation measured in the between-subject domain was shown to lawfully increase in some presumably anxiogenic conditions and in some pathological groups. The main purpose of this paper was to further explore the phenomenon of between-subject delta–beta correlation in terms of its spatial localization, relatedness to state anxiety, and similarity to within-subject amplitude-to-amplitude and phase-to-amplitude coupling. Independent component analysis was used to identify temporally correlated spatial patterns that most reliably show the phenomenon of between-subject delta–beta correlation. Results of this analysis show that in an anxiogenic situation, delta–beta correlation increases in a network of cortical areas which includes the orbitofrontal and the anterior cingulate cortices as its main node. This increase of correlation is accompanied by an increase of delta power and connectivity in the same cortical regions. Analysis of the within-subject delta–beta amplitude-to-amplitude and phase-to-amplitude coupling showed that in an anxiogenic situation, in subjects with higher scores on state anxiety they also tend to increase in the same set of cortical areas. [Copyright &y& Elsevier]

Abstract: In this study, effects of interaction of anger with anxiety on the perception of emotional facial expressions and associated with this perception oscillatory dynamics of cortical responses elicited by presentation of angry, neutral, and happy faces were investigated. Subjects filled out the Buss–Perry aggression scales and the Spielberger’s State Trait Anxiety Inventory. Anxiety moderated the effect of anger both on estimates of angry and happy faces and on face presentation-related spectral perturbations. In the low anxiety group, anger scores were positively related to the extent of face presentation-related theta synchronization. In the high anxiety group this effect was not significant. The results are discussed in light of Corr’s “joint subsystems” hypothesis (). [ABSTRACT FROM AUTHOR]

Hostility is associated with biases in the perception of emotional facial expressions, such that ambiguous or neutral expressions tend to be perceived as threatening or angry. In this study, the effects of hostility and gender on the perception of angry, neutral, and happy faces and on the oscillatory dynamics of cortical responses elicited by these presentations were investigated using time–frequency decomposition by means of wavelet transforms. Feelings of hostility predisposed subjects to perceive happy and neutral faces as less friendly. This effect was more pronounced in women. In hostile subjects, presentation of emotional facial expressions also evoked stronger posterior synchronization in the theta and diminished desynchronization in the alpha band. This may signify a prevalence of emotional responding over cognitive processing. These effects were also more pronounced in females. Hostile females, but not hostile males, additionally showed a widespread synchronization in the alpha band. This synchronization is tentatively explained as a manifestation of inhibitory control which is present in aggressive females, but not in aggressive males. Aggr. Behav. 35:502–513, 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: General understanding in EEG research is that cortical distribution of spectral power varies as a function of time, frequency, state, and experimental condition. There are findings, however, which show that individual-specific patterns of cortical spectral power distribution could be amazingly stable, at least in some experimental conditions. In this study two different experimental datasets were used to analyze stability and variability of individual pattern of cortical spectral power distribution across time, experimental conditions, and frequency bands. First experiment consisted of presentation of pictures of emotional facial expressions. Second experiment was an auditory stop-signal task. In both experiments a number of psychometric measures were obtained from each participant. It has been shown that in spite of high short-term variability, individual-specific patterns of cortical spectral power distribution are remarkably stable across frequency bands, long periods of time, and experimental conditions. These patterns are related to state and trait participant''s characteristics. The antero-posterior spectral power gradient emerged as the most prominent feature associated with important personality dimensions. Relatively higher oscillatory activity in the frontal cortical region relates to female gender and Behavioral Inhibition tendencies. Relatively higher activity at posterior sites is associated with Extraversion. Significant differences in event-related spectral perturbations upon presentation of emotionally loaded stimuli were found between high and low antero-posterior gradient participants. These data show that cortical distribution of oscillatory activity may be seen as a relatively stable individual characteristic. Enhanced or diminished oscillatory activity of some cortical regions, such as the prefrontal cortex, may play an important role in organization of human behavior. [Copyright &y& Elsevier]

Abstract: In the last decade, event-related potential and functional magnetic resonance imaging studies were very useful in temporal and spatial localization of brain processes involved in the recognition of emotional facial expressions. However, frequency characteristics of the underlying processes have been less studied. Besides, most of the studies did not take into account personality-related individual differences. In this study, effects of explicit and implicit anxiety on the oscillatory dynamics of cortical responses elicited by presentation of angry, neutral, and happy faces were investigated using time-frequency decomposition by means of wavelet transform. Both explicit and implicit anxiety were associated with higher alpha band desynchronization, which was most pronounced during presentation of angry faces. Within theta and delta bands, effects appeared to be opposite for explicit and implicit anxiety measures. In implicitly anxious subjects, frontal delta and theta synchronization upon the presentation of angry and happy (but not neutral) faces was found to be higher than in low anxiety ones, whereas explicit anxiety was associated with a lower theta band synchronization. The results are discussed in terms of conscious and controlled vs. unconscious and intuitive information processing associated with explicit and implicit personality measures. [Copyright &y& Elsevier]

Abstract: There is much evidence to confirm the view that slow waves of delta and theta ranges are linked to activation whereas alpha oscillations are somehow related to inhibition processes. In the domain of individual differences, impulsive behavior is frequently associated with increased spectral power of slow oscillations whereas Behavioral Inhibition (BI) may be associated with higher reactivity within alpha band. Here it is hypothesized that Impulsivity would predispose to higher responding in low frequencies whereas BI would predispose to higher responding within alpha band. In a sample of 51 subjects, evoked and induced responses to auditory stimuli were studied in two experimental sessions: 1) in a simple discrimination task and 2) in a stop-signal task in which subjects had to be ready to withdraw the prepared motor response. Impulsive subjects showed higher baseline delta, theta and alpha power and higher magnitude of induced responses in low frequencies. They also showed lower phase-locking in low frequencies to auditory stimuli and higher phase-locking to the overt behavioral response onset. High BI scorers showed higher baseline alpha power and higher desynchronization in this frequency band in response to stimuli. The reported findings appear to support the idea that low frequency oscillations are associated with behavioral approach and alpha with behavioral inhibition tendencies but these associations are only valid for induced responses to stimuli. [Copyright &y& Elsevier]

Abstract: Personality-linked biases in perception of emotional facial expressions were investigated in a sample of 292 subjects aged 11 to 25 years who were presented with pictures of “angry”, “happy”, and “neutral” faces and were asked to rate each face in terms of its friendliness or hostility. The subjects also filled out a set of personality questionnaires. Behavioural Inhibition and trait anxiety predisposed to perception of all faces as more hostile. Similar effects were observed for BAS, anger, physical aggression, hostility and verbal aggression but in these cases the effect was only related to perception of female faces. Intellect, agreeableness and conscientiousness predisposed to perception of all faces as more friendly. For extraversion the same effect was significant only for “happy” faces. These findings show that personality may systematically influence the way people perceive facial expressions of other people. Specifically, anxiety and aggressiveness may predispose to exaggerate hostile intentions in other people. That may have an impact on everyday interpersonal relationships. [Copyright &y& Elsevier]

Abstract: Objective: It is not always clear whether inhibition or attention deficit underlies a failure to stop a prepared motor response. One possible way to approach this question is to resort to measures of evoked oscillations since functional correlates of different frequency oscillations are relatively well understood. Methods: The present study examined event-related oscillations during a stop-signal task in non-clinical adults. In 25% of trials of an auditory discrimination tasks subjects had to refrain from a prepared motor response. Results: In successful stop trials, the Go N2 peaked later and the Stop N2 peaked earlier than in failed stop trials. Relative to successful, failed stop trials were associated with a larger N1–N2 and Go P3, and a smaller Stop P3 in the central and posterior cortical regions. The latter effect was exclusively determined by evoked delta oscillations, whereas all other frequency bands contributed to enhanced responses in failed comparative to successful stop trials. Conclusions: The sum of presented evidence seems to show that success or failure to stop mostly depends on how the subject prepares for the Go and Stop stimuli in advance. If attention is more directed towards the Stop signal, the stopping succeeds, otherwise it fails. Significance: These data may contribute to understanding the cognitive basis of successful and unsuccessful stopping performance. [Copyright &y& Elsevier]

Abstract: Recent studies suggest brain oscillations as a mechanism for cerebral integration. Such integration can exist across a number of functional domains, with different frequency rhythms associated with each domain. Here, evidence is summarized which shows that delta oscillations depend on activity of motivational systems and participate in salience detection. Theta oscillations are involved in memory and emotional regulation. Alpha oscillations participate in inhibitory processes which contribute to a variety of cognitive operations such as attention and memory. The importance of inhibitory functions associated with alpha oscillations increases during the course of evolution. In ontogenesis, these functions develop later and may be more sensitive to a variety of detrimental environmental influences. In a number of developmental stages and pathological conditions, a deficient alpha and/or increased slow-wave activity are associated with cognitive deficits and a lack of inhibitory control. It is shown that slow-wave and alpha oscillations are reciprocally related to each other. This reciprocal relationship may reflect an inhibitory control over motivational and emotional drives which is implemented by the prefrontal cortex. [Copyright &y& Elsevier]

Abstract: A hypothesis was tested which predicts that individuals with high activity of Behavioural Approach System (BAS), as compared to individuals with low BAS activity, must experience higher emotional arousal in a reward and lower arousal in a punishment situation; the emotional arousal should reveal itself in increase of theta and high frequency oscillations (HFO) in cortical EEG and in increased coupling of these rhythms. Thirty-nine subjects were divided into two groups. One group was presented with reward, another one with punishment cues. The subjects also filled out the Carver and White’s BIS/BAS scales. In high Drive scorers, as compared to low Drive scorers, the increase of theta and HFO in the frontal cortical area was higher in the reward and lower in the punishment situation. Increase of theta–gamma coupling was shown in low Drive subjects in the punishment and in high Drive subjects in the reward situation. [Copyright &y& Elsevier]

Abstract: A hypothesis relating personality types to activity of the Behavioural Approach System (BAS) and the Behavioural Inhibition System (BIS) was tested in a sample of 1015 10–18-year-old adolescents. According to this hypothesis, Undercontrollers could be characterized as individuals with overactive BAS, Overcontrollers as individuals with overactive BIS, and Resilients as individuals with low activity of both systems. These predictions were generally confirmed. Psychometrically measured BAS and BIS appeared to be the strongest predictors of Undercontrolled and Overcontrolled prototypes, respectively. Resilients were characterized by low scores on both dimensions. [Copyright &y& Elsevier]

Abstract: Recent findings showing that anxiety is associated with enhanced coupling of EEG rhythms imply higher information exchange between populations of neurons associated with different oscillatory systems. In this study, influence of uncertainty on alpha–delta anticorrelation and delta–beta coupling was studied in 39 subjects (27 females) aged 19 to 30 years who also filled out the State Trait Anxiety Inventory. A measure of alpha–delta anticorrelation showed trait-like properties being uniformly higher in high trait anxiety subjects independent of experimental manipulation. Contrariwise, delta–beta coupling appeared only in anxiogenic situation both in high and low anxiety subjects. [Copyright &y& Elsevier]

Abstract: Although there is much evidence that alpha oscillations are linked with processes of perception, attention and semantic memory, their functional significance remains uncertain. Synchronization in the alpha frequency range is taken to be a marker of cognitive inactivity, active inhibition of sensory information, or a means of inhibition of non-task relevant cortical areas. Here we propose an alternative interpretation which posits that higher alpha power during reference interval signifies higher readiness of alpha system to information processing. Predictions derived from the inhibition and alertness hypotheses were tested during presentation of acoustic stimuli (tone 1000 Hz) and neutral words to 30 males (18–25 years) with different levels of trait anxiety. On the whole, predictions derived from the inhibition theory were not confirmed and findings more corresponded to the alertness hypothesis. High-anxiety subjects showed higher alpha power during reference interval simultaneously with higher magnitude of event-related desynchronization and higher amplitude of phase-locked alpha responses. These findings are discussed in terms of functional significance of alpha band synchronization and desynchronization. [Copyright &y& Elsevier]