Evaluation of PCA and ICA of simulated ERPs: Promax vs. Infomax rotations

Cognitive Control Moderates Associations Between Domains of Temperamental Reactivity and Preschoolers' Social Behaviors

Temperamental characteristics and emerging cognitive control are meaningful predictors of children's development of adaptive and maladaptive social behaviors during the preschool period. However, knowledge of the interplay of these pathways, when examined concurrently to highlight their individual contributions, is limited. Using a cross-sectional sample of 3-year-old children, we examined parent-reported discrete traits of negative (anger, fear, sadness, and shyness) and positive (low- and high-intensity pleasure) temperamental reactivity as predictors of children's prosociality and physical aggression. Further, we tested whether the effects of discrete temperament were moderated by cognitive control, as indexed by the N2 event-related potential, during a go/no-go task. Analyses focus on a subsample of children with an observable N2 (n = 66). When controlling for other relative temperament traits, several significant main effects emerged. Moreover, at low cognitive control (smaller N2), fear was negatively associated with aggression, whereas at high cognitive control, sadness was positively associated with aggression. Heightened anger was linked to reduced prosocial behavior when cognitive control was low but linked to greater prosocial behavior when cognitive control was high. The results highlight that discrete temperament traits predict individual differences in child outcomes but that associations depend on concurrent levels of cognitive control.

Combining recognition, conflict-monitoring and feedback-related ERPs to detect concealed autobiographical information

This study examined the neural signatures associated with conflict-monitoring, recognition and feedback processing in a feedback Concealed Information Test (fCIT), and also examined whether all the ERPs can be used to detect concealed autobiographical information. Participants were randomly assigned to one of two groups (guilty or innocent) and then tested in the fCIT while undergoing electroencephalograms (EEGs). The results showed that the probe (participants' name) elicited a more negative N200, and a more positive recognition P300 than irrelevants among guilty participants. Additionally, feedback following the probe elicited a larger feedback P300 than feedback following irrelevants. Further, we found that three indicators, including the conflict-monitoring N200, recognition P300, and feedback P300, could significantly discriminate between guilty and innocent participants, whereas the FRN could not. Combining them is highly effective in discriminating between guilty and innocent participants (AUC = 0.91). These findings not only shed light on the neural processing of the fCIT but also suggest the potential of using the fCIT to detect concealed autobiographical information.

Brain Evoked Response Qualification Using Multi-Set Consensus Clustering: Toward Single-Trial EEG Analysis

In event-related potential (ERP) analysis, it is commonly assumed that individual trials from a subject share similar properties and originate from comparable neural sources, allowing reliable interpretation of group-averages. Nevertheless, traditional group-level ERP analysis methods, including cluster analysis, often overlook critical information about individual subjects' neural processes due to using fixed measurement intervals derived from averaging. We developed a multi-set consensus clustering pipeline to examine cognitive processes at the individual subject level. Initially, consensus clustering from diverse methods was applied to single-trial EEG epochs of individual subjects. Subsequently, a second level of consensus clustering was performed across the trials of each subject. A newly modified time window determination method was then employed to identify individual subjects' ERP(s) of interest. We validated our method with simulated data for ERP components N2 and P3, and real data from a visual oddball task to confirm the P3 component. Our findings revealed that estimated time windows for individual subjects provide precise ERP identification compared to fixed time windows across all subjects. Additionally, Monte Carlo simulations with synthetic single-trial data demonstrated stable scores for the N2 and P3 components, confirming the reliability of our method. The proposed method enhances the examination of brain-evoked responses at the individual subject level by considering single-trial EEG data, thereby extracting mutual information relevant to the neural process. This approach offers a significant improvement over conventional ERP analysis, which relies on the averaging mechanism and fixed measurement interval.

Native language advantage in electrical brain responses to speech sound changes in passive and active listening condition

It is not clear whether the brain can detect changes in native and non-native speech sounds in both unattended and attended conditions, but this information would be important to understand the nature of potential native language advantage in speech perception. We recorded event-related potentials (ERPs) for changes in duration and in Chinese lexical tone in a repeated vowel /a/ in native speakers of Finnish and Chinese in passive and active listening conditions. ERP amplitudes reflecting deviance detection (mismatch negativity; MMN and N2b) and attentional shifts towards changes in speech sounds (P3a and P3b) were investigated. In the passive listening condition, duration changes elicited increased amplitude in the MMN latency window for both standard and deviant sounds in the Finnish speakers compared to the Chinese speakers, but no group differences were observed for P3a. In passive listening to lexical tones, P3a was increased in amplitude for both standard and deviant stimuli in Chinese speakers compared to Finnish speakers, but the groups did not differ in MMN. In active listening, both tone and duration changes elicited N2b and P3b, but the groups differed only in pattern of results for the deviant type. The results thus suggest an overall increased sensitivity to native speech sounds, especially in passive listening, while the mechanisms of change detection and attentional shifting seem to work well for both native and non-native speech sounds in the attentive mode.

Interpretable single-cell factor decomposition using sciRED

Single-cell RNA sequencing (scRNA-seq) maps gene expression heterogeneity within a tissue. However, identifying biological signals in this data is challenging due to confounding technical factors, sparsity, and high dimensionality. Data factorization methods address this by separating and identifying signals in the data, such as gene expression programs, but the resulting factors must be manually interpreted. We developed Single-Cell Interpretable Residual Decomposition (sciRED) to improve the interpretation of scRNA-seq factor analysis. sciRED removes known confounding effects, uses rotations to improve factor interpretability, maps factors to known covariates, identifies unexplained factors that may capture hidden biological phenomena and determines the genes and biological processes represented by the resulting factors. We apply sciRED to multiple scRNA-seq datasets and identify sex-specific variation in a kidney map, discern strong and weak immune stimulation signals in a PBMC dataset, reduce ambient RNA contamination in a rat liver atlas to help identify strain variation, and reveal rare cell type signatures and anatomical zonation gene programs in a healthy human liver map. These demonstrate that sciRED is useful in characterizing diverse biological signals within scRNA-seq data.

Interpretable single-cell factor decomposition using sciRED

Single-cell RNA sequencing (scRNA-seq) maps gene expression heterogeneity within a tissue. However, identifying biological signals in this data is challenging due to confounding technical factors, sparsity, and high dimensionality. Data factorization methods address this by separating and identifying signals in the data, such as gene expression programs, but the resulting factors must be manually interpreted. We developed Single-Cell Interpretable Residual Decomposition (sciRED) to improve the interpretation of scRNA-seq factor analysis. sciRED removes known confounding effects, uses rotations to improve factor interpretability, maps factors to known covariates, identifies unexplained factors that may capture hidden biological phenomena and determines the genes and biological processes represented by the resulting factors. We apply sciRED to multiple scRNA-seq datasets and identify sex-specific variation in a kidney map, discern strong and weak immune stimulation signals in a PBMC dataset, reduce ambient RNA contamination in a rat liver atlas to help identify strain variation, and reveal rare cell type signatures and anatomical zonation gene programs in a healthy human liver map. These demonstrate that sciRED is useful in characterizing diverse biological signals within scRNA-seq data.

Neural Signals Associated with Orienting Response and Arousal Inhibition in Concealed Information Test

Recent theory suggests that both the orienting response and arousal inhibition play roles in the effect of the concealed information test (CIT). However, the neural signatures associated with these two processes remain unclear. To address this issue, participants were motivated to either conceal or reveal crime-related stimulus during CIT while EEG was recorded. By using a temporal principal component analysis, we found that crime-related stimuli produced a larger early P3 than crime-irrelevant stimuli in both the conceal condition and reveal condition. This result suggests that this early P3 reflects an orienting response. In addition, we found that crime-related stimuli elicited a larger frontal negative slow wave than crime-irrelevant stimuli in the conceal condition but not the reveal condition, which suggests that the frontal negative slow wave reflects the arousal inhibition process. These results provide crucial evidence for understanding the neural basis underlying CIT.

Linking social reward responsiveness and affective responses to the social environment: An ecological momentary assessment study

Social support is a key predictor of well-being, but not everyone experiences mental health benefits from receiving it. However, given that a growing number of interventions are based on social support, it is crucial to identify the features that make individuals more likely to benefit from social ties. Emerging evidence suggests that neural responses to positive social feedback (i.e., social reward) might relate to individual differences in social functioning, but potential mechanisms linking these neural responses to psychological outcomes are yet unclear. This study examined whether neural correlates of social reward processing, indexed by the reward positivity (RewP), relate to individuals' affective experience following self-reported real-world positive social support events. To this aim, 193 university students (71% females) underwent an EEG assessment during the Island Getaway task and completed a 10-day ecological momentary assessment where participants reported their positive and negative affects (PA, NA) nine times a day and the count of daily positive and negative events. Experiencing a higher number of social support positive events was associated with higher PA. The RewP moderated this association, such that individuals with greater neural response to social feedback at baseline had a stronger positive association between social support positive events count and PA. Individual differences in the RewP to social feedback might be one indicator of the likelihood of experiencing positive affect when receiving social support.

Analysis of modulations of mental fatigue on intra-individual variability from single-trial event related potentials

BACKGROUND

Intra-individual variability (IIV), a measure of variance within an individual's performance, has been demonstrated as metrics of brain responses for neural functionality. However, how mental fatigue modulates IIV remains unclear. Consequently, the development of robust mental fatigue detection methods at the single-trial level is challenging.

NEW METHODS

Based on a long-duration flanker task EEG dataset, the modulations of mental fatigue on IIV were explored in terms of response time (RT) and trial-to-trial latency variations of event-related potentials (ERPs). Specifically, latency variations were quantified using residue iteration decomposition (RIDE) to reconstruct latency-corrected ERPs. We compared reconstructed ERPs with raw ERPs by means of temporal principal component analysis (PCA). Furthermore, a single-trial classification pipeline was developed to detect the changes of mental fatigue levels.

RESULTS

We found an increased IIV in the RT metric in the fatigue state compared to the alert state. The same sequence of ERPs (N1, P2, N2, P3a, P3b, and slow wave, or SW) was separated from both raw and reconstructed ERPs using PCA, whereas differences between raw and reconstructed ERPs in explained variances for separated ERPs were found owing to IIV. Particularly, a stronger N2 was detected in the fatigue than alert state after RIDE. The single-trial fatigue detection pipeline yielded an acceptable accuracy of 73.3%.

COMPARISON WITH EXISTING METHODS

The IIV has been linked to aging and brain disorders, and as an extension, our finding demonstrates IIV as an efficient indicator of mental fatigue.

CONCLUSIONS

This study reveals significant modulations of mental fatigue on IIV at the behavioral and neural levels and establishes a robust mental fatigue detection pipeline.

Effects of different speed-accuracy instructions on perception in psychology experiments: evidence from event-related potential and oscillation

Introduction

In cognitive behavioral experiments, we often asked participants to make judgments within a deadline. However, the most common instruction of "do the task quickly and accurately" does not highlight the importance of the balance between being fast and accurate.

Methods

Our research aimed to explore how instructions about speed or accuracy affect perceptual process, focus on event-related potentials (ERPs) and event-related oscillations (EROs) of two brain responses for visual stimuli, known as P1 and N1. Additionally, we compared the conventional analysis approach with principal component analysis (PCA) based methods to analyze P1 and N1 ERP amplitude and ERO power.

Results

The results showed that individuals instructed to respond quickly had lower P1 amplitude and alpha ERO than those who prioritized accuracy, using the PCA-based approach. However, these two groups had no differences between groups in the N1 theta band using both methods. The traditional time-frequency analysis method could not detect any ERP or ERO distinctions between groups due to limitations in detecting specific components in time or frequency domains. That means PCA is effective in separating these components.

Discussion

Our findings indicate that the instructions given regarding speed and accuracy impact perceptual process of subjects during cognitive behavioral experiments. We suggest that future researchers should choose their instructions carefully, considering the purpose of study.

Multi-Algorithm Artifact Correction (MAAC) procedure part one: Algorithm and example

The Multi-Algorithm Artifact Correction (MAAC) procedure is presented for electroencephalographic (EEG) data, as made freely available in the open-source EP Toolkit (Dien, 2010). First the major EEG artifact correction methods (regression, spatial filters, principal components analysis, and independent components analysis) are reviewed. Contrary to the dominant approach of picking one method that is thought to be most effective, this review concludes that none are globally superior, but rather each has strengths and weaknesses. Then each of the major artifact types are reviewed (Blink, Corneo-Retinal Dipole, Saccadic Spike Potential, and Movement). For each one, it is proposed that one of the major correction methods is best matched to address it, resulting in the MAAC procedure. The MAAC itself is then presented, as implemented in the EP Toolkit, in order to provide a sense of the user experience. The primary goal of this present paper is to make the conceptual argument for the MAAC approach.

Decomposing the late positive potential to cannabis cues in regular cannabis users: A temporal-spatial principal component analysis

Cannabis use disorder (CUD) is increasing in the United States, yet, specific neural mechanisms of CUD are not well understood. Disordered substance use is characterized by heightened drug cue incentive salience, which can be measured using the late positive potential (LPP), an event-related potential (ERP) evoked by motivationally significant stimuli. The drug cue LPP is typically quantified by averaging the slow wave's scalp-recorded amplitude across its entire time course, which may obscure distinct underlying factors with differential predictive validity; however, no study to date has examined this possibility. In a sample of 105 cannabis users, temporo-spatial Principal Component Analysis was used to decompose cannabis cue modulation of the LPP into its underlying factors. Acute stress was also inducted to allow for identification of specific cannabis LPP factors sensitive to stress. Factor associations with CUD severity were also explored. Eight factors showed significantly increased amplitudes to cannabis images relative to neutral images. These factors spanned early (~372 ms), middle (~824 ms), and late (>1000 ms) windows across frontal, central, and parietal-occipital sites. CUD phenotype individual differences were primarily associated with frontal, middle/late latency factor amplitudes. Acute stress effects were limited to one early central and one late frontal factor. Taken together, results suggest that the cannabis LPP can be decomposed into distinct, temporal-spatial factors with differential responsivity to acute stress and CUD phenotype variability. Future individual difference studies examining drug cue modulation of the LPP should consider (1) frontalcentral poolings in addition to conventional central-parietal sites, and (2) later LPP time windows.

Orientation and contrast deviance examined: Contrast effects mimic deviant-related negativity yet neither produce the canonical neural correlate of prediction error

The visual mismatch negativity (vMMN) is a negative-going event-related potential (ERP) component that is largest somewhere between 100 and 300 ms after the onset of an unpredictable visual event (i.e., a deviant) in an otherwise predictable sequence of visual events (i.e., standards). Many have argued that the vMMN allows us to monitor our ever-changing visual environment for deviants critical to our survival. Recently, however, it has become unclear whether unpredicted changes in low-level features of visual input, like orientation, can evoke the vMMN. I address this by testing isolated orientation changes, to confirm recent findings, and isolated contrast changes, to determine whether other low-level features of visual input do not evoke the vMMN in a traditional oddball paradigm. Eighteen participants saw sequences of rare, unanticipated, and different deviant stimuli, interspersed among frequent, anticipated, and identical standard stimuli. Stimuli were Gabor patches. Neither deviant produced a vMMN. Therefore, changes in low-level visual properties of well-controlled stimuli-a stimulus in which one property can be manipulated while all others remain unaffected-like Gabor patches do not yield a vMMN.

Unveiling the efficacy of the feedback concealed information test in collaborative crime detection

Collaborative crime poses severe social hazards. In collaborative crime scenarios, previous studies have indicated that perpetrators' collaborative encoding can impair the detection efficiency of P300-based complex trial protocols due to the collaborative encoding deficit. The feedback concealed information test (fCIT), a unique variation of the concealed information test, provides participants with feedback on how well they conceal information from memory. The fCIT, which has proven to be highly efficient, detects concealed information using recognition P300 along with feedback-related event-related potentials, and reflects the subject's motivation to conceal. However, no studies have examined the fCIT's effectiveness in identifying collaborative criminals. We propose that the fCIT's efficiency persists in cases of collaborative crime and test this hypothesis using a sample of 48 participants. The participants in the collaborative groups were instructed to have hushed conversations about theft to simulate the collaborative crime process. Subsequently, they completed the fCIT. The findings indicate a significant decline in recognition P300's detection efficiency when participants committed crimes collaboratively. Nevertheless, the detection efficiency of feedback P300 and feedback-related negativity remained high. This study's outcomes illustrate the capacity of the fCIT to detect perpetrators involved in collaborative crime.

Socioeconomic status moderates neural markers of cognitive reappraisal across preschool

Emotion regulation (ER) is critical for children's healthy socio-emotional development, in part through its modulation of negative emotions that might otherwise place children at risk for psychopathology. The cognitive ER strategy of reappraisal appears to be particularly protective against the development of symptoms of anxiety and depression during childhood. Despite widespread acceptance of the benefits of reappraisal for children's long-term affective function, little is known about the developmental mechanisms that support emerging reappraisal in young children. Proximal mechanisms supporting reappraisal include biological processes; the modulation of reactivity to negative emotional stimuli is visible at the neural level through the Late Positive Potential (LPP). Influences on the developmental course of mechanisms like the LPP almost certainly include contextual factors, including quality of the environment, which have been largely ignored in work to date. The present study included a test of early (age 3-4) socioeconomic status (SES) as a moderator of children's reappraisal, evidenced by differences in the LPP to passive view and reappraisal conditions, at age 5. Results supported the presence of moderation. Reappraisal was visible as differences in LPP across conditions at high, but not low, levels of SES. Findings offer a foundation for delineating the development of reappraisal and understanding contexts that may promote preschoolers' reappraisal. Results also contribute to the delineation of the role of early psychophysiological markers in affective function and early risk for psychopathology.

Differentiating Biomarker Features and Familial Characteristics of B-SNIP Psychosis Biotypes

Idiopathic psychosis shows considerable biological heterogeneity across cases. B-SNIP used psychosis-relevant biomarkers to identity psychosis Biotypes, which will aid etiological and targeted treatment investigations. Psychosis probands from the B-SNIP consortium (n = 1907), their first-degree biological relatives (n = 705), and healthy participants (n = 895) completed a biomarker battery composed of cognition, saccades, and auditory EEG measurements. ERP quantifications were substantially modified from previous iterations of this approach. Multivariate integration reduced multiple biomarker outcomes to 11 "bio-factors". Twenty-four different approaches indicated bio-factor data among probands were best distributed as three subgroups. Numerical taxonomy with k-means constructed psychosis Biotypes, and rand indices evaluated consistency of Biotype assignments. Psychosis subgroups, their non-psychotic first-degree relatives, and healthy individuals were compared across bio-factors. The three psychosis Biotypes differed significantly on all 11 bio-factors, especially prominent for general cognition, antisaccades, ERP magnitude, and intrinsic neural activity. Rand indices showed excellent consistency of clustering membership when samples included at least 1100 subjects. Canonical discriminant analysis described composite bio-factors that simplified group comparisons and captured neural dysregulation, neural vigor, and stimulus salience variates. Neural dysregulation captured Biotype-2, low neural vigor captured Biotype-1, and deviations of stimulus salience captured Biotype-3. First-degree relatives showed similar patterns as their Biotyped proband relatives on general cognition, antisaccades, ERP magnitudes, and intrinsic brain activity. Results extend previous efforts by the B-SNIP consortium to characterize biologically distinct psychosis Biotypes. They also show that at least 1100 observations are necessary to achieve consistent outcomes. First-degree relative data implicate specific bio-factor deviations to the subtype of their proband and may inform studies of genetic risk.

Behavioral and psychiatric correlates of brain responses to social feedback

Maladaptive responses to peer acceptance and rejection arise in numerous psychiatric disorders in adolescence; yet, homogeneity and heterogeneity across disorders suggest common and unique mechanisms of impaired social function. We tested the hypothesis that social feedback is processed similarly to other forms of feedback (e.g., monetary) by examining the correspondence between the brain's response to social acceptance and rejection and behavioral performance on a separate reward and loss task. We also examined the relationship between these brain responses and depression and social anxiety severity. The sample consisted of one hundred and thirteen 16-21-year olds who received virtual peer acceptance/rejection feedback in an event-related potential (ERP) task. We used temporospatial principal component analysis and identified a component consistent with the reward positivity (RewP) or feedback negativity (FN). RewP to social acceptance was not significantly related to reward bias or the FN to social rejection related to loss avoidance. The relationship between RewP and depression severity, while nonsignificant, was of a similar magnitude to prior studies. Exploratory analyses yielded a significant relationship between lower socioeconomic status (SES) and blunted RewP and between lower SES and heightened loss avoidance and blunted reward bias. These findings build on prior work to improve our understanding of the function of the brain's response to social feedback, while also suggesting a pathway for further study, whereby poverty leads to depression via social and reward learning mechanisms.

Temporal characteristics of emotional conflict processing: the modulation role of attachment styles

Theoretical account of attachment proposed that individual differences in adult attachment styles play a key role in adjusting balance between affective evaluation and cognitive control. Yet, little is known about the temporal characteristics of emotional conflict processing modulated by attachment styles. Accordingly, the present study used event-related potentials (ERP) and multivariate pattern analysis (MVPA) combined with an emotional face-word Stroop task to investigate the temporal dynamics of attachment-related cognitive-affective patterns in emotional conflict processing. The ERP results demonstrated multiple-process of emotional conflict modulated by attachment styles. In early sensory processing, positive faces captured avoidant attachment individuals' attention as reflected in greater P1, while the same situation led to greater N170 in secure and anxious individuals. Crucially, impairment in conflict-monitoring function was found in anxious individuals as reflected by the absence of interference effect on N450, leading to impaired ability of inhibitory control as indicated by decreased slow potential. In contrast, avoidant individuals showed greater slow potential for inhibiting emotional interference. Furthermore, MVPA revealed that the corresponding time window for conflict monitoring was found for emotional distractors decoding rather than congruency decoding in the anxious attachment group. Convergent results from ERPs and MVPA indicated that the deficits in emotional conflict monitoring and resolution among anxious individuals might be due to the excessive approach to emotional distractors, as they habitually use emotional evaluation rather than cognitive control. In summary, the present study provides electrophysiological evidence that attachment styles modulated emotional conflict processing, which highlights the contribution of attachment to social information processing.

Chronic stress in peer relationships moderates the association between pubertal development and neural response to emotional faces in adolescence

Adolescence is a period of heightened risk for multiple forms of psychopathology, partly due to greater exposure to interpersonal stress. One way that interpersonal stress may increase risk for psychopathology is by altering the normative development of neural systems that support socio-affective processing. The late positive potential (LPP) is an event-related potential component that reflects sustained attention to motivationally-salient information and is a promising marker of risk for stress-related psychopathology. However, it is not clear how the LPP to socio-affective information changes across adolescence, nor whether exposure to stress with peers interferes with normative developmental differences in the LPP to socio-affective content during this period. In 92 adolescent girls (10-19 years old), we assessed the LPP to task-irrelevant emotional and neutral faces, as well as behavioural measures of interference following the presentation of these faces. Adolescents at more advanced stages of puberty showed a smaller LPP to emotional faces, but adolescents exposed to greater peer stress exhibited a larger LPP to these stimuli. Additionally, for girls exposed to lower levels of peer stress, more advanced pubertal development was associated with a smaller LPP to emotional faces, whereas for girls exposed to higher levels of peer stress, the association between pubertal development and the LPP to emotional faces was not significant. Neither stress nor pubertal stage was significantly associated with behavioural measures. Combined, these data suggest that one pathway through which stress exposure increases risk for psychopathology during adolescence is by interfering with the normative development of socio-affective processing.

Attention is required for canonical brain signature of prediction error despite early encoding of the stimuli

Prediction error is a basic component of predictive-coding theory of brain processing. According to the theory, each stage of brain processing of sensory information generates a model of the current sensory input; subsequent input is compared against the model and only if there is a mismatch, a prediction error, is further processing performed. Recently, Smout and colleagues found that a signature of prediction error, the visual (v) mismatch negativity (MMN), for a fundamental property of visual input-its orientation-was absent without endogenous attention on the stimuli. This is remarkable because the weight of evidence for MMNs from audition and vision is that they occur without endogenous attention. To resolve this discrepancy, we conducted an experiment addressing 2 alternative explanations for Smout and colleagues' finding: that it was from a lack of reproducibility or that participants' visual systems did not encode the stimuli when attention was on something else. We conducted a similar experiment to that of Smout and colleagues. We showed 21 participants sequences of identically oriented Gabor patches, standards, and, unpredictably, otherwise identical, Gabor patches differing in orientation by ±15°, ±30°, and ±60°, deviants. To test whether participants encoded the orientation of the standards, we varied the number of standards preceding a deviant, allowing us to search for a decrease in activity with the number of repetitions of standards-repetition suppression. We diverted participants' attention from the oriented stimuli with a central, letter-detection task. We reproduced Smout and colleagues' finding of no vMMN without endogenous attention, strengthening their finding. We found that our participants showed repetition suppression: They did encode the stimuli preattentively. We also found early processing of deviants. We discuss various explanations why the earlier processing did not extend into the vMMN time window, including low precision of prediction.

Valence precedes value in neural encoding of prediction error

Event-related potentials that follow feedback in reinforcement learning tasks have been proposed to reflect neural encoding of prediction errors. Prior research has shown that in the interval of 240-340 ms multiple different prediction error encodings appear to co-occur, including a value signal carrying signed quantitative prediction error and a valence signal merely carrying sign. The effects used to identify these two encoders, respectively a sign main effect and a sign × size interaction, do not reliably discriminate them. A full discrimination is made possible by comparing tasks in which the reinforcer available on a given trial is set to be either appetitive or aversive against tasks where a trial allows the possibility of either. This study presents a meta-analysis of reinforcement learning experiments, the majority of which presented the possibility of winning or losing money. Value and valence encodings were identified by conventional difference wave methodology but additionally by an analysis of their predicted behavior using a Bayesian analysis that incorporated nulls into the evidence for each encoder. The results suggest that a valence encoding, sensitive only to the available outcomes on the trial at hand precedes a later value encoding sensitive to the outcomes available in the wider experimental context. The implications of this for modeling computational processes of reinforcement learning in humans are discussed.

Electrophysiological correlates of attentional bias towards threat in children with high levels of social anxiety

Pediatric social anxiety is characterized by attentional biases (AB) towards social threats. This study used a new response-based calculation method to assess AB from response times (RT) in a visual dot-probe task and electroencephalography (EEG) to explore its electrophysiological correlates. Twenty, high socially anxious children (HSA) (mean [M ] = 10.1 years; standard deviation [SD] = 1.01) were compared with 22 healthy control children (HC) (M = 10.20 years; SD = 1.30) matched in age and gender. Participants had to identify targets preceded by disgust-neutral, happy-neutral, or neutral-neutral pairs of faces. RT and electroencephalograms were recorded throughout the task. While no significant group difference was found at the behavioral level, principal component analyses performed on EEG data revealed that event-related potentials for threat-related stimuli were impacted by social anxiety. Analyses indicated a larger N170 amplitude in response to all facial stimuli in HC when compared to the HSA. However, we found increased P2 amplitudes for disgust-neutral pairs compared with happy-neutral pairs in has only. Then, thasHSA group showed increased P2 amplitudes for targets following disgusted faces on the opposite side of the screen compared with targets appearing on the same side of the screen. These results suggest that HSA may display an increased anchorage of attention on threatening stimuli and need more effort to disengage their attentional focus from threats and to perform the task correctly. Taken together, our data confirmed the presence of AB in children with high levels of social anxiety, which are reflected by increased neural processing during the confrontation to faces depicting a potential threatening expression.

Single-trial-based temporal principal component analysis on extracting event-related potentials of interest for an individual subject

BACKGROUND

Temporal principal component analysis (tPCA) has been widely used to extract event-related potentials (ERPs) at group level of multiple subjects ERP data and it assumes that the underlying factor loading is fixed across participants. However, such assumption may fail to work if latency and phase for one ERP vary considerably across participants. Furthermore, effect of number of trials on tPCA decomposition has not been systematically examined as well, especially for within-subject PCA.

NEW METHOD

We reanalyzed a real ERP data of an emotional experiment using tPCA to extract N2 and P2 from single-trial EEG of an individual. We also explored influence of the number of trials (consecutively increased from 10 to 42 trials) on PCA decomposition by comparing temporal correlation, the statistical result, Cronbach's alpha, spatial correlation of both N2 and P2 for the proposed method with the conventional time-domain analysis, trial-averaged group PCA, and single-trial-based group PCA.

RESULTS

The results of the proposed method can enhance spatial and temporal consistency. We could obtain stable N2 with few trials (about 20) for the proposed method, but, for P2, approximately 30 trials were needed for all methods.

COMPARISON WITH EXISTING METHOD(S)

About 30 trials for N2 were required and the reconstructed P2 and N2 were poor correlated across participants for the other three methods.

CONCLUSION

The proposed approach may efficiently capture variability of one ERP from an individual that cannot be extracted by group PCA analysis.

Maternal symptoms of depression and anxiety during the postpartum period moderate infants' neural response to emotional faces of their mother and of female strangers

Affective exchanges between mothers and infants are key to the intergenerational transmission of depression and anxiety, possibly via adaptations in neural systems that support infants' attention to facial affect. The current study examined associations between postnatal maternal symptoms of depression, panic and social anxiety, maternal parenting behaviours, and infants' neural responses to emotional facial expressions portrayed by their mother and by female strangers. The Negative Central (Nc), an event-related potential component that indexes attention to salient stimuli and is sensitive to emotional expression, was recorded from 30 infants. Maternal sensitivity, intrusiveness, and warmth, as well as infant's positive engagement with their mothers, were coded from unstructured interactions. Mothers reporting higher levels of postnatal depression symptoms were rated by coders as less sensitive and warm, and their infants exhibited decreased positive engagement with the mothers. In contrast, postnatal maternal symptoms of panic and social anxiety were not significantly associated with experimenter-rated parenting behaviours. Additionally, infants of mothers reporting greater postnatal depression symptoms showed a smaller Nc to their own mother's facial expressions, whereas infants of mothers endorsing greater postnatal symptoms of panic demonstrated a larger Nc to fearful facial expressions posed by both their mother and female strangers. Together, these results suggest that maternal symptoms of depression and anxiety during the postpartum period have distinct effects on infants' neural responses to parent and stranger displays of emotion.

Menstrual cycle and exogenous attention toward emotional expressions

Several studies suggest that the menstrual cycle affects emotional processing. However, these results may be biased by including women with premenstrual syndrome (PMS) in the samples. PMS is characterized by negative emotional symptomatology, such as depression and/or anxiety, during the luteal phase. This study aimed to explore the modulation of exogenous attention to emotional facial expressions as a function of the menstrual cycle in women without PMS. For this purpose, 55 women were selected (from an original volunteer sample of 790) according to rigorous exclusion criteria. Happy, angry, and neutral faces were presented as distractors, while both behavioral performance in a perceptual task and event-related potentials (ERPs) were recorded. This task was applied during both phases of the menstrual cycle (luteal and follicular, counterbalanced), and premenstrual symptomatology was monitored daily. Traditional and Bayesian ANOVAs on behavioral data (reaction times and errors in the task) and ERP indices (P1, N170, N2, and LPP amplitudes) confirmed the expected lack of an interaction of phase and emotion. Taken together, these results indicate that women free of PMS present steady exogenous attention levels to emotionally positive and negative stimuli regardless of the menstrual phase.

The role of conflict processing mechanism in deception responses

A considerable number of studies have described the potential neural mechanism of deception, but most deception studies have relied upon deception from experimental supervisor instruction. Experimental control (participants follow instructions to deceive without any risk) means that the deception occurs in a way that does not come close to the real deception. In the current study, a neural imaging experiment on deception closer to the real deception was conducted. Event-related potential (ERP) and event-related spectral perturbation (ERSP) techniques were used to explore the neural mechanism of deception. The results showed that deceptive response evoked larger medial-frontal negativity (MFN) and smaller response-locked positivity (RLP) than truthful response. We interpret these findings to indicate that conflict detection and emotional processing are associated with deception. In addition, magnitudes of alpha and beta oscillations after the deceptive response were significantly smaller than those after the truthful response, demonstrating that deception is associated with neural oscillations reflecting conflict adjustment. The results comprehensively characterized the physiological properties of the brain oscillations elicited by a deceptive response and provided a theoretical foundation for detection in practical applications.

Belief or disbelief in feedback influences the detection efficiency of the feedback concealed information test

The feedback concealed information test (fCIT) is a new variant of the CIT that added feedback about participants’ concealing performances in the classical CIT. The advantage of the fCIT is that the resulting feedback related event-related potentials (ERPs) can be used to detect concealed information. However, the detection efficiency of feedback-based ERPs varies across studies. The present experiment examined whether the extent participants believed the feedback influenced their detection efficiency. Specifically, participants did a mock crime and were then tested in a fCIT. Following the fCIT, participants were asked to report how much they believed the feedback was accurate. Results showed that there were no significant correlations between the amplitude of the feedback related negativity (FRN), feedback P300, and participants’ self-report at the group level. However, individual analyses showed that the detection efficiency of both the FRN and feedback P300 were influenced by participants’ belief about the presented feedback. The detection efficiency of the FRN and the feedback P300 was higher among participants who believed the feedback. These findings suggest that the fCIT is dependent to some extent on the participants’ level of belief in the feedback.

Effects of Transcranial Direct Current Stimulation on Attentional Bias to Methamphetamine Cues and Its Association With EEG-Derived Functional Brain Network Topology

BACKGROUND

Although transcranial direct current stimulation (tDCS) has shown to potentially mitigate drug craving and attentional bias to drug-related stimuli, individual differences in such modulatory effects of tDCS are less understood. In this study, we aimed to investigate a source of the inter-subject variability in the tDCS effects that can be useful for tDCS-based treatments of individuals with methamphetamine (MA) use disorder (IMUD).

METHODS

Forty-two IMUD (all male) were randomly assigned to receive a single-session of either sham or real bilateral tDCS (anodal right/cathodal left) over the dorsolateral prefrontal cortex. The tDCS effect on MA craving and biased attention to drug stimuli were investigated by quantifying EEG-derived P3 (a measure of initial attentional bias) and late positive potential (LPP; a measure of sustained motivated attention) elicited by these stimuli. To assess the association of changes in P3 and LPP with brain connectivity network (BCN) topology, the correlation between topology metrics, specifically those related to the efficiency of information processing, and the tDCS effect was investigated.

RESULTS

The P3 amplitude significantly decreased following the tDCS session, whereas the amplitudes increased in the sham group. The changes in P3 amplitudes were significantly correlated with communication efficiency measured by BCN topology metrics (r = -0.47, P = .03; r = -0.49, P = .02). There was no significant change in LPP amplitude due to the tDCS application.

CONCLUSIONS

These findings validate that tDCS mitigates initial attentional bias, but not the sustained motivated attention, to MA stimuli. Importantly, however, results also show that the individual differences in the effects of tDCS may be underpinned by communication efficiency of the BCN topology, and therefore, these BCN topology metrics may have the potential to robustly predict the effectiveness of tDCS-based interventions on MA craving and attentional bias to MA stimuli among IMUD.

A tutorial on the use of temporal principal component analysis in developmental ERP research - Opportunities and challenges

Developmental researchers are often interested in event-related potentials (ERPs). Data-analytic approaches based on the observed ERP suffer from major problems such as arbitrary definition of analysis time windows and regions of interest and the observed ERP being a mixture of latent underlying components. Temporal principal component analysis (PCA) can reduce these problems. However, its application in developmental research comes with the unique challenge that the component structure differs between age groups (so-called measurement non-invariance). Separate PCAs for the groups can cope with this challenge. We demonstrate how to make results from separate PCAs accessible for inferential statistics by re-scaling to original units. This tutorial enables readers with a focus on developmental research to conduct a PCA-based ERP analysis of amplitude differences. We explain the benefits of a PCA-based approach, introduce the PCA model and demonstrate its application to a developmental research question using real-data from a child and an adult group (code and data openly available). Finally, we discuss how to cope with typical challenges during the analysis and name potential limitations such as suboptimal decomposition results, data-driven analysis decisions and latency shifts.

The effect of mental countermeasures on a novel brain-based feedback concealed information test

The feedback concealed information test (fCIT) is a novel form of the CIT, providing participants with feedback regarding their memory concealment performance. The fCIT utilizes event-related potentials (recognition-P300 and feedback-related event-related potentials) and has been shown to provide high efficiency in detecting information concealment. However, it is unclear how well the fCIT performs in the presence of mental countermeasures. To address this question, participants were trained to use countermeasures during fCIT. Results showed that the recognition-P300 efficiency decreased when participants used countermeasures. However, the efficiencies of feedback-related negativity and feedback-P300 were unchanged, with feedback-P300 still showing a high detection efficiency (AUC = 0.86) during countermeasures. These findings demonstrate the potential of fCIT for subverting countermeasures.

The time course of reactivity to social acceptance and rejection feedback: An examination of event-related potentials and behavioral measures in a peer interaction task

Measurement of social processes is of interest across areas of research. Event-related potentials (ERPs) measured using electroencephalography (EEG) offer high temporal resolution, but little work has leveraged this strength to characterize the time course of social feedback processing. The present study aimed to replicate and extend previous research by systematically identifying the temporal dynamics of responses to both social acceptance and rejection feedback relative to neutral feedback, examining internal consistency of ERPs, and exploring correspondence with behavioral measures elicited during a peer interaction task. Emerging adults (N = 118) completed a computerized peer interaction task in which they made decisions to accept or reject peers and received rejection, acceptance, and neutral feedback while EEG data were recorded. Principal component analysis was used to derive temporally and spatially distinct ERP components sensitive to positive and negative social feedback. Participant voting patterns and post-task liking ratings for computer-controlled peers were also examined. Replicating prior work, components consistent with N1, P2, reward positivity (RewP), and P3 emerged, but distinct patterns of modulation by acceptance and rejection relative to neutral feedback were observed. Most components showed acceptable internal consistency. Sensitivity to peer feedback assessed through participant voting patterns and liking ratings for peers was correlated with RewP and P3 components. Results highlight the complexity of social feedback processing observable in a computerized peer interaction task and offer promising neural and behavioral measures that can be used to examine individual differences in sensitivity to both social acceptance and rejection feedback.

Event-related potentials to acoustic startle probes during unpredictable threat are associated with individual differences in intolerance of uncertainty

Individual differences in sensitivity to unpredictable threat may be a critical mechanism for internalizing psychopathology phenotypes. The present study examined whether the startle probe-elicited N100 and P300 during unpredictable threat - two event-related potentials indexing early and elaborative attentional processing of unpredictable threat - may be endophenotypes for internalizing psychopathology, including fear and distress/misery disorders and intolerance of uncertainty (IU), a clinical trait that is transdiagnostically associated with internalizing disorders. A large sample of adult siblings (N = 375) completed the no, predictable, and unpredictable threat task, during which the N100 and P300 were recorded. Relative to the no threat condition, N100 was more strongly enhanced in anticipation of unpredictable than predictable threat while P300 was suppressed to both predictable and unpredictable threat. While neither N100 enhancement nor P300 suppression to unpredictable threat was associated with fear or distress/misery disorders, they were negatively linked to inhibitory IU (a facet of IU). Thus, individuals high in inhibitory IU showed reduced attentional engagement with the threatening context when it was unpredictable. Further, N100 enhancement and, to a lesser degree, P300 suppression to unpredictable threat showed familial aggregation - a key criterion for determining whether a biomarker is an endophenotype. In sum, N100 enhancement and P300 suppression to unpredictable threat may be endophenotypes for dimensional measures of internalizing psychopathology.

Psychosis Biotypes: Replication and Validation from the B-SNIP Consortium

Current clinical phenomenological diagnosis in psychiatry neither captures biologically homologous disease entities nor allows for individualized treatment prescriptions based on neurobiology. In this report, we studied two large samples of cases with schizophrenia, schizoaffective, and bipolar I disorder with psychosis, presentations with clinical features of hallucinations, delusions, thought disorder, affective, or negative symptoms. A biomarker approach to subtyping psychosis cases (called psychosis Biotypes) captured neurobiological homology that was missed by conventional clinical diagnoses. Two samples (called "B-SNIP1" with 711 psychosis and 274 healthy persons, and the "replication sample" with 717 psychosis and 198 healthy persons) showed that 44 individual biomarkers, drawn from general cognition (BACS), motor inhibitory (stop signal), saccadic system (pro- and anti-saccades), and auditory EEG/ERP (paired-stimuli and oddball) tasks of psychosis-relevant brain functions were replicable (r's from .96-.99) and temporally stable (r's from .76-.95). Using numerical taxonomy (k-means clustering) with nine groups of integrated biomarker characteristics (called bio-factors) yielded three Biotypes that were virtually identical between the two samples and showed highly similar case assignments to subgroups based on cross-validations (88.5%-89%). Biotypes-1 and -2 shared poor cognition. Biotype-1 was further characterized by low neural response magnitudes, while Biotype-2 was further characterized by overactive neural responses and poor sensory motor inhibition. Biotype-3 was nearly normal on all bio-factors. Construct validation of Biotype EEG/ERP neurophysiology using measures of intrinsic neural activity and auditory steady state stimulation highlighted the robustness of these outcomes. Psychosis Biotypes may yield meaningful neurobiological targets for treatments and etiological investigations.

Neural responses associated with attentional engagement and disengagement from threat in high socially anxious children: Evidence from temporal-spatial PCA

BACKGROUND

Cognitive models indicated that social anxiety disorder (SAD) would be caused and maintained by a biased attentional processing of threatening information. This study investigates whether socially anxious children may present impaired attentional engagement and disengagement from negative emotional faces, as well as their underlying event-related potential responses.

METHODS AND FINDINGS

Fifteen children with high levels of social anxiety (HSA; 9 boys; mean age = 9.99y; SD = 1.14) and twenty low socially anxious children (LSA; 16 boys; mean age = 10.47y; SD = 1.17) participated in a spatial cueing task in which they had to detect targets following neutral/disgusted faces in a valid or invalid location. No group effect was reported on reaction times [p>.05]. However, electrophysiological data showed lower P3a amplitude in HSA children compared with the LSA group when processing facial stimuli. They also reported larger N2 amplitudes for valid-disgusted targets and a larger P3a amplitude for the invalid-disgusted ones.

CONCLUSION

In terms of electrophysiological data, our results validated, the hypothesis of attentional disengagement difficulties in SAD children. We also confirm the idea that high levels of social anxiety are associated with cognitive control impairments and have a greater impact on the processing efficiency than on the performance effectiveness.

Auditory Oddball Responses Across the Schizophrenia-Bipolar Spectrum and Their Relationship to Cognitive and Clinical Features

OBJECTIVE

Neural activations during auditory oddball tasks may be endophenotypes for psychosis and bipolar disorder. The authors investigated oddball neural deviations that discriminate multiple diagnostic groups across the schizophrenia-bipolar spectrum (schizophrenia, schizoaffective disorder, psychotic bipolar disorder, and nonpsychotic bipolar disorder) and clarified their relationship to clinical and cognitive features.

METHODS

Auditory oddball responses to standard and target tones from 64 sensor EEG recordings were compared across patients with psychosis (total N=597; schizophrenia, N=225; schizoaffective disorder, N=201; bipolar disorder with psychosis, N=171), patients with bipolar disorder without psychosis (N=66), and healthy comparison subjects (N=415) from the second iteration of the Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP2) study. EEG activity was analyzed in voltage and in the time-frequency domain (low, beta, and gamma bands). Event-related potentials (ERPs) were compared with those from an independent sample collected during the first iteration of B-SNIP (B-SNIP1; healthy subjects, N=211; psychosis group, N=526) to establish the repeatability of complex oddball ERPs across multiple psychosis syndromes (r values >0.94 between B-SNIP1 and B-SNIP2).

RESULTS

Twenty-six EEG features differentiated the groups; they were used in discriminant and correlational analyses. EEG variables from the N100, P300, and low-frequency ranges separated the groups along a diagnostic continuum from healthy to bipolar disorder with psychosis/bipolar disorder without psychosis to schizoaffective disorder/schizophrenia and were strongly related to general cognitive function (r=0.91). P50 responses to standard trials and early beta/gamma frequency responses separated the bipolar disorder without psychosis group from the bipolar disorder with psychosis group. P200, N200, and late beta/gamma frequency responses separated the two bipolar disorder groups from the other groups.

CONCLUSIONS

Neural deviations during auditory processing are related to psychosis history and bipolar disorder. There is a powerful transdiagnostic relationship between severity of these neural deviations and general cognitive performance. These results have implications for understanding the neurobiology of clinical syndromes across the schizophrenia-bipolar spectrum that may have an impact on future biomarker research.

Voice, rhythm, and beep stimuli differently affect the right hemisphere preponderance and components of stimulus-preceding negativity

The present study investigated whether auditory stimuli with different contents affect right laterality and the components of stimulus-preceding negativity (SPN). A time-estimation task was performed under voice, rhythm, beep, and control conditions. The SPN interval during which participants anticipated the stimulus was divided into quarters to define early and late SPNs. Early and late components of SPN were also extracted using a principal component analysis. The anticipation of voice sounds enhanced the early SPN and the early component, which reflected the anticipation of language processing. Beep sounds elicited the right hemisphere preponderance of the early component, the early SPN, and the late SPN. The rhythmic sound tended to attenuate the amplitude compared with the two other stimuli. These findings further substantiate the existence of separate early and late components of the SPN. In addition, they suggest that the early component reflects selective anticipatory attention toward differing types of auditory feedback.

Objective Extraction of Evoked Event-Related Oscillation from Time-Frequency Representation of Event-Related Potentials

Evoked event-related oscillations (EROs) have been widely used to explore the mechanisms of brain activities for both normal people and neuropsychiatric disease patients. In most previous studies, the calculation of the regions of evoked EROs of interest is commonly based on a predefined time window and a frequency range given by the experimenter, which tends to be subjective. Additionally, evoked EROs sometimes cannot be fully extracted using the conventional time-frequency analysis (TFA) because they may be overlapped with each other or with artifacts in time, frequency, and space domains. To further investigate the related neuronal processes, a novel approach was proposed including three steps: (1) extract the temporal and spatial components of interest simultaneously by temporal principal component analysis (PCA) and Promax rotation and project them to the electrode fields for correcting their variance and polarity indeterminacies, (2) calculate the time-frequency representations (TFRs) of the back-projected components, and (3) compute the regions of evoked EROs of interest on TFRs objectively using the edge detection algorithm. We performed this novel approach, conventional TFA, and TFA-PCA to analyse both the synthetic datasets with different levels of SNR and an actual ERP dataset in a two-factor paradigm of waiting time (short/long) and feedback (loss/gain) separately. Synthetic datasets results indicated that N2-theta and P3-delta oscillations can be stably detected from different SNR-simulated datasets using the proposed approach, but, by comparison, only one oscillation was obtained via the last two approaches. Furthermore, regarding the actual dataset, the statistical results for the proposed approach revealed that P3-delta was sensitive to the waiting time but not for that of the other approaches. This study manifested that the proposed approach could objectively extract evoked EROs of interest, which allows a better understanding of the modulations of the oscillatory responses.

Differentiating stages of reward responsiveness: Neurophysiological measures and associations with facets of the behavioral activation system

The Research Domain Criteria (RDoC) positive valence systems domain include multiple aspects of reward responsiveness with potential to elucidate the understanding of motivational and hedonic deficits in psychological disorders. There is a need for reliable and valid methods to delineate behavioral and biological processes underlying stages of reward responsiveness. Event-related potentials (ERPs) offer a promising method for examining the temporal dynamics of reward processing, but the literature has mainly focused on the feedback stage and often single components. We investigated the electrophysiological aspects of reward anticipation and initial response to reward using an ERP monetary incentive delay task in 114 emerging adults. Principal component analysis was used to derive temporally and spatially distinct ERP components sensitive to reward processing. Components that reflect initial engagement toward a cue indicating potential reward (cue-P3) and anticipation of possible reward feedback (stimulus-preceding negativity; SPN) emerged in the anticipatory stage. In the initial response to reward stage, a reward positivity (RewP) was found. We further tested the association between ERPs and self-reported facets of the behavioral activation system. Greater self-reported reward responsiveness was associated with heightened response in the anticipatory stage (i.e., cue-P3, SPN). Self-reported drive was positively associated with RewP, but fun-seeking was negatively associated with RewP. Additional components were observed beyond those identified in prior work, warranting future research on temporal dynamics of reward processing across stages. Furthermore, examination of a broader range of reward-related ERPs in clinical populations has the potential to more precisely characterize alterations in positive valence systems in psychopathology.

The Event-Related Potentials Responding to Outcome Valence and Expectancy Violation during Feedback Processing

Feedback-related negativity (FRN) is believed to encode reward prediction error (RPE), a term describing whether the outcome is better or worse than expected. However, some studies suggest that it may reflect unsigned prediction error (UPE) instead. Some disagreement remains as to whether FRN is sensitive to the interaction of outcome valence and prediction error (PE) or merely responsive to the absolute size of PE. Moreover, few studies have compared FRN in appetitive and aversive domains to clarify the valence effect or examine PE's quantitative modulation. To investigate the impact of valence and parametrical PE on FRN, we varied the prediction and feedback magnitudes within a probabilistic learning task in valence (gain and loss domains, Experiment 1) and non-valence contexts (pure digits, Experiment 2). Experiment 3 was identical to Experiment 1 except that some blocks emphasized outcome valence, while others highlighted predictive accuracy. Experiments 1 and 2 revealed a UPE encoder; Experiment 3 found an RPE encoder when valence was emphasized and a UPE encoder when predictive accuracy was highlighted. In this investigation, we demonstrate that FRN is sensitive to outcome valence and expectancy violation, exhibiting a preferential response depending on the dimension that is emphasized.

Neural responses to social acceptance predict behavioral adjustments following peer feedback in the context of a real-time social interaction task

Strong social connections are important predictors of both mental and physical health. The ability to effectively process social feedback from other people and adjust behavior accordingly is a critical part of skillfully navigating the social landscape. However, relatively few studies have considered neural systems driving these behavioral adjustments. In this study, 254 participants engaged in a peer interaction game while electroencephalogram (EEG) was recorded. In this game, participants repeatedly "interact" with a small set of virtual peers over a series of rounds, in which they provide feedback to their peers, and receive feedback from them in turn. A reward-sensitive event-related potential called the Reward Positivity (RewP) was extracted from the EEG following positive feedback from peers, and multilevel modeling was used to examine whether the RewP moderated associations between the feedback participants received during the task and their subsequent behavior. Participants were more likely to accept coplayers who had previously voted to accept them, and to like coplayers who had voted to accept them on the same round. A larger RewP was associated with a stronger tendency to modify behavior following feedback from peers, both in terms of voting behavior and expressions of liking. These data suggest that initial neural responsiveness to reward within 300 ms of positive social feedback may guide social behaviors. Thus, this line of research represents an important step toward a more complete understanding of the ways in which neural responses to feedback are involved in human social behaviors.

Auditory paired-stimuli responses across the psychosis and bipolar spectrum and their relationship to clinical features

Background

EEG responses during auditory paired-stimuli paradigms are putative biomarkers of psychosis syndromes. The initial iteration of the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP1) showed unique and common patterns of abnormalities across schizophrenia (SZ), schizoaffective disorder (SAD), and bipolar disorder with psychosis (BDP). This study replicates those findings in new and large samples of psychosis cases and extends them to an important comparison group, bipolar disorder without psychosis (BDNP).

Methods

Paired stimuli responses from 64-sensor EEG recording were compared across psychosis (n = 597; SZ = 225, SAD = 201, BDP = 171), BDNP (n = 66), and healthy (n = 415) subjects from the second iteration of B-SNIP. EEG activity was analyzed in voltage and in the time-frequency domain. Principal component analysis (PCA) over sensors (sPCA) was used to efficiently capture EEG voltage responses to the paired stimuli. Evoked power was calculated via a Morlet wavelet procedure. A frequency PCA divided evoked power data into three frequency bands: Low (4-17 Hz), Beta (18-32 Hz), and Gamma (33-55 Hz). Each time-course (ERP Voltage, Low, Beta, and Gamma) were then segmented into 20 ms bins and analyzed for group differences. To efficiently summarize the multiple EEG components that best captured group differences we used multivariate discriminant and correlational analyses. This approach yields a reduced set of measures that may be useful in subsequent biomarker investigations.

Results

Group ANOVAs identified 17 time-ranges that showed significant group differences (p < .05 after FDR correction), constructively replicating B-SNIP1 findings. Multivariate linear discriminant analysis parsimoniously selected variables that best accounted for group differences: The P50 response to S1 and S2 uniquely separated BDNP from healthy and psychosis subjects (BDNP > all other groups); the S1 N100 response separated groups along an axis of psychopathology severity (HC > BDNP > BDP > SAD > SZ); the S1 P200 response indexed psychosis psychopathology (HC/BDNP > SAD/SZ/BDP); and the preparatory period to the S2 stimulus separated SZ from other groups (SZ > SAD/BDP>HC/BDNP).Canonical correlation identified an association between the neural responses during the S1 N100, S1 N200 and S2 preparatory period and PANSS positive symptoms and social functioning. The neural responses during the S1 P50 and S1 N100 were associated with PANSS Negative/General, MADRS and Young Mania symptoms.

Conclusions

This study constructively replicated prior B-SNIP1 research on auditory deviations observed during the paired stimuli task in SZ, SAD and BDP. Inclusion of a group of BDNP allows for the identification of biomarkers more closely related to affective versus nonaffective clinical phenotypes and neural distinctions between BDP and BDNP. Findings have implications for nosology and future translational work given that some biomarkers are shared across all psychosis and some are unique to affective syndromes.

Cultural Relevance Reduces the Enhanced Neural Processing of Positively Valenced Information in Older Adults

OBJECTIVES

This study investigated (a) whether the age-related enhancement in processing positive relative to negative emotional information happened at the early and/or late processing stages and (b) if the age-related positivity effect was modulated by cultural relevance using event-related brain potential (ERP).

METHODS

Seventeen younger and 19 older Chinese adults judged the emotional valence of Chinese and Western pictures while electroencephalogram (EEG) was recorded and analyzed by temporospatial principal component analysis to dissociate the processing stages.

RESULTS

(a) Larger N100 for negative than positive pictures was observed in younger, but not older adults, while older but not younger adults showed larger late anterior P300 for positive than negative pictures. (b) Older adults showed larger early posterior P300 for positive than negative Western pictures, but not culturally relevant Chinese pictures; such modulation effect by cultural relevance was absent in younger adults.

DISCUSSION

These findings suggest an age-related decrease in sensitivity to negative information in the earlier stage and an age-related increase in sensitivity to positive information in the later stage of cognitive processing. This supports a dual-route model of the age-related positivity effect. Moreover, the age-related positivity effect is more evident for stimuli with less cultural relevance.

Feedback does not influence the recognition-related P300 in a novel concealed information test while feedback-evoked P300 shows promising diagnostic accuracy

The feedback concealed information test (fCIT) is a novel variant of a CIT, which provides participants with feedback regarding their memory concealment performance during the CIT. Previous studies have found that feedback-related ERPs associated with feedback processing in the fCIT can accurately identify concealed information. However, it is still unknown whether the feedback influences the process and ERP signs of recognition during memory concealment, such as the recognition P300. To address this issue, the present study directly compared the recognition-based P300 in CITs with and without feedback. Results showed that the probe elicited a larger recognition P300 than irrelevants in both CITs with and without feedback, and there were no significant differences in recognition P300 between those two CITs. Moreover, the detection rate for recognition-based P300 in both CITs also had no significant difference. The feedback-related ERPs, especially feedback P300, continued to discriminate guilty and innocent subjects with AUCs well above the chance.

Perceived social support moderates neural reactivity to emotionally valenced stimuli during pregnancy

Reactivity to emotional information, measurable at the level of neural activity using event-related potentials, is linked to symptoms of affective disorders. Behavioral evidence suggests that contextual factors, such as social support, can alter emotional reactivity such that affective responding is normalized when social support is high. This possibility remains largely untested at the neural level, specifically through approaches that can offer insight into the mechanistic processes contributing to individual differences in emotional reactivity. Yet, such knowledge could be useful for prevention and intervention efforts, particularly with groups at risk for increased emotional reactivity, such as pregnant mothers for whom emotional distress predicts both maternal and child outcomes. Expectant mothers took part in a longitudinal study that tested whether the late positive potential (LPP), a neural index of reactivity to emotional information, was moderated by maternal perceptions of social support. In the third trimester of pregnancy, lower perceived social support was associated with an absence of a traditional LPP effect, which differentiates valenced from neutral stimuli. Findings suggest that perceptions of social support may normalize emotional processing at the neural level and highlight the potential importance of social support modulation of emotional reactivity during times of known biological change.

Shifts in attentional scope modulate event-related potentials evoked by reward

Emotions broaden or narrow the scope of attention in order to facilitate adaptive responses in threatening and rewarding contexts. In the current study, rather than asking how emotions influence attentional scope, we considered the possibility that the relationship between attentional breadth and emotion is bidirectional by asking whether shifts in attentional scope alter emotional processes using an event-related potential (ERP) paradigm. Participants (N = 30) completed a modified version of a Monetary Incentive Delay (MID) task, wherein their attention was either narrowed or broadened as they attempted to win rewards. Behaviorally, narrowing attention improved task performance in the form of reduced errors and increased monetary winnings. During cue processing, narrowing (compared to broadening) attention reduced the Cue-P3 (irrespective of cue type). During feedback processing, narrowing (compared to broadening) attention reduced the Feedback-P3 to monetary wins and increased the Feedback-P2 and the Feedback-P3 to monetary non-wins. Results highlight complexity and bidirectionality in the relationship between attentional scope and affective processes.

International Energy Security Risk Index—Analysis of the Methodological Settings

The main objective of this paper is to analyze model settings of the International Energy Security Risk Index developed by the U.S. Chamber of Commerce. The study was performed using stepwise regression, principal component analysis, and Promax oblique rotation. The conclusion of the regression analysis shows that Crude Oil Price and Global Coal Reserves are sufficient to explain 90% of the variance of the Index. However, if a model that explains 100% of the variance of the Index is chosen and other variables are added, Global Coal Reserves loses importance due to the presence of other parameters in which it is contained. Regardless of the chosen model of analysis, it is evident that there is room for revising the Index and removing variables that do not contribute to its precision. The research showed that the main disadvantage of the variables that make up the Index rests with the fact that the variables are of different degrees of generality, that is, one parameter is contained in other parameters (unclear which other). The research covers data for 25 countries over a 26-year period, with the first year of the research being 1980 and the last 2016 (the latest available report).