STATSLAB: An open-source EEG toolbox for computing single-subject effects using robust statistics

Children's shyness and early stages of emotional face processing

The ability to detect and recognize facial emotions emerges in childhood and is important for understanding social cues, but we know relatively little about how individual differences in temperament may influence early emotional face processing. We used a sample of 419 children (Mage = 10.57 years, SD = 1.75; 48% female; 77% White) to examine the relation between temperamental shyness and early stages of emotional face processing (assessed using the P100 and N170 event-related potentials) during different facial expressions (neutral, anger, fear, and happy). We found that higher temperamental shyness was related to greater P100 activation to faces expressing anger and fear relative to neutral faces. Further, lower temperamental shyness was related to greater N170 activation to faces expressing anger and fear relative to neutral faces. There were no relations between temperamental shyness and neural activation to happy faces relative to neutral faces for P100 or N170, suggesting specificity to faces signaling threat. We discuss findings in the context of understanding the early processing of facial emotional display of threat among shy children.

Cognitive Event-Related Potentials in Young Adults With Cerebral Palsy: A Proof-of-Concept Study

Cerebral palsy (CP) is a movement and posture disorder often accompanied by cognitive difficulties which can be assessed using event-related potentials (ERPs), an often-overlooked tool in this population. Here we describe our assessment protocol, examine its feasibility, and validate the use of single-subject ERP analyses in adolescents and young adults with CP, an analysis approach which recognizes the heterogeneity of the clinical population. This study involved a final sample of 9 adolescents/young adults with CP participating in the "MyStory" study (age range 16-29 years, Mage = 25.0 years; 6 female; Gross Motor Function Classification System level I [n = 4], II [n = 2], III [n = 1], IV [n = 1], and V [n = 1]). ERP components were elicited over medial prefrontal and central cortex (error- and correct-related negativities [ERN/CRN], error-positivity [Pe], N100, P200, N200, P300), as well as those generated over occipital cortex (P100, N170). Group and single-subject ERP statistics were computed for ERPs recorded over both areas. Using recently developed data analysis methods (independent components analysis and robust bootstrapped single-subject statistics), we measured the number of participants demonstrating significant condition differences at the timing of each ERP component of interest. We demonstrate good validity for ERPs recorded during 2 of our 3 tasks eliciting frontal activation (eg, 4 of 6 participants with usable data showed a significant single-subject medial frontal negativity condition difference in a context-switching task) and good validity for ERPs derived from a task engaging occipital regions (eg, 8 of 9 participants each showed a significant N170 face-object condition effect).

The Relation Between Belief in a Just World and Early Processing of Deserved and Undeserved Outcomes: An ERP Study

We used event-related potentials (ERPs) to examine how quickly people in general, and certain people in particular, process deservingness-relevant information. Female university students completed individual difference measures, including individual differences in the belief in a just world (BJW), a belief that people get what they deserve. They then read stories in which an outcome was deserved, undeserved, or neither deserved nor undeserved (i.e., "neutral") while their ERPs were recorded with scalp electrodes. We found no overall differentiation between early ERP responses (< 300 ms post stimulus onset) to deserved, undeserved, and neutral outcomes. However, BJW correlated with the difference between early ERP responses to these forms of information (rs from |.44| to |.61|; ps from .018 to < .001). The early nature of our effects (e.g., 96 ms after stimulus onset) suggests individual differences in socially-relevant information processing that begins before conscious evaluation of the stimuli. Potential underlying processes include automatic attention to schema-relevant information and to unexpected (and therefore salient) information and automatic processing of belief-consistent information. Our research underscores the importance of the concept of deservingness in human information processing as well as the utility of ERP technology and robust statistical analyses in investigations of complex social stimuli.

Investigating the consistency of ERPs across threatening situations among children and adolescents

Threat sensitivity is thought to be a precursor for anxiety. Yet it remains unknown whether individuals have consistently high neural activation to different threatening situations. The current study (N = 161, M_age = 11.26, SD = 1.79) used three ERPs from different threat-related events: 1) the P3 to receiving negative feedback; 2) the ERN to making mistakes; 3) the N170 to viewing angry faces. Participants also completed self-report measures of threat sensitivity, impulsivity, and demographics. In a follow-up analysis, we also investigated whether the results replicate when using the difference score for each ERP. Youth with higher self-reported sensitivity to threats and lower self-reported impulsivity had consistently higher neural activation to threatening situations. Males also had consistently higher neural activation to threats compared with females. When using the difference score, we found that youth with higher self-reported threat sensitivity had consistently higher neural activation to threats than nonthreats. Although it is common for youth to have high neural activation during at least one threatening situation (e.g., making mistakes), only ~12% of youth have consistently high neural activation across a variety of different threats. Thus, detecting youth who are sensitive to a variety of different threats may be an important avenue to investigate to identify youth most at risk for the development of anxiety.

Increased alpha suppression with age during involuntary memory retrieval

Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited.

An ERP investigation of children and adolescents' sensitivity to wins and losses during a peer observation manipulation

The purpose of this ERP P3 study was to test a peer observation manipulation (being observed by a peer versus being alone) on neural markers of attention to reward (win-feedback) and punishment (loss-feedback) during the Balloon Analogue Risk Task. Participants (126 children, 53 % male, 8–10 years; 196 early adolescents, 50 % male, 11–13 years; and 121 mid-adolescents, 52 % male, 14–16 years) were assessed by age group and pubertal status. Individual differences in how participants felt about being observed by a peer, and self-report personality factors, also were examined. Findings indicated that early and mid-adolescents (and individuals in mid-puberty and late-puberty) were sensitive to peer observation as both groups showed larger neural responses to loss-feedback in the peer condition than in the alone condition. Conversely, children (and individuals in pre- and early-puberty) were unaffected by peer observation. In addition, there clearly were individual differences in how rewarding versus anxiety-provoking participants found the peer experience. Early adolescents and mid-adolescents (and individuals in mid- and late-puberty) who reported feeling more anxious about the peer observation elicited larger neural responses to loss-feedback, and individuals in mid- and late-puberty in particular reported higher worry and lower sensation-seeking scores than those who reported a positive experience.

CA, Klingner CM. The Right Hemisphere Is Responsible for the Greatest Differences in Human Brain Response to High-Arousing Emotional versus Neutral Stimuli: A MEG Study

Studies investigating human brain response to emotional stimuli-particularly high-arousing versus neutral stimuli-have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270-320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

A person-centered examination of emotion dysregulation, sensitivity to threat, and impulsivity among children and adolescents: An ERP study

Objectives

Adolescence often is characterized by the onset of social anxiety and risk taking; yet, not all youth are anxious and/or risk takers. There are several factors that may help differentiate youth with anxiety (e.g., threat sensitivity and emotion dysregulation) and youth who take risks (e.g., impulsivity and emotion dysregulation). We conducted a latent class analysis to identify groups of youth who differ in these processes, and then investigated group differences on the error-related negativity, an ERP that has been differentially associated with threat sensitivity and impulsivity.

Method

Youth (N = 1313, M_age = 11, range = 8–15 years) completed a survey assessing their emotion dysregulation, sensitivity to threat, and impulsivity. A subsample (N = 424) also completed a go/no-go task while EEG was recorded.

Results and conclusions

Four groups were identified with differential levels of emotion dysregulation, sensitivity to threat, and impulsivity. Adolescents had greater odds than children of being in the High_Dysregulation/ThreatSensitivity or ModerateDysregulation/HighImpulsivity Groups in comparison to two other groups with lower scores. The High_Dysregulation/ThreatSensitivity Group had the largest ERN, while the ModerateDysregulation/HighImpulsivity Group had the smallest ERN. The ERN may be a potential biomarker to help distinguish between different profiles of adolescents who may be at risk for either anxiety or risk taking.

EEG Integrated Platform Lossless (EEG-IP-L) pre-processing pipeline for objective signal quality assessment incorporating data annotation and blind source separation

BACKGROUND

The methods available for pre-processing EEG data are rapidly evolving as researchers gain access to vast computational resources; however, the field currently lacks a set of standardized approaches for data characterization, efficient interactive quality control review procedures, and large-scale automated processing that is compatible with High Performance Computing (HPC) resources.

NEW METHOD

In this paper we describe an infrastructure for the development of standardized procedures for semi and fully automated pre-processing of EEG data. Our pipeline incorporates several methods to isolate cortical signal from noise, maintain maximal information from raw recordings and provide comprehensive quality control and data visualization. In addition, batch processing procedures are integrated to scale up analyses for processing hundreds or thousands of data sets using HPC clusters.

RESULTS

We demonstrate here that by using the EEG Integrated Platform Lossless (EEG-IP-L) pipeline's signal quality annotations, significant increase in data retention is achieved when applying subsequent post-processing ERP segment rejection procedures. Further, we demonstrate that the increase in data retention does not attenuate the ERP signal.

CONCLUSIONS

The EEG-IP-L state provides the infrastructure for an integrated platform that includes long-term data storage, minimal data manipulation and maximal signal retention, and flexibility in post processing strategies.

EEG-IP: an international infant EEG data integration platform for the study of risk and resilience in autism and related conditions

BACKGROUND

Establishing reliable predictive and diganostic biomarkers of autism would enhance early identification and facilitate targeted intervention during periods of greatest plasticity in early brain development. High impact research on biomarkers is currently limited by relatively small sample sizes and the complexity of the autism phenotype.

METHODS

EEG-IP is an International Infant EEG Data Integration Platform developed to advance biomarker discovery by enhancing the large scale integration of multi-site data. Currently, this is the largest multi-site standardized dataset of infant EEG data.

RESULTS

First, multi-site data from longitudinal cohort studies of infants at risk for autism was pooled in a common repository with 1382 EEG longitudinal recordings, linked behavioral data, from 432 infants between 3- to 36-months of age. Second, to address challenges of limited comparability across independent recordings, EEG-IP applied the Brain Imaging Data Structure (BIDS)-EEG standard, resulting in a harmonized, extendable, and integrated data state. Finally, the pooled and harmonized raw data was preprocessed using a common signal processing pipeline that maximizes signal isolation and minimizes data reduction. With EEG-IP, we produced a fully standardized data set, of the pooled, harmonized, and pre-processed EEG data from multiple sites.

CONCLUSIONS

Implementing these integrated solutions for the first time with infant data has demonstrated success and challenges in generating a standardized multi-site data state. The challenges relate to annotation of signal sources, time, and ICA analysis during pre-processing. A number of future opportunities also emerge, including validation of analytic pipelines that can replicate existing findings and/or test novel hypotheses.

One-Month Stability of Cyberball Post-Exclusion Ostracism Distress in Adolescents

We examined one-month reliability, internal consistency, and validity of ostracism distress (Need Threat Scale) to simulated social exclusion during Cyberball. Thirty adolescents (13-18 yrs.) completed the Cyberball task, ostracism distress ratings, and measures of related clinical symptoms, repeated over one month. Need Threat Scale ratings of ostracism distress showed adequate test-retest reliability and internal consistency at both occasions. Construct validity was demonstrated via relationships with closely related constructs of anxiety, anxiety sensitivity, and emotion dysregulation, and weaker associations with more distal constructs of state paranoia and subclinical psychosis-like experiences. While ratings of ostracism distress and anxiety were significantly attenuated at retest, most participants continued to experience post-Cyberball ostracism distress at one-month follow-up, which indicates that the social exclusion induction of Cyberball persisted despite participants' familiarity with the paradigm. Overall, results suggest that the primary construct of ostracism distress is preserved over repeated administration of Cyberball, with reliability sufficient for usage in longitudinal research. These findings have important implications for translating this laboratory simulation of social distress into developmental and clinical intervention studies.