Using multilevel models for the analysis of event-related potentials

A registered report of a two-site study of variations of the flanker task: ERN experimental effects and data quality

Error-related negativity is a widely used measure of error monitoring, and many projects are independently moving ERN recorded during a flanker task toward standardization, optimization, and eventual clinical application. However, each project uses a different version of the flanker task and tacitly assumes ERN is functionally equivalent across each version. The routine neglect of a rigorous test of this assumption undermines efforts to integrate ERN findings across tasks, optimize and standardize ERN assessment, and widely apply ERN in clinical trials. The purpose of this registered report was to determine whether ERN shows similar experimental effects (correct vs. error trials) and data quality (intraindividual variability) during three commonly used versions of a flanker task. ERN was recorded from 172 participants during three versions of a flanker task across two study sites. ERN scores showed numerical differences between tasks, raising questions about the comparability of ERN findings across studies and tasks. Although ERN scores from all three versions of the flanker task yielded high data quality and internal consistency, one version did outperform the other two in terms of the size of experimental effects and the data quality. Exploratory analyses of the error positivity (Pe) provided tentative support for the other two versions of the task over the paradigm that appeared optimal for ERN. The present study provides a roadmap for how to statistically compare psychometric characteristics of ERP scores across paradigms and gives preliminary recommendations for flanker tasks to use for ERN- and Pe-focused studies.

Human papillomavirus vaccination and contributing factors of vaccination intention among adolescents and young adults in China from a socio-ecological perspective: A cross-sectional study

OBJECTIVES

Adolescents and young adults are the main target population for human papillomavirus (HPV). The study aimed to investigate school students' HPV vaccination intentions and explore the contributing factors from a socio-ecological perspective.

DESIGN

A questionnaire survey was conducted in three secondary schools and three colleges in China.

SAMPLE

A total of 1756 students aged 14-22 years participated in this study. Among the 1756 participants, 182 students have received the HPV vaccine. For the remaining 1574 students, we analyzed their HPV vaccination intentions and the influencing factors.

MEASUREMENTS

Survey items for sociodemographics, knowledge and awareness of HPV, sexual intercourse and sexual knowledge, subjective socioeconomic status, self-efficacy, eHealth literacy, perceived social support from family, and the availability of HPV vaccine information were measured.

RESULTS

Only 182 (10.4%) had received the HPV vaccine among the 1756 participants. Among the remaining 1574 students, the majority of the students (1403, 89.1%) were willing to receive the HPV vaccine. Binary logistic regression analysis showed that students who were female, had lower self-efficacy, scored higher on sexual knowledge, believed vaccination preventing related diseases, worried about side effects after vaccination, thought oneself at risk of contracting HPV, had higher family support, knew the availability of the HPV vaccine in Mainland China from healthcare institutions, and with family residence in rural areas were more willing to receive the HPV vaccine.

CONCLUSIONS

Students had high HPV vaccination intentions while had low vaccination rate. Intrapersonal, interpersonal and institutional or community factors predicted HPV vaccination intention. Public health nurses in communities and schools could target the modifiable factors to promote students' HPV vaccine uptake.

Prediction-error-dependent processing of immediate and delayed positive feedback

Learning often involves trial-and-error, i.e. repeating behaviours that lead to desired outcomes, and adjusting behaviour when outcomes do not meet our expectations and thus lead to prediction errors (PEs). PEs have been shown to be reflected in the reward positivity (RewP), an event-related potential (ERP) component between 200 and 350 ms after performance feedback which is linked to striatal processing and assessed via electroencephalography (EEG). Here we show that this is also true for delayed feedback processing, for which a critical role of the hippocampus has been suggested. We found a general reduction of the RewP for delayed feedback, but the PE was similarly reflected in the RewP and the later P300 for immediate and delayed positive feedback, while no effect was found for negative feedback. Our results suggest that, despite processing differences between immediate and delayed feedback, positive PEs drive feedback processing and learning irrespective of delay.

Electrophysiological indexes of ingroup bias in a group Stroop task: Evidence from an event-related potential study

Although cognitive system assigns higher attentional resources to ingroup information than outgroup information, but it is unclear whether the ingroup bias can be measured by the processes that are related to allocation of attentional resources to ingroup information. Thus, a group Stroop task was developed to study the issues combining with event-related potential (ERP) technique in this study. Specifically, 34 subjects (17 female, mean age = 20.76 ± 1.26) were firstly divided into blue or red group (17 subjects for each group); then they were asked to categorize four words of Stroop task into "our team" or "other team" based on the ink color (blue/red) of the words whose meaning were also red/blue. The behavioral results showed that outgroup ink color processing was interfered by ingroup word meaning, but the ingroup ink color processing was less/not interfered by outgroup word meaning. The ERP results showed that the amplitude of frontal N100 was enhanced when more attentional resources were automatically captured by ingroup information in early stage than outgroup information; P2/N2 amplitude was reduced or enhanced when outgroup information processing was interfered by ingroup information; enhanced P3b amplitude reflected that attention could be more easily allocated to ingroup information than outgroup information based on target. This study implied a novel direction to study the neural basis of ingroup bias by investigating the roles of ingroup bias in assigning attentional resources to group information.

Mothers' and fathers' neural responses toward gender-stereotype violations by their own children

Gender stereotypes facilitate people's processing of social information by providing assumptions about expected behaviors and preferences. When gendered expectations are violated, people often respond negatively, both on a behavioral and neural level. Little is known about the impact of family kinship on the behavioral and neural reactions to gender-stereotype violations. Therefore, we examined whether parents show different responses when gender stereotypes are violated by their own children vs unknown children. The sample comprised 74 Dutch families with a father (Mage = 37.54), mother (Mage = 35.83), son, and daughter aged 3-6 years. Electroencephalography measurements were obtained while parents viewed pictures of their own and unknown children paired with toy or problem behavior words that violated or confirmed gender stereotypes. In half of the trials, parents evaluated the appropriateness of toy-gender and behavior-gender combinations. Parents showed stronger late positive potential amplitudes toward gender stereotype-violating behaviors by own children compared to unknown children. Moreover, parents' P1 responses toward gender stereotype-violating child behaviors were stronger for boys than for girls and for parents who evaluated gender-stereotype violations as less appropriate than gender-stereotype confirmations. These findings indicated that gender-stereotype violations by parents' own children are particularly salient and viewed as less appropriate than gender-stereotype confirmations.

Domain specificity of error monitoring: An ERP study in young and older adults

Metacognition refers to the ability to monitor and control one's cognitive processes, which plays an important role in decision-making throughout the lifespan. It is still debated whether metacognitive abilities decline with age. Neuroimaging evidence suggests that metacognition is served by domain-specific mechanisms. These domains may differentially decline with increasing age. The current investigates whether the error-related negativity (ERN) and the error positivity (Pe) which reflect error detection and error awareness, respectively, differ across perceptual and memory domains in young and older adults. In total, 38 young adults and 37 older adults completed a classic Flanker Task (perceptual) and an adapted memory-based version. No difference in ERN amplitude was found between young and older adults and across domains. Perceptual ERN peaked earlier than Memory ERN. Memory ΔERN was larger than Perceptual ΔERN. Pe was smaller in older adults and ΔPe was larger for perceptual than memory flanker. Memory Pe peaked earlier in young as compared to older adults. Multivariate analyses of whole scalp data supported cross-domain differences. During the task, ERN decreased in young but not in older adults. Memory Pe decreased in young adults but increased in older adults while no significant change in perceptual Pe was found. The study's findings suggest that neural correlates of error monitoring differ across cognitive domains. Moreover, it was shown that error awareness declines in old age but its within-task dynamics vary across cognitive domains. Possible mechanisms underlying metacognition impairments in aging are discussed.

Beyond single paradigms, pipelines, and outcomes: Embracing multiverse analyses in psychophysiology

Psychophysiological research is an inherently complex undertaking due to the nature of the data, and its analysis is characterized by many decision points that shape the final dataset and a study's findings. These decisions create a "multiverse" of possible outcomes, and each decision from study conceptualization to statistical analysis can lead to different results and interpretations. This review describes the concept of multiverse analyses, a methodological approach designed to understand the impact of different decisions on the robustness of a study's findings and interpretation. The emphasis is on transparently showcasing different reasonable approaches for constructing a final dataset and on highlighting the influence of various decision points, from experimental design to data processing and outcome selection. For example, the choice of an experimental task can significantly impact event-related brain potential (ERP) scores or skin conductance responses (SCRs), and different tasks might elicit unique variances in each measure. This review underscores the importance of transparently embracing the flexibility inherent in psychophysiological research and the potential consequences of not understanding the fragility or robustness of experimental findings. By navigating the intricate terrain of the psychophysiological multiverse, this review serves as an introduction, helping researchers to make informed decisions, improve the collective understanding of psychophysiological findings, and push the boundaries of the field.

Trial-level ERPs predicted behavioral responses during self-referential processing in late childhood

Self-referential information is uniquely salient and preferentially processed even in children. The literature has used the self-referent encoding task (SRET) combined with event-related potentials (ERPs) to study self-referential processing and its associations with youth psychopathology. However, it is unclear how the ERP and behavioral indices of SRET are associated with each other, although this knowledge can promote our mechanistic understanding of this construct and its role in psychopathology. We examined this question in 115 9- to 12-year-old children, a critical period for the development of self-related concepts. By applying a multilevel modeling approach to the trial-level data of SRET, we disaggregated the between- and within-person variability and observed within-person, but not between-person, effects of the P2 and late positive potential (LPP) on behavioral responses: a larger P2 on a given trial predicted a faster response in this trial; a larger LPP on a given trial predicted a higher likelihood of endorsing the word of this trial. We provided novel evidence on how the within-person variability of the ERPs predicted the overt responses of the SRET in children. These findings inform our mechanistic knowledge of self-referential processing and shed light on a better understanding of the role of self-referential processing in the development of psychopathology.

Women are expected to smile: Preliminary evidence for the role of gender in the neurophysiological processing of adult emotional faces in 3-year-old children

Children form stereotyped expectations about the appropriateness of certain emotions for men versus women during the preschool years, based on cues from their social environments. Although ample research has examined the development of gender stereotypes in children, little is known about the neural responses that underlie the processing of gender-stereotyped emotions in children. Therefore, the current study examined whether 3-year-olds differ in the neural processing of emotional stimuli that violate gender stereotypes (i.e., male faces with fearful or happy expressions) or confirm gender stereotypes (i.e., female faces with fearful or happy expressions), and whether boys and girls differ in their neural processing of the violation and confirmation of gender stereotypes. Data from 72 3-year-olds (±6 months, 43% boy) were obtained from the YOUth Cohort Study. Electroencephalography data were obtained when children passively viewed male and female faces displaying neutral, happy, or fearful facial expressions. This study provided first indications that happy male faces elicited larger P1 amplitudes than happy female faces in preschool children, which might reflect increased attentional processing of stimuli that violate gender stereotypes. Moreover, there was preliminary evidence that girls had larger negative central (Nc) responses, associated with salience processing, toward female happy faces than male happy faces, whereas boys had larger Nc responses toward male happy faces than female happy faces. No gender differences were found in the processing of neutral and fearful facial expressions. Our results indicate that electroencephalography measurements can provide insights into preschoolers' gender-stereotype knowledge about emotions, potentially by looking at the early occipital and late fronto-central responses.

Normal congruency sequence effects in psychopathology: A behavioral and electrophysiological examination using a confound-minimized design

Clinical studies of adaptive control emphasize the role disruptions in control play in psychopathology. However, many studies used confound-laden designs and examined only one type of psychopathology. Recent studies of event-related potentials (ERPs) suggest that robust congruency sequence effects (CSEs)-a popular index of adaptive control-appear in confound-minimized designs. Thus, the present study sought to determine whether a confound-minimized CSE paradigm could identify adaptive control dysfunction in people with major depressive disorder (MDD), generalized anxiety disorder (GAD), and obsessive-compulsive disorder (OCD). We predicted that participants with MDD and GAD would show smaller ERP CSEs and that participants with OCD would show larger ERP CSEs than healthy controls. Data from 44 people with GAD, 51 people with MDD, 31 people with OCD, and 56 healthy comparison participants revealed normal CSEs as indexed by response times (RTs) and ERPs in the psychopathology groups. Moreover, psychiatric symptoms did not moderate these CSEs. Finally, we observed a strong mean-variance relationship in RT CSEs, such that participants with stronger post-recruitment of control in mean RT scores showed the most consistent post-conflict responses (i.e., the least intraindividual variability). These findings suggest that prior findings from confound-laden tasks indicating altered CSEs in psychopathology stem from processes that are unrelated to adaptive control. Future research should employ experimental designs that isolate these processes to advance our understanding of abnormal CSEs in psychopathology.

Mismatch Responses to Speech Contrasts in Preschoolers with and without Developmental Language Disorder

This study compared cortical responses to speech in preschoolers with typical language development (TLD) and with Developmental Language Disorder (DLD). We investigated whether top-down language effects modulate speech perception in young children in an adult-like manner. We compared cortical mismatch responses (MMRs) during the passive perception of speech contrasts in three groups of participants: preschoolers with TLD (n = 11), preschoolers with DLD (n = 16), and adults (n = 20). We also measured children's phonological skills and investigated whether they are associated with the cortical discrimination of phonemic changes involving different linguistic complexities. The results indicated top-down language effects in adults, with enhanced cortical discrimination of lexical stimuli but not of non-words. In preschoolers, the TLD and DLD groups did not differ in the MMR measures, and no top-down effects were detected. Moreover, we found no association between MMRs and phonological skills, even though the DLD group's phonological skills were significantly lower. Our findings suggest that top-down language modulations in speech discrimination may not be present during early childhood, and that children with DLD may not exhibit cortical speech perception deficits. The lack of association between phonological and MMR measures indicates that further research is needed to understand the link between language skills and cortical activity in preschoolers.

Towards Optimization of Oscillatory Stimulation During Sleep

BACKGROUND

Oscillatory rhythms during sleep, such as slow oscillations (SOs) and spindles and, most importantly, their coupling, are thought to underlie processes of memory consolidation. External slow oscillatory transcranial direct current stimulation (so-tDCS) with a frequency of 0.75 Hz has been shown to improve this coupling and memory consolidation; however, effects varied quite markedly between individuals, studies, and species. In this study, we aimed to determine how precisely the frequency of stimulation must match the naturally occurring SO frequency in individuals to best improve SO-spindle coupling. Moreover, we systematically tested stimulation durations necessary to induce changes.

MATERIALS AND METHODS

We addressed these questions by comparing so-tDCS with individualized frequency to standardized frequency of 0.75 Hz in a within-subject design with 28 older participants during napping while stimulation train durations were systematically varied between 30 seconds, 2 minutes, and 5 minutes.

RESULTS

Stimulation trains as short as 30 seconds were sufficient to modulate the coupling between SOs and spindle activity. Contrary to our expectations, so-tDCS with standardized frequency indicated stronger aftereffects regarding SO-spindle coupling than individualized frequency. Angle and variance of spindle maxima occurrence during the SO cycle were similarly modulated.

CONCLUSIONS

In sum, short stimulation trains were sufficient to induce significant changes in sleep physiology, allowing for more trains of stimulation, which provides methodological advantages and possibly even larger behavioral effects in future studies. Regarding individualized stimulation frequency, further options of optimization need to be investigated, such as closed-loop stimulation, to calibrate stimulation frequency to the SO frequency at the time of stimulation onset.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT04714879.

Smartphone-based ear-electroencephalography to study sound processing in everyday life

In everyday life, people differ in their sound perception and thus sound processing. Some people may be distracted by construction noise, while others do not even notice. With smartphone-based mobile ear-electroencephalography (ear-EEG), we can measure and quantify sound processing in everyday life by analysing presented sounds and also naturally occurring ones. Twenty-four participants completed four controlled conditions in the lab (1 h) and one condition in the office (3 h). All conditions used the same paired-click stimuli. In the lab, participants listened to click tones under four different instructions: no task towards the sounds, reading a newspaper article, listening to an audio article or counting a rare deviant sound. In the office recording, participants followed daily activities while they were sporadically presented with clicks, without any further instruction. In the beyond-the-lab condition, in addition to the presented sounds, environmental sounds were recorded as acoustic features (i.e., loudness, power spectral density and sounds onsets). We found task-dependent differences in the auditory event-related potentials (ERPs) to the presented click sounds in all lab conditions, which underline that neural processes related to auditory attention can be differentiated with ear-EEG. In the beyond-the-lab condition, we found ERPs comparable to some of the lab conditions. The N1 amplitude to the click sounds beyond the lab was dependent on the background noise, probably due to energetic masking. Contrary to our expectation, we did not find a clear ERP in response to the environmental sounds. Overall, we showed that smartphone-based ear-EEG can be used to study sound processing of well defined-stimuli in everyday life.

An Agent-First Preference in a Patient-First Language During Sentence Comprehension

The language comprehension system preferentially assumes that agents come first during incremental processing. While this might reflect a biologically fixed bias, shared with other domains and other species, the evidence is limited to languages that place agents first, and so the bias could also be learned from usage frequency. Here, we probe the bias with electroencephalography (EEG) in Äiwoo, a language that by default places patients first, but where sentence-initial nouns are still locally ambiguous between patient or agent roles. Comprehenders transiently interpreted nonhuman nouns as patients, eliciting a negativity when disambiguation was toward the less common agent-initial order. By contrast and against frequencies, human nouns were transiently interpreted as agents, eliciting an N400-like negativity when the disambiguation was toward patient-initial order. Consistent with the notion of a fixed property, the agent bias is robust against usage frequency for human referents. However, this bias can be reversed by frequency experience for nonhuman referents.

Inhibition of midfrontal theta with transcranial ultrasound explains greater approach versus withdrawal behavior in humans

Recent reviews highlighted low-intensity transcranial focused ultrasound (TUS) as a promising new tool for non-invasive neuromodulation in basic and applied sciences. Our preregistered double-blind within-subjects study (N = 152) utilized TUS targeting the right prefrontal cortex, which, in earlier work, was found to positively enhance self-reported global mood, decrease negative states of self-reported emotional conflict (anxiety/worrying), and modulate related midfrontal functional magnetic resonance imaging activity in affect regulation brain networks. To further explore TUS effects on objective physiological and behavioral variables, we used a virtual T-maze task that has been established in prior studies to measure motivational conflicts regarding whether participants execute approach versus withdrawal behavior (with free-choice responses via continuous joystick movements) while allowing to record related electroencephalographic data such as midfrontal theta activity (MFT). MFT, a reliable marker of conflict representation on a neuronal level, was of particular interest to us since it has repeatedly been shown to explain related behavior, with relatively low MFT typically preceding approach-like risky behavior and relatively high MFT typically preceding withdrawal-like risk aversion. Our central hypothesis is that TUS decreases MFT in T-maze conflict situations and thereby increases approach and reduces withdrawal. Results indicate that TUS led to significant MFT decreases, which significantly explained increases in approach behavior and decreases in withdrawal behavior. This study expands TUS evidence on a physiological and behavioral level with a large sample size of human subjects, suggesting the promise of further research based on this distinct TUS-MFT-behavior link to influence conflict monitoring and its behavioral consequences. Ultimately, this can serve as a foundation for future clinical work to establish TUS interventions for emotional and motivational mental health.

Age Differences in Physiological Reactivity to Daily Emotional Experiences

How does physiological reactivity to emotional experiences change with age? Previous studies addressing this question have mostly been conducted in laboratory settings during which emotions are induced via pictures, films, or relived memories, raising external validity questions. In the present research, we draw upon two datasets collected using ecological momentary assessment methods (totaling 134,723 daily reports from 14,436 individuals) to examine age differences in heart rate (HR) and blood pressure (BP) reactivity to naturally occurring emotional experiences. We first examined how older and younger individuals differ in the prevalence of emotions varying in valence and arousal. On average, people reported experiencing positive emotions (high or low arousal) more than 70% of the time they were asked, and older (vs. younger) individuals tended to report positive emotions more frequently. In terms of physiological reactivity, we found that age was associated with reduced HR and BP reactivity. Some evidence was also found that the magnitude of such age differences may depend on the valence or arousal of the experienced emotion. The present findings have implications for understanding how emotions can contribute to physical health across the lifespan.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-023-00207-z.

Auditory N1 and P2 Attenuation in Action Observation: An Event-Related Potential Study Considering Effects of Temporal Predictability and Individualism

Tones that are generated by self-performed actions elicit attenuated N1 and P2 amplitudes, as measured by electroencephalography (EEG), compared to identical external tones, which is referred to as neurophysiological sensory attenuation (SA). At the same time, self-generated tones are perceived as less loud compared to external tones (perceptual SA). Action observation led in part to a similar neurophysiological and perceptual SA. The perceptual SA in observers was found in comparison to tones that were temporally predictable, and one study suggested that perceptual SA in observers might depend on the cultural dimension of individualism. In this study, we examined neurophysiological SA for tones elicited by self-performed and observed actions during simultaneous EEG acquisitions in two participants, extending the paradigm with a visual cue condition controlling for effects of temporal predictability. Moreover, we investigated the effect of individualism on neurophysiological SA in action observation. Relative to un-cued external tones, the N1 was only descriptively reduced for tones that were elicited by self-performed or observed actions and significantly attenuated for cued external tones. A P2 attenuation effect relative to un-cued external tones was found in all three conditions, with stronger effects for self- and other-generated tones than for cued external tones. We found no evidence for an effect of individualism. These findings add to previous evidence for neurophysiological SA in action performance and observation with a paradigm well-controlled for the effect of predictability and individualism, showing differential effects of the former on the N1 and P2 components, and no effect of the latter.

Age differences in central auditory system responses to naturalistic music

Aging influences the central auditory system leading to difficulties in the decoding and understanding of overlapping sound signals, such as speech in noise or polyphonic music. Studies on central auditory system evoked responses (ERs) have found in older compared to young listeners increased amplitudes (less inhibition) of the P1 and N1 and decreased amplitudes of the P2, mismatch negativity (MMN), and P3a responses. While preceding research has focused on simplified auditory stimuli, we here tested whether the previously observed age-related differences could be replicated with sounds embedded in medium and highly naturalistic musical contexts. Older (age 55-77 years) and younger adults (age 21-31 years) listened to medium naturalistic (synthesized melody) and highly naturalistic (studio recording of a music piece) stimuli. For the medium naturalistic music, the age group differences on the P1, N1, P2, MMN, and P3a amplitudes were all replicated. The age group differences, however, appeared reduced with the highly compared to the medium naturalistic music. The finding of lower P2 amplitude in older than young was replicated for slow event rates (0.3-2.9Hz) in the highly naturalistic music. Moreover, the ER latencies suggested a gradual slowing of the auditory processing time course for highly compared to medium naturalistic stimuli irrespective of age. These results support that age-related differences on ERs can partly be observed with naturalistic stimuli. This opens new avenues for including naturalistic stimuli in the investigation of age-related central auditory system disorders.

Default categorization of outgroup faces and the other race effect: Commentary on the special issue

This commentary addresses how studies examining the neurophysiological correlates of racial categorization can provide insight into the neurocognitive mechanisms of the other-race effect in recognition memory. Several articles in the special issue describe how event-related potentials (ERPs) have been used to examine processing of faces that vary according to race, some of which have concluded that larger ERP amplitudes elicited by other-race (relative to own-race) faces indicates less efficient visual processing of other-race faces. I describe findings from ERP studies of race categorization that suggest an alternative interpretation-that other-race faces elicit stronger categorization, which impedes individuation of other-race faces. Suggestions for future research are offered.

My view on your actions: Dynamic changes in viewpoint-dependent auditory ERP attenuation during action observation

It has been suggested that during action observation, a sensory representation of the observed action is mapped onto one's own motor system. However, it is largely unexplored what this may imply for the early processing of the action's sensory consequences, whether the observational viewpoint exerts influence on this and how such a modulatory effect might change over time. We tested whether the event-related potential of auditory effects of actions observed from a first- versus third-person perspective show amplitude reductions compared with externally generated sounds, as revealed for self-generated sounds. Multilevel modeling on trial-level data showed distinct dynamic patterns for the two viewpoints on reductions of the N1, P2, and N2 components. For both viewpoints, an N1 reduction for sounds generated by observed actions versus externally generated sounds was observed. However, only during first-person observation, we found a temporal dynamic within experimental runs (i.e., the N1 reduction only emerged with increasing trial number), indicating time-variant, viewpoint-dependent processes involved in sensorimotor prediction during action observation. For the P2, only a viewpoint-independent reduction was found for sounds elicited by observed actions, which disappeared in the second half of the experiment. The opposite pattern was found in an exploratory analysis concerning the N2, revealing a reduction that increased in the second half of the experiment, and, moreover, a temporal dynamic within experimental runs for the first-person perspective, possibly reflecting an agency-related process. Overall, these results suggested that the processing of auditory outcomes of observed actions is dynamically modulated by the viewpoint over time.

Investigating the attentional focus to workplace-related soundscapes in a complex audio-visual-motor task using EEG

Introduction

In demanding work situations (e.g., during a surgery), the processing of complex soundscapes varies over time and can be a burden for medical personnel. Here we study, using mobile electroencephalography (EEG), how humans process workplace-related soundscapes while performing a complex audio-visual-motor task (3D Tetris). Specifically, we wanted to know how the attentional focus changes the processing of the soundscape as a whole.

Method

Participants played a game of 3D Tetris in which they had to use both hands to control falling blocks. At the same time, participants listened to a complex soundscape, similar to what is found in an operating room (i.e., the sound of machinery, people talking in the background, alarm sounds, and instructions). In this within-subject design, participants had to react to instructions (e.g., "place the next block in the upper left corner") and to sounds depending on the experimental condition, either to a specific alarm sound originating from a fixed location or to a beep sound that originated from varying locations. Attention to the alarm reflected a narrow attentional focus, as it was easy to detect and most of the soundscape could be ignored. Attention to the beep reflected a wide attentional focus, as it required the participants to monitor multiple different sound streams.

Results and discussion

Results show the robustness of the N1 and P3 event related potential response during this dynamic task with a complex auditory soundscape. Furthermore, we used temporal response functions to study auditory processing to the whole soundscape. This work is a step toward studying workplace-related sound processing in the operating room using mobile EEG.

Reduced P300 amplitude is consistently associated with trait anhedonia across repeated assessments

Understanding how event-related potentials (ERPs) change following repeated assessments is critical to advance our understanding of neural mechanisms implicated in psychopathology. Specifically, it is unclear if associations between ERPs and individual differences can be reproduced when repeatedly measured within the same participants, or if clinical characteristics impact ERP trajectories over repeated assessments. The present study assessed P300 amplitude and latency from a flanker task at four time points over one month (M = 7.24 days between assessments [SD = 1.02]) in 79 female undergraduates to examine how P300 amplitude/latency changes across repeated assessments, the presence of associations between within- and between-subjects measures of current depressive symptoms and the P300, and if between-subjects depressive symptoms moderated change in P300 over repeated assessment. Results using multilevel modeling indicated a significant reduction in P300 amplitude and latency across assessments. Individuals with increased trait anhedonia (i.e., between-subjects) exhibited reduced P300 amplitudes across assessments; there were no associations of within-subjects fluctuations in anhedonia symptoms and P300 amplitude across assessments. There was also no interaction between number of assessments and between-subjects anhedonia in relation to P300 amplitude. Unlike anhedonia, between-subjects dysphoria was unrelated to P300. These results demonstrate a relatively specific and consistent association between an attenuated P300 amplitude and trait anhedonia across repeated assessments - data that may further suggest that flanker P300 amplitude reflects hedonic and motivational processes.

Acute sensitization of the P3 event-related potential response to beverage images and the risk for alcohol use disorder

Previous research suggests the amplitude of the P3 event-related potential (ERP) response reflects the incentive value of the eliciting stimulus, and that individuals with trait-like lower sensitivity (LS) to the acute effects of alcohol, a potent risk factor for alcohol use disorder (AUD), tend to show exaggerated P3 ERP responses to alcohol beverage cues (compared to their peers with higher sensitivity; HS). No prior research has examined trajectories of the cue-elicited P3 response across repeated trials of nonreinforced cue presentations. Characterizing these trajectories can be informative as to potential mechanisms linking LS with increased AUD risk. Here, we tested whether individual differences in alcohol sensitivity are associated with different trial-by-trial trajectories of the P3 elicited by alcohol and nonalcohol reward cues (infrequent oddball/target stimuli) using a large sample of emerging adults (M _age = 19.53; N = 287; 55% female; 86% White; 90% right-handed) stratified for alcohol sensitivity. Multilevel models adjusted for age, sex, handedness, and alcohol use indicated that: (i) the P3 response to alcohol and nonalcohol reward cues alike sensitized (i.e., increased) across trials; (ii) across the task, the P3 response to alcohol cues was larger for the LS than the HS phenotype; and (iii) the P3 difference score (alcohol - nonalcohol) was larger for the LS than HS phenotype only across the first half of task. Findings suggest that whereas incentive value attribution may be a mechanism for alcohol cue-triggered attentional biases for both LS and HS individuals, LS individuals more consistently over-attribute incentive value to alcohol cues.

Wavelet Based Filters for Artifact Elimination in Electroencephalography Signal: A Review

Electroencephalography (EEG) is a diagnostic test that records and measures the electrical activity of the human brain. Research investigating human behaviors and conditions using EEG has increased from year to year. Therefore, an efficient approach is vital to process the EEG dataset to improve the output signal quality. The wavelet is one of the well-known approaches for processing the EEG signal in time-frequency domain analysis. The wavelet is better than the traditional Fourier Transform because it has good time-frequency localized properties and multi-resolution analysis where the transient information of an EEG signal can be extracted efficiently. Thus, this review article aims to comprehensively describe the application of the wavelet method in denoising the EEG signal based on recent research. This review begins with a brief overview of the basic theory and characteristics of EEG and the wavelet transform method. Then, several wavelet-based methods commonly applied in EEG dataset denoising are described and a considerable number of the latest published EEG research works with wavelet applications are reviewed. Besides, the challenges that exist in current EEG-based wavelet method research are discussed. Finally, alternative solutions to mitigate the issues are recommended.

Behavioral response bias and event-related brain potentials implicate elevated incentive salience attribution to alcohol cues in emerging adults with lower sensitivity to alcohol

AIMS

This study used a behavioral approach-avoidance task including images of alcoholic beverages to test whether low sensitivity to alcohol (LS) is a phenotypical marker of a dispositional propensity to attribute bottom-up incentive value to naturally conditioned alcohol cues.

DESIGN, SETTING AND PARTICIPANTS

Experimental study with a measured individual difference variable at a university psychology laboratory in Missouri, MO, USA. Participants were 178 emerging adults (aged 18-20 years) varying in self-reported sensitivity to alcohol's acute effects.

MEASUREMENTS

Participants completed the alcohol approach-avoidance task while behavior (response time; RT) and the electroencephalogram (EEG) were recorded. Stimulus-locked event-related potentials (ERPs) provided indices of integrated (top-down and bottom-up) stimulus incentive value (P3 amplitude) and conflict between top-down task demands and bottom-up response propensities (N450 amplitude).

FINDINGS

Linear mixed models showed faster RT for 'alcohol-approach' relative to 'alcohol-avoid' trials for lower-sensitivity (LS) [mean_D  ± standard error_D (M_D  ± SE_D ) = 29.51 ± 9.74 ms, t₍₃₂₈₎  = 3.03, P = 0.003] but not higher-sensitivity (HS) individuals (M_D  ± SE_D  = 2.27 ± 9.33 ms, t₍₃₂₈₎  = 0.243, P = 0.808). There was enhanced N450 amplitude (response conflict) for alcohol-avoid relative to alcohol-approach trials for LS participants (M_D  ± SE_D  = 0.811 ± 0.198 μV, Z = 4.108, P < 0.001) and enhanced N450 amplitude for alcohol-approach relative to alcohol-avoid for HS participants (M_D  ± SE_D  = 0.419 ± 0.188 μV, Z = 2.235, P = 0.025). There was also enhanced P3 amplitude for alcohol-approach relative to alcohol-avoid for LS (M_D  ± SE_D  = 0.825 ± 0.204 μV, Z = 4.045, P < 0.001) but not HS (M_D  ± SE_D  = 0.013 ± 0.194 μV, Z = 0.068, P = 0.946).

CONCLUSIONS

Findings from a human laboratory study appear to support the notion that low sensitivity to alcohol indexes a propensity to attribute bottom-up incentive value to naturally conditioned alcohol cues.

Open Science in human electrophysiology

Open science practices are gaining momentum in psychophysiological research, but at the nascent stage of this special issue in the International Journal of Psychophysiology there was no systematic collection of resources to support the adoption of open science practices specific to studies of human electrophysiology (EEG). The purpose of this special issue was to gather and provide resources that identify the idiosyncratic considerations and implications of open science practices specifically for studies of human EEG and event-related potentials (ERPs). Papers also show the importance of promoting good scientific practices in the application of open science principles to EEG and ERPs. This introduction to the special issue provides a roadmap for identifying the resources necessary to begin and improve the application of open science principles to EEG and ERP research. We are optimistic that open science practices will help increase the robustness, rigor, and replicability of EEG research and ultimately become the norm in studies of EEG and ERPs.

Enhanced conditioned "liking" of novel visual cues paired with alcohol or non-alcohol beverage container images among individuals at higher risk for alcohol use disorder

RATIONALE/OBJECTIVE

This study used an evaluative conditioning (EC) procedure to assess the affective properties of a CS for ingested drug reward in humans. Specifically, the study tested whether the evaluative response ("liking"/"disliking") to an arbitrary visual stimulus ("CS₂," e.g., a purple hexagon) could be changed through pairings with an alcohol or non-alcohol beverage cue ("CS₁," e.g., a full wine glass, a juice box), which is ostensibly a conditioned visual predictive stimulus for alcohol or non-alcohol liquid reward, respectively.

METHODS

Participants (N = 369, 18-23 years, 66% female, 79% white, 21% reporting no alcohol use ever or in the past year) received 24 CS₁ pairings with each CS₂. CS₂ and CS₁ evaluations were assessed pre- and post-conditioning.

RESULTS

Alcohol and non-alcohol CS₂ "liking" correlated with alcohol use. "Liking" of the alcohol but not non-alcohol CS₁ also correlated with alcohol use. Alcohol CS₁ "liking" also correlated with alcohol and non-alcohol CS₂ 'liking," whereas non-alcohol CS₁ 'liking" correlated with non-alcohol but not alcohol CS₂ "liking."

CONCLUSIONS

Taken together, findings support the idea that drug-related visual stimuli acquire appetitive (hedonic and/or incentive) properties as a function of individual differences in drug use, which entail individual differences in exposure to the conditioning effects of addictive substances like alcohol. Findings also suggest a link between drug use and the propensity to attribute affective/motivational significance to reward-predictive cues in general.

Utility of Linear Mixed Effects Models for Event-Related Potential Research with Infants and Children

Event-related potentials (ERPs) are advantageous for investigating cognitive development. However, their application in infants/children is challenging given children’s difficulty in sitting through the multiple trials required in an ERP task. Thus, a large problem in developmental ERP research is high subject exclusion due to too few analyzable trials. Common analytic approaches (that involve averaging trials within subjects and excluding subjects with too few trials, as in ANOVA and linear regression) work around this problem, but do not mitigate it. Moreover, these practices can lead to inaccuracies in measuring neural signals. The greater the subject exclusion, the more problematic inaccuracies can be. We review recent developmental ERP studies to illustrate the prevalence of these issues. Critically, we demonstrate an alternative approach to ERP analysis—linear mixed effects (LME) modeling—which offers unique utility in developmental ERP research. We demonstrate with simulated and real ERP data from preschool children that commonly employed ANOVAs yield biased results that become more biased as subject exclusion increases. In contrast, LME models yield accurate, unbiased results even when subjects have low trial-counts, and are better able to detect real condition differences. We include tutorials and example code to facilitate LME analyses in future ERP research.

•

Linear Mixed Effects models (LMEs) have advantages for event-related potential analyses.

•

For infant/child ERPs especially, LME is superior to traditional ANOVA models.

•

In simulated ERP data, ANOVAs returned biased results, but LME was unbiased.

•

In real, child ERP data, LME detected condition differences where ANOVA did not.

•

Tutorial and sample codes given to guide use of LMEs in future research.

Hormonal contraceptive use moderates the association between worry and error-related brain activity

Uncovering mechanisms that can help explain the experience and impact of anxiety in women is important for improving etiological models and treatments to meet the needs of unique individuals. An enlarged error-related negativity (ERN) - an electrophysiological marker of cognitive control-related error monitoring- represents one indicator of neural processes more strongly related to anxiety in women than men. In this study, we further examined this association in women by testing the moderating effect of hormonal contraceptive (HC) use on the relationship between worry - i.e., a transdiagnostic cognitive dimension of anxiety - and the ERN. Results revealed that HCs moderated the worry-ERN association. Specifically, we found a significant and large relationship between worry and enlarged ERN in women using HCs, which was smaller and nonsignificant in naturally cycling women (i.e., those not using HCs). These findings suggest that the interplay among HC use, error-related cognitive control, and worry represents a novel mechanism for better characterizing the expression and impact of worry in women.

The data-processing multiverse of event-related potentials (ERPs): A roadmap for the optimization and standardization of ERP processing and reduction pipelines

In studies of event-related brain potentials (ERPs), numerous decisions about data processing are required to extract ERP scores from continuous data. Unfortunately, the systematic impact of these choices on the data quality and psychometric reliability of ERP scores or even ERP scores themselves is virtually unknown, which is a barrier to the standardization of ERPs. The aim of the present study was to optimize processing pipelines for the error-related negativity (ERN) and error positivity (Pe) by considering a multiverse of data processing choices. A multiverse analysis of a data processing pipeline examines the impact of a large set of different reasonable choices to determine the robustness of effects, such as the impact of different decisions on between-trial standard deviations (i.e., data quality) and between-condition differences (i.e., experimental effects). ERN and Pe data from 298 healthy young adults were used to determine the impact of different methodological choices on data quality and experimental effects (correct vs. error trials) at several key stages: highpass filtering, lowpass filtering, ocular artifact correction, reference, baseline adjustment, scoring sensors, and measurement procedure. This multiverse analysis yielded 3,456 ERN scores and 576 Pe scores per person. An optimized pipeline for ERN included a 15 Hz lowpass filter, ICA-based ocular artifact correction, and a region of interest (ROI) approach to scoring. For Pe, the optimized pipeline included a 0.10 Hz highpass filter, 30 Hz lowpass filter, regression-based ocular artifact correction, a -200 to 0 ms baseline adjustment window, and an ROI approach to scoring. The multiverse approach can be used to optimize pipelines for eventual standardization, which would support efforts toward establishing normative ERP databases. The proposed process of analyzing the data-processing multiverse of ERP scores paves the way for better refinement, identification, and selection of data processing parameters, ultimately improving the precision and utility of ERPs.

Understanding the Error in Psychopathology: Notable Intraindividual Differences in Neural Variability of Performance Monitoring

BACKGROUND

Abnormal performance monitoring is a possible transdiagnostic marker of psychopathology. Research on neural indices of performance monitoring, including the error-related negativity (ERN), typically examines group and interindividual (between-person) differences in mean/average scores. Intraindividual (within-person) variability in activity captures the capacity to dynamically adjust from moment to moment, and excessive variability appears maladaptive. Intraindividual variability in ERN represents a unique and largely unexamined dimension that might impact functioning. We tested whether psychopathology group differences (major depressive disorder [MDD], generalized anxiety disorder [GAD], obsessive-compulsive disorder [OCD]) or corresponding psychiatric symptoms account for intraindividual variability in single-trial ERN scores.

METHODS

High-density electroencephalogram (Electrical Geodesics, Inc.) was recorded during a semantic flanker task in 51 participants with MDD, 44 participants with GAD, 31 participants with OCD, and 56 psychiatrically-healthy participants. Mean ERN amplitude was scored 0-125ms following participant response across four fronto-central sites. Multilevel location-scale models were used to simultaneously examine interindividual and intraindividual differences in ERN.

RESULTS

Analyses indicated considerable intraindividual variability in ERN that was common across groups. However, we did not find strong evidence to support relationships between ERN and psychopathology groups or transdiagnostic symptoms.

CONCLUSIONS

These findings point to important methodological implications for studies of performance monitoring in healthy and clinical populations-the common assumption of fixed intraindividual variability (i.e., residual variance) may be inappropriate for ERN studies. Implementation of multilevel location-scale models in future research can leverage between-person differences in intraindividual variability in performance monitoring to gain a rich understanding of trial-to-trial performance monitoring dynamics.