How is social dominance related to our short-term memory? An EEG/ERP investigation of encoding and retrieval during a working memory task.

Social hierarchies exist in all societies and impact cognitive functions, brain mechanisms, social interactions, and behaviors. High status individuals often exhibit enhanced working memory (WM) performance compared to lower status individuals. This study examined whether individual differences in social dominance, as a predictor of future status, relate to WM abilities. Five hundred and twenty-five students completed the Personality Research Form dominance subscale questionnaire. From this sample, students with the highest and lowest scores were invited to participate in the study. Sixty-four participants volunteered to take part and were subsequently categorized into high- and low-dominance groups based on their dominance subscale questionnaire (PRF_d) scores. They performed a Sternberg WM task with set sizes of 1, 4, or 7 letters while their EEG was recorded. Event-related potential (ERP) and power spectral analysis revealed significantly reduced P3b amplitude and higher event-related synchronization (ERS) of theta and beta during encoding and retrieval phases in the high-than low-dominance group. Despite these neural processing differences, behavioral performance was equivalent between groups, potentially reflecting comparable cognitive load demands of the task across dominance levels. Further, there were similar P3b patterns for each set-size within groups. These findings provide initial evidence that individual differences in social dominance trait correlate with WM functioning, as indexed by neural processing efficiency during WM performance.

Auditory distraction, time perception, and the role of age: ERP evidence from a large cohort study.

Cognitive aging is typically associated with a higher susceptibility to distraction by concurrent, but task-irrelevant stimuli. Here, we studied the cognitive sub-processes involved in a sample of 484 healthy adults aged 20-70 years from the Dortmund Vital Study (Clinicaltrials.gov NCT05155397). Participants judged the duration of tone stimuli of a random sequence of long and short tones, having either a regular (standard) pitch or rare (deviant) pitch. Deviance-related ERPs were explored, reflecting neuro-cognitive correlates of pre-attentive deviance detection (MMN), attention allocation toward (P3a) and processing of (P3b) the deviance, and re-orienting toward the task-relevant stimulus feature (RON). Accuracy was reduced for deviant long tones, possibly due to withdrawing attention from processing the time information, making long stimuli appear shorter. This effect increased with age, and cluster-based permutation tests on the correlation of ERPs and age as well as linear mixed modeling indicated a decrease in MMN, an increase in P3a with long tones, and decreases in P3b and RON. This suggests a greater attentional orienting to the deviant stimulus feature and a reduced re-orienting to the task-relevant feature with increasing age.

EEG might be better left alone, but ERPs must be attended to: Optimizing the late positive potential preprocessing pipeline.

The late positive potential (LPP) is an ERP component commonly used to study emotional processes and has been proposed as a neuroaffective biomarker for research and clinical uses. These applications, however, require standardized procedures for elicitation and ERP data processing. We evaluated the impact of different EEG preprocessing steps on the LPP's data quality and statistical power. Using a diverse sample of 158 adults, we implemented a multiverse analytical approach to compare preprocessing pipelines that progressively incorporated more steps: artifact detection and rejection, bad channel interpolation, and bad segment deletion. We assessed each pipeline's effectiveness by computing the standardized measurement error (SME) and conducting simulated experiments to estimate statistical power in detecting significant LPP differences between emotional and neutral images. Our findings highlighted that artifact rejection is crucial for enhancing data quality and statistical power. Voltage thresholds to reject trials contaminated by artifacts significantly affected SME and statistical power. Once artifact detection was optimized, further steps provided minor improvements in data quality and statistical power. Importantly, different preprocessing pipelines yielded similar outcomes. These results underscore the robustness of the LPP's affective modulation to preprocessing choices and the critical role of effective artifact management. By refining and standardizing preprocessing procedures, the LPP can become a reliable neuroaffective biomarker, supporting personalized clinical interventions for affective disorders.

Characterizing within-person variance in, and menstrual cycle associations with, event-related potentials associated with positive and negative valence systems: The reward positivity and the error-related negativity.

Event-related potentials (ERPs) are widely employed as measures of transdiagnostic cognitive processes that are thought to underlie various clinical disorders (Hajcak et al., 2019). Despite their prevalent use as individual difference measures, the effects of within-person processes, such as the human menstrual cycle, on a broad range of ERPs are poorly understood. The present study leveraged a within-subject design to characterize between- and within-person variance in ERPs as well as effects of the menstrual cycle in two frequently studied ERPs associated with positive and negative valence systems underlying psychopathology-the Reward Positivity (RewP) and the Error- Related Negativity (ERN). Seventy-one naturally-cycling participants completed repeated EEG and ecological momentary assessments of positive and negative affect in the menstrual cycle's early follicular, periovulatory, and mid-luteal phases. We examined the mean degree of change between cycle phases in both ERPs, the between-person variability in the degree of change in both ERPs, and whether an individual's degree of cyclical change in these ERPs show coherence with their degree of cyclical change in positive and negative affect recorded across the cycle. Results revealed no significant changes in positive and negative affect across the cycle and rather small changes in ERP amplitudes. Significant random slopes in our model revealed larger individual differences in trajectories of change in ERP amplitudes and affect, in agreement with prior evidence of heterogeneity in dimensional hormone sensitivity. Additionally, state-variance in these ERPs correlated with positive and negative affect changes across the cycle, suggesting that cycle-mediated ERP changes may have relevance for affect and behavior. Finally, exploratory latent class growth mixture modeling revealed subgroups of individuals that display disparate patterns of change in ERPs that should be further investigated.

The Inhibitory Control Deficit of Internet Gaming Disorder: An Event-Related Potentials(ERPs) Study.

INTRODUCTION: The primary difficulty and challenge encountered by individuals with Internet Gaming Disorder (IGD) is inhibitory control deficit. Given that different types of inhibitory control have different effects on IGD patients, it is critical to investigate the neurological cognitive processes underlying various inhibitory control problems. METHODS: The IGD-20 questionnaire was used to identify Internet game disorder and healthy control group, and finally Internet game disorder in (n=25) and healthy control group (n=28) in Flanker task, Internet game disorder (n=29) and health control group (n=24) in GO/NOGO task. The Flanker task was employed to investigate distractor interference inhibition control in those with IGD, while the Go/NoGo task was used to measure their prepotent response inhibitory control. Event-related potentials (ERPs) were used to evaluate the brain mechanisms difference of both IGD and healthy participants during these different inhibitory control tasks. RESULTS: Findings indicate that compared to healthy control subjects, individuals with Internet Gaming Disorder (IGD) have deficits in inhibitory control tasks during both distraction inhibition and prepotent response inhibition tasks, and distraction inhibition occurs earlier than prepotent response inhibition. In distraction inhibition tasks, the IGD group's N2 amplitude is significantly lower than the healthy control groups. In prepotent response inhibition, the N2 amplitude provoked in the IGD group is not only significantly lower than in the healthy control group, but the P3 amplitude is also significantly larger in the IGD group. The main brain activity areas of interference inhibitory control are the frontal lobe and prefrontal lobe, while the main brain activity areas of prepotent response inhibitory control are the frontal lobe and occipital lobe. CONCLUSION: The present study concentrates on the differential neurophysiological characteristics observed in individuals with Internet gaming problems, notably the ability to avoid distractions and prepotent reactions. The current research provides foundations for the assessment and development of tailored therapy and treatment methods to address the wide variety of cognitive problems reported in individuals with Internet Gaming Disorder (IGD).

On the lasting impact of mild traumatic brain injury on working memory: Behavioural and electrophysiological evidence.

Despite increasing recognition of the significance of mild traumatic brain injury (mTBI), the long-term cognitive consequences of the injury remain unclear. More sensitive measures that can detect subtle cognitive changes and consideration of individual variability are needed to properly characterise cognitive outcomes following mTBI. Here, we used complex behavioural tasks, individual differences approaches, and electrophysiology to investigate the long-term cognitive effects of a history of mTBI. In Experiment 1, participants with self-reported mTBI history (n=82) showed poorer verbal working memory performance on the operation span task compared to control participants (n=88), but there were no group differences in visual working memory, multitasking, cognitive flexibility, attentional control, visuospatial ability, or information processing speed. Individual differences analyses revealed that time since injury and presence of memory loss predicted visual working memory capacity and visuospatial ability, respectively, in those with mTBI history. In Experiment 2, participants with mTBI history (n=20) again demonstrated poorer verbal working memory on the operation span task compared to control participants (n=38), but no group differences were revealed on a visuospatial complex span task or simpler visual working memory measures. We also explored the electrophysiological indices of visual working memory using EEG during a change detection task. No differences were observed in early sensory event-related potentials (P1, N1) or the later negative slow wave associated with visual working memory capacity. Together, these findings suggest that mTBI history may be associated with a lasting, isolated disruption in the subsystem underlying verbal working memory storage. The results emphasize the importance of sensitive cognitive measures and accounting for individual variability in injury characteristics when assessing mTBI outcomes.

The effect of inter-letter spacing on the N170 during visual word recognition: An event-related potentials experiment.

Previous behavioral studies have shown that inter-letter spacing affects visual word recognition and reading. While condensed spacing may hinder the early stages of letter encoding because of increased crowding effects, the impact of expanded inter-letter spacing is still unclear. To examine the electrophysiological signature of inter-letter spacing on visual word recognition, we presented words in three different inter-letter spacing conditions (default, condensed [-1.5 points] or expanded [+1.5 points]) in an event-related potentials go/no-go semantic categorization task. Our focus was on the N170, an event-related potentials component associated with the early encoding of orthographic information, which also is sensitive to crowding effects. Results revealed that the N170 amplitude reached the largest values for the condensed condition than for the default and expanded spacing conditions, which did not differ. While increased crowding impacted the early encoding of orthographic information, extra letter spacing (compared with default spacing) did not. This outcome is consistent with the Modified Receptive Field hypothesis, in which letter receptors adapt their size to cope with letter crowding. These findings reveal that reducing the space between letters more than the default spacing impairs the ability to process written words, whereas slightly expanding the space between letters does not provide any additional benefit.

Neural responses to decision-making in suicide attempters with youth major depressive disorder.

An improved understanding of the factors associated with suicidal attempts in youth suffering from depression is crucial for the identification and prevention of future suicide risk. However, there is limited understanding of how neural activity is modified during the process of decision-making. Our study aimed to investigate the neural responses in suicide attempters with major depressive disorder (MDD) during decision-making. Electroencephalography (EEG) was recorded from 79 individuals aged 16-25 with MDD, including 39 with past suicide attempts (SA group) and 40 without (NSA group), as well as from 40 age- and sex- matched healthy controls (HCs) during the Iowa Gambling Task (IGT). All participants completed diagnostic interviews, self-report questionnaires. Our study examined feedback processing by measuring the feedback-related negativity (FRN), ΔFN (FRN-loss minus FRN-gain), and the P300 as electrophysiological indicators of feedback evaluation. The SA group showed poorest IGT performance. SA group and NSA group, compared with HC group, exhibited specific deficits in decision-making (i.e., exhibited smaller (i.e., blunted) ΔFN). Post hoc analysis found that the SA group was the least sensitive to gains and the most sensitive to losses. In addition, we also found that the larger the value of ΔFN, the better the decision-making ability and the lower the impulsivity. Our study highlights the link between suicide attempts and impaired decision-making in individuals with major depressive disorder. These findings constitute an important step in gaining a better understanding of the specific reward-related abnormalities that could contribute to the young MDD patients with suicide attempts.

Do changes in cerebral blood flow modulate the amplitudes of P300 during cognitive task?

A single session of aerobic or resistance training transiently enhances cognitive function, making it a valuable strategy for dementia prevention in the older people. Despite its acknowledged benefits, the precise mechanism behind exercise-induced cognitive improvement remains controversial. In the present study, we investigated the impact of altered cerebral blood flow (CBF) on brain neural activity originating from motor executive and inhibitory processing using electroencephalographic event-related potentials (EEG-ERPs). Sixteen healthy subjects participated in four sessions, with EEG-ERPs measured during somatosensory Go/No-go tasks. The sessions were conducted under four distinct respiratory conditions presented in random order: normal breathing (NB) and rapid breathing (RB) with room air, normal breathing with hypercapnic gas (5% CO2, 21% O2, and balanced N2) (NB+Gas), and rapid breathing with the same gas (RB+Gas). Changes in CBF were evaluated based on the middle cerebral artery mean blood velocity (MCA Vmean) using transcranial Doppler. PETCO2 was decreased under the RB condition but increased under the NB+Gas condition, thereby decreasing and increasing MCA Vmean, respectively. Under the NB+Gas condition, MCA Vmean significantly increased, but it had no effect on either the executive or inhibitory function. In contrast, the reduction in MCA Vmean induced by RB decreased the peak amplitudes of Go-P300 and No-go-P300. However, even under the RB+Gas condition while MCA Vmean increased, the peak amplitudes of both also decreased. These findings suggest that neither increases nor decreases in CBF affected cognitive function.

Maternal emotion regulation abilities affect adolescent depressive symptoms by mediating their emotion regulation ability: An ERP study.

Adolescents with major depressive disorder (MDD) experience significant difficulties in emotion regulation. This study aimed to explore emotion regulation in adolescents with depression using an emotion regulation paradigm combined with event-related potentials (ERP) while investigating the relationship between maternal emotion regulation and adolescent depressive symptoms through a mediation model. Overall, 38 healthy controls (HC) and 57 adolescents with depression (MDD) rated the pictures they saw according to aversive reappraisal (reappraisal of an aversive picture or down-regulate aversive emotions), aversive watch, and neutral conditions. Adolescents with depression gave more negative ratings to aversive images, and the emotional regulation success index (ERSI) of adolescents with depression was lower than that of healthy individuals. ERP data revealed an elevation in late positive potential (LPP) amplitude during the aversive reappraisal and aversive watch conditions compared with that in the neutral condition in the MDD group. Compared with the HC group, adolescents with depression showed larger LPP amplitudes under aversive watch conditions. The aversive reappraisal condition evoked a larger LPP than that in the other conditions in the HC group in the late time windows. The ΔLPP (separating the variability in the ERP wave associated with emotion regulation) was larger in the HC group than in the MDD group. Mediation analysis revealed that maternal emotion regulation influenced adolescent depression levels through its effect on the adolescent's emotion regulation. These findings provide important insights into the emotion regulation process in adolescents with depression and offer suggestions for clinical interventions.

Skin Carotenoids are Related to Cognitive Abilities among Toddlers.

BACKGROUND: Carotenoids are antioxidant pigments that deposit in human tissues (e.g., skin, macula, and brain) upon dietary consumption. The health implications of skin carotenoids, which reflect overall dietary carotenoid consumption, have not been adequately studied in younger populations. OBJECTIVE: This work aimed to examine links between skin carotenoids and cognitive, language, and motor skills among toddlers. A secondary aim explored relationships between skin carotenoids and neurophysiological outcomes of sensory memory (i.e., mismatch negativity [MMN]) and the functional integrity of the visual pathway (i.e., visual evoked potentials [VEPs]). METHODS: Toddlers 12-18 months (n = 45) participated in a cross-sectional study. Skin carotenoids were measured with reflection spectroscopy via the Veggie MeterTM. Cognitive, language, and motor skills were measured using the Bayley Scale of Infant and Toddler Development IV Screening Test (BSID-IV). MMN and VEPs were collected with an auditory oddball task and a pattern reversal task, respectively, using electroencephalography. Analyses adjusted for age, household income, highest level of parental education, and total carotenoid intake (mg/1000kCal). RESULTS: Regression modelling revealed that skin carotenoids significantly related to cognition (R2 = 0.57, p = 0.04) and not to any other BSID-IV subsets. Neither MMN nor VEP outcomes significantly related to skin carotenoids. CONCLUSIONS: Greater skin carotenoids were selectively related to cognition, indicating that carotenoids may play a role in cognition in toddlers. Additional research is needed to understand links between skin carotenoids and specific domains of cognitive function and brain health in early life. CLINICAL TRIAL REGISTRY: N/A.

Preference for digital media use, biobehavioral attention bias, and anxiety symptoms in adolescents.

Adolescence is a critical developmental period of biological and social change during which 1 in 3 youth experience significant anxiety symptoms. The social-emotional lives of the majority of adolescents are largely conducted via digital media use (DMU; e.g., social media, text messaging). Yet the past decade of research on DMU and anxiety has yielded mixed results (e.g., Keles et al., 2020 review), leaving the complex role that DMU might play in the emergence and maintenance of anxiety poorly understood. A key step forward is to leverage psychophysiology to identify individual differences in cognitive and emotional processes that confer vulnerability to potential negative effects of DMU. Further, given the ubiquity of DMU, a greater focus is needed on measurements that move beyond sheer frequency to capture DMU in comparison to face-to-face (FTF) social interactions. This study examined attention bias (AB), characterized by selective and exaggerated attention toward or away from threat, as a moderator of the link between DMU and anxiety in adolescents (N = 75; 42 female) aged 12-14 years (M = 13.28, SD = 0.87). AB was indexed during a dot probe task using reaction time metrics (i.e., trial-level bias) and via ERPs capturing attentional selection and discrimination (N170) and cognitive control (N2) to threat compared to neutral faces. AB moderated associations between DMU and anxiety. A greater preference to use DMU vs FTF predicted greater anxiety among those with a greater behavioral bias away from threat, blunted N170, and blunted N2 in the presence of threat. Future research should examine potential causal and bidirectional links between DMU and anxiety and explore whether preferences for technology-mediated interactions and individual differences in threat processing increase risk.

Group-member selection for RSVP-based collaborative brain-computer interfaces.

Objective: The brain-computer interface (BCI) systems based on rapid serial visual presentation (RSVP) have been widely utilized for the detection of target and non-target images. Collaborative brain-computer interface (cBCI) effectively fuses electroencephalogram (EEG) data from multiple users to overcome the limitations of low single-user performance in single-trial event-related potential (ERP) detection in RSVP-based BCI systems. In a multi-user cBCI system, a superior group mode may lead to better collaborative performance and lower system cost. However, the key factors that enhance the collaboration capabilities of multiple users and how to further use these factors to optimize group mode remain unclear. Approach: This study proposed a group-member selection strategy to optimize the group mode and improve the system performance for RSVP-based cBCI. In contrast to the conventional grouping of collaborators at random, the group-member selection strategy enabled pairing each user with a better collaborator and allowed tasks to be done with fewer collaborators. Initially, we introduced the maximum individual capability and maximum collaborative capability (MIMC) to select optimal pairs, improving the system classification performance. The sequential forward floating selection (SFFS) combined with MIMC then selected a sub-group, aiming to reduce the hardware and labor expenses in the cBCI system. Moreover, the hierarchical discriminant component analysis (HDCA) was used as a classifier for within-session conditions, and the Euclidean space data alignment (EA) was used to overcome the problem of inter-trial variability for cross-session analysis. Main results: In this paper, we verified the effectiveness of the proposed group-member selection strategy on a public RSVP-based cBCI dataset. For the two-user matching task, the proposed MIMC had a significantly higher AUC and TPR and lower FPR than the common random grouping mode and the potential group-member selection method. Moreover, the SFFS with MIMC enabled a trade-off between maintaining performance and reducing the number of system users. Significance: The results showed that our proposed MIMC effectively optimized the group mode, enhanced the classification performance in the two-user matching task, and could reduce the redundant information by selecting the sub-group in the RSVP-based multi-user cBCI systems.

Influence of presentation duration on filtering of irrelevant stimuli in visual working memory.

In environments teeming with distractions, the ability to selectively focus on relevant information is crucial for advanced cognitive processing. Existing research using event-related potential (ERP) technology has shown active suppression of irrelevant stimuli during the consolidation phase of visual working memory (VWM). In previous studies, participants have always been given sufficient time to consolidate VWM, while suppressing distracting information. However, it remains unclear whether the suppression of irrelevant distractors requires continuous effort throughout their presence or whether this suppression is only necessary after the consolidation of task-relevant information. To address this question, our study examines whether distractor suppression is necessary in scenarios where consolidation time is limited. This research investigates the effect of varying presentation durations on the filtering of distractors in VWM. We tasked participants with memorizing two color stimuli and ignoring four distractors, presented for either 50 ms or 200 ms. Using ERP technology, we discovered that the distractor-induced distractor positivity (PD) amplitude is larger during longer presentation durations compared to shorter ones. These findings underscore the significant impact of presentation duration on the efficacy of distractor suppression in VWM, as prolonged exposure results in a stronger suppression effect on distractors. This study sheds light on the temporal dynamics of attention and memory, emphasizing the critical role of stimulus timing in cognitive tasks. These findings provide valuable insights into the mechanisms underlying VWM and have significant implications for models of attention and memory.

Social addiction or nicotine addiction? The effect of smoking social motivation on inhibitory control under smoking social cues: Evidence from ERPs.

INTRODUCTION: Previous studies and theoretical models suggest that the decreasing effect of smoking-related cues on inhibitory control in individuals who smoke is one of the underlying mechanisms of smoking behavior. However, many studies have overlooked the effects of other types of smoking-related cues, such as social cues. Moreover, previous studies have lacked investigation into whether this decreasing effect is influenced by internal factors. The present study aims to integrate behavioral and electrophysiological indicators to investigate the effect of smoking social cues on inhibitory control in individuals who smoke, as well as the moderating role of social motivations. METHOD: In Experiment 1, a visual Go/NoGo paradigm with four types of backgrounds (neutral, neutral social, smoking object, and smoking social backgrounds) was used to record the error rates and reaction times of 32 participants who smoke. In Experiment 2, the Go/NoGo paradigm with two types of backgrounds (smoking object and smoking social backgrounds) was used to record the error rates, reaction times, and amplitudes of the N2 and P3 event-related potentials among 30 participants who smoke with varying degrees of primed smoking social motivation. RESULTS: (1) Individuals who smoke had higher commission error rates and larger P3 amplitude under smoking social background than under smoking object background; (2) individuals who smoke with primed high smoking social motivation, rather than low motivation had higher commission error rates and larger P3 amplitude under smoking social background than under smoking object background. CONCLUSIONS: Smoking social cues have a greater capacity to decrease inhibitory control in people who smoke than smoking object cues, and this decreasing effect is bolstered by smoking social motivation.

Neurophysiological patterns reflecting vulnerability to delirium subtypes: a resting-state EEG and event-related potential study.

Delirium is a common and acute neurocognitive disorder in older adults associated with increased risk of dementia and death. Understanding the interaction between brain vulnerability and acute stressors is key to delirium pathophysiology, but the neurophysiology of delirium vulnerability is not well defined. This study aimed to identify pre-operative resting-state EEG and event-related potential markers of incident delirium and its subtypes in older adults undergoing elective cardiac procedures. This prospective observational study included 58 older participants (mean age = 75.6 years, SD = 7.1; 46 male/12 female); COVID-19 restrictions limited recruitment. Baseline assessments were conducted in the weeks before elective cardiac procedures and included a 4-min resting-state EEG recording (2-min eyes open and 2-min eyes closed), a 5-min frequency auditory oddball paradigm recording, and cognitive and depression examinations. Periodic peak power, peak frequency and bandwidth measures, and aperiodic offsets and exponents were derived from resting-state EEG data. Event-related potentials were measured as mean component amplitudes (first positive component, first negative component, early third positive component, and mismatch negativity) following standard and deviant auditory stimuli. Incident delirium occurred in 21 participants: 10 hypoactive, 6 mixed, and 5 hyperactive. Incident hyperactive delirium was associated with higher pre-operative eyes open (P = 0.045, d = 1.0) and closed (P = 0.036, d = 1.0) aperiodic offsets. Incident mixed delirium was associated with significantly larger pre-operative first positive component amplitudes to deviants (P = 0.037, d = 1.0) and larger third positive component amplitudes to standards (P = 0.025, d = 1.0) and deviants (P = 0.041, d = 0.9). Other statistically non-significant but moderate-to-large effects were observed in relation to all subtypes. We report evidence of neurophysiological markers of delirium risk weeks prior to elective cardiac procedures in older adults. Despite being underpowered due to COVID-19-related recruitment impacts, these findings indicate pre-operative dysfunction in neural excitation/inhibition balance associated with different delirium subtypes and warrant further investigation on a larger scale.

EEG correlates of static and dynamic face perception: the role of naturalistic motion.

Much of our understanding of how the brain processes dynamic faces comes from research that compares static photographs to dynamic morphs, which exhibit simplified, computer-generated motion. By comparing static, video recorded, and dynamic morphed expressions, we aim to identify the neural correlates of naturalistic facial dynamism, using time-domain and time-frequency analysis. Dynamic morphs were made from the neutral and peak frames of video recorded transitions of happy and fearful expressions, which retained expression change and removed asynchronous and non-linear features of naturalistic facial motion. We found that dynamic morphs elicited increased N400 amplitudes and lower LPP amplitudes compared to other stimulus types. Video recordings elicited higher LPP amplitudes and greater frontal delta activity compared to other stimuli. Thematic analysis of participant interviews using a large language model revealed that participants found it difficult to assess the genuineness of morphed expressions, and easier to analyse the genuineness of happy compared to fearful expressions. Our findings suggest that animating real faces with artificial motion may violate expectations (N400) and reduce the social salience (LPP) of dynamic morphs. Results also suggest that delta oscillations in the frontal region may be involved with the perception of naturalistic facial motion in happy and fearful expressions. Overall, our findings highlight the sensitivity of neural mechanisms required for face perception to subtle changes in facial motion characteristics, which has important implications for neuroimaging research using faces with simplified motion.

Does cognitive control mediate the relationship between peer presence and adolescent risk-taking? An ERP study.

Peer presence influences risk-taking behavior, particularly in adolescence. Based on the dual system model, this event-related potential study examined whether and how the presence of a peer displayed a preference for risky behavior would increase adolescents' risk-taking by disrupting their cognitive control processes in either emotional or non-emotional contexts. A sample of 106 adolescents (17-19 years of age) completed two Stoop tasks and a Balloon Analog Risk Task under three peer presence conditions. Results revealed that compared to other conditions, the presence of a risk-averse peer caused adolescents to make safer decisions through improving their conflict monitoring (more negative N200-diff), whereas a risk-preference peer's presence led adolescents to more risky decisions through disrupting their conflict resolution (more positive N450-diff) but they were only observed on the Emotional Stroop task. These findings suggest that different peer presence contexts could increase or decrease adolescents' risk-taking behaviors by influencing their cognitive control under an emotional context rather than in a non-emotional context.

Is it too loud? Ask your brain!

PURPOSE: In this study, the objectification of the subjective perception of loudness was investigated using electroencephalography (EEG). In particular, the emergence of objective markers in the domain of the acoustic discomfort threshold was examined. METHODS: A cohort of 27 adults with normal hearing, aged between 18 and 30, participated in the study. The participants were presented with 500 ms long noise stimuli via in-ear headphones. The acoustic signals were presented with sound levels of [55, 65, 75, 85, 95 dB]. After each stimulus, the subjects provided their subjective assessment of the perceived loudness using a colored scale on a touchscreen. EEG signals were recorded, and afterward, event-related potentials (ERPs) locked to sound onset were analyzed. RESULTS: Our findings reveal a linear dependency between the N100 component and both the sound level and the subjective loudness categorization of the sound. Additionally, the data demonstrated a nonlinear relationship between the P300 potential and the sound level as well as for the subjective loudness rating. The P300 potential was elicited exclusively when the stimuli had been subjectively rated as "very loud" or "too loud". CONCLUSION: The findings of the present study suggest the possibility of the identification of the subjective uncomfortable loudness level by objective neural parameters.

Association of GAD1 gene polymorphism rs3749034 with the information processing and cognitive event-related potentials in schizophrenia patients and healthy subjects.

OBJECTIVE: Glutamic acid decarboxylase, an enzyme in GABA biosynthesis, is encoded by the GAD1 gene, the transcriptional activity of which is affected by the rs3749034 polymorphism. The aim was to investigate the effects of rs3749034 on cognitive event-related potentials (P300) in healthy subjects and schizophrenic patients. METHODS: Determination of rs3749034 polymorphism was performed in 89 healthy volunteers and 109 schizophrenic patients (males). Two-stimulus oddball task performance and P300 auditory evoked potentials were analyzed and patient symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS). RESULTS: An increased frequency of C allele carriers was disclosed in patients. In controls, superior task performance was observed in cytosine-thymine carriers, while a greater P300 amplitude and shorter latency were found in C/C carriers. Analogous effects were found in patients with a disease onset before 25 years of age. Higher N5 and lower P3 and G5 PANSS scales were revealed in C/C homozygotes. CONCLUSIONS: The findings substantiate an involvement of GABA-ergic mechanisms in maintaining an optimal excitatory-inhibitory balance and an association of rs3749034 with early-onset disorder and negative symptoms of schizophrenia. SIGNIFICANCE: These results are important for understanding underlying mechanisms and the development of evidence-based methods for assessing the risk of schizophrenia.