P300 Component Research Articles

Association Between Early Childhood P300 Deficits and Risk for Preadolescence Depressive Disorder Mediated by Responsiveness to PCIT-ED Treatment.

Preschool-onset major depressive disorder (PO-MDD) is an impairing pediatric mental health disorder that impacts children as young as three years old. There is limited work dedicated to uncovering neural measures of this early childhood disorder which could be leveraged to further understand both treatment responsiveness and future depression risk. Event-related potentials (ERPs) such as the P300 have been employed extensively in adult populations to examine depression-related deficits in cognitive and motivational systems. Few studies examine the prospective relationships between depression and P300, especially in young children. Moreover, limited research examines the relationship between P300 with psychotherapy treatment responsiveness in youths. The current study sought to examine the prospective relationships between pre-intervention P300 (i.e., choice-locked) elicited from the doors task in depressed preschool children (i.e., PO-MDD; ages 3-to-6) with reductions in depressive symptoms after completing an 18-week long dyadic psychotherapy intervention (n = 59). We also explored relations to risk for depression assessed at a follow-up visit during preadolescence (ages 8-to-12; n = 82). Those with PO-MDD exhibiting reduced choice (doors)-locked P300 demonstrated worse treatment response to psychotherapy and were more likely to meet criteria for depression during preadolescence. Moreover, the relationship between pre-intervention P300 and later preadolescence depression was significantly mediated by response to treatment. These findings suggest that deficits in brain systems linked to the choice-locked P300 component (i.e., cognitive and motivational) might be indicative of non-responsiveness to early dyadic psychotherapeutic intervention efforts for depression which impacts risk for recurrent patterns of depression in youths.

Gamma and theta/alpha-band oscillations in the electroencephalogram distinguish the content of inner speech.

Inner speech refers to the silent production of language in one's mind. As a purely mental action without obvious physical manifestations, inner speech has been notoriously difficult to quantify. Inner speech is thought to be closely related to overt speech. Overt speech has been consistently shown to elicit reduced auditory-evoked potentials compared to externally-generated speech (a phenomenon known as speaking-induced suppression), as well as changes in oscillatory activity in the gamma and theta frequency bands. Given the functional similarities between inner and overt speech, the present study used a novel experimental protocol to investigate whether these metrics can be used to distinguish the content of a person's inner speech. Healthy control participants (n = 129) produced an inner syllable at a precisely specified time. An audible syllable was concurrently presented which either matched or mismatched the content of the inner syllable. The N1 component of the auditory evoked potential was suppressed in the Match condition while the P2 component was suppressed in the Mismatch condition, replicating our previous findings. A novel finding was that the Match and Mismatch conditions could be differentiated on the basis of their evoked gamma and theta / alpha oscillations. There was a single gamma-band oscillation in the vicinity of the P2 that differed in spectral power between the Match and Mismatch conditions, which provides support for the idea that 'late' gamma-band activity may index consciously-perceived expectancy violations, or cognitive prediction errors. The Match and Mismatch conditions also differed in terms of their evoked power in a temporally-extended cluster which spanned the theta and alpha bands. The results of this study provide support for the phenomenon of 'inner speaking-induced suppression', and demonstrate that inner syllables can be differentiated using scalp electroencephalography (evoked potentials and oscillations) based on whether their content matches that of a simultaneously-presented audible syllable.Significance statement Inner speech refers to the silent production of language in one's mind. As a purely mental action without obvious physical manifestations, inner speech has been notoriously difficult to quantify empirically. The aim of the present study was to develop an objective, electroencephalography-based marker of inner speech that was sensitive to its content. The results of this study demonstrate that it is possible to distinguish between two syllables produced in inner speech on the basis of their auditory-evoked activity and evoked oscillations in the gamma and theta/alpha bands in the electroencephalogram. The gamma-band oscillation may represent a 'cognitive' prediction error. The ability to determine the content of a person's inner speech on the basis of a non-invasive biometric signal could have significant commercial, industrial, and clinical applications.

Emotional Influences on Remembering and Forgetting Explained by Frontal and Parietal Dynamics.

Based on item-method directed forgetting (DF) task, sixty participants were recruited to explore the influence of emotion (negative, neutral, and positive) on memory encoding processing. Behavioral results showed that participants were more successful at remembering negative pictures that needed to be forgotten, with both higher recognition rates and Pr values compared to neutral pictures. In the brain, parietal activities reflected preferential processing during negative picture viewing through enhanced late parietal positive potentials (LPP) relative to neutral ones. In addition, 'Remember' (R) instruction evoked a larger parietal P3 component, whereas 'Forget' (F) instruction evoked a stronger frontal N2 component, each of which component was significantly associated with the DF effect (i.e., more recognized items of R-cue than that of F-cue), reflecting the fact that inhibitory control and selective rehearsal mechanisms were jointly responsible for the directed forgetting of emotional materials. Finally, we showed the presence of instruction-evoked low-frequency phase synchronization between frontal and parietal regions, and that these synchronization patterns differed between R-cue and F-cue in an emotion-dependent manner. Together, these findings reveal cognitive mechanisms and specific patterns of large-scale phase synchronization underlying active forgetting of emotional memories, deepening our comprehension into the interplay between cognition and emotion.

Machine Learning-Based Diagnosis of Chronic Subjective Tinnitus With Altered Cognitive Function: An Event-Related Potential Study.

Due to the absence of objective diagnostic criteria, tinnitus diagnosis primarily relies on subjective assessments. However, its neuropathological features can be objectively quantified using electroencephalography (EEG). Despite the existing research, the pathophysiology of tinnitus remains unclear. The objective of this study was to gain a deeper comprehension of the neural mechanisms underlying tinnitus through the comparison of cognitive event-related potentials in patients with tinnitus and healthy controls (HCs). Furthermore, we explored the potential of EEG-derived features as biomarkers for tinnitus using machine learning techniques. Forty-eight participants (24 patients with tinnitus and 24 HCs) underwent comprehensive audiological assessments and EEG recordings. We extracted N2 and P3 components of the midline electrodes using an auditory oddball paradigm, to explore the relationship between tinnitus and cognitive function. In addition, the current source density for N2- and P3-related regions of interest was computed. A linear support vector machine classifier was used to distinguish patients with tinnitus from HCs. The P3 peak amplitudes were significantly diminished in patients with tinnitus at the AFz, Fz, Cz, and Pz electrodes, whereas the N2 peak latencies were significantly delayed at Cz electrode. Source analysis revealed notably reduced N2 activities in bilateral fusiform gyrus, bilateral cuneus, bilateral temporal gyrus, and bilateral insula of patients with tinnitus. Correlation analysis revealed significant associations between the Hospital Anxiety and Depression Scale-Depression scores and N2 source activities at left insula, right insula, and left inferior temporal gyrus. The best classification performance showed a validation accuracy of 85.42%, validation sensitivity of 87.50%, and validation specificity of 83.33% in distinguishing between patients with tinnitus and HCs by using a total of 18 features in both sensor- and source-level. This study demonstrated that patients with tinnitus exhibited significantly altered neural processing during the cognitive-related oddball paradigm, including lower P3 amplitudes, delayed N2 latency, and reduced source activities in specific brain regions in cognitive-related oddball paradigm. The correlations between N2 source activities and Hospital Anxiety and Depression Scale-Depression scores suggest a potential link between the physiological symptoms of tinnitus and their neural impact on patients with tinnitus. Such findings underscore the potential diagnostic relevance of N2- and P3-related features in tinnitus, while also highlighting the interplay between the temporal lobe and occipital lobe in tinnitus. Furthermore, the application of machine learning techniques has shown reliable results in distinguishing tinnitus patients from HCs, reinforcing the viability of N2 and P3 features as biomarkers for tinnitus.

ERP correlates of agency processing in joint action.

In the Ouija board phenomenon, the lack of agency experienced by the players leads them to attribute the movement of the planchette to spirits. The aim of this study was to investigate the neural and cognitive mechanisms involved in generating the sense of agency in such a joint action context. Two players (a participant and a confederate) jointly moved a Ouija board style planchette containing a wireless mouse. This, in turn, moved a digital board on the screen. Participants reported greater sense of agency in the condition where they had complete control of the planchette (the self condition), and least agency when they passively held the planchette while it was moved by the confederate (other condition), with the two joint action conditions in between. While the N1 peak did not differ between conditions, the early part of the N1 differentiated between the joint action conditions, and the solo action conditions. In contrast, the Tb and P2 components differed between the other condition and the self and joint conditions. These findings are discussed with reference to motor-prediction, and attentional mechanisms.

Motion-Onset Visually Evoked Potentials (VEPs) are Amplified in The Deaf.

The loss of a sensory modality triggers a phenomenon known as cross-modal plasticity, where areas of the brain responsible for the lost sensory modality are reorganized and repurposed to the benefit of the remaining modalities. After perinatal or congenital deafness, superior visual motion detection abilities have been psychophysically identified in both humans and cats, and this advantage has been causally demonstrated to be mediated by reorganized auditory cortex. In our study, we investigated visually evoked potentials (VEPs) in response to motion-onset stimuli of varying speeds in both hearing and perinatally deafened cats under light anesthesia. While the peak latencies did not differ between the two groups, we observed significantly greater VEP amplitudes in deaf cats, specifically in the P1 component and the signal power of the overall waveform. Through sigmoidal modelling, we identified that the speed offset and steepness at the threshold for 50% maximum neural activity was unchanged, showing that neuronal activity was modulated by motion speeds in a comparable manner between the hearing and deaf subjects and the deaf had greater potentials at all dot speeds. Our results suggests that the increased cortical activity by the auditory and visual cortices of deaf cats may account for their superior behavioral advantage in motion detection and indicates that cross-modal plasticity plays a significant role in the cortical processing of motion.

Cross-validating the electrophysiological markers of early face categorization.

Human face categorization has been extensively studied using event-related potentials (ERPs), positing the N170 ERP component as a robust neural marker of face categorization. Recently, the fast periodic visual stimulation (FPVS) approach relying on steady-state visual evoked potentials (SSVEPs) has also been used to investigate face categorization. FPVS studies consistently report strong bilateral SSVEP face categorization responses over the occipito-temporal cortex, with a right hemispheric dominance, closely mirroring the N170 scalp topography. However, it remains unclear whether SSVEP responses can be considered a proxy for the N170 or are driven by different components. To address this question, we recorded electrophysiological signals from observers viewing face and object images during FPVS and ERP paradigms. We quantified the FPVS response in the frequency domain and extracted ERP components, including the P1, N170, and P2, from both the FPVS time domain and ERP paradigms. Our results revealed little relationship between any single ERP component and the FPVS frequency response. Only the peak-to-peak differences between N170 and P2 components consistently explained the FPVS frequency response. Our data show that the FPVS frequency response reflects a later complex neural integration rather than any isolated ERP component, such as the N170. These findings raise important methodological and theoretical considerations regarding the relationship between SSVEPs and transient ERPs. While both markers are indicative of human face categorization, they appear to capture different stages of this cognitive process.Significance Statement Our study untangles the very nature of the electrophysiological neural responses of face categorization. We recorded and directly compared steady-state visual evoked potentials (SSVEPs) with transient event related potentials (ERP) evoked by faces and objects in human observers. Contrary to the assumption associating SSVEPs with the early N170 ERP component, we found that the N170-P2 difference was consistently associated with the SSVEPs. This finding suggests that SSVEPs in fast periodic visual stimulation (FPVS) may reflect later stages of neural processing. Our findings invite to caution when interpreting SSVEP responses, avoiding premature assumptions about their relationship with ERPs. This work highlights the need for integrated research approaches to better understand the complex interplay between SSVEPs and ERPs across different cognitive domains.

The Impact of Acute Aerobic Exercise on General and Food-Related Inhibitory Function Among Young Adults with Obesity: An Event-Related Potential (ERP) Study.

Backgrounds and Objectives: Obesity presents a significant global public health challenge and is associated with declines in both general and food-related inhibitory control, crucial for maintaining a healthy weight and preventing obesity progression. An increasing body of research suggests that acute aerobic exercise may improve inhibitory function. However, the effects and underlying mechanisms of acute aerobic exercise on both general and food-related inhibition in obese adults remain unclear. This study aimed to explore the potential impacts and underlying neuroelectronic mechanisms of a single session of aerobic exercise at varying intensities on general and food-related inhibitory functions among young adult males with obesity. Design: A within-subject design comprising three sessions (control, low-intensity exercise, moderate-intensity exercise) × three picture types (high-calorie food, low-calorie food, neutral picture) was employed. Methods: Eighteen young adult males with obesity [body mass index (BMI): 34.60 ± 4.21 kg/m2, aged 24.50 ± 5.13 years (Mean ± SD)] were recruited. They participated in three intervention sessions: acute aerobic exercise at low [40-50% maximal Heart Rate (HRmax)], moderate (65-70% HRmax), and a control session (sitting rest), separated by five-day intervals in a counterbalanced order. Following each session, participants performed a food-related Go/No-go task, and EEG recordings (N2 and P3 components) were conducted within 15 min. Results: Moderate-intensity exercise elicited larger N2 amplitudes compared to the control session across different picture types and task conditions. However, there was no significant effect on behavioral indicators or P3 amplitude across sessions. Additionally, food stimuli (both high- and low-calorie) resulted in lower No-go accuracy and smaller N2 amplitudes compared to neutral stimuli. Conclusions: Acute moderate-intensity exercise might influence general and food-related inhibitory function in obese individuals at the neuroelectric stage, potentially by enhancing attentional resources for managing cognitive control and conflict detection. Moreover, reduced N2 amplitudes and No-go accuracy in response to food stimuli compared to non-food stimuli indicate a diminished ability to allocate attentional and neural resources to manage food-related conflicts. However, due to the relatively small sample size, caution is advised when generalizing these findings to the broader population. The pilot test indicated that obese participants had difficulty sustaining high-intensity exercise at 80-90% of their maximum heart rate for a continuous or 20 min period, highlighting potential challenges in exercise adherence at high intensities within this population. Future research is needed to utilize interdisciplinary approaches and multimodal technologies to clarify how exercise influences food-related cognition, appetite regulation, and brain mechanisms in obesity, aiming to better contribute to the prevention and treatment of obesity.

Revisiting the electrophysiological correlates of valence and expectancy in reward processing - A multi-lab replication.

Two event-related brain potential (ERP) components, the frontocentral feedback-related negativity (FRN) and the posterior P300, are key in feedback processing. The FRN typically exhibits greater amplitude in response to negative and unexpected outcomes, whereas the P300 is generally more pronounced for positive outcomes. In an influential ERP study, Hajcak etal., (2005) manipulated outcome valence and expectancy in a guessing task. They found the FRN was larger for negative outcomes regardless of expectancy, and the P300 larger for unexpected outcomes regardless of valence. These findings challenged the dominant Reinforcement Learning Theory of the ERN. We aimed to replicate these results within the #EEGManyLabs project (Pavlov etal., 2021) across thirteen labs. Our replication, including robustness tests, a PCA and Bayesian models, found that both FRN and P300 were significantly modulated by outcome valence and expectancy: FRN amplitudes (no-reward - reward) were largest for unexpected outcomes, and P300 amplitudes were largest for reward outcomes. These results were consistent across different methods and analyses. Although our findings only partially replicate the original study, they underscore the complexity of feedback processing and demonstrate how aspects of Reinforcement Learning Theory may apply to the P300 component, reinforcing the need for rigorous ERP research methodologies.

Intact Neural Responding to Hearing One's Own Name in Children with Autism.

Diminished responding to one's own name is one of the strongest and earliest predictors of autism. However, research on the neural correlates of this response in autism is scarce. Here we investigate neural responses to hearing the own name in school-aged children with and without autism. Thirty-four children with autism and 33 without autism (ages 7-13) were presented with three categories of names (own name, close other's name and unknown other name) as task-irrelevant deviant stimuli in an auditory oddball paradigm, while EEG was recorded. In line with previous findings, parietal P3 amplitudes for the own name were enhanced compared with a close other's name. Older children showed a stronger self-specific effect than younger children. However, this self-preferential effect was not different between groups, despite the fact that parents of children with autism reported significantly less own-name responsiveness in daily life. Neither the N1 component or SON negativity showed self-specific effects. In school-aged children, only the parietal P3 component, and not the N1 or SON negativity, appears to be enhanced for the own name as compared to a close other's name. Age seems to have an effect on the own name modulation of the P3 amplitude, which may explain the relatively small overall effect size. Against expectations, groups did not differ on this self-specific effect. Further research into neural and behavioral responses to hearing one's own name in autism, across different age groups, is warranted.

Measuring Bound Attention During Complex Liver Surgery Planning: Feasibility Study.

The integration of advanced technologies such as augmented reality (AR) and virtual reality (VR) into surgical procedures has garnered significant attention. However, the introduction of these innovations requires thorough evaluation in the context of human-machine interaction. Despite their potential benefits, new technologies can complicate surgical tasks and increase the cognitive load on surgeons, potentially offsetting their intended advantages. It is crucial to evaluate these technologies not only for their functional improvements but also for their impact on the surgeon's workload in clinical settings. A surgical team today must increasingly navigate advanced technologies such as AR and VR, aiming to reduce surgical trauma and enhance patient safety. However, each innovation needs to be evaluated in terms of human-machine interaction. Even if an innovation appears to bring advancements to the field it is applied in, it may complicate the work and increase the surgeon's workload rather than benefiting the surgeon. This study aims to establish a method for objectively determining the additional workload generated using AR or VR glasses in a clinical context for the first time. Electroencephalography (EEG) signals were recorded using a passive auditory oddball paradigm while 9 participants performed surgical planning for liver resection across 3 different conditions: (1) using AR glasses, (2) VR glasses, and (3) the conventional planning software on a computer. The electrophysiological results, that is, the potentials evoked by the auditory stimulus, were compared with the subjectively perceived stress of the participants, as determined by the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire. The AR condition had the highest scores for mental demand (median 75, IQR 70-85), effort (median 55, IQR 30-65), and frustration (median 40, IQR 15-75) compared with the VR and PC conditions. The analysis of the EEG revealed a trend toward a lower amplitude of the N1 component as well as for the P3 component at the central electrodes in the AR condition, suggesting a higher workload for participants when using AR glasses. In addition, EEG components in the VR condition did not reveal any noticeable differences compared with the EEG components in the conventional planning condition. For the P1 component, the VR condition elicited significantly earlier latencies at the Fz electrode (mean 75.3 ms, SD 25.8 ms) compared with the PC condition (mean 99.4 ms, SD 28.6 ms). The results suggest a lower stress level when using VR glasses compared with AR glasses, likely due to the 3D visualization of the liver model. Additionally, the alignment between subjectively determined results and objectively determined results confirms the validity of the study design applied in this research.

Duration of untreated psychosis and cognitive function in first-episode antipsychotic-naïve schizophrenia: Evidence from auditory P300.

The relationship between the duration of untreated psychosis (DUP) and cognitive function in schizophrenia (SZ) patients remains debated, with no empirical evidence from event-related potential (ERP) studies supporting their association. This study aims to investigate the relationship between DUP and cognitive functions, as well as psychiatric symptoms, in first-episode antipsychotic-naïve SZ (FEAN-SZ) patients using ERP. The study included 321 Chinese FEAN-SZ patients and 146 healthy controls. The DUP and sociodemographic characteristics of all participants were collected, and psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale. The P300 (P3) components, including P3a, P3b and N100, were recorded from all participants using auditory oddball paradigm. 25.5 % of patients did not receive timely treatment for over four years, and those with lower educational levels or more severe negative symptoms had longer DUP (p = 0.027, p = 0.020). Compared to healthy controls, FEAN-SZ patients exhibited longer latencies and lower amplitudes in the P3 components (all ps < 0.001). Significant differences in the P3 components were observed among three groups of DUP (< 8 months, 8 to 48 months, and ≥ 48 months) (all ps < 0.001). In the 8 ≤ DUP < 48 months group, the N1 amplitude and P3a latency predicted positive symptom scores and general psychopathology scores, respectively (β = -0.165, p = 0.037; β = 0.541, p < 0.001); P3b latency predicted negative symptom scores in the DUP < 8 months group (β = 0.391, p < 0.001). N1 amplitude predicted general psychopathology scores only in the DUP > 48 months group (β = -0.228, p = 0.040). Multiple linear regression analysis indicated that the latency and amplitude of P3a were independently associated with DUP (B = 0.124, p < 0.001; B = -1.161, p = 0.012). SZ patients who have a longer DUP exhibit more severe P3 deficits, and the P3 components may be indicative of different psychiatric symptom severity in DUPs of different lengths, as well as the P3a component may serve as an electrophysiologic marker to assess the length of DUP.

Effects of stimuli and contralateral noise levels on auditory cortical potentials recorded in school-age children.

One of the functions attributed to the auditory efferent system is related to the processing of acoustic stimuli in noise backgrounds. However, clinical implications and the neurophysiological mechanisms of this system are not yet understood, especially on higher regions of the central nervous system. Only a few researchers studied the effects of noise on cortical auditory evoked potentials (CAEP), but the lack of studies in this area and the contradictory results, especially in children, point to the need to investigate different protocols and parameters that could allow the study of top-down activity in humans. For this reason, the aim of this study was to analyze the effect of varying levels of contralateral noise on efferent activity in children by recording CAEPs with tone burst stimuli. Additionally, we aimed at verifying the effects of contralateral noise on cortical processing of speech stimuli. Monaural CAEPs were recorded using tone burst stimuli in quiet and with contralateral white noise at 60 dB and at 70 dB in 65 typically developing school-aged children (experiment 1), and using speech stimuli with contralateral white noise at 60 dB in 41 children (experiment 2). In experiment 1, noise induced changes were observed only for P1 and P300 components. P1 latency was prolonged at both noise level conditions, P300 latency was prolonged only in the condition with noise at 70 dB, and P300 amplitude was reduced only in the condition with noise at 60 dB. In experiment 2, noise induced latency delays were observed on P1, P2, N2, and P300 components and amplitude reduction was observed only for N1. The effects of noise stimulation were observed on all CAEP components elicited by speech, but the same was not observed in the experiment with tone bursts. The study of noise effects on CAEPs can provide electrophysiological evidence on how difficult listening situations affect sound discrimination and stimulus evaluation at thalamocortical regions.

The Impact of Long-Term Tai Chi Practice on the Trust Behavior of Middle-Aged People.

Trust behavior is of fundamental importance for social stability and development. Middle-aged people, owing to their abundant social resources and extensive experience, have a significant impact through their trust behavior. However, research on enhancing their trust behavior is relatively scarce. Tai Chi, as an activity that combines physical and mental exercise characteristics, may potentially influence the trust behavior of middle-aged people, yet direct research in this regard is lacking. The objective of this study is to explore the impact of Tai Chi on the trust behavior of middle-aged people and its underlying neural mechanisms. This study recruited two groups of middle-aged individuals as research participants. Specifically, the Tai Chi group consisted of 37 middle-aged people with long-term Tai Chi practice experience, while the control group comprised 29 middle-aged individuals without any Tai Chi practice background. The behavioral performance and EEG data of the participants in both groups were recorded during their participation in the trust game. At the behavioral level, the trust rate of the Tai Chi group was higher than the random level (50%), and they made decisions more quickly. The event-related potential (ERP) data revealed that there were interaction effects between the Tai Chi group and the control group in the P2 and N2 components, which are ERP indicators during the decision-making stage. Moreover, in the feedback stage, the feedback-related negativity (FRN) amplitude evoked in the Tai Chi group was smaller than that in the control group. Long-term practice of Tai Chi can enhance decision-making speed and influence brain activity. It provides important reference for understanding the relationship between Tai Chi and the trust behavior of middle-aged people. Although there are limitations in this study, it lays a foundation for future research.

Abnormal electrical brain responses to time deviance in beat deafness

Humans have the spontaneous capacity to track the beat of music. Yet some individuals show marked difficulties. To investigate the neural correlates of this condition known as beat deafness, the cortical electric activity of ten beat-deaf adults, the largest cohort studied so far, as well as of 14 matched controls (Experiment 2), and 16 university students (Experiment 1) were examined. All were actively engaged in detecting anisochronous time-deviants in otherwise isochronous, metronome-like, sequences. As expected, participants with beat-deafness performed more poorly than controls; this behavioral impairment was accompanied by a reduced P300 component at the neurophysiological level, yet with intact N200. Additionally, the MMN following task-irrelevant intensity-deviants was not different between groups. Together the results suggest normal auditory predictions regarding upcoming tones but unreliable access to its representations. These results mirror the findings with pitch deviants in the pitch-based form of congenital amusia and provide a similar neural signature of the disorder on the pitch and time dimension.

The influence of lexical word properties on selective attention to emotional words: Support for the attentional tuning of valent word forms.

Using event-related potentials, it was found that selective attention to valence facilitates early affective discrimination of words with task-relevant valence and inhibits affective processing of words with task-irrelevant valence. This attention-based modulation of affective processing presumably relies on prior associative learning linking visual word forms with their affects. To investigate this hypothesis, we employed a valence-detection task and manipulated lexical (length, frequency) and affective (arousal) word features. Since we assumed that these features strongly influence the strength of visual form-affect associations, we expected them to play a crucial role in early affective discrimination. Fifty-eight participants made speeded responses only to words of one predefined target level of valence (negative, neutral, or positive), which varied across three blocks. As expected, the visual P1 component yielded greater valence discrimination for the target than for nontarget words. This interactive effect was most prominent for short, high-frequency and low-arousal words, respectively. Regarding the N170 component, low-frequency words showed higher amplitudes when they were either positive low-arousing or negative high-arousing compared with the other two sets of words, independently of target status. Additionally, an average-referenced EPN-like posterior negativity (150-270 ms) revealed a target-independent interaction between valence and arousal and increased amplitudes for negative target words. Results extend previous research in showing that particularly short and highly frequent valent word forms can be tuned by selective attention to valence, facilitating early affective discrimination. Finally, findings support the notion that valence and arousal interact during early preattentive, bottom-up processing which is interpreted within the valence-arousal conflict theory.

Prediction of Phenoconversion into Alpha-Synucleinopathy in Patients with isolated REM Sleep Behavior Disorder Using Event-Related Potentials During Visuospatial Attention Tasks.

Isolated REM sleep behavior disorder (iRBD) is recognized as a prodromal stage of alpha-synucleinopathies. Predicting phenoconversion in iRBD patients remains a key challenge. We aimed to investigate whether event-related potentials (ERPs) recorded during visuospatial attention task can serve as predictors of phenoconversion in iRBD patients. We conducted a longitudinal study with 126 iRBD patients (aged 67.1 ± 6.4, 77 males) and 41 healthy controls (HCs; aged 66.1 ± 6.9, 29 males). Among the patients, those who further developed synucleinopathies during the follow-up period (average 6.3 years) were classified as converters (iRBD-CV), while the others as non-converters (iRBD-NC). Posner's visuospatial cueing task was performed at baseline. The N2 and P3 components were acquired for both the cue and target (valid and invalid) stimuli. Based on group comparisons, Kaplan-Meier survival analysis was performed. Twenty-nine patients converted to alpha-synucleinopathies (aged 69.4 ± 7.1, 14 males). iRBD patients exhibited overall reductions in N2 components for cue, valid, and invalid stimuli compared to HC (p = 0.012, 0.047, and 0.001, respectively). iRBD-CV patients displayed a significant increase in cue-elicited P3 (p < 0.001) and a decreasing trend in cue-elicited N2 (p = 0.079) compared to iRBD-NC. These ERP alterations were strongly associated with faster rate of phenoconversion (p < 0.001 for both components). Our findings suggest that altered cue-elicited ERPs could serve as early biomarkers for predicting phenoconversion in iRBD patients, likely reflecting attention-related neurodegeneration pathways. These biomarkers potentially enable the detection of preclinical phenotypes in alpha-synucleinopathies, facilitating timely intervention.

Non-Linear Effects of Acute Sleep Deprivation on Spatial Working Memory: Cognitive Depletion and Neural Compensation.

Spatial working memory is crucial for processing visual and spatial information, serving as a foundation for complex cognitive tasks. However, the effects of prolonged sleep deprivation on its dynamics and underlying neural mechanisms remain unclear. This study aims to investigate the specific trends and neural mechanisms underlying spatial working memory alterations during 36 h of acute sleep deprivation. Twenty participants underwent a 36 h protocol of acute sleep deprivation. Utilizing the spatial 2-back task for assessing spatial working memory, combined with event-related potential (ERP) technology, we compared behavioral and neural responses at four critical time points-before deprivation, and after 12, 24, and 36 h of sleep deprivation-to uncover dynamic cognitive changes. The findings indicate that the impact of sleep deprivation on spatial working memory exhibits significant temporal dependence. After 24 h of deprivation, both behavioral performance and ERP component amplitudes showed significant declines. During the period from 24 to 36 h, the amplitudes of the P2, N2, and P3 components exhibited a recovery trend, potentially reflecting neural compensatory mechanisms. The impact of 36 h acute sleep deprivation on spatial working memory is characterized by time-dependent and phase-specific effects. Initially, sleep deprivation leads to severe cognitive depletion, followed by an adaptive compensatory phase where neural mechanisms may partially restore function. These findings highlight the non-linear nature of cognitive impairment due to sleep deprivation, involving complex self-regulatory and compensatory mechanisms, with implications for understanding cognitive resilience and adaptive processes.

Objective Visual Acuity Estimates in Amblyopia Are More Accurate With Optotype-Based P300 Than With VEP Measurements.

Traditional visual acuity (VA) measurements depend on subjective responses, which can be unreliable, especially with uncooperative participants. Objective measurements with visual evoked potentials (VEP) address this issue but can overestimate VA in amblyopia. This study aims to establish the P300 component of the event-related potential as an objective VA test for amblyopia and compare its performance to subjective (psychophysical) and VEP-based VA estimates. Psychophysical, VEP-based, and P300-based VA estimates were obtained for amblyopic and fellow eyes of 18 participants (aged 19-65) in a bicentric study. VEP-based VA was determined from the spatial frequency threshold derived from occipital cortex pattern-pulse responses to check-sizes ranging from 0.048° to 8.95°. P300 responses were collected using visual oddball sequences with circular optotypes. The threshold was estimated from the sigmoid function of parietal P300 amplitude versus optotype gap size. Mean VA values for amblyopic eyes were compared across methods. VEP-based VA of the amblyopic eyes overestimated psychophysical VA by 0.18 ± 0.06 logMAR (P = 0.0016). In contrast, P300-based VA showed no significant difference from psychophysical VA (0.00 ± 0.04 logMAR, P > 0.05). In amblyopia, P300-based optotype VA aligns more closely with psychophysical VA than VEP-based VA, suggesting that P300-based VA is a valid objective alternative for estimating VA in amblyopic eyes. This study highlights the potential of P300-based VA testing as a reliable and objective method for assessing VA in amblyopic eyes, offering a promising tool for clinical and research applications where traditional methods fall short.

Differential neural processing of reward and self-relevance in a social gambling paradigm.

We preferentially process self-related information. However, less is known about how this advantage extends to reward processing and if this process is sensitive to a continuum of self-relevance. Specifically, do we dissociate ourselves from all others when processing rewards, or do those we know personally also enjoy self-related biases? To address this, we recorded electroencephalographic (EEG) data from 30 undergraduate student participants who played a simple two-choice "bandit" gambling game where a photo presented before each gamble indicated whether it benefited either the participant, an individual they knew, or a person they did not know. Temporal spatial principal components analysis (tsPCA) of EEG data evoked by target photos revealed a component consistent with attention and early perceptual processing (the P200), while analysis of data evoked by the feedback stimuli revealed a component consistent with reward processing (the reward positivity). Results demonstrated that P200 component scores were larger for self-gambles than both known- and unknown-other target photos. Interestingly, and contrary to previous findings, reward positivity component scores were similar for all gambles independent of perceived ownership. Our findings suggest that, when gambling for individuals on a continuum of self-relevance, the potential for monetary gain based on the self-relevance cues is differentially processed for ourselves while the actual reward is not. We suggest that the known-other gambling target introduced an empathy-like effect, contesting the self-bias in reward processing.