P300 Amplitude Research Articles

Acute Concurrent Exercise Improves Inhibitory Control Without Mediating the Role of Lactate: An Event-Related Potential Study

BackgroundConcurrent exercise (CE), an emerging exercise modality characterized by sequential bouts of aerobic (AE) and resistance exercise (RE), has demonstrated acute benefits on executive functions (EFs) and neuroelectric P3 amplitude. However, the effect of acute CE on inhibitory control, a sub-component of EFs, and P3 amplitude remains inconclusive. Moreover, exploring the mechanisms underlying the effects of acute exercise on EFs contributes to scientific comprehension, with lactate recognized as a crucial candidate positively correlated with EFs. Therefore, this study aimed to determine the effects of acute CE on inhibitory control via behavioral and event-related potential approaches and to examine its potential mediational role on lactate.MethodsSeventy-eight adults (mean age = 22.95, SD = 1.75 years) were randomly assigned to either a CE, AE, or control (CON) group. Participants in the CE group engaged in 12-min of AE (40–59% of heart rate reserve [HRR]) coupled with 13-min of RE (1 set, with 75% of 10-repetition maximum, and 12 repetitions of 8 movements). The AE group participated in 25 min of AE (40–59% HRR). Prior to and following exercise onset, participants in both the CE and AE groups completed a 5-min warm-up and cool-down. Participants in the CON group read books for 35 min. Lactate concentrations were measured at timepoints of 0-, 17-, and 30-min relative to the treatment onset. Response time (RT) and accuracy in the Stroop test, as well as P3 amplitude, were assessed before and after the treatment.ResultsThe results revealed that both the CE and AE groups had significantly shorter RTs compared to the CON group, with no significant differences in accuracy among groups. A decrease in P3 amplitude was observed for the CE group compared to the AE and CON groups. The mediating effects of lactate between acute exercise and inhibitory control were insignificant.ConclusionsThe findings suggest that both CE and AE improve inhibitory control and CE potentially enhances the efficient allocation of attention resources. The lack of a significant mediating effect of lactate warrants further investigation.Trial registration: ClinicalTrials.gov, NCT06370286. Registered 12 April 2024—Retrospectively registered, https://clinicaltrials.gov/study/NCT06370286.

Individuals' Food Preferences can be Influenced by the Music Styles: An ERP Study.

Studies have shown that a cross-modal association between listening to music and eating. This study aims to explore the influence of music style on individuals' food preferences and provide evidence for understanding multi-sensory research. Twenty-seven participants participated in the experiment which consisted of two parts. First, participants completed basic demographic information, followed by a food choice task after exposure to four different music styles: classical, jazz, rap, and rock, with ERP data recorded simultaneously. The behavioral results showed that participants selected more high-calorie foods after exposure to jazz and rock music compared to low-calorie foods. Additionally, during jazz and rock music, participants selected more high-calorie foods, while they favored low-calorie foods during classical music. The ERP results showed that the N1 amplitudes were smallest during the food choice task following the classical music and greatest during the food choice task following the rock music, while the N450 amplitudes were smallest during the food choice task following the jazz music. P2 amplitudes were smallest during the food choice task following the rock music and greatest during the food choice task following the classical music, and P3 amplitudes during the food choice task following jazz music were the greatest. The aforementioned ERP differences were observed irrespective of food choices. However, we did not find a significant interaction between foods (high and low-calorie) and music. Pearson correlation analysis revealed a positive relationship between body satisfaction and P3 amplitudes for classical, jazz, and rock music, with BMI negatively correlated with body satisfaction. This study provides innovative practical perspectives for healthy eating.

The effect of bilingualism on obligatory components of auditory late responses in young adults: a cross-sectional study

IntroductionBilingualism significantly contributes to neuroplasticity in the brain, with research indicating enhanced auditory processing in bilingual individuals. Obligatory sensory components of the auditory late responses (ALRs) reflect primary and secondary auditory cortex activity, serving as an electrophysiological measure of auditory processing. This study aims to compare ALRs' obligatory components (P1-N1-P2) in bilingual (Turkish-Persian) and monolingual (Persian) young adults.MethodThis cross-sectional study analyzed ALRs in 28 monolingual and 28 bilingual participants aged 19 to 30 years, using a 70 dB nHL speech stimulus (/da/). ALRs were recorded monaurally with insert earphones. The study then compared the mean latency and amplitude of P1- N1- P2 complex in the right and left ear between two groups.ResultThe study revealed shorter latency for all three ALRs components in bilingual participants compared to monolinguals. This difference was statistically significant (P-value < 0.05) for N1 with right ear stimulation and P2 with right and left ear stimulations. No significant differences were found in the amplitude of P1-N1 and N1-P2 between the groups.ConclusionThe significant reduction in N1 and P2 latency observed in bilingual subjects' ALRs likely results from neural plasticity. This may enhance neural transmission and accelerate speech sound processing in the respective cortical regions. These latency changes could serve as a cortical neural biomarker distinguishing monolinguals from bilinguals, highlighting the impact of bilingualism on auditory processing efficiency.

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.

Training method and difficulty modulate electrophysiological correlates of visual perceptual learning.

The present study focused on the influence of training methods and task difficulty on event-related potentials (ERPs) at early and later visual perceptual learning (VPL) on a coherent motion identification task. Sixty participants were randomly divided into four groups for training with an adaptive stimulus (staircase group) and three constant stimuli (moderate, easy and difficult intensity groups). Visual performance improved in the staircase and moderate training groups but not in the easy or difficult training groups. ERP results revealed a decreased P1 amplitude in all groups. Additionally, staircase training increased the frontal P2 amplitude; accordingly, moderate constant stimulus training reduced the frontal P2 amplitude and increased the frontal N2 amplitude. Importantly, the change in frontal P2 amplitude was correlated with improved performance, indicating the involvement of cortices responsible for higher-order cognitive processes in VPL. Additionally, the difference in frontal P2 amplitude changes suggests the modulation of training methods (adaptive and consistent) on the role of attention in VPL. Furthermore, although behavior changes were not observed, the brains in the easy and difficult groups still presented different ERP changes. In summary, the results provide electrophysiological evidence for the modulation of training methods and task difficulty in VPL-related neuroplasticity.

Hardy-Rand-Rittler colour vision testing in cone and cone-rod dystrophies: correlation with structural and functional outcome measures.

To determine how Hardy-Rand-Rittler (HRR) colour vision testing correlates with visual functional and structural assessments in Cone and Cone-Rod Dystrophy. Thirty-four Cone and 69 Cone-Rod Dystrophy patients diagnosed by electroretinography (ERG) at the Save Sight Institute in Sydney were included in a retrospective analysis. Each patient's HRR colour vision test scores were compared with markers of cone and rod system function including visual acuity (VA), ERG responses, changes on Spectral Domain Optical Coherence Tomography (OCT) and Fundus Autofluorescence. The number of plates identified on HRR testing correlated with logMAR best-corrected distance VA; r(101) = -0.49, p < 0.0001. HRR scores correlated with markers of cone and macula function including OCT Ellipsoid Zone Gap Width, Central Macular and Outer Nuclear Layer Thickness, Full Field ERG 30 Hz flicker amplitudes, light adapted 3.0 b-wave amplitudes and Pattern ERG 15- and 30-degree p50 amplitudes. HRR colour vision testing correlates with structural and functional measures in Cone and Cone-Rod Dystrophy. HRR colour vision testing provides a simple clinic-based option to monitor disease changes in Cone and Cone-Rod Dystrophy patients, especially when ERG testing is not available.

Math-anxious people suffer more in math-related events: The perspective of reward processing on motivated behavior.

Individuals with high math anxiety (HMA) demonstrate a tendency to avoid math-related tasks, a behavior that perpetuates a detrimental cycle of limited practice, poor performance, increased anxiety, and further avoidance. This study delves into the cognitive and neural bases of math avoidance behavior in HMA through the lens of reward processing. In Experiment 1, participants reported their satisfaction level in response to the reward provided after solving an arithmetic problem. In Experiment 2, participants weighed the economic benefits against the cognitive costs of solving a calculation problem. This decision-making process was framed in terms of either retaining or losing some monetary reward, creating positive or negative contexts, respectively. Experiment 1 showed that HMA participants were more punishment-sensitive and less satisfied with incorrect answers. Experiment 2 revealed that HMA individuals were less willing to tackle math challenges when their satisfaction dipped after errors. HMAs exhibited increased math avoidance and a notably reduced P3 amplitude in negative contexts, a response unique to the HMA group. HMAs also displayed an elevated feedback-related negativity amplitude in both contexts. This study suggests a potential impairment in reward processing in negative contexts and under negative appraisal among those with high math anxiety.

Honesty threshold affects individuals’ resistance to monetary temptations

This study investigated whether honesty is a stable trait or varies depending on situational factors. Using a coin flip guessing paradigm with monetary rewards, 33 participants completed trials with rewards ranging from 0.01 to 3 yuan. Modeling of behavioral data showed individuals have varying “honesty thresholds” where they switch from honest to dishonest behavior. EEG analysis revealed increased P300 amplitude when resisting greater monetary temptation, and individuals with higher honesty thresholds had lower P300 amplitudes for the same rewards. A late positive component indicated greater cognitive conflict when the reward amount neared an individual’s honesty threshold. These findings challenge the conception of honesty as a stable trait, instead demonstrating it varies based on contextual factors like reward size. Computational modeling and EEG provide insight into the cognitive processes underlying contextual shifts in honest behavior.

Social presence effect in language comprehension: evidence from event-related potential (ERP) research.

This study aimed to examine the impact of social presence on Chinese reading comprehension and associated neural responses. Participants tasked with reading Chinese sentences either alone or in the presence of others and subsequently assessing the accuracy of the sentences' meanings. Concurrently, we recorded the participants' electrical brain responses to critical word processing. Behavioral results indicated no significant effect of social presence on the judgment of sentence accuracy. Electroencephalogram (EEG) results, however, revealed that reading in the presence of others elicited more pronounced left anterior negativity (LAN) components in the left front of the scalp compared to reading alone. Additionally, incorrect meanings triggered larger N400 and P600 amplitudes in the mid-parietal region than correct meanings. Social presence intensifies early neural responses during the reading of Chinese sentences, although it does not influence semantic integration or conflict resolution. These findings support the notion that social context affects language processing.

Visual Reliance in Severe Hearing Loss: Visual Evoked Potentials (VEPs) Study.

Whether to rely on the visual cues in cases with severe hearing loss with adequate amplification is a matter of debate. So, this study aims to study visual evoked potentials (VEPs) in children with severe or profound HL, whether fitted with HAs or CIs. This study included three groups of children matched in age and gender: normal hearing, children with hearing thresholds >70 dBHL and fitted with power HAs, and children fitted with CIs. All cases were subjected to pure tone audiometry (aided and unaided), speech discrimination scores, ophthalmic examinations, and visual evoked potentials (VEPs). SD% scores significantly improved with the use of VCs in both CI and HL groups, and a significantly higher P100 amplitude of VEPs in both CI and HL groups (more in children fitted with CIs). Cross-modal reorganization in severe degrees of HL is of great benefit whether they are fitted with HAs or CIs.

The P200 ERP Response in Mild Cognitive Impairment and the Aging Population.

Evoked potential metrics extracted from an EEG exam can provide novel sources of information regarding brain function. While the P300 occurring around 300 ms post-stimulus has been extensively investigated in relation to mild cognitive impairment (MCI), with decreased amplitude and increased latency, the P200 response has not, particularly in an oddball-stimulus paradigm. This study compares the auditory P200 amplitudes between MCI (28 patients aged 74(8)) and non-MCI, (35 aged 72(4)). Data were collected in routine clinical evaluations where EEG with audio oddball ERPs were measured as part of a health screening exam from 2 clinics serving MCI patients and one clinic serving a non-MCI population as part of a wellness/preventative care program. We also investigated the disease course for 3 patients as case studies. The results revealed the P200 amplitudes to be significantly increased in the MCI compared to the non-MCI groups, alongside the expected reduction in P300, Trail Making, and reaction time. Moreover, the ratio of P200-to-P300 was also increased in the MCI groups even in cases where the P300 was strong. This trend continued for patients who were tracked from early-to-later stages in the case studies. While the pathophysiology of the P200 response in a 2-tone auditory oddball protocol is not well understood, this measure may help indicate signs of early MCI, particularly in cases where the P300 is still strong.

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.

The impact of reducing cognitive load in RT and P300 concealed information tests with importance related fillers.

Lukács et al. (2017) enhanced the Reaction Time Concealed Information Test (RT CIT) by incorporating "filler" items. Fillers are intended to increase attention and cognitive load, which should potentially enhance the P300 based CIT (P300-CIT) too. Despite these hypotheses, Olson et al. (2020) found no clear effects of fillers on P300 amplitude and suggested that excessive cognitive load may counteract an increase in attention. Wojciechowski and Lukács (2022) introduced "importance-related" fillers to the RT-CIT in an imaginary mock crime scenario, theorizing they would be more intuitive and easier for participants to follow. This study aims to replicate their findings in a classic episodic mock crime scenario, and with semantic information, to test if a fillers-related enhancement effect on P300 may be observed when cognitive load is reduced. The study compares three protocols: the importance-themed enhanced CIT (E-CIT), a less cognitively demanding version of the E-CIT, the inducer CIT (I-CIT), and the classic three-stimulus protocol (3SP-CIT). The study investigates whether the I-CIT yields a superior P300-CIT effect due to reduced cognitive load and induced semantic context of importance. Reaction time analyses replicated the RT-CIT effect enhancement in the E-CIT compared to the classic 3SP-CIT. Elevated response times in the E-CIT compared to the 3SP-CIT and I-CIT suggest higher cognitive load in the E-CIT. Response times were comparable between the 3SP-CIT and I-CIT, suggesting similar cognitive load. For the P300-CIT results, similar to Olson et al. (2020), fillers did not affect P300 amplitude or latency in the E-CIT group, with Bayes factors supporting the null. Contrary to expectations, no clear enhancement of P300 was observed in the I-CIT, suggesting that cognitive load imposed by fillers does not counteract P300 amplitude.

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.

Can guilt enhance sensitivity to other's suffering? An EEG investigation into moral emotions and pain empathy.

As a unique form of empathy, pain empathy often has a close relationship with society and morality. Research has revealed that moral emotions can influence pain empathy. The underlying physiological mechanism still needs to be further examined to understand how moral emotions affect pain empathy. This study employs EEG and Machine Learning techniques, using a painful image induction paradigm to explore the impact of moral emotion (guilt)-on pain empathy and its neural mechanisms. Participants without pain sensation were instructed to observe and evaluate pictures of an anonymous hand in painful or non-painful pictures under feelings of guilt or neutral emotion. Results found slower reaction times and higher pain ratings for painful pictures. Furthermore, guilt led to higher pain ratings. Under conditions of painful pictures, guilt-induced greater P3(350-450ms) amplitudes and higher α oscillations and enhanced the functional connectivity between the prefrontal cortex, the central frontal region, and the parieto-occipital lobe. K-nearest neighbor can effectively classify high and low-pain empathy under guilt emotion. The result showed that guilt promotes the brain's processing of painful picture, causing individuals to pay high attention and engage in deep cognitive processing. This study provides insights into enhancing empathy and fostering interpersonal relationships.

Characteristics of Cognitive Event-Related Potential Components and N170 Source Analysis in Patients with Acute Cerebellar Infarction.

This study aims to evaluate cognitive impairments in patients with acute cerebellar infarction using event-related potentials (ERP) and electrophysiological source imaging (ESI). Thirty patients with acute cerebellar infarction and 32 healthy volunteers were selected. Cognitive potentials were recorded and measured using a visual Oddball paradigm. Source analysis of the N170 component was performed using standardized low-resolution brain electromagnetic tomography (sLORETA) to compare the standardized current density distribution between the two groups under different stimuli.For inverted and upright face stimuli, the amplitudes of N170, VPP, and N300 in the patient group were significantly lower than those in the control group (p < 0.05). For upright house stimuli, the VPP amplitude in the patient group was also lower than that in the control group (p < 0.05). Source analysis revealed that the brain regions with significant differences between the acute cerebellar infarction group and the control group included the temporal and parietal lobes. Specifically, activation in the precuneus was reduced during inverted face stimuli; activation in the middle temporal gyrus was reduced during upright face stimuli; and activation in the middle temporal gyrus and fusiform gyrus was increased during both inverted and upright house stimuli.Patients with acute cerebellar infarction exhibit abnormal P100, N170/VPP, and N300 amplitudes. Source analysis of the N170 component revealed altered activation in the middle and inferior temporal gyri, fusiform gyrus, middle occipital gyrus, and precuneus, which play a role in selective cognitive impairments following cerebellar infarction.

Age-related Electrophysical Correlates of Cross-modal Attention Switching.

The human experience demands seamless attentional switches between sensory modalities. Aging raises questions about how declines in auditory and visual processing affect cross-modal attention switching. This study used a cued cross-modal attention-switching paradigm where visual and auditory stimuli were simultaneously presented on either spatially congruent or incongruent sides. A modality cue indicated the target modality, requiring a spatially left versus right key-press response. EEG recordings were collected during task performance. We investigated whether the mixing costs (decreased performance for repetition trials in a mixed task compared with a single task) and switch costs (decreased performance for a switch of target modality compared with a repetition) in cross-modal attention-switching paradigms would exhibit similarities in terms of behavioral performance and the ERP components to those observed in the traditional unimodal attention-switching paradigms. Specifically, we focused on the ERP components: cue-locked P3 (mixing/switch-related increased positivity), target-locked P3 (mixing/switch-related decreased positivity), and target-locked lateralized readiness potential (mixing/switch-related longer latency). In addition, we assessed how aging impacts cross-modal attention-switching performance. Results revealed that older adults exhibited more pronounced mixing and switch costs than younger adults, especially when visual and auditory stimuli were presented on incongruent sides. ERP findings showed increased cue-locked P3 amplitude, prolonged cue-locked P3 latency, decreased target-locked P3 amplitude, prolonged target-locked P3 latency in association with switch costs, and prolonged onset latency of the target-locked lateralized readiness potential in association with the mixing costs. Age-related effects were significant only for cue-locked P3 amplitude, cue-locked P3 latency (switch-related), and target-locked P3 latency (switch-related). These findings suggest that the larger mixing costs and switch costs in older adults were due to the inefficient use of modality cues to update a representation of the relevant task sets, requiring more processing time for evaluating and categorizing the target.

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.

Neural markers of human aggression and cooperation are influenced by zero-sum or non-zero-sum groups.

Cooperation and competition in social interaction are important to social development. There are many studies examining the neural mechanism underlying these behaviors; however, little is known about the potential role of payoff norms in social interactions. This study introduced two distinct payoff norms: zero-sum (ZS) and non-zero-sum (NZS). In the ZS group, only the player with the highest total score would receive a reward; while in the NZS group, rewards were determined by the combined total score of both players, and individual rewards were prorated according to each player's contribution to the total score. Electroencephalography was used to examine individuals' neural responses during the Chicken Game in these different groups. The behavioral findings revealed a higher rate of cooperation in the NZS group compared to the ZS group. Aggressive behaviors from opponents elicited larger feedback-related negativity (FRN) and lower P300 amplitudes in both groups. Notably, larger FRN and smaller P300 amplitudes were elicited by participants' aggressive behaviors compared to their cooperative behaviors in the ZS group, whereas larger P300 amplitudes were elicited by aggressive behaviors compared to cooperative behaviors in the NZS group. Additionally, a greater theta event-related synchronization (ERS) was observed solely when participants exhibited aggression in the NZS group. The type of group moderated the association between posterior theta-ERS and cooperative rates. Specifically, theta-ERS was negatively associated with cooperative rates in the NZS group, whereas a reversed association was found in the ZS group. These findings provide valuable insights into the neurobiological foundations of cooperation under different economic payoff norms.