Event-related Potentials Research Articles

Right is it right? Influence of the type of motor response on behavioral and electrophysiological indicators during the orthographic decision task

The role of the sensorimotor component in the processing of verbal information is currently widely discussed. We hypothesize that the type of motor response may influence behavioral and electrophysiological performance in an orthographic decision task. Event-related potentials (ERPs) were recorded in 42 right-handers during an orthographic decision task. Half of the participants were instructed to press the right button with their right hand upon encountering correctly spelled words and the left button with their left hand upon encountering misspelled words, while the other half followed the opposite instruction. The motor response to correctly spelled words was shorter for the dominant hand compared to the non-dominant hand, which may be due to the coincidence of semantic and motor representations (stimulus-response compatibility effect). In addition, reaction times to incorrectly spelled words were longer than to correctly spelled words only in the group of participants who responded with their dominant hand to correctly spelled words. The P200 and N400 ERP components did not depend on the type of motor response. However, in the group of participants who pressed correctly spelled words with their right hand, the amplitude of the P600 component was greater for misspelled words compared to correctly spelled words. Thus, the type of motor response influenced the effects associated with word spelling recognition.

Event-related potentials in studies of the implicit component of cognitive biases

The review analyzes neurophysiological correlates of the implicit component of cognitive bias in the processes of perception and decision-making. The review identifies the leading methodological pipeline for analysis of the implicit component of cognitive bias, and justifies its choice in terms of the objectives of this review. The method of recording event-related potentials (ERPs) was chosen as the main approach to determining neurophysiological indicators of implicit processes. The analysis of literature allowed us to identify ERP components reproduced in the works of different authors using different variants of experimental designs for studying implicit bias, which may indicate the presence of common neurophysiological mechanisms associated with implicit processes in cognitive bias. The possibility of using other approaches to the analysis of EEG data to obtain new information about the mechanisms of implicit components in cognitive bias is also discussed.

Effects of different types of high-definition transcranial electrical stimulation on visual working memory and contralateral delayed activity

Background and purposeWorking memory is critical for individuals and has been found to be improved by electrical stimulation of the left dorsolateral prefrontal cortex (DLPFC). However, the effects of different types of transcranial electrical stimulation on working memory are controversial, and the underlying mechanism remains uncertain. In this study, high-definition transcranial direct current stimulation (HD-tDCS) and high-definition transcranial random noise stimulation (HD-tRNS) were applied to the DLPFC to observe the different effects on visual working memory (VWM). The aim was to explore the causal relationship between the electrical activity of the DLPFC and the posterior parietal cortex (PPC) electrical activity and the contralateral delayed activity (CDA).MethodsThirty-three healthy subjects received HD-tDCS, HD-tRNS and sham stimulation in a random order. Stimulation was applied to the left DLPFC for 20 min. The subjects underwent a color change-detection task as our VWM task and an auditory digit span test (DST) immediately after stimulation. Event-related potential (ERP) data were collected during the VWM task.ResultsThe results revealed significant differences between the different types of HD-tES. There was a remarkable increase in VWM capacity following HD-tDCS compared with both HD-tRNS (pa = 0.038) and sham stimulation (pa = 0.038). Additionally, the CDA from the PPC differed after stimulation of the DLPFC. Both HD-tDCS and HD-tRNS expanded the maximum CDA amplitude from set size of 4 to 6, whereas after sham stimulation, the maximum CDA was maintained at a set size of 4. Compared with the sham condition, only HD-tDCS induced a noteworthy increase in CDA amplitude (pa = 0.012). Notably, a significant correlation emerged between the mean CDA amplitude and VWM capacity (p < 0.001, r = − 0.402).ConclusionThese findings underscore the ability of HD-tDCS to target the DLPFC to augment working memory capacity while concurrently amplifying CDA amplitudes in the PPC through the frontoparietal network.Trial registration ChiCTR2300074898.

Comparing retro-cue benefit mechanisms in visual working memory: completely valid vs. highly valid retro-cues

Visual working memory (VWM) plays a crucial role in temporarily maintaining and manipulating visual information. Retro-cue benefit (RCB) refers to the enhancement of memory performance when attention is directed toward a subset of items in VWM after their initial encoding. Our recent electroencephalogram (EEG) studies indicate that cue validity affects the mechanisms underlying RCB formation. However, previous research has not thoroughly examined whether these mechanisms differ between completely valid and highly valid cue conditions. This study investigates the consistency of RCB mechanisms under conditions of complete (100%) and high (80%) retro-cue validity. We manipulated retro-cue validity and examined cognitive processing mechanisms under different validity conditions using EEG. Specifically, we focused on the N2pc component, which reflects attentional resource allocation, and the contralateral delay activity (CDA) component, which reflects the quantity of information retained in VWM. The results, encompassing both behavioral and event-related potential (ERP) findings, show that participants in both the 100% and 80% cue validity conditions exhibit robust RCB. Notably, the degree of RCB remains consistent across these conditions, indicating that participants utilize retro-cues to enhance VWM performance to the same extent. In the 80% cue validity condition, a significant retro-cue cost (RCC) was observed, indicating that participants selectively discarded uncued items from VWM. In invalid trials, response accuracy drops to chance levels, supporting the removal hypothesis. ERP results reveal that attentional resource allocation (N2pc) and the quantity of retained information (CDA) remain uniform across cue validity conditions. The mechanism responsible for RCB formation appears to involve an all-or-nothing process of discarding uncued information rather than a flexible resource allocation strategy. This study provides insights into attention allocation and information-processing mechanisms in VWM, suggesting that conclusions drawn from tasks with completely valid retro-cues can be integrated with findings from highly valid cue tasks. These findings also illuminate the flexibility of internal attentional resource allocation during RCB formation and contribute to our understanding of attention processes in VWM.

Do smaller P300 amplitudes in schizophrenia result from larger variability in temporal processing?

The P3b is a prominent event-related potential (ERP) with maximal amplitude between 250 ms and 500 ms after the onset of a rare target stimulus within a sequence of standard non-target stimuli (oddball paradigm). Several studies found reduced P3b amplitudes in patients with schizophrenia compared to neurotypicals. Our work and the literature suggest that temporal imprecision may play a large pathophysiological role in schizophrenia. Here, we investigated whether reduced P3b amplitudes result from reduced neural activity (power) or temporal imprecision (inter-trial phase coherence; ITC) in delta and theta bands, using two EEG datasets from different studies with different oddball paradigms (Study 1: 19 patients with schizophrenia and 17 matched controls, Study 2: 26 patients and 26 controls). Both studies revealed typical P3b ERP components with smaller amplitudes in patients. Reduced ITC in patients was found in the delta band, which correlated with P3b peak amplitudes for all participant groups (ρ = 0.58–0.89). In Study 1, we also found significant differences between patients and controls in ITC in the theta band, which also correlated with P3b peak amplitudes (patients’ ρ = 0.64, controls’ ρ = 0.54). This was not found in Study 2. The results indicate that P3b amplitude reduction in patients with schizophrenia is linked to a reduction in temporal precision of neural activity. These results expand the notion of imprecision in temporal processing at phenomenological, psychological, and neurological levels that have been related to disturbances of the sense of self. They confirm that temporal imprecision may be more important than the reduction of neural activity itself.

Effects of Alcohol on EEG Activity: A Systematic Review Focused on Sex-Related Differences in Youth.

Most electroencephalographic (EEG) investigations on alcohol have focused on adults, and scarce data is available about the potential of EEG measurements to detect young people at high-risk, as well as, to understand possible sex differences in alcohol impact on the brain. This systematic review aimed to explore sex-related differences in EEG among young people with alcohol misuse, alcohol use disorder (AUD), and offspring of families with AUD. A systematic review of the literature was conducted following PRISMA guidelines. Review protocol was registered in Prospero (ID: CRD42024511471). After article selection process and quality assessment, 25 studies were included in our review. The search included participants between 12 and 30 years old with problematic alcohol consumption, as defined by DSM, AUDIT, or specific alcohol misuse questionnaires. It seems that beta was generally higher in young males with AUD, and they usually exhibited greater interhemispheric connectivity (interHC), whereas young females with AUD tended towards enhanced intraHC. P3 appears to be particularly sensitive to alcohol misuse, with males typically exhibiting a lower amplitude than young females. Other event related potentials (ERPs) such as N415, P640, and the error-related negativity (ERN) lacked sufficient methodological support to draw conclusions regarding sex differences, N340 and P540 suggested avenues for expanding research on memory processing, indicating differences in amplitude between males and females. Considering sex variables in clinical research will enhance our understanding of alterations in brain function and structure with the goal of tailoring treatment strategies for AUD.

From oxygen shortage to neurocognitive challenges: behavioral patterns and imaging insights

Environmental hypoxia, resulting from reduced oxygen supply, poses a significant risk of dysfunctioning and damaging the neurocognitive system, particularly in relation to anxiety and stress. Inadequate oxygenation can lead to acute and chronic brain damage. Scholars used behavioral, hemodynamic, and electromagnetic neurofunctional techniques to investigate the effects of normobaric and hypobaric hypoxia on neurocognitive systems. They found a correlation between hypoxia, altered psychomotor responses, and changes in EEG alpha, theta, beta, and gamma rhythms, which affect spatial attention and memory. Hypoxia affects event related potential (ERP) components differently depending on latency. Perceptual responses N1 and P2 remain largely unaffected, while the amplitudes of preattentive MMN, vMMN, and P3a are significantly altered. Late latency components related to attention, particularly P3b, are also altered. These changes illustrate the spectrum from sensory detection to more complex cognitive processing, highlighting the brain's efficiency in managing information. Interestingly, the amplitudes of P3b, ADAN and CNV can increase with increased cognitive demands in hypoxia. This suggests a compensatory response. Prolonged exposure exacerbates these effects, resulting in compensatory delayed behavioral responses and alterations in behavioral monitoring and conflict inhibitory control, as reflected by reduced amplitudes in some attention related ERP components, including N2, N2pc, and ERN. Thus, neurocognitive function and integrity are under stress. ERP sources and hemodynamic images reveal that vulnerable brain regions include the frontal prefrontal cortices, hippocampus, basal ganglia, and parietal and visual cortices, which are essential for attention related processes like decision making and spatial memory. The auditory system appears less affected.

Treatment strategies for smartphone addiction: efficacy study of transcranial direct current stimulation and exergaming

ObjectiveSmartphone addiction is on the rise globally. This study aimed to compare the rehabilitative effects of transcranial direct current stimulation (tDCS) and exergames on smartphone addiction among college students. Additionally, we discussed the central mechanisms through changes in electroencephalography (EEG) to provide clinical insights.MethodsThirty-six participants were randomly assigned to three groups: control group, tDCS group (bilateral dorsolateral prefrontal cortex stimulation), and exergame group. The intervention lasted for 4 weeks with twice-weekly sessions. Outcome measures included the Smartphone Addiction Scale - Chinese Version (SAS-C), Iowa Gambling Task (IGT) net scores, and event-related potential (ERP) data collected during the IGT, focusing on P300 and feedback-related negativity (FRN) amplitudes.ResultsAll groups showed significant reductions in SAS-C scores post-intervention. Behaviorally, post-intervention scores improved, indicating significant effects of different interventions on participants’ strategy choices. P300 amplitudes increased significantly at outcome electrode sites for all groups, with the most notable increase in tDCS group FC2 and CP1. FRN amplitudes decreased significantly post-intervention in the control and tDCS groups, with significant differences between the two groups.ConclusionAll three interventions appeared to have alleviating effect on smartphone addiction. After 4 weeks, participants showed improved executive control and decision-making abilities. Specifically, significant effects were observed in the tDCS group, with increased P300 amplitudes in the frontal, parietal, and central regions, as well as FRN amplitudes in the central and frontal regions. This suggested that tDCS enhanced psychological resources and improved inhibition control capabilities.

Speech Mismatch Negativity (MMN) in Schizophrenia with Auditory Verbal Hallucinations.

Auditory verbal hallucinations (AVH) are experienced by many individuals with schizophrenia (SZ), a neurodevelopmental disease that encumbers the quality of life and psychosocial outcome of those afflicted by it. While many hypotheses attempt to better define the etiology of AVHs in SZ, their neural profile and its moderation by current neuroleptics remains limited. The Mismatch Negativity (MMN) is an event related potential (ERP) measured from electroencephalographic (EEG) activity during the presentation of a deviance detection auditory paradigm. The neural regions and activity underlying the generation of the MMN include the primary auditory cortex and the prefrontal cortex which are regions also found to be activated during the experience of AVHs. Decreased MMN amplitudes have been robustly noted in SZ patients during the presentation of MMN tasks using auditory tones. However, the MMN generation to speech stimuli has not been extensively examined in SZ nor in relation to AVHs. The primary objective of this study was to examine the MMN to five speech-based deviants in SZ patients and healthy controls. Second, we assessed MMN features with AVH characteristics in 19 SZ patients and 21 HC. While AVH features did not correlate with measures of MMN, we found decreased MMN amplitudes to speech-based frequency and vowel change deviants in SZ patients compared to HC potentially reflecting deficiencies in basic speech processing mechanisms.

Classification of EEG event-related potentials based on channel attention mechanism

Classification of EEG event-related potentials based on channel attention mechanism

Auditory N1 event-related potential amplitude is predictive of serum concentration of BPN14770 in fragile X syndrome

Fragile X syndrome (FXS) is a rare neurodevelopmental disorder caused by a CGG repeat expansion ≥ 200 repeats in 5’ untranslated region of the FMR1 gene, leading to intellectual disability and cognitive difficulties, including in the domain of communication. A recent phase 2a clinical trial testing BPN14770, a phosphodiesterase 4D inhibitor, showed improved cognition in 30 adult males with FXS on drug relative to placebo. The initial study found significant improvements in clinical measures assessing cognition, language, and daily functioning in addition to marginal improvements in electroencephalography (EEG) results for the amplitude of the N1 event-related potential (ERP) component. These EEG results suggest BPN14770 improved neural hyperexcitability in FXS. The current study investigated the relationship between BPN14770 pharmacokinetics and the amplitude of the N1 ERP component from the initial data. Consistent with the original group-level finding post-period 1 of the study, participants who received BPN14770 in period 1 showed a significant correlation between N1 amplitude and serum concentration of BPN14770 measured at the end of period 1. These findings strengthen the validity of the original result, indicating that BPN14770 improves cognitive performance by modulating neural hyperexcitability. This study represents the first report of a significant correlation between a reliably abnormal EEG marker and serum concentration of a novel pharmaceutical in FXS.

Does level of cognitive load affect susceptibility?

We compared how different levels of cognitive load affect frontal P3 (fP3) Event-Related Potential (ERP) to novel sounds. Previous studies demonstrated the predictive value of the probe-elicited frontal P3 (fP3) ERP for subsequent detection failures. They also demonstrated how fP3 is reduced when performing visual and/or manual and/or cognitively demanding tasks. These results are consistent with fP3 indexing orienting to novels or, more neutrally: susceptibility. Here, we tested how fP3 is affected by a threefold variation of cognitive load induced by the verb (generation) task. Participants heard a noun and either listened to it, repeated it, or generated a semantically related verb. These conditions were manipulated between groups. One group (N = 16) experienced the listen and repeat condition; the other group (N = 16) experienced the listen and generate condition. When fP3 was probed 0 or 200 ms after noun offset, it was reduced (relative to no noun) only while repeating or generating, not while listening. An additional probe-elicited ERP was identified as novelty-related negativity, and its contaminating influence on fP3 estimation accounted for by a novel vector-filter procedure. We conclude that cognitive load does not affect fP3-indexed susceptibility. Instead, fP3-indexed susceptibility is affected by presentation of the stimulus, with the most pronounced effect in conditions where a vocal response is needed (i.e., repeat or generate, but not listen), independent of the complexity of the response.

Neurophysiological measures of covert semantic processing in neurotypical adolescents actively ignoring spoken sentence inputs: A high-density event-related potential (ERP) study

Language comprehension requires semantic processing of individual words and their context within a sentence. Well-characterized event-related potential (ERP) components (the N400 and late positivity component (LPC/P600)) provide neuromarkers of semantic processing, and are robustly evoked when semantic errors are introduced into sentences. These measures are useful for evaluating semantic processing in clinical populations, but it is not known whether they can be evoked in more severe neurodevelopmental disorders where explicit attention to the sentence inputs cannot be objectively assessed (i.e., when sentences are passively listened to). We evaluated whether N400 and LPC/P600 could be detected in adolescents who were explicitly ignoring sentence inputs. Specifically, it was asked whether explicit attention to spoken inputs was required for semantic processing, or if a degree of automatic processing occurs when the focus of attention is directed elsewhere? High-density ERPs were acquired from twenty-two adolescents (12–17 years), under two experimental conditions: 1. individuals actively determined whether the final word in a sentence was congruent or incongruent with sentence context, or 2. passively listened to background sentences while watching a video. When sentences were ignored, N400 and LPC/P600 were robustly evoked to semantic errors, albeit with reduced amplitudes and protracted/delayed latencies. Statistically distinct topographic distributions during passive versus active paradigms pointed to distinct generator configurations for semantic processing as a function of attention. Covert semantic processing continues in neurotypical adolescents when explicit attention is withdrawn from sentence inputs. As such, this approach could be used to objectively investigate semantic processing in populations with communication deficits.

Objective assessment of cognitive fatigue: a bibliometric analysis

AimThe objective of this study was to gain insight into the nature of cognitive fatigue and to identify future trends of objective assessment techniques in this field.MethodsOne thousand and eighty-five articles were retrieved from the Web of Science Core Collection database. R version 4.3.1, VOSviewer 1.6.20, CiteSpace 6.2.R4, and Microsoft Excel 2019 were used to perform the analysis.ResultsA total of 704 institutes from 56 countries participated in the relevant research, while the People’s Republic of China contributed 126 articles and was the leading country. The most productive institute was the University of Gothenburg. Johansson Birgitta from the University of Gothenburg has posted the most articles (n = 13). The PLOS ONE published most papers (n = 38). The Neurosciences covered the most citations (n = 1,094). A total of 3,116 keywords were extracted and those with high frequency were mental fatigue, performance, quality-of-life, etc. Keywords mapping analysis indicated that cognitive fatigue caused by continuous work and traumatic brain injury, as well as its rehabilitation, have become the current research trend. The most co-cited literature was published in Sports Medicine. The strongest citation burst was related to electroencephalogram (EEG) event-related potential and spectral power analysis.ConclusionPublication information of related literature on the objective assessment of cognitive fatigue from 2007 to 2024 was summarized, including country and institute of origin, authors, and published journal, offering the current hotspots and novel directions in this field.

Effectiveness of vestibular therapy as an adjunct to cognitive therapy to improve cognition in elderly with mild cognitive impairment (MCI)

The rapid global increase in aging populations is leading to a rise in age-related conditions like mild cognitive impairment (MCI), necessitating new treatment strategies. This study will conduct a double-blinded, three-arm, randomized controlled trial to evaluate the effectiveness of adding vestibular therapy to cognitive therapy (VT+CT) compared to cognitive therapy (CT) alone and a control group. Participants will be assigned to one of three groups: VT+CT, CT only, or a control group. The VT+CT group will receive vestibular rehabilitation exercises along with a computerized brain program, while the CT group will get only the computerized brain program. Primary outcomes will include electroencephalography (EEG), the Digit Symbol Substitution Test (DSST), and event-related potential (ERP-P300). Secondary outcomes will be the Stroop Color Word Test (SCWT), Trail-Making Test (TMT), and European Quality 5 Dimensions (EQ-5D-5L). This research aims to determine if VT+CT improves cognitive function in elderly individuals with MCI.

Event-related potentials of familiar monosyllabic words with unexpected lexical tones: A picture-word study of Mandarin-speaking preschoolers with and without a history of late talking.

This study examined how Mandarin-speaking preschoolers with and without a history of late talking (LT) process familiar monosyllabic words with unexpected lexical tones, focusing on both phonological and semantic violations. This study initially enrolled 64 Mandarin-speaking toddlers: 31 with a history of LT (mean age: 27.67 months) and 33 without a history of LT (non-LT) (mean age: 27.85 months). Event-related potentials were recorded at the age of 4 years during a picture-word mismatch task (LT mean age: 51.36 months; non-LT mean age: 51.20 months); in this task, the participants were presented with auditory words either matching (Tone 3) or mismatching with images in terms of their lexical tones; the mismatches encompassed acoustically dissimilar (Tone 1) and similar (Tone 2) mismatches. A significant difference in the phonological mapping negativity (PMN) responses to Tones 1 and 3 was observed only in the non-LT group. However, differences in the N400 responses to Tones 1 and 3 remained consistent across both groups. In addition, greater differences in the PMN responses between Tones 1 and 3 were associated with higher language proficiency during the preschool period. The PMN response serves as an indicator of neural correlates in lexical tone processing, reflecting challenges encountered by preschoolers with a history of LT when processing the lexical tones of familiar words. Furthermore, the PMN response was correlated with concurrent language abilities. These findings indicate the importance of early tonal perception development for Mandarin speakers with a history of LT. RESEARCH HIGHLIGHTS: Preschoolers with a history of late talking (LT), similar to preschoolers without such a history, can establish word expectations and detect the lexical tone violation in real time. However, those with a history of LT require additional time to process acoustic cues and differentiate between word semantics based on lexical tone information. The phonological mapping negativity response serves as an indicator of neural correlates in lexical tone processing, reflecting challenges encountered by preschoolers with a history of LT when processing the lexical tones of familiar words. The present findings indicate the importance of early intervention for Mandarin speakers with a history of LT, with an emphasis on lexical tone processing from toddlerhood.

Behavioral and neurophysiological signatures of cognitive control in humans and rats.

Deficits in cognitive control are implicated in numerous neuropsychiatric disorders. However, relevant pharmacological treatments are limited, likely due to weak translational validity of applicable preclinical models used. Neural indices derived from electroencephalography may prove useful in comparing and translating the effects of cognition-enhancing drugs between species. In the current study, we aimed to extend our previous cross-species results by examining if methylphenidate (MPH) modulates behavioral and neural indices of cognitive control in independent cohorts of humans and rats. We measured continuous electroencephalography data from healthy adults (n = 25; 14 female) and Long Evans rats (n = 22; 8 female) and compared both stimulus- and response-locked event-related potentials and spectral power measures across species, and their MPH-related moderation following treatment with vehicle (placebo) or 1 of 2 doses of MPH. Across both species, linear mixed effects modeling confirmed the expected Flanker interference effect on behavior (eg, accuracy) and response-related event-related potentials. Unexpectedly, in contrast to past work, we did not observe any task-related effects on the spectral power of rodents. Moreover, MPH generally did not modulate cognitive control of either species, although some species-specific patterns offer insight for future research. Collectively, these findings in independent human and rodent subjects replicate some of our previously reported behavioral and neurophysiological patterns partly consistent with the notion that similar neural mechanisms may regulate cognitive control in both species. Nonetheless, these results showcase an approach to accelerate translation using a coordinated between-species platform to evaluate pro-cognitive treatments.

Searching Across Realities: Investigating ERPs and Eye-Tracking Correlates of Visual Search in Mixed Reality.

Mixed Reality allows us to integrate virtual and physical content into users' environments seamlessly. Yet, how this fusion affects perceptual and cognitive resources and our ability to find virtual or physical objects remains uncertain. Displaying virtual and physical information simultaneously might lead to divided attention and increased visual complexity, impacting users' visual processing, performance, and workload. In a visual search task, we asked participants to locate virtual and physical objects in Augmented Reality and Augmented Virtuality to understand the effects on performance. We evaluated search efficiency and attention allocation for virtual and physical objects using event-related potentials, fixation and saccade metrics, and behavioral measures. We found that users were more efficient in identifying objects in Augmented Virtuality, while virtual objects gained saliency in Augmented Virtuality. This suggests that visual fidelity might increase the perceptual load of the scene. Reduced amplitude in distractor positivity ERP, and fixation patterns supported improved distractor suppression and search efficiency in Augmented Virtuality. We discuss design implications for mixed reality adaptive systems based on physiological inputs for interaction.

Temporal dynamics of implicit moral evaluation: from empathy for pain to mentalizing processes

To understand how we evaluate harm to others, it is crucial to consider the offender’s intent and the victim’s suffering. Previous research investigating event-related potentials (ERPs) during moral evaluation has been limited by small sample sizes and a priori selection of electrodes and time windows that may bias the results. To overcome these limitations, we examined ERPs in 66 healthy human adults using a data-driven analytic approach involving cluster-based permutation tests. Participants performed an implicit moral evaluation task requiring to observe scenarios depicting intentional harm (IHS), accidental harm (AHS), and neutral actions (NAS) while judging whether each scenario was set indoors or outdoors. Our results revealed two distinct clusters, peaking at ∼170 and ∼250 ms, showing differences between harm scenarios (IHS and AHS) and NAS, suggesting rapid processing of the victim’s physical outcome. The difference between IHS and AHS scenarios emerged later, at ∼400 ms, potentially reflecting subsequent evaluation of the agent’s intentions. Source analysis showed that brain regions associated with empathy for pain were associated with the earlier peaks at ∼170 and ∼250 ms, while the modulation of the activity of the mentalizing network was presented at ∼250 and ∼400 ms. These findings advance our understanding of the neural mechanisms underlying implicit moral evaluation. Notably, they provide electrocortical new insights for models of implicit moral evaluation, suggesting an early neural response linked to empathy for pain, with subsequent integration of empathy response with mentalizing processes, followed by later cognitive evaluations, likely reflecting the assessment of the agent’s moral responsibility.

Evaluation of consumer-grade wireless EEG systems for brain-computer interface applications.

With the growing popularity of consumer-grade electroencephalogram (EEG) devices for health, entertainment, and cognitive research, assessing their signal quality is essential. In this study, we evaluated four consumer-grade wireless and dry-electrode EEG systems widely used for brain-computer interface (BCI) research and applications, comparing them with a research-grade system. We designed an EEG phantom method that reproduced µV-level amplitude EEG signals and evaluated the five devices based on their spectral responses, temporal patterns of event-related potential (ERP), and spectral patterns of resting-state EEG. We discovered that the consumer-grade devices had limited bandwidth compared with the research-grade device. A late component (e.g., P300) was detectable in the consumer-grade devices, but the overall ERP temporal pattern was distorted. Only one device showed an ERP temporal pattern comparable to that of the research-grade device. On the other hand, we confirmed that the activation of the alpha rhythm was observable in all devices. The results provide valuable insights for researchers and developers when it comes to selecting suitable EEG devices for BCI research and applications.