Differences In Event-related Potentials Research Articles

Electrophysiological signatures of spelling sensitivity development from primary school age to adulthood

Recognizing spelling errors is important for correct writing and reading, and develops over an extended period. The neural bases of the development of orthographic sensitivity remain poorly understood. We investigated event-related potentials (ERPs) associated with spelling error recognition when performing the orthographic decision task with correctly spelled and misspelled words in children aged 8–10 years old, early adolescents aged 11–14 years old, and adults. Spelling processing in adults included an early stage associated with the initial recognition of conflict between orthography and phonology (reflected in the N400 time window) and a later stage (reflected in the P600 time window) related to re-checking the spelling. In children 8–10 years old, there were no differences in ERPs to correct and misspelled words; in addition, their behavioral scores were worse than those of early adolescents, implying that the ability to quickly recognize the correct spelling is just beginning to develop at this age. In early adolescents, spelling recognition was reflected only at the later stage, corresponding to the P600 component. At the behavioral level, they were worse than adults at recognizing misspelled words. Our data suggest that orthographic sensitivity can develop beyond 14 years.

The specificity of the auditory P300 responses and its association with clinical outcomes in youth with psychosis risk syndrome

BackgroundSchizophrenia often occurs in youth, and psychosis risk syndrome (PRS) occurs before the onset of psychosis. Assessing the neuropsychological abnormalities of PRS individuals can help in early identification and active intervention of mental illness. Auditory P300 amplitude defect is an important manifestation of attention processing abnormality in PRS, but it is still unclear whether there are abnormalities in the attention processing of rhythmic compound tone stimuli in PRS individuals, and whether the P300 amplitude induced by these stimuli is specific to PRS individuals and related to their clinical outcomes. MethodsIn total, 226 participants, including 122 patients with PRS, 51 patients with emotional disorders (ED), and 53 healthy controls (HC) were assessed. Baseline electroencephalography was recorded during the compound tone oddball task. The event-related potentials (ERPs) induced by rhythmic compound tone stimuli of two frequencies (20-Hz, 40-Hz) were measured. Almost all patients with PRS were followed up for 12 months and reclassified into four groups: PRS-conversion, PRS-symptomatic, PRS-emotional disorder, and PRS-complete remission. The differences in baseline ERPs were compared among the clinical outcome groups. ResultsRegardless of the stimulation frequency, the average P300 amplitude were significantly higher in patients with PRS than in those with ED (p = 0.003, d = 0.48) and in HC (p = 0.002, d = 0.44) group. The average P300 amplitude of PRS-conversion group was significantly higher than that of the PRS-complete remission (p = 0.016, d = 0.72) and HC group (p = 0.001, d = 0.76), and the average P300 amplitude of PRS-symptomatic group was significantly higher than that of the HC group (p = 0.006, d = 0.48). Regardless of the groups (PRS, ED, HC) or the PRS clinical outcome groups, the average P300 amplitude induced by 20-Hz tone stimulation was significantly higher than that induced by 40-Hz stimulation (ps < 0.001, Ƞ2 = 0.074–0.082). The average reaction times of PRS was significantly faster than that of ED (p = 0.01, d = 0.38), and the average reaction times of the participants to 20-Hz target stimulation was significantly faster than that to 40-Hz target stimulation (p < 0.001, d = 0.21). ConclusionThe auditory P300 amplitude induced by rhythmic compound tone stimuli is a specific electrophysiological manifestation of PRS, and the auditory P300 amplitude induced by compound tone stimuli shows promise as a putative prognostic biomarker for PRS clinical outcomes, including conversion to psychosis and clinical complete remission.

High - definition transcranial direct current stimulation (HD-tDCS) to the medial prefrontal cortex (mPFC) alleviates occupational gender stereotypes

Occupational gender stereotypes are widely held misconceptions that individuals use to classify occupations according to gender. Alleviating occupational gender stereotypes would be beneficial for individuals to choose occupations more freely, without the influence of gender-based expectations. Transcranial direct current stimulation (tDCS) has shown effectiveness in alleviating stereotypical beliefs. The present study aims to explore the positive effects of tDCS targeting the medial prefrontal cortex (mPFC) on occupational gender stereotypes and uses event-related potentials (ERPs) to investigate the neural correlates of tDCS in modulating occupational gender stereotypes. Participants (N = 60) were recruited and randomly assigned to either the anodal tDCS group (n = 30) or the sham tDCS group (n = 30). All participants were asked to complete the Implicit Association Test (IAT) in the pre- and post-stimulation, while EEG data were recorded simultaneously. The behavioral results showed a decreased D value and reaction time (RT) after the tDCS in the anodal group. However, no significant difference in ERPs were observed after tDCS between the two groups. This study contributes to our understanding of occupational gender stereotypes and provides further evidence supporting the use of tDCS. The findings highlight the importance of considering the mPFC in research on occupational gender stereotypes and pave the way for future investigations utilizing brain stimulation techniques to address stereotypes.

An ERP measure of non-conscious memory reveals dissociable implicit processes in human recognition using an open-source automated analytic pipeline.

Non-conscious processing of human memory has traditionally been difficult to objectively measure and thus understand. A prior study on a group of hippocampal amnesia (N = 3) patients and healthy controls (N = 6) used a novel procedure for capturing neural correlates of implicit memory using event-related potentials (ERPs): old and new items were equated for varying levels of memory awareness, with ERP differences observed from 400 to 800 ms in bilateral parietal regions that were hippocampal-dependent. The current investigation sought to address the limitations of that study by increasing the sample of healthy subjects (N = 54), applying new controls for construct validity, and developing an improved, open-source tool for automated analysis of the procedure used for equating levels of memory awareness. Results faithfully reproduced prior ERP findings of parietal effects that a series of systematic control analyses validated were not contributed to nor contaminated by explicit memory. Implicit memory effects extended from 600 to 1000 ms, localized to right parietal sites. These ERP effects were found to be behaviorally relevant and specific in predicting implicit memory response times, and were topographically dissociable from other traditional ERP measures of implicit memory (miss vs. correct rejections) that instead occurred in left parietal regions. Results suggest first that equating for reported awareness of memory strength is a valid, powerful new method for revealing neural correlates of non-conscious human memory, and second, behavioral correlations suggest that these implicit effects reflect a pure form of priming, whereas misses represent fluency leading to the subjective experience of familiarity.

Real‐time Neurofeedback Rewards Memory‐related Potentials in Older Brains

AbstractBackgroundElectroencephalogram (EEG)‐based neurofeedback (NF) allows reward of desired brain activity in milliseconds. Compared to frequency power‐based approach during resting state EEG, event‐related potentials (ERPs) based NF during a task is technically challenging because of the cost of computation over a time window. We have previously established that left‐frontal memory‐related potentials discriminate normal cognitive aging from age‐ and education‐ matched older adults with risk of mild cognitive impairment (MCI). To modulate brainwaves during working memory retrieval towards healthier patterns, we develop an ERP‐based neurofeedback protocol to reward better memory‐related potentials.MethodThe training protocol is developed based on a modified delayed match‐to‐sample task also known as Bluegrass working memory paradigm. During each memory trial, a participant holds the sample target image in his/her working memory and responds whether each subsequent image is a Match or Nonmatch to the memory target by pressing the button. Real‐time classification of extracted ERP features is analyzed after stimulus onset, the dynamic machine‐learning program then modifies the stimulus by turning it into vivid color (reward) or leaving it with black‐and‐white (unrewarded). The processing pipeline has been developed using ERPs of older adults with and without MCI. The left frontal sites (F3 and F7) were preprocessed by re‐referencing and filtering with a 0.05 – 40 Hz band‐pass filter. For each participant, the EEG of 5 offline base trials in a 300‐600ms time window was used as a baseline. The ERP difference of the baseline versus the subsequent single trial is calculated to determine whether the image will be colored or left at black‐and‐white.ResultOur newly developed ERP‐neurofeedback protocol has succeeded in providing visual feedback based on fluctuation of single trial ERP in real time. The program was also designed to fit in each individual due to varied sensibility to NF. Currently we are to examine the feasibility and effectiveness of the proposed protocol by measuring memory indicators before and after NF training sessions.ConclusionWe have developed a new protocol using ERP‐based neurofeedback to improve personalized memory retrieval. The program is the first step to intervention trials for enhancing successful memory by rewarding desired memory‐related potentials in older brains.

Investigating app icon recognition with event-related potentials.

In modern society, visual symbols such as logos, icons, and letters have become essential for communication and cognition, playing a crucial role in daily life. This study focuses on app icons, a frequently encountered type of symbol, and aims to investigate the neural mechanisms involved in their recognition. Specifically, our objective is to identify the timing and location of brain activity associated with this process. We presented participants with familiar and unfamiliar app icons and asked them to perform a repetition detection task while recording the event-related potentials (ERPs) elicited by these stimuli. Statistical analysis revealed a significant difference in the ERPs between familiar and unfamiliar icons, occurring around 220 ms in the parietooccipital scalp region. The source analysis indicated that this ERP difference originated in the ventral occipitotemporal cortex, specifically the fusiform gyrus. These findings suggest that the recognition of familiar app icons results in the activation of the ventral occipitotemporal cortex approximately 220 ms after exposure. Additionally, our findings, in conjunction with previous research on visual word recognition, suggest that the lexical orthographic processing of visual words is dependent on general visual processing mechanisms that are also involved in the recognition of familiar app icons. In essence, the ventral occipitotemporal cortex likely plays a crucial role in memorizing and recognizing visual symbols and objects, including familiar visual words.

Visual event-related potentials reveal the early whole-word lexical processing of Chinese two-character words

Morphologically complex words are common across different languages, especially in Chinese, because more than 90% of common modern Chinese words are complex words. Many behavioral studies have suggested the whole-word processing of Chinese complex words, but the neural correlates of whole-word processing remain unclear. Previous electrophysiological studies revealed automatic and early (∼250 ms) access to the orthographic forms of monomorphic words in the ventral occipitotemporal area. In this study, we investigated whether there is also automatic and early orthographic recognition of Chinese complex words (as whole units) by recording event-related potentials (ERPs). A total of 150 two-character words and 150 two-character pseudowords composed of the same 300 characters (morphemes) were pseudorandomly presented to proficient Chinese readers. Participants were required to determine the color of each stimulus in the color decision task and to determine whether each stimulus was a word in the lexical decision task. The two constituent characters of each stimulus were horizontally arranged in Experiment 1 and vertically arranged in Experiment 2. The results revealed a significant early ERP difference between words and pseudowords approximately 250–300 ms after stimulus onset in the parieto-occipital scalp region. The early ERP difference was more prominent in the color decision task than in the lexical decision task, more prominent in Experiment 1 than in Experiment 2, and more prominent in the left parieto-occipital scalp region than in the right. Source analysis results showed that the early ERP difference originated from the left ventral occipitotemporal cortex. These results reflected early and automatic access to whole-word orthographic representations of Chinese complex words in the left ventral occipitotemporal cortex.

Electrophysiological correlates of response time outliers: Outlier related potentials.

In response time (RT) research, RTs which largely deviate from the RT distribution are considered "outliers". Outliers are typically excluded from RT analysis building upon the implicit assumption that cognitive processing is distorted in outlier trials. The present study aims to test this assumption by comparing cognitive processing indexed by event-related potentials (ERP) of trials with outliers and valid trials in two different tasks. To this end, we compared stimulus- and response-locked ERPs for outliers identified by nine different methods with valid trials, using cluster-based permutation tests. Consistently across outlier exclusion methods and tasks, the late positive complex (P3) associated with response-related processes was reduced in outliers. Analyses of response-locked ERPs related this P3 attenuation to a slower and temporally more extended increase of the P3, possibly indexing reduced evidence accumulation speed in outliers. P3 peak amplitude in response-locked ERPs was similar between outliers and valid trials, suggesting that the absolute amount of evidence required for a response remained comparable. Furthermore, in addition to these more general ERP correlates of outliers, the contingent negative variation (CNV) ERP component was reduced in outliers as a function of preparatory demands of the task. Hence, electrophysiological correlates, and thus cognitive processing, are altered in outliers compared to valid trials. In order to avoid distortion of observed ERP differences between conditions, the RT outlier distribution should be considered for the analysis of ERPs in combined ERP and RT studies.

Perinatal nicotine exposure relates to stimulus-locked event-related potentials in early adolescence during an emotional go/no-go task

Nicotine exposure is associated with negative consequences on the developing brain, both in utero and after birth. We investigated the relationship between perinatal nicotine exposure and electroencephalographic brain activity recorded during an emotional faces Go/No-Go task among adolescents. Seventy-one adolescents aged 12–15 years completed a Go/No-Go task using fearful and happy faces. Parents completed questionnaire measures of their child's temperament and self-regulation and retrospectively reported on nicotine exposure during the perinatal period. Perinatally exposed children (n = 20) showed increased and prolonged frontal event-related potential (ERP) differentiation in stimulus-locked analyses; that is, greater emotion and condition differentiation in comparison with their non-exposed peers (n = 51). However, non-exposed children showed greater late emotion differentiation recorded over posterior sites. Response-locked ERP differences were not found. ERP effects were not related to temperamental, self-regulatory, or parental education and income-related factors. This study is the first to demonstrate a relationship between perinatal nicotine exposure and ERPs in an emotional Go/No-Go task among adolescents. Findings suggest that while conflict detection remains intact for adolescents with perinatal nicotine exposure, their attentional allocation to behaviourally relevant stimuli may be magnified to beyond optimal levels, particularly when emotion is salient in information processing. Future studies can extend these findings by isolating prenatal nicotine exposure and comparing its effects to isolated postnatal exposure and clarifying the implications of the face and performance processing differences in adolescence.

視認する単純な画像の形と色を反映する脳波信号特徴量とその判別の研究

In this study, as a basic investigation for EEG-based visual image reconstruction, we investigated whether EEG signal features reflect shapes and colors of simple visual images which subjects viewed and whether the features can be discriminated. First, we investigated how the shapes and the colors are reflected in event-related potentials (ERP), the event-related spectrum perturbations (ERSP), and the inter-trial phase synchronization (ITC). The results showed statistically significant differences in ERP among the colors and ERP, ERSP and ITC among the shapes depending on time periods, frequency bands and electrodes. Second, based on the results, we explored learnable input data sets. Then, learnability for discriminating the shapes were shown in EEG waveforms on 100ms time periods in single trials at all channels and phase of time frequency analysis on the limited time-frequency domain and electrodes. Finally, we investigated whether two discriminators using LSTM and CNN discriminate the shapes from the learnable data for each subject. Then, it was found that accuracies of discrimination of the shapes were over a chance level with all the learnable data sets, subjects, and discriminators. We concluded that the distinct shapes can be discriminated from EEG signals by exploring appropriate features of input signals for discriminators.

Quantity Processing in Object Counting Task Based on Event-Related Potentials

In the preliminary event-dependent potentials study, our team found that the neural mechanism of Chinese singular and plural picture naming is different, and explained that the differences might lie in the different numbers of quantitative processing. However, previous studies have lacked separate neural processing of objects in singular-plural pictures. This study intends to explore the neural differences in quantity processing in singular and plural pictures by using an object counting task and combining Event-related potential (ERP). It is expected to prove that the neural differences of naming Chinese single and plural pictures found in our previous ERP research are neural processing differences of different quantities, further demonstrating that the quantity processing in Chinese singular and plural picture naming is automatic. The experimental results showed no significant differences in object counting accuracy (P=0.139) and reaction time (P=0.231) between the singular and plural groups. However, there was a noticeable difference in ERPs between the two groups (P<0.05) and statistical analysis showed that the P1 effect of the parieto-occipital lobe was greater in plural pictures than in singular pictures (140-180ms) and the P2 effect of the parieto-occipital lobe was more significant in singular pictures than in plural pictures (200-320ms). There are differences in the quantity processing of healthy adults in object counting tasks. These differences are similar to the neural differences in Chinese singular-plural picture naming, indicating that the quantity is automatically processed in this process.

Intention affects fairness processing: Evidence from behavior and representational similarity analysis of event-related potential signals.

In an ultimatum game, the responder must decide between pursuing self-interest and insisting on fairness, and these choices are affected by the intentions of the proposer. However, the time course of this social decision-making process is unclear. Representational similarity analysis (RSA) is a useful technique for linking brain activity with rich behavioral data sets. In this study, electroencephalography (EEG) was used to measure the time course of neural responses to proposed allocation schemes with different intentions. Twenty-eight participants played an ultimatum game as responders. They had to choose between accepting and rejecting the fair or unfair money allocation schemes of proposers. The schemes were offered based on the proposer's selfish intention (monetary gain), altruistic intention (donation to charity), or ambiguous intention (unknown to the responder). We used a spatiotemporal RSA and inter-subject RSA (IS-RSA) to explore the connections between event-related potentials (ERPs) after offer presentation and intention presentation with four types of behavioral data (acceptance, response time, fairness ratings, and pleasantness ratings). The spatiotemporal RSA results revealed that only response time variation was linked with the difference in ERPs at 432-592 ms after offer presentation on the posterior parietal and prefrontal regions. Meanwhile, the IS-RSA results found a significant association between inter-individual differences in response time and differences in ERP activity at 596-812 ms after the presentation of ambiguous intention, particularly in the prefrontal region. This study expands the intention-based reciprocal model to the third-party context and demonstrates that brain activity can represent response time differences in social decision-making.

Effects of respiratory phases on the processing of emotional and non-emotional visual stimuli.

The number of studies investigating the relationship between respiratory phases and cognitive/neural processing of external events has been increasing, but the findings remain controversial. This registered report examined the effect of the respiratory phase on the discrimination accuracy of visual stimuli in the emotional and non-emotional domains. Forty-two healthy young participants were asked to choose fearful over neutral facial expressions and to choose high-contrast over low-contrast Gabor patches during spontaneous nasal respiration. Event-related potentials (ERPs) were also recorded for each type of stimulus presented during each respiratory phase. It was hypothesized that discrimination accuracy would be higher when the stimuli were presented during inhalation than during exhalation. It was also hypothesized that the amplitudes of ERPs elicited by the stimuli would be greater during inhalation than during exhalation. For comparison, the effect of the cardiac phase was examined, with the expectation that discrimination accuracy would be higher when the stimuli were presented during systole than during diastole. It was also hypothesized that the amplitudes of ERPs elicited by the stimuli would be greater during systole than during diastole. As expected, the results indicated that fear discrimination accuracy was higher during inhalation than exhalation and during systole than diastole. However, this was not the case for contrast discrimination. No differences in ERPs were observed between respiratory phases in either task. These results suggest that natural breathing in through the nose facilitates the discrimination of emotional stimuli, possibly via subcortical processes.

P300 event-related potentials in patients with different subtypes of depressive disorders.

To explore the differences in event-related potentials (ERPs) of the subclinical types of major depressive disorders (MDD): melancholic (MEL), atypical (ATY), and anxious (ANX). Patients with MDD treated in the Clinical Department of Shanghai Mental Health Center between September 2017 and December 2020 were prospectively included. This study was approved by the Ethics Committee of the Shanghai Mental Health Center. They were evaluated using the Mini-International Neuropsychiatric Interview (MINI), 17-item Hamilton Depression Scale (HAMD-17), 30-item Self-rated Inventory of Depressive Symptomatology (IDS-30SR), 16-item Quick Inventory of Negative Symptom Scale (QIDS-16SR), and auditory and visual P300 ERPs. Finally, 27, 14, and 20 patients with MEL, ATY, and ANX MDD were included in this study, respectively. There were no significant differences in demographic characteristics and HAMD-17, IDS-30SR, and QIDS-16SR total scores among the three groups (all P > 0.05). On the C3 lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 373.89 ± 6.60 vs. 344.79 ± 9.78 vs. 359.33 ± 7.62, P = 0.039). On the Pz lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 376.14 ± 6.51 vs. 347.21 ± 9.42 vs. 362.22 ± 8.63, P = 0.047). There were no differences in visual P300 ERPs among the three groups. There are significant differences in auditory C3 and Pz latency among MEL, ATY, and ANX MDD. These differences could help diagnose the subtype of MDD.

Cortical Brain Perfusion and Cognitive Event Related Potentials in Patients with Psychomotor Retardation in Late Onset Depression.

Late onset depression is characterised by pronounced cognitive impairment, more somatic complaints and psychomotor retardation. Psychomotor slowing may be due to impairment in either motor or cognitive domain. Electrophysiology may be particularly convenient as a tool in studies of psychomotor retardation, as it can separate central cognitive processing from the motor processing. In this study we compared event related potentials (ERP) in the two groups of patients with late onset depression and psychomotor slowing as measured by reaction time (RT): a group of patients with lower RT was compared to a group with a higher RT. Twenty patients with late onset depression were included in the study after they had reached remission. Four weeks after reaching remission patients were reevaluated clinically using Hamilton Depression Rating Scale, Mini Mental State Examination, and with a computer version of the Stroop task. ERP, accuracy and RTs were simultaneously recorded. Both groups of patients aditionaly underwent a perfusion SPECT imaging. There were no differences between the short and long RT groups of patients in amplitudes of the late positive Stroop related potentials. The group of patients with longer RTs showed significant hyperperfusion in precentral gyrus, parietal regions, cuneus and hypoperfusion within insular, frontal, temporal and limbic (parahyppocampal gyrus and anterior cingulate) cortices, as well as cerebellum. We found no ERP differences between the two groups suggesting that although patients may differ on psychomotor retardation measured as RT, their cognitive abilities may be quite similar. Perfusion SPECT imaging however revealed a significant difference between them. This may be due to a process of compensation and applying different strategies to cope with cognitive impairment in the two groups.

Spontaneous quantitative processing in Chinese singular and plural picture naming: An event-related potentials analysis.

Chinese nouns lack inflection and cannot reflect the quantitative relationship between singular and plural numbers. However, neural processes of picture naming are different from those of words. We assume that Chinese single and plural picture naming is different, and they may involve quantitative processing. Therefore, Experiment 1 was designed by picking picture naming as the task and Chinese as the target language and compared the accuracy, reaction time, and event-related potentials (ERPs) between single and plural picture naming, where two types of pictures were mixed. Although the T-test showed no significant differences in behavioral data, there were differences in ERPs. ERP differences involved two effects: P1 of 160–180 ms and P2 of 220–260 ms in the parietal-occipital lobe. These differences are suggested to reflect the neural differences in quantitative processing. Therefore, Chinese singular and plural picture naming consists of word production and implicit quantitative processing simultaneously. To explore the relationship between the two processings, we added a semantic factor (inanimate vs. animate items) to the quantity factor of Experiment 1 and carried out Experiment 2, with the observation indexes unchanged. There were no significant differences in behavioral data among the four conditions. After variance analysis, ERPs results indicated an interaction between semantic and quantitative factors in the central area at 180–280 ms. In summary, we suggest that Chinese singular and plural picture naming includes two simultaneous neural processing tasks: word production and quantitative processing, which interact in the central area at 180–280 ms.

Neurophysiological correlates of memory change in children with fetal alcohol spectrum disorders treated with choline.

BackgroundPrenatal and early postnatal choline supplementation reduces cognitive and behavioral deficits in animal models of Fetal Alcohol Spectrum Disorder (FASD). In a previously published 9-month clinical trial of choline supplementation in children with FASD, we reported that postnatal choline was associated with improved performance on a hippocampal-dependent recognition memory task. The current paper describes the neurophysiological correlates of that memory performance for trial completers.MethodsChildren with FASD (N = 24) who were enrolled in a clinical trial of choline supplementation were followed for 9 months. Delayed recall on a 9-step elicited imitation task (EI) served as the behavioral measure of recognition memory. Neurophysiological correlates of memory were assessed via event-related potentials (ERP).ResultsDelayed recall on EI was correlated with two ERP components commonly associated with recognition memory in young children: middle latency negative component (Nc amplitude; range: r = −0.41 to r = −0.44) and positive slow wave (PSW area under the curve; range: r = −0.45 to r = −0.63). No significant ERP differences were observed between the choline and placebo groups at the conclusion of the trial.ConclusionAlthough the small sample size limits the ability to draw clear conclusions about the treatment effect of choline on ERP, the results suggest a relationship between memory performance and underlying neurophysiological status in FASD. This trial was registered.1

Context dissociations of the FN400 and N400 are evidence for recognition based on relative or absolute familiarity

Fluency, the ease of processing, can increase familiarity and the ability to recognize previously encountered information. Mixing or blocking the pre-experimental familiarity of test probes alters the pattern of recognition Event-Related Potentials (ERPs) for picture stimuli (Bruett & Leynes, 2015). The present study tested this idea further by mixing or blocking pre-experimental familiarity of word stimuli. A test with only pre-experimentally familiar words (Experiment 1) elicited the prototypical mid-frontal FN400 old/new ERP difference, which is a correlate of familiarity. However, tests with a mix of pre-experimentally familiar and unfamiliar words (Experiment 2) elicited posterior N400 old/new differences. Based on the Unexpected Fluency Attribution model (Mecklinger & Bader, 2020), this pattern of results suggests that pre-experimental fluency can influence the use of relative (changes from recent exposure) or absolute (baseline levels accrued from experience) familiarity to make a recognition judgment.

Bring a map when exploring the ERP data processing multiverse: A commentary on Clayson et al. 2021

Clayson et al. (2021) describe an innovative multiverse analysis to evaluate effects of data processing choices on event-related potential (ERP) measures. Based on their results, they provide data processing recommendations for studies measuring the error-related negativity and error positivity components. We argue that, although their data-driven approach is useful for identifying how data processing choices influence ERP results, it is not sufficient for devising optimal data processing pipelines. As an example, we focus on the inappropriate use of pre-response ERP baselines in their analyses, which leads to biased error positivity amplitude measures. Results of multiverse analyses should be supplemented with further investigation into why differences in ERP results occur across data processing choices before devising general recommendations.

FOCAL EPILEPSY AND EXECUTIVE DYSFUNCTION IN AUTISM SPECTRUM DISORDER (ASD)

Recent advances in neuroscience have allowed researchers to introduce functional neuromarkers of autism spectrum disorders (ASD) into clinical practice. Most promising are studies of brain work in milliseconds, such as quantitative EEGs, event-related potentials (ERPs), low resolution electromagnetic tomography(sLORETA), especially when it is possible to use Human Brain Index (HBI) methodology to compare test results obtained by a child with ASD with the normative database. The use of HBI methodology make possible to determine functional neuromarkers of ASD and comorbidities, such as epilepsy, impaired cognitive and emotional control or executive function (FF) disorders. Such procedure can contribute to more effective diagnosis, as well as provide personalized care for patients with ASD. In this case study we use the HBI methodology for more effective diagnosis of the child with ASD (level 2) with focal epilepsy and EF dysfunction in hope that we can provide more effective therapies which might improve her quality of life. We present the case of a 11-years-old girl with an initial diagnosis of ASD with focal epilepsy and EF dysfunction. The patient was sent to the Teaching-Reintegration Centre in Kraków with remarks that she simply could not function in everyday life. A neuropsychological examination using standardized batteries to assess the girl's cognitive, emotional and social functioning confirmed the presence of ASD (level 2), and co-occurring executive function disorders (EF). She was also analyzed from the clinical EEG perspective as well as from the QEEG/ERPs perspective and current coexistence of 3 Hz Spike-Wave Discharges on EEG and focal epilepsy was found. In the examination several episodes of 3 Hz paroxysms were found in the ventro-lateral prefrontal cortex (BA 11) in 40 min EEG recoding in Eyes open, Eyes closed as well as in task conditions. The patient’s ERPs showed that to the first stimulus (continue cue) temporal P2 wave with larger duration and longer latency was elicited in comparison to the average of the norm for her age from the Human Brain Index (HBI) normative database at Chur, Switzerland. The P30 cue was smaller in the patient than in the healthy controls from HBI and statistically significant deviations from the average were found. Also in response to NOGO stimulus no positive parietal-central P3 was observed, which appears in the ERPs of ealthy controls from HBI. The ERPs differences in the VCPT show statistically significant deviations in the patient’s brain function when compared to the ealthy controls from HBI. It should be stressed that the number of trials for the first stimulus presentation and NOGO condition were large enough for computing reliable ERPs, as it was indicated by Kropotov (2009; 2016). HBI methodology was helpful in finding functional neuromarkers of co-existence of 3 Hz Spike-Wave Discharges on EEG with focal epilepsy and EF disorder in girl with ASD (level 2). Therefore, it was possible to offer more effective rehabilitation of the disorders, which will contribute to the integration of the self system and better quality of her life.