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Visual symmetry at fixation generates a bilateral Event Related Potential (ERP) called the Sustained Posterior Negativity (SPN). Symmetry presented in the left visual hemifield generates a contralateral SPN over the right hemisphere and vice versa. The current study examined whether the contralateral SPN is modulated by the focus of spatial attention. On each trial there were two dot patterns, one to the left of fixation, and one to the right of fixation. A central arrow cue pointed to one of the patterns and participants discriminated its regularity (symmetry or random). We compared contralateral SPN amplitude generated by symmetry at attended and unattended spatial locations. While the response to attended symmetry was slightly enhanced, the response to unattended symmetry was still substantial. Although visual symmetry detection is a computational challenge, we conclude that the brain processes visual symmetry in unattended parts of the visual field.

Agar dapat berinteraksi secara efisien terhadap banyaknya informasi sensori, otak memiliki strategi heuristis yang dapat menyaring informasi sekaligus mengarahkan atensi ketika muncul informasi yang penting dan krusial. Penelitian tentang otak telah mengungkapkan salah satu penanda atas sistem tersebut, yang disebut sebagai Mismatch Negativity (MMN). MMN merupakan salah satu komponen dari Event-Related brain Potentials (ERP) yang diasosiasikan dengan penanda sistem pendeteksi perubahan dan pelanggaran tiba-tiba terhadap aturan abstrak dari stimulus suara, dan dapat digunakan sebagai indikator objektif mengenai akurasi diskriminasi suara, sensori memori, maupun proses praatensi. Komponen MMN muncul sebagai gelombang negatif yang terpicu oleh stimulus yang menyimpang dari keteraturan. Metode MMN telah banyak digunakan dalam berbagai bidang penelitian hingga konteks klinis. MMN juga merupakan metode yang sangat bermanfaat untuk menyelidiki mekanisme pemrosesan kognitif pada populasi yang memiliki kesulitan untuk mengikuti prosedur eksperimen, misalnya pada anak-anak, atau pasien klinis karena sifatnya yang otomatis dan tidak membutuhkan atensi. Artikel ini bertujuan untuk memberikan pengenalan mengenai konsep dan prinsip dasar dalam MMN, paradigma eksperimen, hingga contoh aplikasi, dan potensi penelitian yang dapat dilakukan menggunakan metode ini.

The current study investigated whether vocabulary relates to phonetic categorization at neural level in early childhood. Electoencephalogram (EEG) responses were collected from 53 Dutch 20-month-old children in a passive oddball paradigm, in which they were presented with two nonwords " giep " [ɣip] and " gip " [ɣɪp] that were contrasted solely by the vowel. In the multiple-speaker condition, both nonwords were produced by twelve different speakers; while, in the single-speaker condition, one single token of each word was used as stimuli. Infant positive mismatch responses (p-MMR) were elicited in both conditions without significant amplitude differences. When the infants were median split based on vocabulary level, the large and small vocabulary groups showed comparable p-MMR amplitudes yet different scalp distribution in both conditions. These results suggest successful phonetic categorization of native similar sounding vowels at 20 months, and a close relationship between speech categorization and vocabulary development.

Introduction: The purpose of this study is to investigate the effects of sleep deprivation on individual attentional function and related electrophysiological mechanisms., Methods: Twenty healthy men who were deprived of sleep for 24 h were evaluated by selective attention test, persistent attention test, and event-related potentials (ERP) experiment., Results: After 24 h of sleep deprivation, the subjects' selective attention decreased, mainly manifested as prolonged response time, decreased motion stability, increased rate of neglect error, decreased sustained attention, prolonged latency of P300 at Cz ( p =0.001), and decreased amplitude ( p =0.000)., Conclusion: After 24 h of sleep deprivation, the attentional ability decreased significantly, and behavioral and ERP indicators showed certain changes., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Wu et al.)

In order to interact efficiently with the continuous stream of sensory information, the brain utilizes a heuristic strategy that can filter out background information and direct attention when important and crucial information emerges. Brain research has revealed such a marker for this system, known as Mismatch Negativity (MMN). MMN is one of the components of Event-Related brain Potentials (ERP) which is associated with change detection’s marker and violations of abstract rules established by a sequence of auditory stimuli and can be used as an objective indicator of the accuracy of sound discrimination, sensory memory, and pre-attentive processes. The MMN component appears as negative deflection that is triggered by a stimulus that deviates from the regularity. The MMN method has been widely used in various research fields to clinical contexts. Because of its automatic mechanism, the MMN is also an indispensable tool to study the processing mechanisms in populations where overt behavioral responses are difficult to elicit, for example in infants or certain clinical patients. This article is a literature review which aims to introduce the basic concepts and principles in MMN, its experimental paradigm, and examples of applications and potential research that can be conducted using this method. [ABSTRACT FROM AUTHOR]

Speech discrimination is used by audiologists in diagnosing and determining treatment for hearing loss patients. Usually, assessing speech discrimination requires subjective responses. Using electroencephalography (EEG), a method that is based on event-related potentials (ERPs), could provide objective speech discrimination. In this work we proposed a visual-ERP-based method to assess speech discrimination using pictures that represent word meaning. The proposed method was implemented with three strategies, each with different number of pictures and test sequences. Machine learning was adopted to classify between the task conditions based on features that were extracted from EEG signals. The results from the proposed method were compared to that of a similar visual-ERP-based method using letters and a method that is based on the auditory mismatch negativity (MMN) component. The P3 component and the late positive potential (LPP) component were observed in the two visual-ERP-based methods while MMN was observed during the MMN-based method. A total of two out of three strategies of the proposed method, along with the MMN-based method, achieved approximately 80% average classification accuracy by a combination of support vector machine (SVM) and common spatial pattern (CSP). Potentially, these methods could serve as a pre-screening tool to make speech discrimination assessment more accessible, particularly in areas with a shortage of audiologists.

Objective The electrophysiological characteristics may serve as valuable biomarkers for the genetic vulnerability underlying alcoholism. The purpose of this study was to evaluate the potential associations between single nucleotide polymorphisms (SNPs) located in the SGIP1 gene and the theta ERP quantitative traits. Method The theta band (4–7 Hz) visual ERP occurring in the P300 response in the resting EEG were examined to explore the electrophysiological effects of alcohol on the brain in five regions: frontal, central, parietal, temporal and occipital in patients with alcohol addiction. In addition, we tested the potential associations between single nucleotide polymorphisms (SNPs) located in the SGIP1 gene and ERP quantitative traits. Results We found that the amplitude of the auditory P300 response differed considerably among groups of alcoholics in the frontal, central and temporal areas of the brain and it was lower in the studied brain regions in alcoholics in comparison to non-alcoholics. However, among subjects in the young adult group (GR-1) there was no statistical difference in amplitude of P300 response with control subjects in all studied brain regions in comparison with non-alcoholics. Moreover, we revealed that SNP rs10889635 had a significant effect on P300 amplitude in the central and temporal regions. The reduced P300 amplitude was in AA carriers in comparison to both carriers of GG and GA alleles. Conclusions The present study demonstrated a possible association of target P300 evoked theta and of alcohol dependence with SNPs from the gene SGIP1 in the region of rs10889635, but further studies are required.

Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly activated during the generation of the SPN. Processing a gain significantly altered the amplitude of the P300 compared to an absence of gain, particularly on centroparietal electrodes. One of the generators of the P300 was located on the vmPFC, a cerebral structure involved in the choice between two positive results and their predictions, during loss processing. Both the SPN and the P300 appear to be reliable neural markers of motivation. We postulate that the SPN represents the strength of the motivational level, while the P300 represents the impact of motivation on updating memories of the feedback.

Ketamine is a non-competitive N-Methyl-D-Aspartate (NMDA) receptor antagonist whose effect in subanesthetic doses has been studied for chronic pain and mood disorders treatment. It has been proposed that ketamine could change the perception of nociceptive stimuli by modulating the cortical connectivity and altering the top-down mechanisms that control conscious pain perception. As this is a strictly central effect, it would be relevant to provide fresh insight into ketamine's effect on cortical response to external stimuli. Event-related potentials (ERPs) reflect the combined synchronic activity of postsynaptic potentials of many cortical pyramidal neurons similarly oriented, being a well-established technique to study cortical responses to sensory input. Therefore, the aim of this study was to examine the current evidence of subanesthetic ketamine doses on patterns of cortical activity based on ERPs in healthy subjects. To answer the question whether ERPs could be potential markers of the cortical effects of ketamine, we conducted a systematic review of ketamine's effect on ERPs after single and repeated doses. We have searched PubMed, EMBASE and Cochrane Databases and pre-selected 141 articles, 18 of which met the inclusion criteria. Our findings suggest that after ketamine administration some ERP parameters are reduced (reduced N2, P2, and P3 amplitudes, PN and MMN) while others remain stable or are even increased (P50 reduction, PPI, P1, and N1 amplitudes). The current understanding of these effects is that ketamine alters the perceived contrast between distinct visual and auditory stimuli. The analgesic effect of ketamine might also be influenced by a decreased affective discrimination of sensorial information, a finding from studies using ketamine as a model for schizophrenia, but that can give an important hint not only for the treatment of mood disorders, but also to treat pain and ketamine abuse.

Humans are fast and accurate in categorizing complex natural images. It is, however, unclear what features of visual information are exploited by brain to perceive the images with such speed and accuracy. It has been shown that low-level contrast statistics of natural scenes can explain the variance of amplitude of event-related potentials (ERP) in response to rapidly presented images. In this study, we investigated the effect of these statistics on frequency content of ERPs. We recorded ERPs from human subjects, while they viewed natural images each presented for 70 ms. Our results showed that Weibull contrast statistics, as a biologically plausible model, explained the variance of ERPs the best, compared to other image statistics that we assessed. Our time-frequency analysis revealed a significant correlation between these statistics and ERPs’ power within theta frequency band (~3-7 Hz). This is interesting, as theta band is believed to be involved in context updating and semantic encoding. This correlation became significant at ~110 ms after stimulus onset, and peaked at 138 ms. Our results show that not only the amplitude but also the frequency of neural responses can be modulated with low-level contrast statistics of natural images and highlights their potential role in scene perception.

IntroductionConsumer behavior on the Internet is influenced by factors that can affect consumers’ perceptions and attention to products. Understanding these processes at the neurobiological level can help to understand consumers’ implicit responses to marketing stimuli. The objective of this study is to use electroencephalography (EEG) to investigate the differential effects of selected online purchase decision factors that are becoming increasingly important in online shopping.MethodsUsing event-related potentials (ERPs) and simultaneous eye-tracking measurements, we identified differences in the perception of utilitarian and hedonic products when the products are exposed together with visual elements of the factors review, discount, and quantity discount. The ERP analysis focused on the P200 and late positive potential components (LPP).ResultsBy allowing free-viewing of stimuli during measurement, early automatic and later more complex attentional affective responses could be observed. The results suggest that the review and discount factors are processed faster than the product itself. However, the eye-tracking data indicate that the brain processes the factor without looking at it directly, i.e., from a peripheral view.DiscussionThe study also demonstrates the possibilities of using new objective methods based on neurobiology and how they can be applied, especially in areas where the use of neuroscience is still rare, yet so much needed to objectify consumers’ knowledge of their need satisfaction behavior.

BackgroundHypnotherapy has a potential role in modulating attention bias to treat social anxiety disorder (SAD). This study aimed to verify whether hypnotherapy can reduce social anxiety by changing attentional bias. The primary objective of our study is to explore the influence of hypnosis on various aspects of attention processes, specifically focusing on how it affects attention bias and social anxiety.MethodsThis study included 69 participants with SAD who were assigned to three groups based on their scores on the Liebowitz Social Anxiety Scale (LSAS). The experimental group (n = 23) received a hypnosis treatment once a week, for a total of six sessions, while the control group (n = 23) and the baseline group (n = 23) did not receive any treatment. To evaluate whether hypnosis could alleviate SAD and attention bias towards threatening stimuli, we employed questionnaires and an odd-one-out task accompanied by electroencephalography (EEG) recordings.ResultsUnder the attention sensitivity conditions, the experimental group exhibited a reduced N170 and LPP at the posttest stage, and a similar N170 and LPP reduction under the attention disengagement conditions. Notably, the symptom improvements were positively correlated with the reduction in N170 and LPP amplitude across conditions.ConclusionHypnosis treatment modulates the early face processing and late emotional evaluation of threat-related stimuli in SAD patients. These findings suggest that N170 and LPP are important biomarkers for the treatment of SAD.

Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly activated during the generation of the SPN. Processing a gain significantly altered the amplitude of the P300 compared to an absence of gain, particularly on centroparietal electrodes. One of the generators of the P300 was located on the vmPFC, a cerebral structure involved in the choice between two positive results and their predictions, during loss processing. Both the SPN and the P300 appear to be reliable neural markers of motivation. We postulate that the SPN represents the strength of the motivational level, while the P300 represents the impact of motivation on updating memories of the feedback.

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