Event-related Brain Potentials Components Research Articles

N400 Evidence That the Early Stages of Lexical Access Ignore Knowledge About Phonological Alternations.

Hearing a word that was already expected often facilitates comprehension, attenuating the amplitude of the N400 event-related brain potential component. On the other hand, hearing a word that was not expected elicits a larger N400. In the present study, we examined whether the N400 would be attenuated when a person hears something that is not exactly what they expected but is a viable alternative pronunciation of the morpheme they expected. This was done using Mandarin syllables, some of which can be pronounced with different lexical tones depending on the context. In two large-sample experiments (total n = 160) testing syllables in isolation and in phonologically viable contexts, we found little evidence that hearing an alternative pronunciation of the expected word attenuates the N400. These results suggest that comprehenders do not take advantage of their knowledge about systematic phonological alternations during the early stages of prediction or discrimination.

The effects of sleep and wakefulness on human fear conditioning

IntroductionStudies on fear conditioning have made important contributions to the understanding of affective learning mechanisms as well as its applications (e.g., anxiety disorders, post-traumatic stress disorder). However, central mechanisms of sleep related consolidation of fear memory in humans have been almost neglected by previous studies.ObjectivesIn the current study we aimed to test effects of sleep and a period wakefulness on fear conditioned responses.MethodsIn our experiment in a group 18 healthy volunteers event-related brain potentials (ERP), heart rate variability (HRV) and behavioral responses were recorded during a fear conditioning procedure presented twice, before daytime sleep (2h) or control intervention (a period of wakefulness) and after. The conditioning procedure involved pairing of a neutral tone (CS+) with a highly unpleasant sound (UCS+).ResultsDifferential conditioning manifested itself in the contingent negative variance (CNV)-like slow ERP component. Both period of sleep and wakefulness resulted in an increased amplitude of the CNV to CS+. But we did not find an interaction effect of Time (Pre-Post) by Intervention (Sleep-Wake), suggesting that sleep did not affect the conditioned response differently as compared to a period of wakefulness. An apparent increase in HRV after a period of wakefulness did not affect fear conditioned responses (CNV and valence ratings).ConclusionsTo summarize, the data indicate that fear memories are consolidated with the course of time with no beneficial effect of sleep; relearning of fear causes stronger differential responses as measured by slow wave amplitude but not behavior; increase of HRV does not affect fear learning.

Reduced early fearful face processing during perceptual distraction in high trait anxious participants

Fearful facial expressions are prioritized across different stages of information processing as reflected by early, mid-latency, and late components of event-related brain potentials (ERP). Trait anxiety has been proposed to modulate these responses, but it is yet unclear how such modulations depend on feature-based attention. In this preregistered study (N=80), we investigated the effects of trait anxiety on ERP differences between fearful and neutral faces across three different tasks. Participants had to discriminate either the orientation of lines overlaid onto the faces, the gender of the face, or the emotional expression, thus increasing attention to emotionally relevant facial features across the tasks. Fearful versus neutral faces elicited increased P1 and N170 amplitudes across tasks and potentiated amplitudes when attention was directed to faces (early posterior negativity [EPN]) or the expression (EPN and late positive potential). Higher trait anxiety was related to smaller EPN differences between fearful and neutral faces during the perceptual discrimination task. This early relationship suggests reduced instead of amplified processing of fearful faces for high trait anxious participants under perceptual distraction.

Reaching Out for Food: How Food Incentives Modulate Peripersonal Space Perception.

Two experiments were conducted to determine, first, whether food items influence participants’ estimations of the size of their subjective peripersonal space. It was of particular interest whether this representation is influenced by satiated/hungry states and is differentially affected by valence and calorie content of depicted stimuli. Second, event-related brain potentials (ERPs) were used, in order to obtain information about the time course of the observed effects and how they depend on the spatial location of the food pictures. For that purpose, participants had to decide whether food items shown at various distances along a horizontal plane in front of them, were reachable or not. In Experiment 1, when participants were hungry, they perceived an increase of their peripersonal space modulated by high-calorie items which were experienced as being more reachable than low-calorie items. In Experiment 2, the reachability findings were replicated and early and late components of ERPs showed an attentional enhancement in far space for food items when participants were hungry. These findings suggest that participants’ subjective peripersonal space increased while being hungry, especially for high-calorie contents. Attention also seems to be oriented more strongly to far space items due to their expected incentive-related salience, expanding the subjective representation of peripersonal space.

Neurobehavioral Correlates of Surprisal in Language Comprehension: A Neurocomputational Model.

Expectation-based theories of language comprehension, in particular Surprisal Theory, go a long way in accounting for the behavioral correlates of word-by-word processing difficulty, such as reading times. An open question, however, is in which component(s) of the Event-Related brain Potential (ERP) signal Surprisal is reflected, and how these electrophysiological correlates relate to behavioral processing indices. Here, we address this question by instantiating an explicit neurocomputational model of incremental, word-by-word language comprehension that produces estimates of the N400 and the P600—the two most salient ERP components for language processing—as well as estimates of “comprehension-centric” Surprisal for each word in a sentence. We derive model predictions for a recent experimental design that directly investigates “world-knowledge”-induced Surprisal. By relating these predictions to both empirical electrophysiological and behavioral results, we establish a close link between Surprisal, as indexed by reading times, and the P600 component of the ERP signal. The resultant model thus offers an integrated neurobehavioral account of processing difficulty in language comprehension.

Neural time course of pain observation in infancy.

Perception of pain in others is of great evolutionary significance for the development of human empathy. However, infants' sensitivity to others' painful experiences has not been investigated so far. Here, we explored the neural time course of infants' processing of others' pain by measuring event-related brain potentials (ERPs) while 6-month-old infants observed a painful tactile stimulation directed towards the eye and a neutral tactile stimulation on the eyebrow. We analyzed both the Negative Central (Nc) and the later Late Positive Potential (LPP) ERP components, indexing respectively attention allocation and cognitive evaluation of perceptual stimuli. Results showed that observing painful touch elicits a mid-latency Nc (300-500ms) over the right fronto-central site, which is greater in amplitude as compared to neutral touch. A divergent activity was also visible in the centro-parietal early (550-750ms) and late (800-1000ms) LPP, showing increased amplitudes in response to neutral compared to painful touch. The cognitive evaluation of painful stimuli, reflected by the LPP, might thus not be fully developed at 6months of age, as adults typically show a larger LPP in response to painful as compared to neutral stimuli. Overall, infants show early attentional attuning to others' pain. This early sensitivity to others' painful tactile experiences might form a prerequisite for the development of human empathy.

Neurophysiological markers of ADHD symptoms in typically-developing children

Children with attention-deficit/hyperactivity disorder (ADHD) are characterized by symptoms of inattention, impulsivity, and hyperactivity. Neurophysiological correlates of ADHD include changes in the P3 component of event-related brain potentials (ERPs). Motivated by recent advances towards a more dimensional understanding of ADHD, we investigate whether ADHD-related ERP markers relate to continuous variations in attention and executive functioning also in typically-developing children. ERPs were measured while 31 school children (9–11 years) completed an adapted version of the Continuous Performance Task that additionally to inhibitory processes also isolates effects of physical stimulus salience. Children with higher levels of parent-reported ADHD symptoms did not differ in task performance, but exhibited smaller P3 amplitudes related to stimulus salience. Furthermore, ADHD symptoms were associated with the variability of neural responses over time: Children with higher levels of ADHD symptoms demonstrated lower variability in inhibition- and salience-related P3 amplitudes. No effects were observed for ERP latencies and the salience-related N2. By demonstrating that ADHD-associated neurophysiological mechanisms of inhibition and salience processing covary with attention and executive functioning in a children community sample, our study provides neurophysiological support for dimensional models of ADHD. Also, temporal variability in event-related potentials is highlighted as additional indicator of ADHD requiring further investigation.

The effects of acute aerobic exercise on inhibitory control and resting state heart rate variability in children with ADHD

The current study examined the effects of acute moderate-intensity aerobic exercise (MAE) on inhibitory control and resting-state heart rate variability (HRV) in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Our data show that acute MAE resulted in higher response accuracy of a modified flanker task regardless of task difficulty for 60 min (p = .001). Aerobic exercise further resulted in more effective conflict detection, as measured by greater amplitude (p = .012) and shorter latency (p = .029) of the N2 component of event-related brain potential, for 60 min regardless of task difficulty. In contrast, acute MAE did not modulate sympathovagal balance signified by HRV at either 30 min or 60 min following exercise cessation. Collectively, our findings suggest that the beneficial effects of acute aerobic exercise on inhibitory control are sustained for 60 min in children with ADHD. However, acute aerobic exercise may not modulate sympathovagal balance during the post-exercise recovery. Overall, we highlight the importance of acute aerobic exercise for children with ADHD as a potential means to facilitate brain health.

Electrophysiological dynamics of visuocortical processing in hoarding disorder.

Individuals with hoarding disorder (HD) typically perform worse than peers on neuropsychological tasks involving visual perception. Functional neuroimaging shows diffusely increased activity in the visual cortex, consistent with inefficient visual processing in HD. The temporal locus of these inefficiencies in HD is unknown. This study examined the temporal unfolding of visual event-related brain potentials (ERPs) to help better define the neurophysiological mechanisms underlying visual dysfunction in HD. Thirty-three individuals with HD and 35 healthy controls (HC) were assessed using a 64-channel EEG during a modified flanker task. Permutation-controlled analyses were conducted to detect group differences in visual evoked ERPs on a millisecond-to-millisecond basis. Bayesian ANCOVAs and linear regressions that included hoarding and age were conducted to identify the best-fit model for the identified VEPs, compared to a null model that included depression and anxiety severity. Three temporal regions (175ms, 270ms, and 440ms), showed differences in amplitude between HD and HC and were consistent with ERP components N1, P1/N2, and a late negative slow wave (LNSW), respectively. After controlling for depression and anxiety, HD demonstrated an enhanced ERP amplitude at N1 and an attenuated amplitude in LNSW compared to HC but did not show differences at P1/N2. For the N1 and LNSW, there was also a primary effect of the interaction between hoarding and age. This study indicates that altered visuocortical reactivity in HD first occurs at the level of visuocortical processing after 170ms, indicating alterations of middle and later, but not early, processing in occipitotemporal visual cortex.

Can posthypnotic suggestions boost updating in working memory? Behavioral and ERP evidence

Updating is an essential executive function (EF), responsible for storing, retrieving, and substituting information in working memory (WM). Here we investigated whether posthypnotic suggestions (PHS) given to high-hypnotizable participants can enhance updating in WM and measured neural correlates of the observed effects by recording event-related brain potentials (ERP). In a tone-monitoring task different syllables were presented in random order, requiring a response to every fourth presentation of a given syllable. Experiment 1 (n = 19) established the relationship between performance and several ERP components across updating load (different numbers of syllables). In Experiment 2 (n = 18), a no-hypnosis (NH) and a hypnosis-plus-PHS session were administrated in counterbalanced order. Task instructions, presented at the beginning of the sessions, emphasized a cognitive strategy, demanding imagination of visual counters, a strategy that was also emphasized during PHS. PHS additionally contained suggestions stimulating cognitive simulation of the task, where participants were advised to apply the suggested strategy. Relative to the NH session, PHS enhanced WM performance with medium to large effect sizes. In ERPs, PHS increased the P2 and P3 components, indicating the proactive recruitment of control-related attention and updating-related cognitive control processes, respectively. PHS also reduced updating load effects in the posterior recognition component, suggesting diminished demands on WM buffers. These ERP findings suggest that PHS enhanced updating in WM by strengthening proactive control, which may have diminished the necessity for reactive control. Hence, the present results suggest that our PHS had worked like mental practice helping participants to develop an efficient and context-dependent trigger-action contingency. Consequentially, the present study provides a new framework for employing PHSs, which may be used as a basis for developing new training regimes for modifying WM or other EFs.

Regular Open-Skill Exercise Generally Enhances Attentional Resources Related to Perceptual Processing in Young Males.

This study aimed to examine whether the regular open-skill exercise led to a selective improvement or a general improvement on cognitive function in healthy young males. Besides, we also intend to expand previous studies by looking into the temporal dynamics of early information processes and cognitive processes through appraising the extensive temporal series of stimulus-locked ERP components. Sixty healthy young males were classified into two groups: those who regularly participated in the open-skill exercise for at least 2 years (n = 30), and those who exercised rarely. The participants conducted the Stroop task with event-related brain potential (ERP) recorded. The results indicated that compared with the rare exercise group, the open-skill exercise group led to a selective improvement for accuracy under the incongruent condition. And the open-skill exercise group also led to a selective improvement for response time under the incongruent condition. Moreover, the open-skill exercise group yielded larger P200 amplitudes under both the congruent and incongruent conditions compared with the rare exercise group. The findings suggest that the regular open-skill exercise may promote executive function by an increase in the allocation of attentional resources related to perceptual processing and greater interference control during cognitively demanding tasks in healthy young males.

Sex-specific relationships between face memory and the N170 component in event-related potentials.

At the group level, women consistently perform better in face memory tasks than men and also show earlier and larger N170 components of event-related brain potentials (ERP), considered to indicate perceptual structural encoding of faces. Here we investigated sex differences in the relationship between the N170 and face memory performance in 152 men and 141 women at group mean and individual differences levels. ERPs and performance were measured in separate tasks, avoiding statistical dependency between the two. We confirmed previous findings about superior face memory in women and a—sex-independent—negative relationship between N170 latency and face memory. However, whereas in men, better face memory was related to larger N170 components, face memory in women was unrelated with the amplitude or latency of the N170. These data provide solid evidence that individual differences in face memory within men are at least partially related to more intense structural face encoding.

Neurophysiological evidence for evaluative feedback processing depending on goal relevance

Feedback signaling the success or failure of actions is readily exploited to implement goal-directed behavior. Two event-related brain potentials (ERPs) have been identified as reliable markers of evaluative feedback processing: the Feedback-Related Negativity (FRN) and the P3. Recent ERP studies have shown a substantial reduction of these components when the feedback’s goal relevance (in terms of goal informativeness) was decreased. However, it remains unclear whether this lowering of evaluative feedback processing at the FRN and P3 levels (i) reflects a common regulation process operating across them or (ii) indirectly and mostly depends on valence processing. To address these questions, 44 participants performed a time estimation task wherein the perceived goal relevance of the feedback following each decision was manipulated via instructions in different blocks. We recorded 64-channel EEG and collected subjective ratings of feedback valence and relevance, separately for goal-relevant and irrelevant conditions. ERP results showed a substantial reduction of the FRN and P3 components for irrelevant than relevant feedback, despite the balanced task relevance between them. Moreover, a Principal Component Analysis (PCA) showed that these two successive ERP effects had dissociable spatiotemporal properties. Crucially, a multivariate multiple regression analysis revealed that goal relevance per se, but not valence, was the unique significant predictor of the amplitude reduction of the FRN and P3 when the feedback was goal irrelevant. Our results suggest that although these ERP components exhibit non-overlapping spatiotemporal properties and performance monitoring effects, they can both be modulated by a common, valence-unspecific process related to goal relevance.

The Effect of Aging on the ERP Correlates of Feedback Processing in the Probabilistic Selection Task.

Feedback processing contributes to efficient learning, decision making, and social interaction. Studies using event-related brain potentials (ERPs) reveal that feedback processing is associated with transient ERP components over the medial frontal and posterior regions of the scalp that distinguish between positive and negative feedback. There is some evidence indicating that aging has differential effects on the ERP correlates of feedback processing in a gambling task, and the current study was designed to extend these findings to a reinforcement learning paradigm. Younger and older adults performed the probabilistic selection task while ERPs elicited by feedback cues indicating a correct or incorrect choice were recorded during the learning phase. The ERPs revealed that the amplitude of the feedback negativity and frontal P3 were attenuated in older adults relative to younger adults. The amplitude of a temporal positivity was also attenuated in older adults; in contrast, the amplitude of an occipital negativity was insensitive to the effects of aging. These findings indicate that aging may be associated with the disruption of both local activity and long-range connectivity between neural structures related to feedback processing.

Quasi-compositional mapping from form to meaning: a neural network-based approach to capturing neural responses during human language comprehension.

We argue that natural language can be usefully described as quasi-compositional and we suggest that deep learning-based neural language models bear long-term promise to capture how language conveys meaning. We also note that a successful account of human language processing should explain both the outcome of the comprehension process and the continuous internal processes underlying this performance. These points motivate our discussion of a neural network model of sentence comprehension, the Sentence Gestalt model, which we have used to account for the N400 component of the event-related brain potential (ERP), which tracks meaning processing as it happens in real time. The model, which shares features with recent deep learning-based language models, simulates N400 amplitude as the automatic update of a probabilistic representation of the situation or event described by the sentence, corresponding to a temporal difference learning signal at the level of meaning. We suggest that this process happens relatively automatically, and that sometimes a more-controlled attention-dependent process is necessary for successful comprehension, which may be reflected in the subsequent P600 ERP component. We relate this account to current deep learning models as well as classic linguistic theory, and use it to illustrate a domain general perspective on some specific linguistic operations postulated based on compositional analyses of natural language. This article is part of the theme issue 'Towards mechanistic models of meaning composition'.

P300 indicates context-dependent change in speech quality beyond phonological change

Objective. Non-invasive physiological methods like electroencephalography (EEG) are increasingly employed to assess human information processing during exposure to multimedia signals. In the quality engineering field, previous research has promoted the utility of the P300 event-related brain potential (ERP) component for indicating variation in quality perception. The present study provides a starting point to test whether the P300 and its two subcomponents, P3a and P3b, are truly reflective of changes in the perceived quality of transmitted speech signals given the presence of other, quality-unrelated changes in acoustic stimulation. Approach. High-quality and degraded variants of spoken words were presented in a two-feature oddball task, which required participants to actively respond to rarely occurring ‘target’ stimuli within a series of frequent ‘standard’ stimuli, thereby eliciting ERP waveforms. Target presentations involved either single quality changes or concurrent double changes in quality and the initial phoneme. Main results. In case additional phonological change was present, only varying quality of standard stimuli caused significant modulations in P3a and P3b characteristics (N = 32). Thus, the formation of different short-term quality references exerted a persisting influence on the auditory processing of transmitted speech. Significance. The obtained results elucidate the importance of contextual and content-related influencing factors for proving the validity of the P300 as a psychophysiological indicator of speech quality change. Associated questions regarding the transfer of ERP-based quality assessment into more practically relevant measurement contexts are discussed.

Cognitive resources are distributed among the entire auditory landscape in auditory scene analysis.

Although attention has been shown to enhance neural representations of selected inputs, the fate of unselected background sounds is still debated. The goal of the current study was to understand how processing resources are distributed among attended and unattended sounds during auditory scene analysis. We used a three-stream paradigm with four acoustic features uniquely defining each sound stream (frequency, envelope shape, spatial location, tone quality). We manipulated task load by having participants perform a difficult auditory task and an easy movie-viewing task with the same set of sounds in separate conditions. The mismatch negativity (MMN) component of event-related brain potentials (ERPs) was measured to evaluate sound processing in both conditions. We found no effect of task demands on unattended sound processing: MMNs were elicited by unattended deviants during both low- and high-load task conditions. A key factor of this result was the use of unique tone feature combinations to distinguish each of the three sound streams, strengthening the segregation of streams. In the auditory task, the P3b component demonstrates a two-stage process of target evaluation. Thus, these results, in conjunction with results of previous studies, suggest that stimulus-driven factors that strengthen stream segregation can free up processing capacity for higher-level analyses. The results illustrate the interactive nature of top-down and stimulus-driven processes in stream formation, supporting a distributive theory of attention that balances the strength of the bottom-up input with perceptual goals in analyzing the auditory scene.

Learning own- and other-race facial identities: Testing implicit recognition with event-related brain potentials

Exposure to varying images of the same person can encourage the formation of a representation that is sufficiently robust to allow recognition of previously unseen images of this person. While behavioural work suggests that face identity learning is harder for other-race faces, the present experiment investigated the neural correlates underlying own- and other-race face learning. Participants sorted own- and other-race identities into separate identity clusters and were further familiarised with these identities in a matching task. Subsequently, we compared event-related brain potentials (ERPs) in an implicit recognition (butterfly detection) task for learnt and previously unseen identities. We observed better sorting and matching for own- than other-race identities, and behavioural learning effects were restricted to own-race identities. Similarly, the N170 ERP component showed clear learning effects for own-race faces only. The N250, a component more closely associated with face learning was more negative for learnt than novel identities. ERP findings thus suggests a processing advantage for own-race identities at an early perceptual level whereas later correlates of identity learning were unaffected by ethnicity. These results suggest learning advantages for own-race identities, which underscores the importance of perceptual expertise in the own-race bias.

ERP Evidence for Inhibitory Control Deficits in Test-Anxious Individuals.

Introduction: Individuals with test anxiety [i.e., high test anxiety (HTA)] always treat tests/examinations as a potential threat. This cognitive mode impairs these individuals’ ability of inhibitory control and leads to a high level of anxiety. However, characterizing aspects of HTA’s impaired inhibitory control ability are unclear and need to be studied. Methods: Forty-six participants were recruited and divided into a HTA (N = 26) and low test anxiety (LTA; i.e., healthy control; N = 20) group. Self-reports (Test Anxiety Scale, State-Trait Anxiety Inventory for negative emotions) were obtained. An emotional Stroop (ES) task and a numerical Stroop (NS) task, causing different types of interferences, were used for assessing the emotional and cognitive aspects of attentional control ability (behavioral data). Event-related brain potentials (ERPs) were registered to further assess processing stages related to different aspects of attentional control ability. Results: Compared with the LTA group, the HTA group has inhibitory control deficits of both emotional (see ERP components P1-P2-N2 and P3) and cognitive (see ERP component P3) interference. Compared with the LTA group, the HTA doesn't have lower accuracy in neither ES nor NS but displays longer reaction times only in ES. Additionally, the HTA group’s ES results also show that (1) the degree of emotional interference indicates the level of an individual’s anxiety, and (2) the ERP component P2 may serve as an index of the level of test anxiety. Conclusion: HTA individuals have extensive inhibitory deficits for both emotional and cognitive aspects; however, impairment impacts more on emotional aspects than on cognitive aspects. Additionally, as compared to NS, the negative impact of more impaired processing stages on task performance is more substantial in ES.

Emotional Control is Predicted by Brain Reward Processing in Athletes with Previous Concussions

Abstract Purpose Limited research examines how electrophysiological markers of reward sensitivity in athletes with concussion history may relate to corresponding executive behavior. Therefore, the present study aimed to examine the relationship between event-related brain potentials (ERPs) elicited during a reward-processing task, and self-report of emotional control and initiation problems in athletes with and without a history of concussion. Methods A total of 38 collegiate athletes (53% females, ages 18-27 years) completed a reward task in a “virtual T-maze” environment, as well as the BRIEF-A. The reward positivity (RewP), an ERP component associated with reward processing, was regressed on endorsement of emotional control and initiation problems in athletes with a history of concussion (n=16) and in athletes with no concussion history (n=22). Results A multiple regression analysis showed that in the concussion group, RewP peak amplitude explained a significant proportion of variance in emotional control, r2=.36, F(1,13)=6.76, p=.02, but did not for initiation, r2=.05, F(1,13)=.60, p>.05. For athletes with no history of concussion, RewP peak amplitude did not explain a significant proportion of variance in either emotional control, r2=.003, F(1,21)=.05, p>.05, or initiation, r2=.11, F(1,21)=2.49, p=.13. Conclusion Results indicate that for athletes with a history of concussion, a lower electrophysiological response to reward may predict greater problems concerning emotional control. Potential implications are discussed for how decision-making, an integral cognitive process driven by reward processing, might impact emotional regulation following concussion.