Event-related Brain Potentials Components Research Articles

Suppression and omission effects in auditory predictive processing-Two of the same?

Recent theories describe perception as an inferential process based on internal predictive models that are adjusted by prediction violations (prediction error). Two different modulations of the auditory N1 event-related brain potential component are often discussed as an expression of auditory predictive processing. The sound-related N1 component is attenuated for self-generated sounds compared to the N1 elicited by externally generated sounds (N1 suppression). An omission-related component in the N1 time-range is elicited when the self-generated sounds are occasionally omitted (omission N1). Both phenomena were explained by action-related forward modelling, which takes place when the sensory input is predictable: prediction error signals are reduced when predicted sensory input is presented (N1 suppression) and elicited when predicted sensory input is omitted (omission N1). This common theoretical account is appealing but has not yet been directly tested. We manipulated the predictability of a sound in a self-generation paradigm in which, in two conditions, either 80% or 50% of the button presses did generate a sound, inducing a strong or a weak expectation for the occurrence of the sound. Consistent with the forward modelling account, an omission N1 was observed in the 80% but not in the 50% condition. However, N1 suppression was highly similar in both conditions. Thus, our results demonstrate a clear effect of predictability for the omission N1 but not for the N1 suppression. These results imply that the two phenomena rely (at least in part) on different mechanisms and challenge prediction related accounts of N1 suppression.

Beyond Explicit Acknowledgment: Brain Response Evidence of Human Skepticism towards Robotic Emotions

Using the N400 component of event-related brain potentials, a neurophysiological marker associated with processing incongruity, we examined brain responses to sentences spoken by a robot that had no arms or legs. Statements concerning physically impossible actions (e.g., knitting) elicit significant N400 responses, reflecting that participants perceived these statements as incongruent with the robot’s physical condition. However, this effect was attenuated for participants who indicated that the robot could have hidden limbs, indicating that expectations modify the way an agent’s utterances are interpreted. When it came to statements relating to emotional capabilities a distinct pattern was found. Although participants acknowledged that the robot could have emotions, there were significant N400 responses to statements about the robot’s emotional experiences (e.g., feeling happy). This effect was not modified by participants’ beliefs, suggesting a cognitive challenge of accepting robots as capable of experiencing emotions. Our findings thus point to a boundary in human acceptance of artificial social agents: while physical attributes may be negotiable based on expectations, emotional expressions are more difficult to establish as credible. By elucidating the cognitive mechanisms at play, our study informs the design of social robots that are capable of more effective communication to better support social connectivity and human well-being.

From psychophysiology to brain imaging: forty-five years MMN history of investigating acoustic change sensitivity.

Forty-five years have passed since the first publication of the mismatch negativity (MMN) event-related brain potential (ERP) component. The first 10years of research hardly gained any particular attention of the scientific community interested in acoustic perception. Debates on the nature of sensation versus perception were going on, and the technical possibilities to record ERPs, called in general evoked potentials, were very limited. Subtle changes in pure tone frequency or intensity giving rise to the MMN component were first investigated in humans. The background of the theoretical model developed by Risto Näätänen was the orientation reaction model of E.N. Sokolov published in 1963 so that the MMN was seen first as an electrophysiological correlate of auditory change detection. This fundamental ability of the auditory system seen as crucial for survival led to the development of the first animal model of the MMN (Csépe et al. in Clin Neurophysiol 66: 571-578, 1987). Indeed, it was confirmed that the MMN was the brain correlate of subtle changes detected that might alert to potential threats in the environment and direct the behavioral orientation. The investigations performed after 2000 introduced complex models and more sophisticated methods, both in animal and human studies, so that the MMN method was on the way to become a tool on the first place and not the main goal of research. This approach was further strengthened by the increasing number of studies on different clinical populations aiming at future applications. The aim of our review is to describe and redefine what the MMN may reflect in auditory perception and to show why and how this brain correlate of changes in the auditory scene can be used as a valuable tool in cognitive neuroscience research. We refer to publications selectedto underly theargument the MMN cannot be classified anymore as a sign of simple change detection and not all the indicators used to confirm howgenuine theMMN elicited byvariations of tones are valid for those tospeechcontrasts. We provide a fresh view on the broadly used MMN models, provided by some influential publications as well as on the unwritten history of MMN research aiming to give revised picture on what the MMN may truly reflect. We show how the focus and terminology of the MMN research have changed and what kind of misunderstandings and seemingly contradictive results prevent the MMN community to accept a generally usable cognitive model.

Event-Related Brain Potentials N140 and P300 during Somatosensory Go/NoGo Tasks Are Modulated by Movement Preparation.

The Go/NoGo task requires attention and sensory processing to distinguish a motor action cue or 'Go stimulus' from a 'NoGo stimulus' requiring no action, as well as motor preparation for a rapid Go stimulus response. The neural activity mediating these response phases can be examined non-invasively by measuring specific event-related brain potentials (ERPs) using electroencephalography. However, it is critical to determine how different task conditions, such as the relationship between attention site and movement site, influence ERPs and task performance. In this study, we compared attention-associated ERP components N140 and P300, the performance metrics reaction time (RT) and accuracy (%Error) and movement-related cortical potentials (MRCPs) between Go/NoGo task trials in which attention target and movement site were the same (right index finger movement in response to right index finger stimulation) or different (right index finger movement in response to fifth finger stimulation). In other Count trials, participants kept a running count of target stimuli presented but did not initiate a motor response. The N140 amplitudes at electrode site Cz were significantly larger in Movement trials than in Count trials regardless of the stimulation site-movement site condition. In contrast, the P300 amplitude at Cz was significantly smaller in Movement trials than in Count trials. The temporal windows of N140 and P300 overlapped with the MRCP. This superposition may influence N140 and P300 through summation, possibly independent of changes in attentional allocation.

Effects of the cardiac cycle on auditory processing: A preregistered study on mismatch negativity.

The systolic and diastolic phases of the cardiac cycle are known to affect perception and cognition differently. Higher order processing tends to be facilitated at systole, whereas sensory processing of external stimuli tends to be impaired at systole compared to diastole. The current study aims to examine whether the cardiac cycle affects auditory deviance detection, as reflected in the mismatch negativity (MMN) of the event-related brain potential (ERP). We recorded the intensity deviance response to deviant tones (70 dB) presented among standard tones (60 or 80 dB, depending on blocks) and calculated the MMN by subtracting standard ERP waveforms from deviant ERP waveforms. We also assessed intensity-dependent N1 and P2 amplitude changes by subtracting ERPs elicited by soft standard tones (60 dB) from ERPs elicited by loud standard tones (80 dB). These subtraction methods were used to eliminate phase-locked cardiac-related electric artifacts that overlap auditory ERPs. The endogenous MMN was expected to be larger at systole, reflecting the facilitation of memory-based auditory deviance detection, whereas the exogenous N1 and P2 would be smaller at systole, reflecting impaired exteroceptive sensory processing. However, after the elimination of cardiac-related artifacts, there were no significant differences between systole and diastole in any ERP components. The intensity-dependent N1 and P2 amplitude changes were not obvious in either cardiac phase, probably because of the short interstimulus intervals. The lack of a cardiac phase effect on MMN amplitude suggests that preattentive auditory processing may not be affected by bodily signals from the heart.

Searching for a tactile target: the impact of set-size on the N140cc.

The time needed to find a visual target amongst distractors (search task) can increase as a function of the distractors' number (set-size) in the search-array (inefficient search). While the allocation of attention in search tasks has been extensively investigated and debated in the visual domain, little is known about these mechanisms in touch. Initial behavioral evidence shows inefficient search behavior when participants have to distinguish between target and distractors defined by their vibro-tactile frequencies. In the present study, to investigate the allocation of attention to items of the search-array we measured the N140cc during a tactile task in which the set-size was manipulated. The N140cc is a lateralized component of event-related brain potentials recently described as a psychophysiological marker of attentional allocation in tactile search tasks. Participants localized the target, a singleton frequency, while ignoring one, three or five homogeneous distractors. Results showed that error rates linearly increased as a function of set-size, while response times were not affected. Reliable N140cc components were observed for all set-sizes. Crucially, the N140cc amplitude decreased as the number of distractors increased. We argue that the presence of additional distractors hindered the preattentive analysis of the search array resulting in increased uncertainty about the target location (inefficient preattentive stage). This, in turn, increased the variability of the deployment of attention to the target, resulting in reduced N140cc amplitudes. Consistent with existing behavioral evidence, these findings highlight systematic differences between the visual and the tactile attentional systems.

How low can you go? Measuring human event-related brain potentials from a two-channel EEG system

Over the past ten years, there has been a rapid increase in the availability and use of mobile electroencephalography (mEEG) in research. Indeed, researchers using mEEG have recorded EEG and event-related brain potentials in a wide range of environments - for example, while walking (Debener et al., 2012), riding a bike (Scanlon et al., 2020), or even in a shopping mall (Krigolson et al., 2021). However, given that low-cost, ease-of-use, and setup speed provide the primary advantages of an mEEG system over large array traditional EEG systems, an important and unresolved question is just how many electrodes does an mEEG system need to collect research-quality EEG data? Here, we tested whether or not a two-channel forehead-mounted mEEG system – the “Patch” – could measure event-related brain potentials within their established amplitude and latency characteristics (Luck, 2014). In the present study, participants performed a visual oddball task while we recorded EEG data from the Patch. Our results demonstrated that we could capture and quantify the N200 and P300 event-related brain potential components using a minimal electrode array forehead-mounted EEG system. Our data further support the idea that mEEG can be used for quick and rapid EEG-based assessments, such as measuring the impact of concussions on the sports field (Fickling et al., 2021) or assessing the impact of stroke severity in a hospital (Wilkinson et al., 2020).

Testing stimulus exposure time as the critical factor of increased EPN and LPP amplitudes for fearful faces during perceptual distraction tasks

Fearful facial expressions are prioritized across different information processing stages, as evident in early, intermediate, and late components of event-related brain potentials (ERPs). Recent studies showed that, in contrast to early N170 modulations, mid-latency (Early Posterior Negativity, EPN) and late (Late Positive Potential, LPP) emotional modulations depend on the attended perceptual feature. Nevertheless, several studies reported significant differences between emotional and neutral faces for the EPN or LPP components during distraction tasks. One cause for these conflicting findings might be that when faces are presented sufficiently long, participants attend to task-irrelevant features of the faces. In this registered report, we tested whether the presentation duration of faces is the critical factor for differences between reported emotional modulations during perceptual distraction tasks. To this end, 48 participants were required to discriminate the orientation of lines overlaid onto fearful or neutral faces, while face presentation varied (100 msec, 300 msec, 1,000 msec, 2,000 msec). While participants did not need to pay attention to the faces, we observed main effects of emotion for the EPN and LPP, but no interaction between emotion and presentation duration. Of note, unregistered exploratory tests per presentation duration showed no significant EPN and LPP emotion differences during short durations (100 and 300 msec) but significant differences with longer durations. While the presentation duration seems not to be a critical factor for EPN and LPP emotion effects, future studies are needed to investigate the role of threshold effects and the applied analytic designs to explain conflicting findings in the literature.

Fear memory in humans is consolidated over time independently of sleep

Fear memories can be altered after acquisition by processes, such as fear memory consolidation or fear extinction, even without further exposure to the fear-eliciting stimuli, but factors contributing to these processes are not well understood. Sleep is known to consolidate, strengthen, and change newly acquired declarative and procedural memories. However, evidence on the role of time and sleep in the consolidation of fear memories is inconclusive. We used highly sensitive electrophysiological measures to examine the development of fear-conditioned responses over time and sleep in humans. We assessed event-related brain potentials (ERP) in 18 healthy, young individuals during fear conditioning before and after a 2-hour afternoon nap or a corresponding wake interval in a counterbalanced within-subject design. The procedure involved pairing a neutral tone (CS+) with a highly unpleasant sound. As a control, another neutral tone (CS−) was paired with a neutral sound. Fear responses were examined before the interval during a habituation phase and an acquisition phase as well as after the interval during an extinction phase and a reacquisition phase. Differential fear conditioning during acquisition was evidenced by a more negative slow ERP component (stimulus-preceding negativity) developing before the unconditioned stimulus (loud noise). This differential fear response was even stronger after the interval during reacquisition compared with initial acquisition, but this effect was similarly pronounced after sleep and wakefulness. These findings suggest that fear memories are consolidated over time, with this effect being independent of intervening sleep.

Cosmetic makeup enhances facial attractiveness and affective neural responses.

Although it is well established that cosmetic makeup enhances perceived facial attractiveness, few studies have examined whether facial makeup modulates neural responses to face images. This study investigated behavioral and attractiveness-related brain responses to self-applied makeup, focusing on the N170, early posterior negativity, P300, and late positive potential components of event-related brain potentials. A total of 77 Japanese women participated in two experiments (N = 34 and 43 for Experiments 1 and 2, respectively). Experiment 1 assessed the effects of self-applied makeup on attractiveness-related event-related potential amplitudes using facial images during a makeup identification task in which makeup was directly relevant to task demands. Experiment 2 examined the effects of self-applied makeup using images of one's own face and another female's face when performing a gender classification task, where the presence of makeup had no explicit connection to facial gender classification. In both experiments, faces with makeup were rated as more attractive and elicited more negative early posterior negativity and more positive late positive potential components, regardless of the participant's own face or another person's face. These findings suggest that people are spontaneously motivated to pay visual attention to faces with makeup, which supports the idea that makeup adds reward value to the facial appearance of the human. Moreover, neural evidence empirically confirmed that the benefits of makeup are not just limited to how others see your face but also extend to how you see your own face.

Conflict-based speech error monitoring in bilinguals: Differences between first and second language monitoring

All speakers must monitor their speech for errors. However, few studies have investigated speech monitoring in bilinguals. We examined whether monolinguals and bilinguals differ in first (L1) and second (L2) language speech monitoring. Participants included 18 English monolinguals, 20 English-French and 21 French-English sequential bilinguals who learned their two languages one after the other, and 15 simultaneous bilinguals who learned their two languages from birth. All participants performed an English phoneme substitution task while an electroencephalogram (EEG) was recorded. Three event-related brain potential (ERP) components were analyzed: the stimulus-locked P200 and N200, and the response-locked error-related negativity. All groups performed the task equally well despite showing differences in ERP patterns on correct and incorrect trials. Only simultaneous bilinguals showed a larger P200 preceding incorrect compared to correct responses, suggesting a role for lexical activation processes in the production of speech errors. All language groups showed evidence of pre-articulatory, conflict-based error monitoring through the N200. Only French-English sequential bilinguals, in their L2, showed a reliable ERN effect following speech errors. Thus, speech error monitoring processes were found to be influenced by whether one is speaking in their L1 versus L2 depending on the stage of monitoring, with response conflict being more informative for post-articulatory error monitoring during L2 compared to L1 speech production.

Deficiency in Re-Orienting of Attention in Adults with Attention-Deficit Hyperactivity Disorder.

Objective: To characterize potential brain indexes of attention deficit hyperactivity disorder (ADHD) in adults. Methods: In an effort to develop objective, laboratory-based tests that can help to establish ADHD diagnosis, the brain indexes of distractibility was investigated in a group of adults. We used event-related brain potentials (ERPs) and performance measures in a forced-choice visual task. Results: Behaviorally aberrant distractibility in the ADHD group was significantly higher. Across three ERP components of distraction: N1 enhancement, P300 (P3a), and Reorienting Negativity (RON) the significant difference between ADHD and matched controls was found in the amplitude of the RON. We used non-parametric randomization tests, enabling us to statistically validated this difference between-group. Conclusions: Our main results of this feasibility study suggest that among other ERP components associated with auditory distraction, the RON response is promising index for a potential biomarker of deficient re-orienting of attention in adults s with ADHD.

Different stages of emotional prosody processing in healthy ageing-evidence from behavioural responses, ERPs, tDCS, and tRNS.

Past research suggests that the ability to recognise the emotional intent of a speaker decreases as a function of age. Yet, few studies have looked at the underlying cause for this effect in a systematic way. This paper builds on the view that emotional prosody perception is a multi-stage process and explores which step of the recognition processing line is impaired in healthy ageing using time-sensitive event-related brain potentials (ERPs). Results suggest that early processes linked to salience detection as reflected in the P200 component and initial build-up of emotional representation as linked to a subsequent negative ERP component are largely unaffected in healthy ageing. The two groups show, however, emotional prosody recognition differences: older participants recognise emotional intentions of speakers less well than younger participants do. These findings were followed up by two neuro-stimulation studies specifically targeting the inferior frontal cortex to test if recognition improves during active stimulation relative to sham. Overall, results suggests that neither tDCS nor high-frequency tRNS stimulation at 2mA for 30 minutes facilitates emotional prosody recognition rates in healthy older adults.

The Multi-Determined Nature of Online Verbal Irony Processing: A Review of Empirical Studies Employing Eye-Tracking and Event-Related Potentials

Methodologies used in behavioral studies on the processing of figurative languages have been criticized for lack of sufficiently fine-grained recordings. Thus, recent literature on empirical studies on irony processing often talks about advantages of online-processing employing techniques with higher temporal resolution. This article reviews a series of selected Event-Related Brain Potentials (ERPs) and eye-tracking studies on the recognition and comprehension of verbal irony to provide an informed state of knowledge on this particular figurative language. First of all, we will introduce some common eye-tacking measures and ERP components recorded in these empirical studies; then we will enumerate factors involved in verbal irony processing from three differing but closely related dimensions. In this way, we expect to propose future research directions that could embrace more cognitive difference of individuals within the framework of theories about verbal irony comprehension.

The complexity of simple counting: ERP findings reveal early perceptual and late numerical processes in different arrangements

The counting process can only be fully understood when taking into account the visual characteristics of the sets counted. Comparing behavioral data as well as event-related brain potentials (ERPs) evoked by different task-irrelevant arrangements of dots during an exact enumeration task, we aimed to investigate the effect of illusory contour detection on the counting process while other grouping cues like proximity were controlled and dot sparsity did not provide a cue to the numerosity of sets. Adult participants (N = 37) enumerated dots (8–12) in irregular and two different types of regular arrangements which differed in the shape of their illusory dot lattices. Enumeration speed was affected by both arrangement and magnitude. The type of arrangement influenced an early ERP negativity peaking at about 270 ms after stimulus onset, whereas numerosity only affected later ERP components (> 300 ms). We also observed that without perceptual cues, magnitude was constructed at a later stage of cognitive processing. We suggest that chunking is a prerequisite for more fluent counting which influences automatic processing (< 300 ms) during enumeration. We conclude that the procedure of exact enumeration depends on the interaction of several perceptual and numerical processes that are influenced by magnitude and arrangement.

Banknote authenticity is signalled by rapid neural responses

Authenticating valuable objects is widely assumed to involve protracted scrutiny for detection of reproduction flaws. Yet, accurate authentication of banknotes is possible within one second of viewing, suggesting that rapid neural processes may underpin counterfeit detection. To investigate, we measured event-related brain potentials (ERPs) in response to briefly viewed genuine or forensically recovered counterfeit banknotes presented in a visual oddball counterfeit detection task. Three ERP components, P1, P3, and extended P3, were assessed for each combination of banknote type (genuine, counterfeit) and overt response (“real”, “fake”). P1 amplitude was greater for oddballs, demonstrating that the initial feedforward sweep of visual processing yields the essential information for differentiating genuine from counterfeit. A similar oddball effect was found for P3. The magnitude of this P3 effect was positively correlated with behavioural counterfeit sensitivity, although the corresponding correlation for P1 was not. For the extended P3, amplitude was greatest for correctly detected counterfeits and similarly small for missed counterfeits, incorrectly and correctly categorised genuine banknotes. These results show that authentication of complex stimuli involves a cascade of neural processes that unfolds in under a second, beginning with a very rapid sensory analysis, followed by a later decision stage requiring higher level processing.

Interactive Human Interface for ERP Component Extraction from Gifted Children

In the last century, scientists started to give importance to gifted children (GC) and to understand their behavior. Since then, research has pursued the various categories of these children and their early diagnosis in order to find the best control of their skills. Therefore, most researchers focus on recent advances in electroencephalogram (EEG) and cognitive events. The event-related brain potentials (ERPs) technique is generally used in the cognitive neuroscience process. However, it is still a challenge to extract these potentials from a few trials of electroencephalogram (EEG) data. The N400 ERP component is an important part of the studies of cerebral science and clinical neuropsychology. In this ongoing study, a new experimentation protocol and human tablet interactive equipment were assigned to analyze the brain activity. A combination of two techniques the Integral Shape Averaging (ISA) and Integral Shape Averaging applied on belated window (ISA-BW) was built to extract the semantic component from a single trial and to enhance the signal-to-noise ratio (S/N). The results obtained were compared with the most used method in the medical field Grand Average (GA). In addition, a statistical study was performed on a database for accurate characterization of children using feature reduction. The experimental results show the efficiency of the suggested approach which manifests the discriminant statistical feature extraction (J = 2.032) from ERP component dataset that can contribute to the recognition of GC. The proposed method is reinforced by a pilot device processed by an electrical engineer to improve the protocol simulation. The experimental procedure proves that the present approach is very interesting and helpful for improving the identification of such gifted children.

When two languages are competing

Abstract Past studies have shown that expert interpreters were better than novices at using contextual cues to anticipate upcoming information. However, whether such sensitivity to contextual cues can be traced by means of neural signatures is relatively unexplored. The present study used event-related brain potentials (ERPs) along with a language-switching paradigm – including non-switched (Chinese–Chinese, L1–L1) and switched (Chinese–English, L1–L2) conditions – to investigate whether interpreters with many years of experience, interpreters with a few years of experience and post-graduate-level interpreting students differed in the way they process contextually congruent or incongruent sentence-final target words. The results show that while the manipulations of congruency and switching independently induced a strong brain response in all three groups, the interaction between the two factors elicited different patterns across groups during 500–700 ms: (1) while a sustained congruency effect was found in the two less-experienced groups for the switched condition, such an effect was observed in the most experienced group for both switched and non-switched conditions; (2) only the least-experienced group showed a frontal negativity towards incongruent trials in the switched condition. These 200 ms transient group differences revealed that it might be possible to trace the development of interpreting ability by examining the ERP components in a language-switching setting.

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.