ERP Components Research Articles

Characterizing PTSD Using Electrophysiology: Towards A Precision Medicine Approach

Objective. Resting-state EEG measures have shown potential in distinguishing individuals with PTSD from healthy controls. ERP components such as N2, P3, and late positive potential have been consistently linked to cognitive abnormalities in PTSD, especially in tasks involving emotional or trauma-related stimuli. However, meta-analyses have reported inconsistent findings. The understanding of biomarkers that can classify the varied symptoms of PTSD remains limited. This study aimed to develop a concise set of electrophysiological biomarkers, using neutral cognitive tasks, that could be applied across psychiatric conditions, and to identify biomarkers associated with the anxiety and depression dimensions of PTSD. Approach. Continuous simultaneous recordings of EEG and electrocardiogram (ECG) were obtained in veterans with PTSD (n = 29) and healthy controls (n = 62) during computerized tasks. EEG, ERP, and heart rate measures were evaluated in terms of their ability to discriminate between the groups or correlate with psychological measures. Results. The PTSD cohort exhibited faster alpha oscillations, reduced alpha power, and a flatter power spectrum. Furthermore, stronger reduction in alpha power was associated with higher trait anxiety, while a flatter slope was related to more severe depression symptoms in individuals with PTSD. In ERP tasks of visual memory and sustained attention, the PTSD cohort demonstrated delayed and exaggerated early components, along with attenuated LPP amplitudes. The three tasks revealed distinct and complementary EEG signatures PTSD. Significance. Multimodal individualized biomarkers based on EEG, cognitive ERPs, and ECG show promise as objective tools for assessing mood and anxiety disturbances within the PTSD spectrum.

Age-related Electrophysical Correlates of Cross-modal Attention Switching.

The human experience demands seamless attentional switches between sensory modalities. Aging raises questions about how declines in auditory and visual processing affect cross-modal attention switching. This study used a cued cross-modal attention-switching paradigm where visual and auditory stimuli were simultaneously presented on either spatially congruent or incongruent sides. A modality cue indicated the target modality, requiring a spatially left versus right key-press response. EEG recordings were collected during task performance. We investigated whether the mixing costs (decreased performance for repetition trials in a mixed task compared with a single task) and switch costs (decreased performance for a switch of target modality compared with a repetition) in cross-modal attention-switching paradigms would exhibit similarities in terms of behavioral performance and the ERP components to those observed in the traditional unimodal attention-switching paradigms. Specifically, we focused on the ERP components: cue-locked P3 (mixing/switch-related increased positivity), target-locked P3 (mixing/switch-related decreased positivity), and target-locked lateralized readiness potential (mixing/switch-related longer latency). In addition, we assessed how aging impacts cross-modal attention-switching performance. Results revealed that older adults exhibited more pronounced mixing and switch costs than younger adults, especially when visual and auditory stimuli were presented on incongruent sides. ERP findings showed increased cue-locked P3 amplitude, prolonged cue-locked P3 latency, decreased target-locked P3 amplitude, prolonged target-locked P3 latency in association with switch costs, and prolonged onset latency of the target-locked lateralized readiness potential in association with the mixing costs. Age-related effects were significant only for cue-locked P3 amplitude, cue-locked P3 latency (switch-related), and target-locked P3 latency (switch-related). These findings suggest that the larger mixing costs and switch costs in older adults were due to the inefficient use of modality cues to update a representation of the relevant task sets, requiring more processing time for evaluating and categorizing the target.

Neural Markers of Attention at 6 Months Associate With Later Attentional Control Performance.

Attentional control is key to the development of executive functions. Previous research indicates that individual differences in attentional control behaviour may be stable from 6 months. Here, we analyse electroencephalogram data collected from 59 6-month-olds to gain insights into the neural processes underlying attentional control in infancy. First, we examine the neural activity preceding distinct looking behaviours in an attentional control task at 6 months. Second, we test whether those neural markers show predictive associations to behavioural measures of attentional control (Freeze-Frame task) and executive function (A-not-B task) in the same infants at 9 months. Whilst our data do not show evidence that 6-9Hz power is implicated in attentional control at 6 months, or that the P1 ERP component plays a role in our attentional control task, we do find evidence that corroborates and extends research linking 3-6Hz power to attentional control. At the group level, frontal 3-6Hz power recorded whilst looking to a central target before the onset of a peripheral distractor was greater during trials where infants subsequently looked to the distractor, compared with trials where they did not look. Higher 3-6Hz power in trials where the infant did not look to a peripheral distractor was predictive of less distractibility at 9 months, and higher 3Hz power in trials where infants did look to the distractor strengthened the predictive association from 6-month EEG to 9-month behaviour. We suggest 3-6Hz activity may be sensitive to multiple processes, such as anticipatory attention, and the ability to maintain attention on a target.

The Phonological Mapping Negativity (PMN) as a language-specific component: Exploring responses to linguistic vs musical mismatch.

The Phonological Mismatch Negativity (PMN) is an ERP component said to index the processing of phonological information, and is known to increase in amplitude when phonological expectations are violated. For example, in a context that generates expectation of a certain phoneme, the PMN will become relatively more negative if the phoneme is switched for an alternative. The response is comparable to other temporally-proximate components, insofar as it indicates a neurological response to unexpected auditory input, but remains considered distinct by the field on the basis of its proposed specific sensitivity to phonology. Despite this, reports of the PMN overlap notably, both in temporal and topographic distribution, with the Mismatch Negativity (MMN) and the N400, and limited research to date has been conducted to establish whether these extant distinctions withstand testing. In the present study, we investigate the PMN's sensitivity to non-linguistic mismatches so as to test the response's specific language sensitivity. Participants heard primes-three-syllable words-played simultaneously to three-note tunes, with the instructions to attend exclusively to either the linguistic or musical content. They were then tasked with removing the first syllable (phoneme manipulation) or note (music manipulation) to form the target. Targets either matched or mismatched primes, thus achieving physically identical note or phoneme mismatches. Results show that a PMN was not elicited during the musical mismatch condition, a finding which supports suggestions that the PMN may be a language-specific response. However, our results also indicate that further research is necessary to determine the relationship between the PMN and N400. Though our paper probes a previously unstudied dimension of the PMN, questions still remain surrounding whether the PMN, although seemingly language-specific, is truly a phonology-specific component.

Exploring the Utility of the Muse Headset for Capturing the N400: Dependability and Single-Trial Analysis.

Consumer-grade EEG devices, such as the InteraXon Muse 2 headband, present a promising opportunity to enhance the accessibility and inclusivity of neuroscience research. However, their effectiveness in capturing language-related ERP components, such as the N400, remains underexplored. This study thus aimed to investigate the feasibility of using the Muse 2 to measure the N400 effect in a semantic relatedness judgment task. Thirty-seven participants evaluated the semantic relatedness of word pairs while their EEG was recorded using the Muse 2. Single-trial ERPs were analyzed using robust Yuen t-tests and hierarchical linear modeling (HLM) to assess the N400 difference between semantically related and unrelated target words. ERP analyses indicated a significantly larger N400 effect in response to unrelated word pairs over the right frontal electrode. Additionally, dependability estimates suggested acceptable internal consistency for the N400 data. Overall, these findings illustrate the capability of the Muse 2 to reliably measure the N400 effect, reinforcing its potential as a valuable tool for language research. This study highlights the potential of affordable, wearable EEG technology to expand access to brain research by offering an affordable and portable way to study language and cognition in diverse populations and settings.

Neural Correlates of Emotion Regulation and Associations With Disordered Eating During Preadolescence.

Difficulties with emotion regulation have been documented in individuals with eating and internalizing disorders. However, there is limited research examining the cognitive processes underlying these difficulties. Using a dimensional approach, the current study examined the link between the behavioral and neural correlates of response inhibition, disordered eating, and internalizing symptoms in a community sample of preadolescents. A total of 50 children (M age=10.9years; 58% male) completed an emotion Go/No-Go task, while ERP components were recorded, as well as self-report measures of disordered eating and internalizing symptoms. In addition, children completed an emotion recognition task to establish whether there were fundamental differences in emotion recognition across high and low levels of disordered eating and internalizing symptoms. Increased disordered eating was associated with increased mean P3-NoGo amplitudes when inhibiting responses to happy facial expressions, as well as poorer recognition of happy faces. These associations were not found for internalizing symptoms. Our findings suggest an early disruption in response inhibition, specifically for happy emotional expressions, may be relevant to the development of disordered eating behaviors in preadolescence.

Infant neural processing of mother's face is associated with falling reactivity in the first year of life.

It is well established that faces evoke a distinct neural response in the adult and infant brain. Past research has focused on how the infant face-sensitive ERP components (N290, P400, Nc) reflect different aspects of face processing, however there is still a lack of understanding of how these components reflect face familiarity and how they change over time. Further, there are only a few studies on whether these neural responses correlate with other aspects of development, such as infant temperament. In this longitudinal study (N∼60), we recorded infant visual ERPs in response to mother and stranger face stimuli at 4, 6 and 9 months of age. Our results showed that, compared to a stranger face, the mother face evoked a larger N290 at 4 months and a larger P400 at 6 months. At 9 months, no difference was found between mother and stranger faces. However, at 9 months we found that the P400 and Nc amplitudes evoked by the mother face were associated with infant falling reactivity. We conclude that the neural responses associated with the processing of faces, and specifically the face of the mother, are related to the development of infant individual characteristics.

Emotion Regulation Moderates the Prospective Association between ERN and Anxiety in Early Adolescence: An Age-Specific Moderation of Cognitive Reappraisal but not Expressive Suppression.

The increasing prevalence of anxiety problems during adolescence underscores the importance of a better understanding of the development of anxiety. Existing literature has documented a prospective association between error responsivity - characterized by the ERP component of error-related negativity (ERN) - and anxiety in youths. However, it remains unclear to what extent the ERN-anxiety relationship may be moderated by emotion regulation, another attribute critical to the development of anxiety. We collected two waves of data from 115 healthy early adolescents (66 girls; Mean age/SD at T1 = 11.00/1.16 years), approximately one year apart. Participants completed an EEG Go/No-Go task and reported on their anxiety symptoms at T1 and T2; they also reported on their emotion regulation tendencies (i.e., cognitive reappraisal [CR] and expressive suppression [ES]) at T2. The ERN was quantified via a principal component analysis. We found a moderating effect of ES on the ERN-anxiety association. Specifically, a larger T1 ERN predicted greater T2 anxiety symptoms for youths with higher, but not lower, ES. Interestingly, the moderating effect of CR on the ERN-symptom association was conditioned on age. Among older youths (upper age tercile) only, the association between T1 ERN and T2 symptoms was significant for those with lower, but not higher, CR. These findings contribute novel evidence on the moderating effect of emotion regulation on the prospective ERN-anxiety relationship in early adolescence. Our results elucidate age-specific patterns in the moderating effect of CR. Future studies can leverage these findings to tailor emotion regulation interventions for youths of different ages.

Endogenous Attention Affects Decision-related Neural Activity but Not Afferent Visual Responses.

Endogenous shifts of spatial attention toward an upcoming stimulus are associated with improvements in behavioral responses to the stimulus, preparatory retinotopic shifts in alpha power, and changes in ERPs. Although attentional modulation of several early sensory ERPs is well established, there is still debate about under what circumstances attention affects the earliest cortical visual evoked response-the C1 ERP component-which is putatively generated from afferent input into primary visual cortex. Moreover, the effects of spatial attention on the recently discovered ERP signature of evidence accumulation-the central parietal positivity (CPP)-have not been fully characterized. The present study assessed the effect of spatial attention on the C1 and CPP components through a spatially cued contrast discrimination task using stimuli that were specifically designed to produce large-amplitude C1 responses and that varied in sensory evidence strength to characterize the CPP. Participants responded according to which of two checkerboard stimuli had greater contrast following an 80% valid cue toward the upper or lower visual field. Prestimulus alpha power changed topographically based on the cue, suggesting participants shifted attention to prepare for the upcoming stimuli. Despite these attentional shifts in alpha power and the fact that the stimuli reliably elicited C1 responses several times greater than many prior studies, there was no evidence of an attention effect on the C1. The CPP, however, showed a clear increase in build-up rate on valid trials. Our findings suggest that endogenous attention may not affect the early C1 ERP component but may improve behavior at a decision stage, as reflected in brain signals related to evidence accumulation (the CPP).

Non-classical event-related potentials reveal attention network alteration in patients with temporal lobe epilepsy

ObjectiveTo explore the characteristic changes of multiple ERP components associated with attention impairments in patients with temporal lobe epilepsy (TLE). MethodsA total of 92 patients diagnosed with TLE at Xiangya Hospital during May 2022 and January 2023 and 85 healthy controls were included in this study. Participants were asked to complete attention network test with recording of electroencephalogram. ResultsCompared with healthy controls, significant lower amplitudes (cue-related N1, N2 and CNV) and longer latencies (target-related N2) were found in TLE patients. Besides classical components, other components could also reveal the impairments of attention function. Cue-related N1 (p ≤ 0.007) and N2 (p ≤ 0.01) components indicated impaired alerting and orienting network in TLE. And cue-related CNV-E component (p = 0.003) promoted the alerting network was damaged and target-related N2 component (p = 0.008) indicated the executive control network was impaired. ConclusionThese findings consummate the non-classical ERP features of attention impairments in TLE patients. SignificanceThe above findings have strong clinical guiding significance for early identification and intervention.

Changes in P300 amplitude to negative emotional stimuli correlate with treatment responsiveness to sertraline in adolescents with depression

ObjectiveAdolescents with depression is characterized by high rates of recurrence and functional impairment, with a significant association with suicide risk. Antidepressants are commonly prescribed to treat depression, yet few reproducible neurobiological markers for depression and antidepressant treatment response have been identified. Therefore, discovering a stable and reliable neurobiological marker holds significant value for both the clinical diagnosis and treatment of depression in adolescents. MethodsOne hundred and seven patients with major depressive disorder (MDD group, 30 males, 77 females, mean age: 14.80 years), and 25 healthy subjects (HC group, 13 males, 12 females, mean age: 15.72 years) were recruited to perform a two-choice oddball task related to negative emotional cues. All participants completed a self-administered questionnaire to gather demographic information. A trained psychiatrist administered the Hamilton Depression Scale (HAMD-17) to assess depression severity. Of the 107 adolescents with depression, 61 received antidepressant medication for 8 weeks, and 61 of these patients were followed up. Multichannel EEG was recorded continuously from 64 scalp electrodes using the Curry 8 system. EEG signal preprocessing and analysis was performed offline using the EEGLAB toolbox in MATLAB. The ERP component characteristics associated with emotional processing were extracted from the difference waves and statistically analyzed. ResultsAdolescents with depression exhibited significantly larger P300 amplitudes than healthy controls in response to both neutral and negative emotional cues. Following sertraline treatment, both depression scores and P300 amplitudes decreased significantly in adolescents with depression. Moreover, a strong positive correlation was observed between changes in depression scores and changes in P300 amplitude in response to negative emotional cues before and after treatment. ConclusionsChanges in neural reactivity to negative emotional stimuli among adolescents with depression can be selectively modulated by sertraline and are significantly associated with improvements in depressive symptoms. SignificanceChanges in P300 amplitude to negative emotional stimuli significantly correlate with treatment responsiveness to sertraline in adolescents with depression.

Registered Report Stage II: Decoding the category information from evoked potentials to visible and invisible visual objects

Previous studies that use decoding methods and EEG to investigate the neural representation of the category information of visual objects focused mainly on consciously processed visual objects. It remains unclear whether the category information of unconsciously processed visual objects can be decoded and whether the decoding performance is different for consciously and unconsciously processed visual objects. The present study compared the neural decoding of the animacy category of visible and invisible visual objects via EEG and decoding methods. The results revealed that the animacy of visible visual objects could be decoded above the chance level by the P200, N300, and N400, but not by the early N/P100. However, the animacy of invisible visual objects could not be decoded above the chance level by neither early nor late ERP components. The decoding accuracy was greater for visible visual objects than that for invisible visual objects for the P200, N300 and N400. These results suggested that access to animacy category information for visual objects requires conscious processing.

Complex trade-offs in a dual-target visual search task are indexed by lateralised ERP components

In everyday tasks, the choices we make incorporate complex trade-offs between conflicting factors that affect how we will achieve our goals. Previous experimental research has used dual-target visual search to determine how people flexibly adjust their behaviour and make choices that optimise their decisions. In this experiment, we leveraged a visual search task that incorporates complex trade-offs, and electroencephalography (EEG), to understand how neural mechanisms of selective attention contribute to choice behaviour in these tasks. On each trial, participants could choose to respond to the gap location on either of two possible targets. Each target was colour coded such that colour indicated which of the two had the easier gap discrimination. Orthogonally, we manipulated the set size of coloured distractors to modulate how efficiently each target could be found. As a result, optimised task performance required participants to trade-off conflicts between the ease of finding a target given the current set size, and the ease of making its associated gap discrimination. Our results confirm that participants are able to flexibly adjust their behaviour, and trade-off these two factors to maintain their response speed and accuracy. Additionally, the N2pc and SPCN components elicited by search displays could reliably predict the choice that participants would ultimately make on a given trial. These results suggest that initial attentional processes may help to determine the choice participants make, highlighting the central role that attention may play in optimising performance on complex tasks.

EEG might be better left alone, but ERPs must be attended to: Optimizing the late positive potential preprocessing pipeline

The late positive potential (LPP) is an ERP component commonly used to study emotional processes and has been proposed as a neuroaffective biomarker for research and clinical uses. These applications, however, require standardized procedures for elicitation and ERP data processing.We evaluated the impact of different EEG preprocessing steps on the LPP's data quality and statistical power. Using a diverse sample of 158 adults, we implemented a multiverse analytical approach to compare preprocessing pipelines that progressively incorporated more steps: artifact detection and rejection, bad channel interpolation, and bad segment deletion. We assessed each pipeline's effectiveness by computing the standardized measurement error (SME) and conducting simulated experiments to estimate statistical power in detecting significant LPP differences between emotional and neutral images.Our findings highlighted that artifact rejection is crucial for enhancing data quality and statistical power. Voltage thresholds to reject trials contaminated by artifacts significantly affected SME and statistical power. Once artifact detection was optimized, further steps provided minor improvements in data quality and statistical power. Importantly, different preprocessing pipelines yielded similar outcomes.These results underscore the robustness of the LPP's affective modulation to preprocessing choices and the critical role of effective artifact management. By refining and standardizing preprocessing procedures, the LPP can become a reliable neuroaffective biomarker, supporting personalized clinical interventions for affective disorders.

Stronger adaptation of middle-to-late ERP components to object silhouette images before versus after object priming in Aphantasia

Stronger adaptation of middle-to-late ERP components to object silhouette images before versus after object priming in Aphantasia

Inter-participant transfer learning with attention based domain adversarial training for P300 detection

A Brain-computer interface (BCI) system establishes a novel communication channel between the human brain and a computer. Most event related potential-based BCI applications make use of decoding models, which requires training. This training process is often time-consuming and inconvenient for new users. In recent years, deep learning models, especially participant-independent models, have garnered significant attention in the domain of ERP classification. However, individual differences in EEG signals hamper model generalization, as the ERP component and other aspects of the EEG signal vary across participants, even when they are exposed to the same stimuli. This paper proposes a novel One-source domain transfer learning method based Attention Domain Adversarial Neural Network (OADANN) to mitigate data distribution discrepancies for cross-participant classification tasks. We train and validate our proposed model on both a publicly available OpenBMI dataset and a Self-collected dataset, employing a leave one participant out cross validation scheme. Experimental results demonstrate that the proposed OADANN method achieves the highest and most robust classification performance and exhibits significant improvements when compared to baseline methods (CNN, EEGNet, ShallowNet, DeepCovNet) and domain generalization methods (ERM, Mixup, and Groupdro). These findings underscore the efficacy of our proposed method.

Event-related potentials and behavioral correlates of emotional recognition memory in late pregnancy.

Research on cognitive and emotional functions during pregnancy challenges the prevalent perception of cognitive decline in pregnant women. This study investigates the behavioral and neural dynamics of cognitive-affective processing in third-trimester pregnant women, comparing them with non-pregnant controls. Using a 64-channel EEG-ERP system, we recorded brain activity as participants engaged in an emotional word recognition task. This task involved initially viewing a sequence of emotional and neutral words, followed by a recognition test where participants identified each word as 'new' or 'previously seen'. Contrary to widespread beliefs about diminished recognition ability during late pregnancy, our results revealed no significant differences in error rates between groups. However, pregnant participants demonstrated slower reaction times. In terms of neural responses, pregnant women exhibited increased amplitudes in the N1, P2, and N400 ERP components, suggesting that they may require additional brain resources compared with non-pregnant individuals to process perceptual information. A significant interaction was observed between pregnancy status and the emotional valence of stimuli. Pregnant women showed heightened N1 and N400 responses to negative words, indicating increased sensitivity to stimuli potentially representing threat. This enhanced response was not observed for positive or neutral words. Furthermore, there was an amplified N1 response to 'new' words, but not to 'old' words. These findings suggest that late pregnancy is characterized by heightened responsiveness to new and particularly negative stimuli, potentially leading to a more cautious behavioral approach. Heightened vigilance and sensitivity could offer evolutionary advantages, optimizing fetal development and enhancing maternal well-being.

Beyond primary visual cortex: The leading role of lateral occipital complex in early conscious visual processing

The study of the neural substrates that serve conscious vision is one of the unsolved questions of cognitive neuroscience. So far, consciousness literature has endeavoured to disentangle which brain areas and in what order are involved in giving rise to visual awareness, but the problem of consciousness still remains unsolved. Availing of two different but complementary sources of data (i.e., Fast Optical Imaging and EEG), we sought to unravel the neural dynamics responsible for the emergence of a conscious visual experience. Our results revealed that conscious vision is characterized by a significant increase of activation in extra-striate visual areas, specifically in the Lateral Occipital Complex (LOC), and that, more interestingly, such activity occurred in the temporal window of the ERP component commonly thought to represent the electrophysiological signature of visual awareness, i.e., the Visual Awareness Negativity (VAN). Furthermore, Granger causality analysis, performed to further investigate the flow of activity occurring in the investigated areas, unveiled that neural processes relating to conscious perception mainly originated in LOC and subsequently spread towards visual and motor areas. In general, the results of the present study seem to advocate for an early contribution of LOC in conscious vision, thus suggesting that it could represent a reliable neural correlate of visual awareness. Conversely, striate visual areas, showing awareness-related activity only in later stages of stimulus processing, could be part of the cascade of neural events following awareness emergence.

Investigating the impact of early deafness on learned action-effect contingency for action linked to peripheral sensory effects

Investigating peripheral visual processing in individuals with early auditory deprivation is a critical research area in the field of neuroscience, since it helps understanding the phenomenon of sensory adaptation and brain plasticity after sensory loss. Prior research has already demonstrated that the absence of auditory input, which is crucial to detect events occurring out of the central egocentric visual space, leads to an improved processing of visual and tactile stimuli occurring in peripheral regions of the sensory space. Nevertheless, no prior studies have explored whether such enhanced processing also takes place within the domain of action, particularly when individuals are required to perform actions that produce peripheral sensory outcomes. To test this hypothesis, we recruited 15 hearing (31 ± 3.3 years) and 15 early deaf adults (42 ± 2.6 years) for a neuro-behavioral experiment involving: 1) a behavioral task where participants executed a simple motor action (i.e., a button press) and received a visual feedback either in the center or in a peripheral region of the visual field, and 2) the electrophysiological recording of brain electrical potentials (EEG). We measured and compared neural activity preceding the motor action (the readiness potentials) and visual evoked responses (the N1 and P2 ERP components) and found that deaf individuals did not exhibit more pronounced modulation of neural responses when their motor actions resulted in peripheral visual stimuli compared to their hearing counterparts. Instead they showed a reduced modulation when visual stimuli were presented in the center. Our results suggest a redistribution of attentional resources from center to periphery in deaf individuals during sensorimotor coupling.

Neurophysiological markers of printed word processing and reading fluency in adolescence

ABSTRACT Reading fluency is one of key facets of reading performance. At the neurophysiological level, as reading skills improve, latencies of P100 and N170 shorten, and the functional role of these ERPs components is expanding. While in primary schoolchildren, only orthographic N170 effects are observed, lexical and grammatical N170 effects are traceable in adulthood. However, previous studies neglect the adolescent sample. The goal of this study was to determine whether adolescents exhibit lexical and grammatical N170 effects and explore the link between reading fluency and P100 and N170 components. We assessed 32 adolescents in the context of a grammaticality judgment ERP experiment and estimated reading fluency. We registered lexical N170 effects indicative of the presence of an adult-like lexical representation system. Moreover, we observed negative correlations between reading fluency and P100 and N170 latencies, which suggest that reading fluency is affected by the speed of visual processing captured by these latencies.