Amplitude Of Late Positive Component Research Articles

The late positive event-related potential component is time locked to the decision in recognition memory tasks

Two event-related potential (ERP) components are commonly observed in recognition memory tasks: the Frontal Negativity (FN400) and the Late Positive Component (LPC). These components are widely interpreted as neural correlates of familiarity and recollection, respectively. However, the interpretation of LPC effects is complicated by inconsistent results regarding the timing of ERP amplitude differences. There are also mixed findings regarding how LPC amplitudes covary with decision confidence. Critically, LPC effects have almost always been measured using fixed time windows relative to memory probe stimulus onset, yet it has not been determined whether LPC effects are time locked to the stimulus or the recognition memory decision. To investigate this, we analysed a large (n = 132) existing dataset recorded during recognition memory tasks with old/new decisions followed by post-decisional confidence ratings. We used ERP deconvolution to disentangle contributions to LPC effects (defined as differences between hits and correct rejections) that were time locked to either the stimulus or the vocal old/new response. We identified a left-lateralised parietal LPC effect that was time locked to the vocal response rather than probe stimulus onset. We also isolated a response-locked, midline parietal ERP correlate of confidence that influenced measures of LPC amplitudes at left parietal electrodes. Our findings demonstrate that, contrary to widespread assumptions, the LPC effect is time locked to the recognition memory decision and is best measured using response-locked ERPs. By extension, differences in response time distributions across conditions of interest may lead to substantial measurement biases when analysing stimulus-locked ERPs. Our findings highlight important confounding factors that further complicate the interpretation of existing stimulus-locked LPC effects as neural correlates of recollection. We recommend that future studies adopt our analytic approach to better isolate LPC effects and their sensitivity to manipulations in recognition memory tasks.

Effect of contextual prediction on emotional word processing: an evidence from ERPNR-D-24-00189.

This study examined the effect of context on the prediction of emotional words with varying valences. It investigated the neural mechanisms underlying the processing differences of emotion words with different valences in both predictable and unpredictable contexts. Additionally, it aimed to address the conflicting results regarding the processing time in predictive contexts reported in previous studies. Participants were instructed to carefully read the text that included the specified emotion words. Event-related potentials elicited by emotional words were measured. To ensure that the participants can read the text carefully, 33% of the texts are followed by comprehension problems. After reading the text, the comprehension questions were answered based on the text content. The study revealed that the N400 amplitude elicited by an unpredictable context was greater than that elicited by a predictable context. Additionally, the N400 amplitude triggered by positive emotion words was larger than that triggered by negative emotion words. However, there was no significant difference in late positive component amplitude observed between contextual prediction and emotional word valence. The present study suggests that predictive processing takes place at an intermediate stage of speech processing, approximately 400 ms after stimulus onset. Furthermore, the presence of a predictive context enhances the processing of emotional information. Notably, brain activity is more pronounced during the processing of positive emotional stimuli compared to negative emotional stimuli. Additionally, the facilitative effect of a predictable context diminishes in the advanced phase of Chinese speech comprehension.

"I heard it before … or not": time-course of ERP response and behavioural correlates associated with false recognition memory.

Electrophysiological and behavioural correlates of true and false memories were examined in the Deese/Roediger-McDermont (DRM) paradigm. A mass univariate approach for analysing event-related potentials (ERP) in the temporal domain was used to examine the electrophysiological effects associated with this paradigm precisely (point-by-point) and without bias (data-driven). Behaviourally, true and false recognition did not differ, and the predicted DRM effect was observed, as false recognition of critical lures (i.e., new words semantically related to studied words) was higher than false alarms of new (unrelated) words. Neurally, an expected old/new effect was observed during the time-range of the late positive component (LPC) over left centro-parietal scalp electrodes. Furthermore, true recognition also evoked larger LPC amplitudes than false recognition over both left centro-parietal and fronto-central scalp electrodes. However, we did not observe LPC-related differences between critical lures and new words, nor between correct rejections of critical lures and new words. In contrast, correct rejections of critical lures were accompanied by higher activation of a sustained positive slow wave (SPSW) in right fronto-central electrodes beyond 1200 ms. This result reveals a key role of post-retrieval processes in recognition. Results are discussed in light of theoretical approaches to false memory in the DRM paradigm.

The effects of word and beat priming on Mandarin lexical stress recognition: an event-related potential study

Abstract Music and language are unique communication tools in human society, where stress plays a crucial role. Many studies have examined the recognition of lexical stress in Indo-European languages using beat/rhythm priming, but few studies have examined the cross-domain relationship between musical and linguistic stress in tonal languages. The current study investigates how musical stress and lexical stress influence lexical stress recognition in Mandarin. In the auditory priming experiment, disyllabic Mandarin words with initial or final stress were primed by disyllabic words or beats with either congruent or incongruent stress patterns. Results showed that the incongruent condition elicited larger P2 and the late positive component (LPC) amplitudes than the congruent condition. Moreover, the Strong-Weak primes elicited larger N400 amplitudes than the Weak-Strong primes, and the Weak-Strong primes yielded larger LPC amplitudes than the Strong-Weak primes. The findings reveal the neural correlates of the cross-domain influence between music and language during lexical stress recognition in Mandarin.

The influence of emotional context on emotional word processing in discourse comprehension: evidence from event-related potential.

This research utilized event-related potential (ERP) recording technology to examine the effect of emotional context on the processing of emotional information in sentences. Three types of emotion-consistent discourse materials (neutral-neutral, positive-positive and negative-negative) were constructed to specifically express neutral, positive and negative emotions, respectively. Each discourse comprised two sentences, with the emotionally significant words embedded at the penultimate position of the second sentence. Participants were asked to read these texts, respond to reading comprehension questions and the ERP amplitude induced by the emotional words was recorded. The results indicated a tripartite interaction in the N400 and Late positive component amplitudes involving emotional context, emotional words and brain hemispheres, observed in both frontal and central brain regions. Notably, there was a significant difference in response to positive words between positive and negative contexts. The findings suggest that emotional context has a substantial effect on the processing of emotional words. Positive words, in comparison to negative ones, are more influenced by emotional context, particularly in the frontal and central regions of the brain.

Post-interval potentials in temporal judgements

Research suggests that post-stimulus positive deflections could be associated with timing. We compared offset-locked potentials N1, P2, N1P2, and late positive component (LPC) in temporal generalization and temporal bisection—with visual probe intervals. In both tasks, the LPC amplitude decreased with the duration of the current probe interval. A larger LPC was found after shorter intervals, whereas other ERP amplitudes did not change between tasks or across durations. We also found that the LPC for different responses indicates subjective time. We discussed our findings in relation to theories of human timing.

Chemosensation in anxiety: the trigeminal system matters.

The presence of a perceptual bias due to anxiety is well demonstrated in cognitive and sensory task for the visual and auditory modality. Event-related potentials, by their specific measurement of neural processes, have strongly contributed to this evidence. There is still no consensus as to whether such a bias exists in the chemical senses; chemosensory event-related potentials (CSERPs) are an excellent tool to clarify the heterogeneous results, especially since the Late Positive Component (LPC) may be an indicator of emotional involvement after chemosensory stimulation. This research examined the association between state and trait anxiety and the amplitude and latency of pure olfactory and mixed olfactory-trigeminal LPC. In this study, 20 healthy participants (11 women) with a mean age of 24.6 years (SD = 2.6) completed a validated questionnaire to measure anxiety (STAI), and CSERP was recorded during 40 pure olfactory stimulations (phenyl ethanol) and 40 mixed olfactory-trigeminal stimulations (eucalyptol). LPC latency and amplitude were measured at Cz (electrode located at midline central) for each participant. We observed a significant negative correlation between LPC latencies and the state anxiety scores for the mixed olfactory-trigeminal condition (r(18) = -0.513; P = 0.021), but not for the pure olfactory condition. We did not observe any effect on LPC amplitudes. This study suggests that a higher level of state anxiety is related to a more rapid perceptual electrophysiological response for mixed olfactory-trigeminal stimuli but not for pure odors.

Cost or advantage? Intra-sentential language switching could facilitate L2 emotional words' comprehension in auditory modality

Language switching is encountered commonly and inevitably in bilingual society and often induces costs for target language's production. However, for auditory words' comprehension at sentence level, the limited research showed divergent findings. Some research observed comprehension costs when the language of target words was switched with the code of sentential contexts kept constant; but a potential switch advantage was also showed in non-dominant targets' processing when sentential context switches occurred. Additionally, it's well documented that the words' emotional connotations play a key role in both L1 and L2 word comprehension. Therefore, we aimed to explore which switch effect would occur when bilinguals comprehended L1/L2 emotional target nouns in auditory modality at behavioral and neural level through a visual object selection task. Behaviorally, switch related costs occurred in L1 targets' comprehension, whereas advantage effects were found in L2. Moreover, greater switch advantage occurred for positive and negative targets than for neutral ones. Consistently, larger LPC (Late Positive Component) defection was elicited for L2-Switch trials relative to L2-Nonswitch trials and the differences of LPC's amplitude could predict the behavioral advantageous effects of switching in nondominant targets' comprehension, which suggest that language switching lead to deeper re-analyses for emotional words. Taken together, it's suggested that bilinguals can adaptively utilize top-down (sentential prediction) and bottom-up (words' emotional information) cues to access weaker L2 representations.

Semantic Activation in Badminton Action Processing and Its Modulation by Action Duration: An ERP Study.

Action processing is crucial for sports activities. Using event-related potentials (ERPs), the present study investigated whether semantics were activated in action processing and, if so, whether semantic activation was modulated by action duration. Badminton athletes were recruited to finish a lexical decision task following an action-semantic priming paradigm, in which short (400 ms) or long (1000 ms) action videos served as primes, and semantically congruent or incongruent action words served as targets. The ERP results showed a P300 effect, that is, larger P300 amplitudes were observed for targets primed by semantically incongruent action videos than for targets primed by semantically congruent action videos, only when the action videos were long and not when the action videos were short. Moreover, a late positive component (LPC) was only sensitive to action duration, showing that the targets primed by long action videos elicited larger LPC amplitudes compared to the targets primed by short action videos. These results suggested that semantics could be activated in action processing and that semantic activation was modulated by action duration, supporting a link between the language system and action processing.

Taxonomically-related Word Pairs Evoke both N400 and LPC at Long SOA in Turkish.

Semantic priming in Turkish was examined in 36 right-handed healthy participants in a delayed lexical decision task via taxonomic relations using EEG. Prime-target relations included related- unrelated- and pseudo-words. Taxonomically related words at long stimulus onset asynchrony (SOA) were shown to modulate N400 and late positive component (LPC) amplitudes. N400 semantic priming effect in the time window of 300-500 ms was the largest for pseudo-words, intermediate for semantically-unrelated targets, and smallest for semantically-related targets as a reflection of lexical-semantic retrieval. This finding contributes to the ERP literature showing how remarkably universal the N400 brain potential is, with similar effects across languages and orthography. The ERP data also revealed different influences of related, unrelated, and pseudo-word conditions on the amplitude of the LPC. Attention scores and mean LPC amplitudes of related words in parietal region showed a moderate correlation, indicating LPC may be related to "relationship-detection process".

The ERP correlates of self-knowledge in ageing

Self-knowledge is a type of personal semantic knowledge that concerns one’s self-image and personal identity. It has most often been operationalized as the summary of one’s personality traits (“I am a stubborn person”). Interestingly, recent studies have revealed that the neural correlates of self-knowledge can be dissociated from those of general semantic and episodic memory in young adults. However, studies of “dedifferentiation” or loss of distinctiveness of neural representations in ageing suggest that the neural correlates of self-knowledge might be less distinct from those of semantic and episodic memory in older adults. We investigated this question in an event-related potential (ERP) study with 28 young and 26 older adults while they categorised personality traits for their self-relevance (self-knowledge conditions), and their relevance to certain groups of people (general semantic condition). Participants then performed a recognition test for previously seen traits (episodic condition). The amplitude of the late positive component (LPC), associated with episodic recollection processes, differentiated the self-knowledge, general semantic, and episodic conditions in young adults, but not in older adults. However, in older adults, participants with higher composite episodic memory scores had more differentiated LPC amplitudes across experimental conditions. Moreover, consistent with the fact that age-related neural dedifferentiation may be material and region specific, in both age groups some differences between memory types were observed for the N400 component, associated with semantic processing. Taken together, these findings suggest that declarative memory subtypes are less distinct in ageing, but that the amount of differentiation varies with episodic memory function.

Electrophysiological Correlates of Character Transposition in the Left and Right Visual Fields.

This study examined the brain activity elicited by the hemispheric asymmetries and morpheme transposition of two-character Chinese words (canonical and transposed word) and pseudowords using event-related potentials (ERPs) with a dual-target rapid serial visual presentation (RSVP) task. Electrophysiological results showed facilitation effects for canonical words with centrally presented visual field (CVF) and right visual field (RVF) presentations but not with left visual field (LVF) presentations, as reflected by less negative N400 amplitudes. Moreover, more positive late positive component (LPC) amplitudes were observed for both canonical words and transposed words irrespective of the visual fields. More importantly, transposed words elicited a more negative N400 amplitude and a less positive LPC amplitude compared with the amplitudes elicited by canonical words for CVF and RVF presentations. For LVF presentations, transposed words elicited a less negative N250 amplitude compared with canonical words, and there was no significant difference between canonical words and transposed words in the N400 effect. Taken together, we concluded that character transposition facilitated the mapping of whole-word orthographic representation to semantic information in the LVF, as reflected by the N250 component, and such morpheme transposition influenced whole-word semantic processing in CVF and RVF presentations, as reflected by N400 and LPC components.

Regulation of Mindfulness-Based Music Listening on Negative Emotions Related to COVID-19: An ERP Study.

The current study aimed to explore the behavioral and neural correlates of mindfulness-based music listening regulation of induced negative emotions related to COVID-19 using the face–word Stroop task. Eighty-five young adults visited the laboratory and were randomly assigned to three groups: a calm music group (CMG: n = 28), a happy music group (HMG: n = 30), and a sad music group (SMG: n = 27). Negative emotions were induced in all participants using a COVID-19 video, followed by the music intervention condition. Participants underwent the face–word Stroop tasks during which event-related potentials (ERPs) were recorded. The N2, N3, P3, and late positive component (LPC) were investigated. The results showed that calm music and happy music effectively regulate young adults’ induced negative emotions, while young adults experienced more negative emotions when listening to sad music; the negative mood states at the post-induction phase inhibited the reaction of conflict control in face–word Stroop tasks, which manifested as lower accuracy (ACC) and slower reaction times (RTs). ERP results showed negative mood states elicited greater N2, N3, and LPC amplitudes and smaller P3 amplitudes. Further studies are needed to develop intervention strategies to enhance emotion regulation related to COVID-19 for other groups.

Electrophysiological correlates of the somatotopically organized tactile duration aftereffect

Adaptation to sensory events of long or short duration leads to a negative aftereffect, in which a new target event (of median duration) following the adaptation will be perceived to be shorter or longer than is actually the case. This illusion has been observed in visual, auditory, and tactile modalities. This study used event-related potentials (ERPs) to examine the tactile duration aftereffect, using the contingent negative variation (CNV) and the late positive component (LPC) as a way to characterize the temporal processes. The tactile duration adaptation was found to induce a significant aftereffect within a somatotopic framework. Moreover, the CNV in the contralateral scalp and the LPC in the fronto-central scalp were both modulated by the tactile duration adaptation. Specifically, adaptation to a short tactile duration increased the CNV and LPC amplitudes, whereas adaptation to a long tactile duration decreased them. This modulation was contingent on the topographic distance between fingers, which was only observed when the adapting and test fingers were consistent or adjacent, but not homologous. In sum, these results reveal a coherent behavioral-electrophysiological link in the somatotopically organized tactile duration aftereffect.

Brain responses of dysphoric and control participants during a self-esteem implicit association test.

Previous studies have reported lowered implicit self-esteem at the behavioral level among depressed individuals. However, brain responses related to the lowered implicit self-esteem have not been investigated in people with depression. Here, event-related potentials were measured in 28 dysphoric participants (individuals with elevated amounts of depressive symptoms) and 30 control participants during performance of an implicit association task (IAT) suggested to reflect implicit self-esteem. Despite equivalent behavioral performance, differences in brain responses were observed between the dysphoric and the control groups in late positive component (LPC) within 400-1,000ms poststimulus latency. For the dysphoric group, self-negativity mapping stimuli (me with negative word pairing and not-me with positive word pairing) induced significantly larger LPC amplitude as compared to self-positivity mapping stimuli (me with positive pairing and not-me with negative pairing), whereas the control group showed the opposite pattern. These results suggest a more efficient categorization toward implicit self-is-negative association, possibly reflecting lower implicit self-esteem among the dysphoric participants, in comparison to the controls. These results demonstrate the need for further investigation into the functional significance of LPC modulation during IAT and determination of whether LPC can be used as a neural marker of depressive-related implicit self-esteem.

Differences in Explicit Stereotype Activation among Social Groups Based on the Stereotype Content Model: Behavioral and Electrophysiological Evidence in Chinese Sample.

The stereotype content model (SCM; Fiske, Cuddy, Glick and Xu, 2002) identifies four basic categories of stereotyped social groups: high warmth-high competence (HW-HC), high warmth-low competence (HW-LC), low warmth-high competence (LW-HC), and low warmth-low competence (LW-LC). However, many of these groups have not been directly examined in stereotype activation research. The purpose of the present research was to extend stereotype activation research to groups that more fully represent those identified under the SCM. Employing explicit sequential priming task, participants responded to prime-target stimulus pairs that were either congruent or incongruent with stereotypes of social groups from all four SCM quadrants in two studies in the current investigation. Study 1 was to determine the behavioral pattern of explicit stereotype activation among four quadrants (the sample included 60 Chinese undergraduate students, 51%—female). Study 2 further employed event-related brain potentials (ERPs) technique to track the time course and electrophysiological underpinnings of explicit stereotype activation (the sample included 22 right-handed Chinese undergraduate students, 76%—female). In Study 1, participants responded more quickly and accurately on stereotype congruent trials than incongruent trials for all social groups except LW-LC groups. This reverse priming effect on LW-LC social groups in RTs was also replicated in Study 2. ERPs findings further showed that incongruent targets elicited larger N400 amplitudes than congruent targets for all four SCM quadrants. Moreover, congruent targets elicited larger P2 than incongruent targets, but only found for the LW-LC social groups. In addition, congruent targets elicited larger amplitudes of late positive component than incongruent targets for the low warmth (LW-LC and LW-HC) groups. Together, these results highlight the unique processing that LW-LC groups receive throughout the cognitive stream, ultimately manifesting in distinctive behavioral responses. Unconscious activation of egalitarian goals, disgust, and distrust accounts are discussed.

The enhancement of appetite through the use of colored light in case of a cake: Preliminary evidence from event‐related potentials

AbstractAppetites are strongly affected by the color of the food and it has been found that different colors can affect the brain reflexes that impact the appetite. In this study, event‐related potential was used as a measurement tool to detect brain wave responses to assess foods under different colors of light, and to compare the appetite performance of participants. The food samples were captured under incandescent lights and colored lights (red and green lights under 5200 K). The incandescent lights were divided into the differential color temperature (2700, 4000, 6500 and 7500 K). Seventeen participants were invited to the experiment. The event‐related potential results showed that the warm incandescent light (4000 K) significantly increased appetite. Moreover, the red light enhances the late positive component amplitude and enhances the consumer's visual attraction and impression. The conclusions showed that the color of lighting can affect consumers' emotions, behaviors, psychology, and even appetite, and preliminary scientific evidence has been obtained from event‐related potential.

Older Adults Encode Task-Irrelevant Stimuli, but Can This Side-Effect be Useful to Them?

We studied whether, due to deteriorating inhibitory functions, older people are more likely to process irrelevant stimuli; and if so, could they later use this information better than young adults. In the study phase of our experiment, a Posner-type gaze-cued version of a Simon task was performed in which we presented task-irrelevant cues, where faces or patches with either left- or right-looking dots for the pupil of the eye preceded the task to press a button congruent or incongruent with the presentation side of the target stimulus. In the follow-up test phase, participants completed an unexpected facial recognition test. In the study phase not only a decreased P1, but also an increased N170 amplitude of the event-related potentials (ERPs) were found in older, compared to younger adults, and also for faces compared to patches. Even though in the test phase both age-groups could recognize the faces better than statistically by chance, neither the older nor the younger participants could discriminate them effectively. The late positive component (LPC)—the ERP correlates of the old/new effect, being the higher amplitude for the earlier presented stimuli when compared with the unseen stimuli during the recognition test—was not evolved in the older group, while a reversed old/new effect was seen in younger participants: higher amplitude was found in New-Right and Old-Wrong conditions (for faces they did not recognize independent of seeing them before) compared to Old-Right and New-Wrong conditions (for faces they thought they recognized from the study phase). In conclusion, although older adults showed enhanced processing of task-irrelevant stimuli compared to younger adults, as indicated by the N170 amplitude, however, they were not able to utilize this information in a later task, as was suggested by the recognition rate and LPC amplitude results.

Electrophysiological correlates of emotion word processing in Spanish–English bilinguals

AbstractWe examined how proficiency influences the processing of emotion words in Spanish–English bilinguals (22 balanced and 20 unbalanced). All unbalanced bilinguals were more proficient in English than Spanish. Participants rated the valence of negative, neutral, and positive words in both languages while EEG was being recorded. ERP latencies and amplitudes were analyzed for two components. The language effect was significant on the late positive component (LPC) amplitude, which was larger for emotion than for neutral words for both groups in English. The unbalanced group presented larger LPC amplitudes for positive than for neutral and for neutral than for negative words in Spanish, suggesting emotion processing differences in these participants’ less proficient language. Valence effects were consistent across languages for the balanced group, but not for the unbalanced group, perhaps reflecting differences in reactivity to emotion words in the less proficient language.

Neural Correlates of Own- and Other-Face Perception in Body Dysmorphic Disorder.

BackgroundBody dysmorphic disorder (BDD) is characterized by an excessive preoccupation with one or more perceived flaws in one’s own appearance. Previous studies provided evidence for deficits in configural and holistic processing in BDD. Preliminary evidence suggests abnormalities at an early stage of visual processing. The present study is the first examining early neurocognitive perception of the own face in BDD by using electroencephalography (EEG). We investigated the face inversion effect, in which inverted (upside-down) faces are disproportionately poorly processed compared to upright faces. This effect reflects a disruption of configural and holistic processing, and in consequence a preponderance of featural face processing.MethodsWe recorded face-sensitive event-related potentials (ERPs) in 16 BDD patients and 16 healthy controls, all unmedicated. Participants viewed upright and inverted (upside-down) images of their own face and an unfamiliar other face, each in two facial emotional expressions (neutral vs. smiling). We calculated the early ERP components P100, N170, P200, N250, and the late positive component (LPC), and compared amplitudes among both groups.ResultsIn the early P100, no face inversion effects were found in both groups. In the N170, both groups exhibited the common face inversion effects, with significantly larger N170 amplitudes for inverted than upright faces. In the P200, both groups exhibited larger inversion effects to other (relative to own) faces, with larger P200 amplitudes for other upright than inverted faces. In the N250, no significant group differences were found in face processing. In the LPC, both groups exhibited larger inversion effects to other (relative to own) faces, with larger LPC amplitudes for other inverted than upright faces. These overall patterns appeared to be comparable for both groups. Smaller inversion effects to own (relative to other) faces were observed in none of these components in BDD, relative to controls.ConclusionsThe findings suggest no evidence for abnormalities at all levels of early face processing in our observed sample of BDD patients. Further research should investigate the neural substrates underlying BDD symptomatology.