Event-related Brain Potentials Research Articles

Rhythm-based Temporal Expectations: Unique Contributions of Predictability and Periodicity.

Anticipating events and focusing attention accordingly are crucial for navigating our dynamic environment. Rhythmic patterns of sensory input offer valuable cues for temporal expectations and facilitate perceptual processing. Rhythm-based temporal expectations may rely on oscillatory entrainment, where neural activity and perceptual sensitivity synchronize with periodic stimuli. However, whether entrainment models can account for aperiodic predictable rhythms remains unclear. Our study aimed to delineate the distinct roles of predictability and periodicity in rhythm-based expectations. Participants performed a pitch-identification task preceded by periodic predictable, aperiodic predictable, or aperiodic unpredictable temporal sequences. By manipulating the temporal position of the target sound, we observed how auditory perceptual performance was modulated by the target position's relative phase relationship to the preceding sequences. Results revealed a significant performance advantage for predictable sequences, both periodic and aperiodic, compared with unpredictable ones. However, only the periodic sequence induced an entrained modulation pattern, with performance peaking in synchrony with the inherent sequence continuation. Event-related brain potentials corroborated these findings. The target-evoked P3b, possibly a neural marker of attention allocation, mirrored the behavioral performance patterns. This supports our hypothesis that temporal attention guided by rhythm-based expectations modulates perceptual performance. Furthermore, the predictive sequences were associated with enhanced target-preceding negativity (akin to the contingent negative variation), indicating enhanced target preparation. The periodic-specific modulation likely reflects more precise temporal expectations, potentially involving neural entrainment and/or more focused attention. Our findings suggest that predictability and periodicity influence perception through distinct mechanisms.

A beautiful face is good when we're judged by others, a moral character is better.

Moral beauty, reflected in one's actions, and facial beauty both affect how we're judged. Here, we investigated how moral and facial beauty interactively affect social judgments and emotional responses, employing event-related brain potentials. Participants (all female) associated positive, neutral, or negative verbal information with faces scoring high or low on attractiveness and performed ratings of the faces as manipulation checks. In a separate test phase, the faces were presented again, and participants made valenced social judgments of the persons. Results show a dominance of moral beauty in valenced social judgments as well as ERPs related to reflexive and evaluative emotional responses (early posterior negativity, EPN, late positive potential, LPP), whereas facial attractiveness mattered little. In contrast, facial attractiveness affected visual processing (N170). Similarly, relatively shallow impressions of attractiveness and likability that require no knowledge about the person were influenced by both facial attractiveness and social-emotional information. This pattern of dominant effects of social-emotional information regardless of attractiveness shows that when it comes to our emotional responses and social judgments, moral beauty is what matters most, even in the face of physical beauty.

Memory-related brain potentials for visual objects in early AD show impairment and compensatory mechanisms.

Impaired episodic memory is the primary feature of early Alzheimer's disease (AD), but not all memories are equally affected. Patients with AD and amnestic Mild Cognitive Impairment (aMCI) remember pictures better than words, to a greater extent than healthy elderly. We investigated neural mechanisms for visual object recognition in 30 patients (14AD, 16 aMCI) and 36 cognitively unimpaired healthy (19 in the "preclinical" stage of AD). Event-related brain potentials (ERPs) were recorded while participants performed a visual object recognition task. Hippocampal occupancy (integrity), amyloid (florbetapir) PET, and neuropsychological measures of verbal & visual memory, executive function were also collected. A right-frontal ERP recognition effect (500-700ms post-stimulus) was seen in cognitively unimpaired participants only, and significantly correlated with memory and executive function abilities. A later right-posterior negative ERP effect (700-900ms) correlated with visual memory abilities across participants with low verbal memory ability, and may reflect a compensatory mechanism. A correlation of this retrieval-related negativity with right hippocampal occupancy (r = 0.55), implicates the hippocampus in the engagement of compensatory perceptual retrieval mechanisms. Our results suggest that early AD patients are impaired in goal-directed retrieval processing, but may engage compensatory perceptual mechanisms which rely on hippocampal function.

The Competition Model and Adult Second Language Learning: Cross-Language Similarity and L2 Morphosyntax Learning

Adult second language learners arrive at the language learning situation with an already formed first language grammar system in place. The study of cross-language similarity across the first and second languages explores how the similarities and differences in the two languages make learning more or less difficult, particularly for adult learners. From a Competition Model (MacWhinney, 1997) framework, the authors and their colleagues have conducted research examining the relationship between cross-language similarity and adult second language learning and processing with actual learners and in training paradigms with naïve learners; converging methodological approaches have been used (eye tracking, event related brain potentials, self- paced reading, and grammaticality judgments). We review these studies and describe the predictions derived from the Competition Model framework as a function of whether grammatical constructions are formed similarly or differently in the two languages or are unique to the second language. We conclude with a description of Brian MacWhinney’s influence on this body of research.

Cortical oscillations and event-related brain potentials during the preparation and execution of deceptive behavior.

Deception often occurs in response to a preceding cue (e.g., a precarious question) alerting us about the need to subsequently lie. Here, we simulate this process by adapting a previously established paradigm of intentionally false responding, now instructing participants about the need for deception (vs. truthful responses) by means of a simple cue occurring before each response-relevant target. We analyzed event-related brain potentials (ERPs) as well as cortical oscillations recorded from the scalp. In an experimental study (N = 44), we show that a cue signaling the need for deception involves increased attentional selection (P2, P3a, P3b). Moreover, in the period following the cue and leading up to the target, ERP and oscillatory signatures of anticipation and preparation (Contingent Negative Variation, alpha suppression) were found to be increased during trials requiring a deceptive as compared to a truthful response. Additionally, we replicated earlier findings that target processing involves enhanced motivated attention toward words requiring a deceptive response (LPC). Moreover, a signature of integration effort and semantic inhibition (N400) was observed to be larger for words to which responses have to be intentionally false as compared to those to which responses must be truthful. Our findings support the view of the involvement of a series of basic cognitive processes (especially attention and cognitive control) when responses are deliberately wrong instead of right. Moreover, preceding cues signaling the subsequent need for lying already elicit attentional and preparatory mechanisms facilitating the cognitive operations necessary for later successful lying.

A revisit to interactions of stimulus quality and semantic context on N400 in visual word recognition.

Much behavioral research has revealed interactive effects between stimulus quality and semantic priming in visual word recognition, practically in favor of the interactive activation model. However, the limited number of event-related brain potential (ERP) studies have yielded inconsistent results considering this interaction's impact on N400 amplitude. The current ERP study aimed to examine whether the joint effects of stimulus quality and semantic priming were specific to the lexical decision task. We used both behavioral measures and ERP recordings to evaluate the joint effects of stimulus degradation (i.e. highly vs. slightly degraded) and semantic priming (i.e. semantically related vs. unrelated) in a lexical decision task involving visual recognition of Chinese characters. The results showed significant degradation-by-priming interactions on response times and N400 amplitude ( P < 0.05), with larger semantic priming effects on slightly degraded targets. These converging behavioral and electrophysiological findings provide evidence in accordance with the interactive activation models of visual word recognition, in which the early-stage visual processing (i.e. degradation) cascades into the later-stage semantic processing (i.e. priming), thus yielding interactions observed in N400 amplitude.

N400 or P600?—A Systematic Review of ERP Studies on Gender Stereotype Violations

ABSTRACTPsycholinguistic studies using the event‐related brain potential (ERP) technique have found both N400 and P600 effects for gender stereotype violations. The finding of a P600 effect for this type of world knowledge violation is surprizing given that this component is traditionally associated with syntactic violations. In this paper, we set out to systematically analyse design‐ and task patterns of ERP studies investigating gender stereotype violations. Based on our review, we propose a scheme that predicts a P600 effect for gender stereotype violations for stimuli comprising entire sentences, and specifically when the gender stereotype serves to establish coherence in inferences (i.e., expecting a specific referent gender or a stereotype‐appropriate behaviour of the sentence subject based on the gender stereotype information). We predict an N400 effect for gender stereotype information that does not serve to establish coherence in inferences, as well as in priming paradigms. By extension, our predictive scheme suggests that the N400 may reflect a hybrid process of semantic retrieval and integration, while the P600 may reflect a cognitive process of error monitoring, and mental revision. Our study can aid in the interpretation of previous findings and inform future studies investigating gender stereotyping.

Domain-specific control for cognitive and emotional conflict: Evidence from the transfer of proportion congruency effects.

There is ongoing debate about whether control-related processing related to cognitive conflict and emotional conflict operate independently. This study manipulated the proportion of congruent to incongruent trials to determine the domain specificity or generality of these two types of conflict control. Two experiments were conducted in which spatial Simon conflict was combined with emotional face-word conflict. In Experiment 1, the proportion congruency (PC) of spatial conflict was manipulated, and in Experiment 2, the PC of emotional conflict was manipulated. The aim was to determine whether control-related processes elicited by cognitive or emotional conflict show domain-specific (within cognitive or within emotional control-related effects) or domain-general effects, where control elicited by cognitive conflict benefits emotional control processes and vice versa. Behavioral findings indicated that spatial and emotional conflict exhibited within-domain PC effects. For event-related brain potential (ERP) activity, PC effects were primarily reflected in a late slow potential, rather than an early negativity, suggesting that control-related adjustments impacted conflict resolution rather than conflict detection. Furthermore, the results did not show evidence of PC effects across domains for behavioral or ERP data, indicating that proactive control elicited by PC manipulation does not transfer across cognitive and emotional conflict. This study supports the modular nature of proactive control for processes related to cognitive and emotional control.

The temporal dynamics of familiar face recognition: Event-related brain potentials reveal the efficient activation of facial identity representations

While it is widely known that humans are typically highly accurate at recognizing familiar faces, it is less clear how efficiently recognition is achieved. In a series of three experiments, we used event-related brain potentials (ERP) in a repetition priming paradigm to examine the efficiency of familiar face recognition. Specifically, we varied the presentation time of the prime stimulus between 500 ms and 33 ms (Experiments 1 and 2), and additionally used backward masks (Experiment 3) to prevent the potential occurrence of visual aftereffects. Crucially, to test for the recognition of facial identity rather than a specific picture, we used different images of the same facial identities in repetition conditions. We observed clear ERP repetition priming effects between 300 and 500 ms after target onset at all prime durations, which suggests that the prime stimulus was sufficiently well processed to allow for facilitated recognition of the target in all conditions. This finding held true even in severely restricted viewing conditions including very brief prime durations and backward masks. We conclude that the facial recognition system is both highly effective and efficient, thus allowing for our impressive ability to recognise the faces that we know.

Functional benefits of continuous vs. categorical listening strategies on the neural encoding and perception of noise-degraded speech

Acoustic information in speech changes continuously, yet listeners form discrete perceptual categories to ease the demands of perception. Being a more continuous/gradient as opposed to a more discrete/categorical listener may be further advantageous for understanding speech in noise by increasing perceptual flexibility and resolving ambiguity. The degree to which a listener’s responses to a continuum of speech sounds are categorical versus continuous can be quantified using visual analog scaling (VAS) during speech labeling tasks. Here, we recorded event-related brain potentials (ERPs) to vowels along an acoustic–phonetic continuum (/u/ to /a/) while listeners categorized phonemes in both clean and noise conditions. Behavior was assessed using standard two alternative forced choice (2AFC) and VAS paradigms to evaluate categorization under task structures that promote discrete vs. continuous hearing, respectively. Behaviorally, identification curves were steeper under 2AFC vs. VAS categorization but were relatively immune to noise, suggesting robust access to abstract, phonetic categories even under signal degradation. Behavioral slopes were correlated with listeners’ QuickSIN scores; shallower slopes corresponded with better speech in noise performance, suggesting a perceptual advantage to noise degraded speech comprehension conferred by a more gradient listening strategy. At the neural level, P2 amplitudes and latencies of the ERPs were modulated by task and noise; VAS responses were larger and showed greater noise-related latency delays than 2AFC responses. More gradient responders had smaller shifts in ERP latency with noise, suggesting their neural encoding of speech was more resilient to noise degradation. Interestingly, source-resolved ERPs showed that more gradient listening was also correlated with stronger neural responses in left superior temporal gyrus. Our results demonstrate that listening strategy modulates the categorical organization of speech and behavioral success, with more continuous/gradient listening being advantageous to sentential speech in noise perception.

Music training is associated with better audio-visual integration in Chinese language

In the present study, we aimed to investigate whether long-term music training could improve audio-visual speech integration in Chinese, using event-related brain potential (ERP) measurements. Specifically, we recruited musicians and non-musicians to participate in our experiment where visual Chinese characters were presented simultaneously with congruent or incongruent speech sounds. In order to maintain participants' focus on both auditory and visual modalities, they were instructed to perform a probe detection task. Our study revealed that for the musicians, audiovisual incongruent stimuli elicited larger N1 and N400 amplitudes compared to audiovisual congruent stimuli. Conversely, for the non-musicians, only a larger N400 amplitude was observed for incongruent stimuli relative to congruent stimuli, without a significant difference in N1 amplitude. Furthermore, correlation analyses indicated that more years of music training was associated with a larger N1 effect for the musicians. These results suggest that musicians were capable of detecting character-speech sound incongruence at an earlier time window compared to non-musicians. Overall, our findings provide compelling evidence that music training is associated with better integration of visual characters and auditory speech sounds in language processing.

Conflict Detection in Language Processing: Using Affect Control Theory to Predict Neural Correlates of Affective Incongruency in Social Interactions

Affect control theory (ACT) is a sociological theory of meaning processing in social interactions. Meaning, according to ACT, derives from cultural institutions and situational affordances, having denotative (declarative) as well as connotative (affective) properties. Mathematical formalizations of ACT allow predictions of affective incongruency (in the terminology of ACT, deflection), which arises from conflicting institutional and situational meanings in a given interaction context. Although ACT is theoretically consistent, its propositions regarding cognitive and affective processing have rarely been tested. The present study fills this gap by investigating the neural processing of affective incongruency in linguistic descriptions of social interactions. Following a neurosociological paradigm, the study draws on neurocognitive evidence on the effects of words’ affective content on word processing as well as on a previous electroencephalography study that investigated processing of affective incongruency using event-related brain potentials. We hypothesized that affective incongruency is associated with activation in the anterior cingulate cortex (ACC), a brain area known for conflict processing. To test this hypothesis, we replicated the electroencephalography study using functional magnetic resonance imaging: We visually presented sentences describing social interactions to 23 participants in a silent reading task while measuring differences in the hemodynamic response in two conditions of affective congruency. Results show expected increases in neural activity for affectively incongruent sentences in the left ACC, supporting the assumption that affective language content influences meaning-making at very early semantic processing stages. The results also add to the emerging neuroscientific evidence for ACT’s mathematical model of impression formation.

Neural evidence of core foundations and conceptual change in preschool numeracy.

Symbolic numeracy first emerges as children learn the meanings of number words and how to use them to precisely count sets of objects. This development starts before children enter school and forms a foundation for lifelong mathematics achievement. Despite its importance, exactly how children acquire this basic knowledge is unclear. Here we test competing theories of early number learning by measuring event-related brain potentials during a novel number word-quantity comparison task in 3-4-year-old preschool children (N=128). We find several qualitative differences in neural processing of number by conceptual stage of development. Specifically, we find differences in early attention-related parietal electrophysiology (N1), suggesting that less conceptually advanced children process arrays as individual objects and more advanced children distribute attention over the entire set. Subsequently, we find that only more conceptually advanced children show later-going frontal (N2) sensitivity to the numerical-distance relationship between the number word and visual quantity. The nature of this response suggested thatexact rather than approximate numerical meanings were being associated with number words over frontal sites. No evidence of numerical distance effects was observed over posterior scalp sites. Together these results suggest that children may engage parallel individuation of objects to learn the meanings of the first few number words, but, ultimately, create new exact cardinal value representations for number words that cannot be defined in terms of core, nonverbal number systems. More broadly, these results document an interaction between attentional and general cognitive mechanisms in cognitive development. RESEARCH HIGHLIGHTS: Conceptual development in numeracy is associated with a shift in attention from objects to sets. Children acquire meanings of the first few number words through associations with parallel attentional individuation of objects. Understanding of cardinality is associated with attentional processing of sets rather than individuals. Brain signatures suggest children attribute exact rather than approximate numerical meanings to the first few number words. Number-quantity relationship processing for the first few number words is evident in frontal but not parietal scalp electrophysiology of young children.

Unravelling the origin of the reward positivity: a human intracranial event-related brain potential study.

The reward positivity (RewP) is an event-related brain potential (ERP) component that emerges approximately 250 to 350 milliseconds (ms) after receiving reward-related feedback stimuli and is believed to be important for reinforcement learning and reward processing. Although numerous localization studies have indicated that the anterior cingulate cortex (ACC) is the neural generator of this component, other studies have identified sources outside of the ACC, fuelling a debate about its origin. Because the results of EEG and MEG source localization studies are severely limited by the inverse problem, we addressed this question by leveraging the high spatial and temporal resolution of intracranial EEG. We predicted that we would identify a neural generator of the RewP in the caudal ACC. We recorded intracranial EEG in 19 refractory epilepsy patients who underwent invasive video-EEG monitoring at Ghent University Hospital, Belgium. Participants engaged in the virtual T-maze task (vTMT), a trial-and-error task known to elicit a canonical RewP, while scalp and intracranial EEG were simultaneously recorded. The RewP was identified using a difference wave approach for both scalp and intracranial EEG. The data were aggregated across participants to create a virtual "meta-participant" that contained all the recorded intracranial ERPs (iERPs) with respect to their intracranial contact locations. We used both a hypothesis-driven (focused on ACC) and exploratory (whole-brain analysis) approach to segment the brain into regions of interest (ROI). For each ROI, we evaluated the degree to which the time course of the absolute current density (ACD) activity mirrored the time course of the RewP, and confirmed the statistical significance of the results using permutation analysis. The grand average waveform of the scalp data revealed a RewP at 309 ms after reward feedback with a frontocentral scalp distribution, consistent with the identification of this component as the RewP. The meta-participant contained iERPs recorded from 582 intracranial contacts in total. The ACD activity of the aggregated iERPs were most similar to the RewP in left caudal ACC, left dorsolateral prefrontal cortex, left frontomedial cortex, and left white matter, with the highest score attributed to caudal ACC, as predicted. To our knowledge, this is the first study that uses intracranial EEG aggregated across multiple human epilepsy patients and current source density analysis to identify the neural generator(s) of the RewP. These results provide direct evidence that the ACC is a neural generator of the RewP.

Lower frequency range of auditory input facilitates stream segregation in older adults

The current study investigated the effect of lower frequency input on stream segregation acuity in older, normal hearing adults. Using event-related brain potentials (ERPs) and perceptual performance measures, we previously showed that stream segregation abilities were less proficient in older compared to younger adults. However, in that study we used frequency ranges greater than 1500 Hz. In the current study, we lowered the target frequency range below 1500 Hz and found similar stream segregation abilities in younger and older adults. These results indicate that the perception of complex auditory scenes is influenced by the spectral content of the auditory input and suggest that lower frequency ranges of input in older adults may facilitate listening ability in complex auditory environments. These results also have implications for the advancement of prosthetic devices.

“Beyond the literal meaning” processing implied emotion in second language discourse: an ERP study

ABSTRACT Emotion is processed incrementally during sentence comprehension in a first language (L1) due to unification operations. Since processing multiple types of information is cognitively more demanding in a second language (L2), we investigated implied emotion processing in L1 and L2 using event-related brain potentials. We presented native Spanish speakers with sentences whose context rendered neutral words either negative-congruent, neutral-congruent or neutral-incongruent in Spanish (L1) and English (L2). Results showed differences in early emotion processing across languages: a larger N100 for neutral than negative sentences in L1 and a more positive P300 for negative than neutral sentences in L2. Effects in the N400 and LPP time windows were not language dependent. An N400 semantic incongruity effect was present in both languages. A gradual LPP effect was larger for negative than incongruent sentences in both languages, with neutral sentences in between. Results indicate early time-window differences in implied emotion processing across languages.

Integrating dynamic psychophysiological indices across time and contexts: Elucidating mechanisms, risk markers, and intervention targets.

Why should researchers measure psychophysiological processes repeatedly over time? The study of psychophysiology inherently involves sampling biological processes as they manifest over time. The most common approach is to use a brief sample to make conclusions about how individuals or groups differ. Although these types of between-subject comparisons have utility for understanding individual and group differences, many of the important conceptual questions in the field involve processes that are dynamic, varying within individuals over time. Using examples from the literature on affect regulation, this conceptual review contrasts three types of study designs: the classic single-observation design and the aggregated and temporally linked repeated observation designs, which have great promise for measuring variables that fluctuate dynamically over time. Importantly, these designs can be integrated to elucidate research questions about risk (when and for whom will the likelihood of an unwanted outcome occurring increase?), mechanisms (how and why does a change in psychophysiology contribute to a change in another process of interest?), and interventions (how and when should interventions take place to modify an outcome?). Researchers are encouraged to implement intensive sampling in their research, which can be conducted in traditional laboratory settings (e.g., fMRI, event-related brain potentials, and heart rate variability) and in ecologically valid contexts in everyday life using ambulatory assessment.

Mismatch negativity between discriminating and undiscriminating participants on the front-back sound localization

Sound localization in the front-back dimension is reported to be challenging, with individual differences. We investigated whether auditory discrimination processing in the brain differs based on front-back sound localization ability. This study conducted an auditory oddball task using speakers in front of and behind the participants. We used event-related brain potentials to examine the deviance detection process between groups that could and could not discriminate front-back sound localization. The results indicated that mismatch negativity (MMN) occurred during the deviance detection process, and P2 amplitude differed between standard and deviant locations in both groups. However, the latency of MMN was shorter in the group that could discriminate front-back sounds than in the group that could not. Additionally, N1 amplitude increased for deviant locations compared to standard ones only in the discriminating group. In conclusion, the sensory memories matching process based on traces of previously presented stimuli (MMN, P2) occurred regardless of discrimination ability. However, the response to changes in the physical properties of sounds (MMN latency, N1 amplitude) differed depending on the ability to discriminate front-back sounds. Our findings suggest that the brain may have different processing strategies for the two directions even without subjective recognition of the front-back direction of incoming sounds.

Automatic processing of unattended mean emotion: Evidence from visual mismatch responses

The mean emotion from multiple facial expressions can be extracted rapidly and precisely. However, it remains debated whether mean emotion processing is automatic which can occur under no attention. To address this question, we used a passive oddball paradigm and recorded event-related brain potentials when participants discriminated the changes in the central fixation while a set of four faces was presented in the periphery. The face set consisted of one happy and three angry expressions (mean negative) or one angry and three happy expressions (mean positive), and the mean negative and mean positive face sets were shown with a probability of 20% (deviant) and 80% (standard) respectively in the sequence, or the vice versa. The cluster-based permutation analyses showed that the visual mismatch negativity started early at around 92 ms and was also observed in later time windows when the mean emotion was negative, while a mismatch positivity was observed at around 168- 266 ms when the mean emotion was positive. The results suggest that there might be different mechanisms underlying the processing of mean negative and mean positive emotions. More importantly, the brain can detect the changes in the mean emotion automatically, and ensemble coding for multiple facial expressions can occur in an automatic fashion without attention.

You're Beautiful When You Smile: Event-Related Brain Potential (ERP) Evidence of Early Opposite-Gender Bias in Happy Faces.

Studies of social cognition have shown gender differences regarding human face processing. One interesting finding is the enhanced processing of opposite-gender faces at different time stages, as revealed by event-related brain potentials. Crucially, from an evolutionary perspective, such a bias might interact with the emotional expression of the face. To investigate this, 100 participants (50 female, 50 male) completed an expression-detection task while their EEG was recorded. In three blocks, fearful, happy and neutral faces (female and male) were randomly presented, with participants instructed to respond to only one predefined target expression level in each block. Using linear mixed models, we observed both faster reaction times as well as larger P1 and late positive potential (LPP) amplitudes for women compared to men, supporting a generally greater female interest in faces. Highly interestingly, the analysis revealed an opposite-gender bias at P1 for happy target faces. This suggests that participants' attentional templates may include more opposite-gender facial features when selectively attending to happy faces. While N170 was influenced by neither the face nor the participant gender, LPP was modulated by the face gender and specific combinations of the target status, face gender and expression, which is interpreted in the context of gender-emotion stereotypes. Future research should further investigate this expression and attention dependency of early opposite-gender biases.