Modulation of face processing by top-down attention: Insights from early ERP waveforms.

The face fusiform area (FFA) plays a pivotal role in face recognition, yet the precise timeline of its activity remains debated. Using EEG, we conducted three experiments to investigate how expectancy-consistent versus expectancy-inconsistent visual stimuli influence processing dynamics. Participants viewed images of faces, houses, and tools (Experiment 1), celebrity faces (Experiment 2), or animal faces (Experiment 3), preceded by a priming question. Notably, both conditions presented identical visual stimulation, ensuring that observed differences stemmed from cognitive processing rather than sensory input. Our results from Experiments 2 and 3 reveal that while the initial 150 ms period, crucial for unconscious face detection, remained unaffected, subsequent processing exhibited a delay of several milliseconds for expectancy-inconsistent stimuli, indicating additional processing time required for unexpected recognition. Importantly, no significant differences were observed in Experiment 1, where less demanding tasks or generic mental imagery were used, suggesting that the priming effect was not as pronounced in this context. These findings underscore the critical role of the period immediately following the first 150 ms in face identification and individuation, highlighting the influence of top-down attention on face recognition dynamics. This study provides novel insights into the temporal dynamics of face processing and the neural mechanisms underlying top-down attentional modulation.

EEG correlates of static and dynamic face perception: the role of naturalistic motion.

Much of our understanding of how the brain processes dynamic faces comes from research that compares static photographs to dynamic morphs, which exhibit simplified, computer-generated motion. By comparing static, video recorded, and dynamic morphed expressions, we aim to identify the neural correlates of naturalistic facial dynamism, using time-domain and time-frequency analysis. Dynamic morphs were made from the neutral and peak frames of video recorded transitions of happy and fearful expressions, which retained expression change and removed asynchronous and non-linear features of naturalistic facial motion. We found that dynamic morphs elicited increased N400 amplitudes and lower LPP amplitudes compared to other stimulus types. Video recordings elicited higher LPP amplitudes and greater frontal delta activity compared to other stimuli. Thematic analysis of participant interviews using a large language model revealed that participants found it difficult to assess the genuineness of morphed expressions, and easier to analyse the genuineness of happy compared to fearful expressions. Our findings suggest that animating real faces with artificial motion may violate expectations (N400) and reduce the social salience (LPP) of dynamic morphs. Results also suggest that delta oscillations in the frontal region may be involved with the perception of naturalistic facial motion in happy and fearful expressions. Overall, our findings highlight the sensitivity of neural mechanisms required for face perception to subtle changes in facial motion characteristics, which has important implications for neuroimaging research using faces with simplified motion.

The neuronal signature of surprised facial expression processing under different attentional focuses: A time-domain and time-frequency study.

Previous studies have shown that high-arousal positive and negative facial expressions influence event-related potential (ERP) and time-frequency responses depending on attentional focuses. However, little is known about how relevant neural responses are influenced by surprised facial expressions, which are also high in arousal but ambiguous in valence. To address the issue, 38 participants were presented with surprised, happy, angry and neutral facial expressions. Attention was manipulated to focus on facial emotional attributes, facial non-emotional attributes, non-facial attributes, or was free to the participants. ERP results showed larger N170 responses to surprised compared to neutral facial expressions when attention focused on facial attributes and to surprised compared to angry and neutral facial expressions when attention focused on facial non-emotional attributes. Time-frequency analyses revealed reduced power of early occipital theta to surprised compared to happy and angry expressions when attention focused on facial emotions and to surprised compared to angry expressions when attention focused on non-facial stimuli. Parietal delta power was smaller for surprised facial expressions than for angry facial expressions when attention focused on facial emotions and for surprised facial expressions than for angry and neutral facial expressions when attention was directed to non-facial stimuli. These findings might suggest that neural responses to surprised facial expressions are modulated by attentional focus.

The left-lateralized N170 for visual specialization in advanced L2 Chinese learners.

Visual word recognition is crucial for improving reading skills in second language learners (L2Ls). It is unclear whether L2Ls who are native speakers of languages that use alphabetic scripts can recognize Chinese characters at an early stage of visual processing and if their visual specialization can reach a level of word recognition comparable to that of native Chinese speakers. This study aims to uncover the visual specialization mechanism of Chinese L2Ls. A delayed-color matching task was carried out with participants who were Chinese first language speakers (L1Ss) and advanced Chinese L2Ls with Indonesian as their first language. The results of the event-related potentials (ERPs) indicated that L2Ls exhibited significant visual specialization with a predominant distribution of the left-lateralized N170, along with some activation in the right hemisphere. These findings suggest that the early processing stage of Chinese characters by advanced L2Ls is similar to that of adult native speakers, although it is still influenced by their first language and its writing system.

Predictability modulates the early neural coding of spatially unattended fearful faces.

In this study, we assessed whether predictability affected the early processing of facial expressions. To achieve this, we measured lateralised early- and mid-latency event-related potentials associated with visual processing. Twenty-two participants were shown pairs of bilaterally presented fearful, happy, angry, or scrambled faces. Participants were required to identify angry faces on a spatially attended side whilst ignoring happy, fearful, and scrambled faces. Each block began with the word HAPPY or FEARFUL which informed participants the probability at which these faces would appear. Attention effects were found for the lateralised P1, suggesting that emotions do not modulate the P1 differentially, nor do predictions relating to emotions. Pairwise comparisons demonstrated that, when spatially unattended, unpredicted fearful faces produced larger lateralised N170 amplitudes compared to predicted fearful faces and unpredicted happy faces. Finally, attention towards faces increased lateralised EPN amplitudes, as did both fearful expressions and low predictability. Thus, we demonstrate that the N170 and EPN are sensitive to top-down predictions relating to facial expressions and that low predictability appears to specifically affect the early encoding of fearful faces when unattended, possibly to initiate attentional capture.

Emotional text messages affect the early processing of emoticons depending on their emotional congruence: evidence from the N170 and EPN event related potentials.

Emoticons have been considered pragmatic cues that enhance emotional expressivity during computer-mediated communication. Yet, it is unclear how emoticons are processed in ambiguous text-based communication due to incongruences between the emoticon's emotional valence and its context. In this study, we investigated the electrophysiological correlates of contextual influence on the early emotional processing of emoticons, during an emotional congruence judgment task. Participants were instructed to judge the congruence between a text message expressing an emotional situation (positive or negative), and a subsequent emoticon expressing positive or negative emotions. We analyzed early event-related potentials elicited by emoticons related to face processing (N170) and emotional salience in visual perception processing (Early Posterior Negativity, EPN). Our results show that accuracy and Reaction Times depend on the interaction between the emotional valence of the context and the emoticon. Negative emoticons elicited a larger N170, suggesting that the emotional information of the emoticon is integrated at the early stages of the perceptual process. During emoticon processing, a valence effect was observed with enhanced EPN amplitudes in occipital areas for emoticons representing negative valences. Moreover, we observed a congruence effect in parieto-temporal sites within the same time-window, with larger amplitudes for the congruent condition. We conclude that, similar to face processing, emoticons are processed differently according to their emotional content and the context in which they are embedded. A congruent context might enhance the emotional salience of the emoticon (and therefore, its emotional expression) during the early stages of their processing.

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.

Social anxiety modulating early processing for social threat words: an ERP study.

Even though some recent research revealed individuals with HSA typically display enhanced processing in the early stages of emotional information processing due to hypervigilance and vulnerability to negative stimuli, it is still unclear whether social anxiety affects the time course underlying processing bias for emotional stimuli. Therefore, the present study aimed to explore the early stage of processing social threat stimuli in high social anxiety (HSA) individuals by recording RTs and EEG data in the emotional Stroop task. Behavioral data showed that the HSA group responded to the threat words faster than neutral words (i.e. negative bias), but no emotional effects in the low social anxiety (LSA) group. Although the P1 component did not show any early effects, ERP data exhibited an enhanced N170 for HSA than for LSA groups. Threat words elicited larger N170 than neutral words in the LSA group only; this emotion effect was not evident in the HSA group. These findings indicated that social anxiety modulates early processing for social threat words. This study revealed the neural mechanisms underlying early emotional processing in individuals with social anxiety, providing insights for the evaluation and intervention of social anxiety.

EEG responses to infant faces in young adults can be influenced by the quality of early care experiences with caregivers.

BACKGROUND: The quality of early experiences with caregivers affects individual adjustment and can modulate adults' responses to salient social stimuli, like infant faces. However, in the framework of Interpersonal Acceptance-Rejection Theory (IPARTheory), no research to date has examined whether early experiences of acceptance or rejection from caregivers are associated with individual differences in the electrophysiological (EEG) responses to infant faces. OBJECTIVE: This study examined the associations between the perceived quality of care during childhood and the behavioral and EEG responses to infant and adult faces in non-parent young adults. METHODS: N = 60 non-parent young adults (30 males; 30 females) completed an Emotion Recognition task displaying emotional and unemotional infant and adult faces during an EEG recording. Memories of past care experiences with mothers and fathers were collected using the short form version of the Parental Acceptance-Rejection scale. RESULTS: At the behavioral level, slower Reaction Times (RTs) in recognizing all faces were related to higher levels of perceived maternal rejection in young adults; in particular, males who reported higher levels of maternal rejection displayed longer RTs in recognizing faces compared to females. At the neurophysiological level, as the level of perceived paternal rejection increased, the N170 amplitude to infant faces increased. Females who reported higher levels of paternal rejection, compared to males, had a larger increase in the N170 amplitude and a larger decrease in the LPP amplitude in response to emotional faces. CONCLUSIONS: While a higher perception of maternal rejection hindered the behavioral responses of adults in recognizing faces, those who felt more rejected by their own father during childhood showed an enhanced N170 amplitude to infant faces. This might reflect a greater need for discrimination resources, at a very early stage of infant face processing, in those adults who perceived higher levels of paternal rejection. Adults' sex modulated the associations found at the behavioral and neurophysiological levels. Overall, our findings extended the IPARTheory postulates that being neglected during childhood might trigger perceptual changes in adults, hindering the elaboration of social cues like infant and adult faces at different levels.

Reduced early neural processing of faces in children and adolescents with social anxiety disorder.

Social anxiety disorder (SAD) is one of the most common mental disorders during childhood and adolescence. Yet, little is known about its maintenance in youth. Cognitive models of SAD indicate that attentional biases play a key role in the dysfunctional processing of social information, such as emotional faces. However, previous research investigating neural correlates of childhood SAD has produced inconsistent findings. The current study aims to investigate neural face processing in children and adolescents with SAD, while taking into consideration methodological limitations of previous studies. We measured event-related potentials (P100, N170, EPN, LPP) in response to happy, neutral, and angry adult faces, and non-social household objects, in a sample of youth (aged 10-15 years) with SAD (n = 57), clinical controls with specific phobias (SP; n = 41), and healthy controls (HC; n = 61). Participants completed an emotion/object identification task while continuous EEG was recorded. Analyses revealed lower N170 amplitudes in the SAD group compared to HCs, irrespective of emotion. In addition, younger children (aged 10-12 years) with SAD showed lower EPN amplitudes and higher early LPP amplitudes (only trend level) in response to neutral and happy faces compared to younger HCs. These effects were specific to faces and were not evident in the neural processing of non-social household objects. Overall, the findings indicate that different neural response patterns are already present in youth with SAD. Group differences, particularly in younger children, suggest age-related differences in neural face processing in childhood SAD and underpin the necessity of developmental approaches.

Electrophysiological evidence of lexical processing impacted by foreign language reading anxiety.

Extensive studies have been conducted on the impact of foreign language reading anxiety on reading, primarily focusing on pedagogy and behavior but lacking electrophysiological evidence. The current study aimed to investigate the influence of foreign language reading anxiety on reading and its underlying mechanisms. The results revealed a negative correlation between foreign language reading anxiety and foreign language reading performance, irrespective of the native language. Adults with low levels of foreign language reading anxiety (LFLRA) demonstrated a significant difference in early lexical component N170 amplitude between foreign and native languages. However, this effect was not observed in adults with high levels of foreign language reading anxiety (HFLRA). In terms of N170 latency, HFLRA showed a longer N170 for the foreign language compared to the native language. Furthermore, the N170 effects were predominantly localized over the left occipitotemporal electrodes. Regarding N400 latency, a significant difference was found in LFLRA individuals between foreign and native language processing, while HFLRA individuals did not exhibit this difference. These findings suggest that HFLRA individuals experience inefficient lexical processing (such as orthography or semantics) during reading in foreign language.

Attention modulates facial expression processing in subsyndromal depression: A behavioral and ERP study.

Impaired facial expression perception is a core element in depression, but the underlying mechanism remains controversial. This event-related potential study investigated how attention modulates facial expression perception in depression using a nonclinical sample. A group of healthy controls (HC, N = 39) and a group of individuals with subsyndromal depression (SD, N = 39) categorized faces based on either facial expression (happy vs. sad) or gender (male vs. female). Behaviorally, the SD group was less sensitive to the emotional valence of facial expression than the HC group when their attention was directed to facial expression, as revealed by comparable subjective ratings and accuracy rates in response to facial expressions. When attention was directed towards facial gender, the SD group versus the HC group showed a negative bias, as revealed by a faster N170 for sad faces than happy faces. Together, our findings suggest that attention plays a role in understanding the relationship between depression and facial expression perception.

Intervention Effect of Group Sensory Integration Training on Social Responsiveness and N170 Event-Related Potential of Children with Autism.

The objective of this study was to examine the intervention effect of group sensory integration training on social responsiveness, and the latency and amplitude of N170 event-related potential of children with autism. The social responsiveness scale was employed to assess alterations in the social response of individuals with ASD before and after training, while event-related potentials were utilized to measure changes in N170 latency and amplitude. This study revealed that group sensory integration training can significantly enhance social responsiveness in children diagnosed with ASD. Children with ASD exhibit atypical N170 responses to faces in the right parietal region. The latency of N170 changes may serve as a valuable indicator for assessing the effectiveness of an intervention or diagnosing ASD.

Impaired social reward processing in individuals with Internet gaming disorder and its relationship with early face perception.

Previous research has found that individuals with Internet gaming disorder (IGD) show different patterns of social function impairments in game-related and real-life social contexts. Impaired social reward processing may be the underlying mechanism according to the Social Motivation Theory. Thus, in this study, event-related potentials were recorded from 24 individuals with IGD and 24 healthy gamers during a social judgement task. We focused on reward positivity (RewP) elicited by game-related and real-life social rewards, and N170 elicited by game avatar faces and real faces. These indicators were used to explore the neurocognitive mechanism of impaired social reward processing in individuals with IGD and its relationship with early face perception. Results showed that (1) the RewP elicited by real-life social reward was considerably reduced in individuals with IGD relative to healthy gamers. (2) The N170 elicited by game avatar faces in individuals with IGD was larger than that elicited by real faces. However, the N170 was not associated with RewP in either group. (3) The score for IGD severity was correlated with the RewP elicited by real-life social reward and the N170 elicited by game avatar face. In conclusion, the present study suggests that the impaired social reward processing in individuals with IGD is mainly manifested in a decreased neural sensitivity to real-life social reward. Meanwhile, the reduced RewP elicited by real-life social reward and the enhanced N170 elicited by game avatar face might serve as potential biomarkers for IGD.

Music literacy improves reading skills via bilateral orthographic development.

Considerable evidence suggests that musical education induces structural and functional neuroplasticity in the brain. This study aimed to explore the potential impact of such changes on word-reading proficiency. We investigated whether musical training promotes the development of uncharted orthographic regions in the right hemisphere leading to better reading abilities. A total of 60 healthy, right-handed culturally matched professional musicians and controls took part in this research. They were categorised as normo-typical readers based on their reading speed (syl/sec) and subdivided into two groups of relatively good and poor readers. High density EEG/ERPs were recorded while participants engaged in a note or letter detection task. Musicians were more fluent in word, non-word and text reading tests, and faster in detecting both notes and words. They also exhibited greater N170 and P300 responses, and target-non target differences for words than controls. Similarly, good readers showed larger N170 and P300 responses than poor readers. Increased reading skills were associated to a bilateral activation of the occipito/temporal cortex, during music and word reading. Source reconstruction also showed a reduced activation of the left fusiform gyrus, and of areas devoted to attentional/ocular shifting in poor vs. good readers, and in controls vs. musicians. Data suggest that music literacy acquired early in time can shape reading circuits by promoting the specialization of a right-sided reading area, whose activity was here associated with enhanced reading proficiency. In conclusion, music literacy induces measurable neuroplastic changes in the left and right OT cortex responsible for improved word reading ability.

Reduced pre-attentive threat versus nonthreat signal discrimination in clinically healthy military personnel with recurrent combat exposure history: A preliminary event-related potential (ERP) study.

Evidence now suggests that traumatic-stress impacts brain functions even in the absence of acute-onset post-traumatic stress disorder (PTSD) symptoms. These neurophysiological changes have also been suggested to account for increased risks of PTSD symptoms later developing in the aftermath of subsequent trauma. However, surprisingly few studies have explicitly examined brain function dynamics in high-risk populations, such as combat exposed military personnel without diagnosable PTSD. To extend available research, facial expression sensitive N170 event-related potential (ERP) amplitudes were examined in a clinically healthy sample of active service military personnel with recurrent combat exposure history. Consistent with several established theories of delayed-onset PTSD vulnerability, higher N170 amplitudes to backward-masked fearful and neutral facial expressions correlated with higher levels of past combat exposure. Significantly elevated amplitudes to nonthreatening neutral facial expressions also resulted in an absence of normal threat-versus-nonthreat signal processing specificity. While a modest sample size and cross-sectional design are key limitations here, ongoing prospective-longitudinal follow-ups may shed further light on the precise aetiology and prognostic utility of these preliminary findings in the near future.

An ERP Study of Face Processing in Schizophrenia, Bipolar Disorder, and Socially Isolated Individuals from the Community.

People with schizophrenia (SCZ) and bipolar disorder (BD) have impairments in processing social information, including faces. The neural correlates of face processing are widely studied with the N170 ERP component. However, it is unclear whether N170 deficits reflect neural abnormalities associated with these clinical conditions or differences in social environments. The goal of this study was to determine whether N170 deficits would still be present in SCZ and BD when compared with socially isolated community members. Participants included 66 people with SCZ, 37 with BD, and 125 community members (76 "Community-Isolated"; 49 "Community-Connected"). Electroencephalography was recorded during a face processing task in which participants identified the gender of a face, the emotion of a face (angry, happy, neutral), or the number of stories in a building. We examined group differences in the N170 face effect (greater amplitudes for faces vs buildings) and the N170 emotion effect (greater amplitudes for emotional vs neutral expressions). Groups significantly differed in levels of social isolation (Community-Isolated > SCZ > BD = Community-Connected). SCZ participants had significantly reduced N170 amplitudes to faces compared with both community groups, which did not differ from each other. The BD group was intermediate and did not differ from any group. There were no significant group differences in the processing of specific emotional facial expressions. The N170 is abnormal in SCZ even when compared to socially isolated community members. Hence, the N170 seems to reflect a social processing impairment in SCZ that is separate from level of social isolation.

Meanness and affective processing: A meta-analysis of EEG findings on emotional face processing in individuals with psychopathic traits.

BACKGROUND: The triarchic model (Patrick et al., 2009) conceptualizes psychopathy as a multidimensional construct encompassing three biobehavioral dimensions: meanness, boldness, and disinhibition. Meanness entails low empathy, shallow affect, and lack of remorse, and is associated with poor facial emotion recognition; however, the mechanistic processes contributing to these deficits are unclear. Emotional face processing can be examined on a neurophysiological level using event-related potentials (ERPs) such as N170, P200, and LPP. No quantitative review to date has examined the extent to which amplitude of these ERP components may be modulated by psychopathic traits. METHOD: The current study performed random-effects model meta-analyses of nine studies (N = 1131) which examined affective face processing ERPs in individuals with psychopathic traits to provide an overall effect size for the association between meanness, boldness, and disinhibition and N170, P200, and LPP amplitudes across studies. Analyses were also conducted examining potential moderators and publication bias. RESULTS: N170 amplitudes were significantly smaller (r =.18) among individuals high in meanness when processing fearful faces. Significant effects were not found for N170 amplitude when processing angry or happy faces, nor for LPP and P200 amplitudes across stimulus types. Additionally, significant effects were not found for the association between N170 amplitude and other dimensions of psychopathy. Meta-regression analyses indicated the manipulation of facial stimuli was significant in explaining some between-study heterogeneity of the meanness N170-fear model. No evidence of publication bias was found. CONCLUSIONS: Diminished amplitude of the N170 when viewing fear faces appears to be a neurophysiological marker of psychopathic meanness. Deficits in early encoding of faces may account for empathy deficits characteristic of psychopathy.

Looming Angry Faces: Preliminary Evidence of Differential Electrophysiological Dynamics for Filtered Stimuli via Low and High Spatial Frequencies.

Looming motion interacts with threatening emotional cues in the initial stages of visual processing. However, the underlying neural networks are unclear. The current study investigated if the interactive effect of threat elicited by angry and looming faces is favoured by rapid, magnocellular neural pathways and if exogenous or endogenous attention influences such processing. Here, EEG/ERP techniques were used to explore the early ERP responses to moving emotional faces filtered for high spatial frequencies (HSF) and low spatial frequencies (LSF). Experiment 1 applied a passive-viewing paradigm, presenting filtered angry and neutral faces in static, approaching, or receding motions on a depth-cued background. In the second experiment, broadband faces (BSF) were included, and endogenous attention was directed to the expression of faces. Our main results showed that regardless of attentional control, P1 was enhanced by BSF angry faces, but neither HSF nor LSF faces drove the effect of facial expressions. Such findings indicate that looming motion and threatening expressions are integrated rapidly at the P1 level but that this processing relies neither on LSF nor on HSF information in isolation. The N170 was enhanced for BSF angry faces regardless of attention but was enhanced for LSF angry faces during passive viewing. These results suggest the involvement of a neural pathway reliant on LSF information at the N170 level. Taken together with previous reports from the literature, this may indicate the involvement of multiple parallel neural pathways during early visual processing of approaching emotional faces.

Age-related similarities and differences in cognitive and neural processing revealed by task-related microstate analysis.

We explored neural processing differences associated with aging across four cognitive functions. In addition to ERP analysis, we included task-related microstate analyses, which identified stable states of neural activity across the scalp over time, to explore whole-head neural activation differences. Younger and older adults (YA, OA) completed face perception (N170), word-pair judgment (N400), visual oddball (P3), and flanker (ERN) tasks. Age-related effects differed across tasks. Despite age-related delayed latencies, N170 ERP and microstate analyses indicated no age-related differences in amplitudes or microstates. However, age-related condition differences were found for P3 and N00 amplitudes and scalp topographies: smaller condition differences were found for in OAs as well as broader centroparietal scalp distributions. Age group comparisons for the ERN revealed similar focal frontocentral activation loci, but differential activation patterns. Our findings of differential age effects across tasks are most consistent with the STAC-r framework which proposes that age-related effects differ depending on the resources available and the kinds of processing and cognitive load required of various tasks.