Visual verbal working memory processing may be interfered by previously seen faces.

Processing and maintenance in working memory involve active attention allocation; consequently, it is possible that a recognition process could interfere with the performance of highly demanding working memory tasks. Event-related brain potentials (ERPs) were recorded while fourteen healthy male adults performed a visual verbal dual working memory task. Three conditions were examined: A) reference (with no preceding stimuli); B) happy, angry or neutral faces presented 250 ms prior to task onset for 30 ms; and, C) visual noise control condition. Behavioral results showed that reaction times were significantly longer in the condition preceded by the presentation of faces, regardless of their emotional content. ERPs showed a predominantly right temporo-occipital negative component at around 170 ms during conditions B and C (higher amplitude in B), which probably reflects the pre-categorical structural encoding of the face. Succeeding task-onset, an early positive right temporo-parietal component (P380) appeared during condition B, probably reflecting a delayed reallocation of working memory attentional resources to carry out the task requirements. Afterwards, two other main fronto-parietal components were observed in the three conditions: a positive wave that peaked at around 410 ms, and a subsequent negative component (N585). This latter waveform reached a significantly higher amplitude during the reference condition (A) and was interpreted as mirroring the phonologic-lexical manipulation of the stimuli in working memory. These results suggest that early face detection could induce an attentional decrement that interfere a subsequent visual verbal working memory task performance. They also suggest that while face detection and facial emotional content analysis might be parallel processes, they are not onset-synchronized.     

Attention modulates emotional expression processing

To investigate the time course of emotional expression processing, we recorded ERPs to facial stimuli. The first task was to discriminate emotional expressions. Enhanced negativity of the face-specific N170 was elicited by emotional as opposed to neutral faces, followed by the occipital negativity (240-340 ms poststimulus). The second task was to classify face gender. Here, N170 was unaffected by the emotional expression. However, emotional expression effect was expressed in the anterior positivity (160-250 ms poststimulus) and subsequent occipital negativity (240-340 ms poststimulus). Results support the thesis that structural encoding relevant to gender recognition and simultaneous expression analysis are independent processes. Attention modulates facial emotion processing 140-185 ms poststimulus. Involuntary differentiation of facial expression was observed later (160-340 ms poststimulus), suggesting unintentional attention capture.     

Differential modulations of reward expectation on implicit facial emotion processing: ERP evidence

Implicit emotional processing refers to the preferential processing of emotional content even if it is task irrelevant. Given that motivation enhances executive control by biasing attentional resources toward target stimuli, here we investigated the effects of reward expectation on implicit facial emotional processing in two experiments using ERPs. A precue signaling additional monetary reward for fast and accurate response for the upcoming trial (incentive condition; relative to a cue indicating no such additional reward, i.e., nonincentive condition) was followed by the presentation of a happy, angry, or neutral face. Participants had to determine the gender of the face in Experiment 1 and decide whether a number superimposed on the face was even or odd in Experiment 2. In both experiments, incentive cues elicited larger P3 and contingent negative variation responses, and the targets following incentive cues elicited more positive‐going ERPs (200–700 ms), compared with the nonincentive condition. Importantly, the N2 responses (200–280 ms) to the target exhibited differential patterns of Reward × Emotion interaction: relative to the nonincentive condition, the N2 amplitude differences between emotional (i.e., happy and/or angry) and neutral faces increased in the incentive condition in Experiment 1, but diminished in Experiment 2. These results indicate that reward expectation can differentially modulate implicit processing of facial expressions, with increased sensitivity to emotions when the processing of whole faces is required, but with reduced sensitivity when the processing of faces is distractive. This study enriches the evidence for interactions between reward‐related executive control and implicit emotional processing.     

The impact of the stimulus features and task instructions on facial processing in social anxiety: An ERP investigation

Social anxiety has been characterized by an attentional bias towards threatening faces. Electrophysiological studies have demonstrated modulations of cognitive processing from 100 ms after stimulus presentation. However, the impact of the stimulus features and task instructions on facial processing remains unclear. Event-related potentials were recorded while high and low socially anxious individuals performed an adapted Stroop paradigm that included a colour-naming task with non-emotional stimuli, an emotion-naming task (the explicit task) and a colour-naming task (the implicit task) on happy, angry and neutral faces. Whereas the impact of task factors was examined by contrasting an explicit and an implicit emotional task, the effects of perceptual changes on facial processing were explored by including upright and inverted faces. The findings showed an enhanced P1 in social anxiety during the three tasks, without a moderating effect of the type of task or stimulus. These results suggest a global modulation of attentional processing in performance situations.     

Startle modulation by affective faces

Startle reflex modulation by affective pictures is a well-established effect in human emotion research. However, much less is known about startle modulation by affective faces, despite the growing evidence that facial expressions robustly activate emotion-related brain circuits. In this study, acoustic startle probes were administered to 37 young adult participants (20 women) during the viewing of slides from the Pictures of Facial Affect set including neutral, happy, angry, and fearful faces. The effect of expression valence (happy, neutral, and negative) on startle magnitude was highly significant (p < .001). Startle reflex was strongly potentiated by negative expressions (fearful and angry), however, no attenuation by happy faces was observed. A significant valence by gender interaction suggests stronger startle potentiation effects in females. These results demonstrate that affective facial expressions can produce significant modulation of the startle reflex.     

Neural correlates of infants' visual responsiveness to facial expressions of emotion

An extensive literature documents the infant's ability to recognize and discriminate a variety of facial expressions of emotion. However, little is known about the neural bases of this ability. To examine the neural processes that may underlie infants' responses to facial expressions, we recorded event-related potentials (ERPs) while 7-month-olds watched pictures of a happy face and a fearful face (Experiment 1) or an angry face and a fearful face (Experiment 2). In both experiments an early positive component, a middle-latency negative component and a later positive component were elicited. However, only when the infants saw the happy and fearful faces did the components differ for the two expressions. These results are discussed in the context of the neurobiological processes involved in perceiving facial expressions. © 1996 John Wiley & Sons, Inc.     

Threat sensitivity as assessed by automatic amygdala response to fearful faces predicts speed of visual search for facial expression

It has been argued that the amygdala represents an integral component of a vigilance system that is primarily involved in the perception of ambiguous stimuli of biological relevance. The present investigation was conducted to examine the relationship between automatic amygdala responsivity to fearful faces which may be interpreted as an index of trait-like threat sensitivity and spatial processing characteristics of facial emotions. During 3T fMRI scanning, pictures of human faces bearing fearful, angry, and happy expressions were presented to 20 healthy volunteers using a backward masking procedure based on neutral facial expressions. Subsequently, a computer-based face-in-the-crowd task using schematic face stimuli was administered. The neural response of the (right) amygdala to masked fearful faces correlated consistently with response speed to negative and neutral faces. Neither amygdala activation during the masked presentation of angry faces nor amygdala activation during the presentation of happy faces was correlated with any of the response latencies in the face-in-the-crowd task. Our results suggest that amygdala responsivity to masked facial expression is differentially related to the general visual search speed for facial expression. Neurobiologically defined threat sensitivity seems to represent an important determinant of visual scanning behaviour.     

Attentional selectivity for emotional faces: Evidence from human electrophysiology

This study investigated the temporal course of attentional biases for threat-related (angry) and positive (happy) facial expressions. Electrophysiological (event-related potential) and behavioral (reaction time [RT]) data were recorded while participants viewed pairs of faces (e.g., angry face paired with neutral face) shown for 500 ms and followed by a probe. Behavioral results indicated that RTs were faster to probes replacing emotional versus neutral faces, consistent with an attentional bias for emotional information. Electrophysiological results revealed that attentional orienting to threatening faces emerged earlier (early N2pc time window; 180–250 ms) than orienting to positive faces (after 250 ms), and that attention was sustained toward emotional faces during the 250–500-ms time window (late N2pc and SPCN components). These findings are consistent with models of attention and emotion that posit rapid attentional prioritization of threat.     

Selective attention to threatening faces in delusion‐prone individuals

Introduction. Selective attention to threat‐related information has been associated with clinical delusions in schizophrenia and nonclinical delusional ideation in healthy individuals. However, it is unclear whether biased attention for threat reflects early engagement effects on selective attention, or later difficulties in disengaging attention from perceived threat. The present study examined which of these processes operate in nonclinical delusion‐prone individuals.

Methods. A total of 100 psychologically healthy participants completed the Peters et al. () Delusions Inventory (PDI). Twenty‐two scoring in the upper quartile (high‐PDI group) and 22 scoring in the lower quartile (low‐PDI group) completed a modified dot‐probe task. Participants detected dot‐probes appearing 200, 500, or 1250 ms after an angry‐neutral face pair or a happy‐neutral face pair.

Results. High‐PDI individuals responded faster to dot‐probes presented in the same location as angry compared to happy faces at the short 200 ms stimulus onset asynchrony (SOA), but only when the emotional faces were presented to the left visual field. At the two longer SOAs (500 ms, 1250 ms), the high‐PDI group were also faster to respond to dot‐probes presented in the same location as angry compared to happy faces and slower to respond to dot‐probes presented in different spatial locations to angry (vs. happy) faces. The latter effects were seen whether emotional faces were presented to the left or the right visual field.

Conclusions. Results support the operation of emotion‐selective engagement and defective disengagement for threat‐related facial expressions (i.e., anger) in delusion‐prone individuals.     

An event-related potential study on cross-modal conversion of Chinese characters

In the current study, we explored the effects of ERPs (event-related potentials), related to the cross-modal transfer from visual input to phonological retrieval. Using Chinese single-character words, participants were asked to make orthographic (intra-modal) and phonological (cross-modal) responses to visually presented words. By comparing the cross-modal and intra-modal tasks, we found that both tasks evoke similar activity in the early stage of lexical processing, showing the same pattern of N2 effect (a negative component peaking around 220 ms) and P2 effect (a positive component peaking around 270 ms). However, the effect of the task was significant in the 300-700 ms time window, consisting of a frontal-based N400 effect and a parietal based late positive component (LPC) effect. These findings suggest that the frontal-based N400 is associated with orthography-to-phonology mapping in Chinese, and the LPC reflects greater requirement of maintaining retrieved information in working memory for the cross-modal processing.     

Virtual friend or threat? The effects of facial expression and gaze interaction on psychophysiological responses and emotional experience

The present study aimed to investigate the impact of facial expression, gaze interaction, and gender on attention allocation, physiological arousal, facial muscle responses, and emotional experience in simulated social interactions. Participants viewed animated virtual characters varying in terms of gender, gaze interaction, and facial expression. We recorded facial EMG, fixation duration, pupil size, and subjective experience. Subject's rapid facial reactions (RFRs) differentiated more clearly between the character's happy and angry expression in the condition of mutual eye-to-eye contact. This finding provides evidence for the idea that RFRs are not simply motor responses, but part of an emotional reaction. Eye movement data showed that fixations were longer in response to both angry and neutral faces than to happy faces, thereby suggesting that attention is preferentially allocated to cues indicating potential threat during social interaction.     

Current status of the anger superiority hypothesis: A meta‐analytic review of N2pc studies

Numerous investigators have tested contentions that angry faces capture early attention more completely than happy faces do in the context of other faces. However, syntheses of studies on early event‐related potentials related to the anger superiority hypothesis have yet to be conducted, particularly in relation to the N200 posterior‐contralateral (N2pc) component which provides a reliable electrophysiological index related to orienting of attention suitable for testing this hypothesis. Fifteen samples (N = 534) from 13 studies featuring the assessment of N2pc amplitudes during exposure to angry‐neutral and/or happy‐neutral facial expression arrays were included for meta‐analysis. Moderating effects of study design features and sample characteristics on effect size variability were also assessed. N2pc amplitudes elicited by affectively valenced expressions (angry and happy) were significantly more pronounced than those elicited by neutral expressions. However, the mean effect size difference between angry and happy expressions was ns. N2pc effect sizes were moderated by sample age, number of trials, and nature of facial images used (schematic vs. real) with larger effect sizes observed when samples were comparatively younger, more task trials were presented and schematic face arrays were used. N2pc results did not support anger superiority hypothesis. Instead, attentional resources allocated to angry versus happy facial expressions were similar in early stages of processing. As such, possible adaptive advantages of biases in orienting toward both anger and happy expressions warrant consideration in revisions of related theory.     

Electrophysiological correlates of emotional and structural face processing in humans

In order to study brain potentials related to decoding of facial expressions of emotions and those, related to basic perception of faces 16 right-handed subjects performed tasks on facial emotion recognition and perception of blurred faces and objects. Electroencephalograph (EEG) recordings during performance of the tasks revealed similar event-related potentials during the presentation of faces at 120 and 170 ms after stimulus onset in both of the tasks but significant differences in amplitudes between 180 and 300 ms. Whereas faces in the emotion recognition task produced high amplitudes in that latency range, potentials in response to faces in the blurred object condition were virtually absent. These data point to the assumption that decoding of facial expressions starts early in the brain and might be processed separately from basic stages of face perception.     

Hemispheric Asymmetry in Conditioning to Facial Emotional Expressions

In the present experiment, we report a right hemisphere advantage for autonomic conditioning to facial emotional expressions. Specifically, angry, but not happy, facial expressions showed significantly more resistance to extinction when presented initially to the right as compared to the left hemisphere. Slides of happy and angry faces were used as conditioned stimuli (CS+ and CS-) with shock as the unconditioned stimulus (UCS). Half of the subjects (n = 15) had the angry face as CS+ (and the happy face as CS-), the other half had the happy face as CS+ (and the angry face as CS-). During acquisition, the CSs were presented foveally. During extinction, using the Visual Half-Field (VHF) technique, half of the CS+ and CS- trials were randomly presented in the right visual half-field (initially to the left hemisphere), and half of the trials were presented in the left half-field (initially to the right hemisphere). Stimuli were presented for 210 ms during acquisition, and for 30 ms during extinction. Bilateral skin conductance responses (SCRs) were recorded. The results showed effects of acquisition only for the angry CS+ group. During extinction, there was a significant Conditioning X Half-field interaction which was due to greater SCRs to the CS+ angry face when it was presented in the left half-field. It is concluded that the present results reveal hemisphere asymmetry effects in facial emotional conditioning.     

Perceived parental support predicts enhanced late positive event-related brain potentials to parent faces

This study examined event-related brain potentials in college students viewing facial pictures of their parents, celebrities, and strangers in the context of a guessing task. A temporal principal component analysis of data obtained from midline electrode sites was used to extract a component reflecting the mid- to late-positive deflection observed between 200 and 500 ms following stimulus onset. Parent faces elicited enhanced positivity compared to celebrity and stranger faces suggesting greater attention allocation to parent faces. In addition, greater perceived parental support predicted larger factor scores to parent faces relative to non-parent faces. Greater perceived negative interaction with parent, however, attenuated this relationship.     

Enhanced neural reactivity and selective attention to threat in anxiety

Attentional bias towards threat is implicated in the etiology and maintenance of anxiety disorders. We examined the neural correlates of threat bias in anxious and nonanxious participants to shed light on the neural chronometry of this cognitive bias. In this study, event-related potentials (ERPs) were recorded while anxious (n = 23) and nonanxious (n = 23) young adults performed a probe-discrimination task measuring attentional bias towards threat (angry) and positive (happy) face stimuli. Results showed an attention bias towards threat among anxious participants, but not among nonanxious participants. No bias to positive faces was found. ERP data revealed enhanced C1 amplitude (∼80 ms following threat onset) in anxious relative to nonanxious participants when cue displays contained threat faces. Additionally, P2 amplitude to the faces display was higher in the anxious relative to the nonanxious group regardless of emotion condition (angry/happy/neutral). None of the ERP analyses associated with target processing were significant. In conclusion, our data suggest that a core feature of threat processing in anxiety lies in functional perturbations of a brain circuitry that reacts rapidly and vigorously to threat. It is this over-activation that may set the stage for the attention bias towards threat observed in anxious individuals.     

Schizophrenia patients' perceptual biases in response to positively and negatively valenced emotion chimeras

BACKGROUND: In a prior study, we observed that schizophrenia patients display atypical perceptual biases in response to emotional (happy/neutral) facial chimeras. METHODS: The present study was an attempt to replicate and extend those findings, using emotional stimuli with negative affective valence (angry/neutral chimeras) as well as positive valence, and including more than one type of non-affective facial comparison task. We compared schizophrenia patients (N = 37) and controls (N = 48) on free-vision tasks that typically yield left spatial field biases indicative of right hemisphere activation. There were six chimera tasks, including two emotion (happy, angry) chimeras, two non-emotion (gender, age) chimeras and two non-face (dots, gradients) chimeras. RESULTS: We observed a Group x Task interaction, with schizophrenia patients displaying significantly less of the expected left spatial perceptual bias in response to the happy/neutral chimeras and the angry/neutral chimeras relative to the controls. In contrast, the patients and controls did not differ in terms of their response to the Gender, Age, Dots, or Gradients tasks. CONCLUSIONS: These findings are consistent with the assertion that, compared with healthy controls individuals with schizophrenia perceive emotion differently.     

Timing and voluntary suppression of facial mimicry to smiling faces in a Go/NoGo task—An EMG study

Results obtained with a novel emotional Go/NoGo task allowing the investigation of facial mimicry (FM) during the production and inhibition of voluntary smiles are discussed. Healthy participants were asked to smile rapidly to happy faces and maintain a neutral expression to neutral faces, or the reverse. Replicating and extending previous results, happy faces induced FM, as shown by stronger and faster zygomatic activation to happy than neutral faces in Go trials, and a greater number of false alarms to happy faces in NoGo trials. Facial mimicry effects remained present during participants’ active inhibition of facial movement. Latencies of FM were short with 126-250 ms in Go trials, and 251-375 ms in NoGo trials. The utility of the Go/NoGo task, which allows the assessment of response inhibition in the domain of facial expression by installing strong prepotent motor responses via short stimulus presentation times and a great number of Go trials, is discussed.     

Attentional biases for angry faces in unipolar depression

BACKGROUND: Past research has demonstrated that depression is associated with dysfunctional processing of emotional information. Recent studies demonstrate that a bias in the attentional processing of negative information may be an important cognitive vulnerability factor underlying the onset and maintenance of depression. However, to date, the nature of this attentional bias is still poorly understood and further exploration of this topic to advance current knowledge of attentional biases in depression seems imperative. METHOD: This study examined attentional biases for angry facial expressions presented for 1000 ms in 20 patients with major depressive disorder (MDD) and 20 non-depressed control participants (NC) matched for age and gender using an emotional modification of the Exogenous Cueing task. RESULTS: Patients with MDD showed maintained attention for angry faces compared with neutral faces. In comparison with non-depressed participants they showed a stronger attentional engagement for angry faces. In contrast, the NC group directed attention away from angry faces, more rapidly disengaging their attention compared with neutral faces. CONCLUSIONS: This pattern of results supports the assumption that MDD is characterized by deficits in the attentional processing of negative, interpersonal information and suggests a 'protective' bias in non-depressed individuals. Implications in relation to previous research exploring cognitive and interpersonal functioning in depression are discussed.     

The time line of threat processing and vagal withdrawal in response to a self‐threatening stressor in cognitive avoidant copers: Evidence for vigilance‐avoidance theory

Using a spatial cueing paradigm with emotional and neutral facial expressions as cues, we examined early and late patterns of information processing in cognitive avoidant coping (CAV). Participants were required to detect a target that appeared either in the same location as the cue (valid) or in a different location (invalid). Cue–target onset asynchrony (CTOA) was manipulated to be short (250 ms) or long (750 ms). CAV was associated with early facilitation and faster disengagement from angry faces. No effects were found for happy or neutral faces. After completing the spatial cueing task, participants prepared and delivered a public speech and heart rate variability (HRV) was recorded. Disengagement from angry faces was related to a decrease in HRV in response to this task. Together, these data suggest that CAV is related to early engagement followed by disengagement from threat‐related cues that might impact physiological stress responses.