Event-related brain potential correlates of emotional face processing

Emotion and attention: event-related brain potential studies

This chapter provides a comprehensive overview of the functional roles of the orbitofrontal cortex (OFC) and the basal ganglia (BG) in the processing of vocal emotional expressions in humans. We suggest that the two structures may interface during the integration of verbal and non-verbal vocal emotional expressions during late, cognitive processing stages as evidenced by recent event-related brain potential (ERP) and behavioural patient evidence. In accordance with our recent network model on emotional speech processing (Schirmer and Kotz 2006), we propose that the BG and the OFC are critically involved in the integration and evaluation of vocal emotional expressions. However, the overview will also reveal that the OFC is functionally differentiated and may thus respond to emotional expressions during both early automatic and late controlled, evaluative processing stages. Which processing stages the OFC responds to may critically hinge on the nature of stimulus and task type. As both structural and functional subcomponents of the orbito-striatal interface appear to be comparable in humans and non-human primates, we finally speculate that this system may be involved in the processing of emotional vocalizations across different species.

Premenstrual dysphoric disorder is a depressive disorder affecting 5%-8% of people with menstrual cycles. Despite evidence that facial emotion detection is altered in depressive disorders, with enhanced detection of negative emotions (negativity bias), minimal research exists on premenstrual dysphoric disorder. The goal of this study was to investigate the effect of premenstrual dysphoric disorder symptoms and the premenstrual phase on accuracy and intensity at detection of facial emotions. Cross-sectional quasi-experimental design. The Facial Emotion Detection Task was administered to 72 individuals assigned female at birth with no premenstrual dysphoric disorder (n = 30), and provisional PMDD (n = 42), based on a retrospective Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition-based measure of premenstrual dysphoric disorder. Facial emotion detection was examined both irrespective of menstrual cycle phase, and as a function of premenstrual phase (yes, no). The task used neutral-to-emotional facial expression morphs (15 images/morph). Participants indicated the emotion detected for each image within the progressive intensity morph. For all six basic emotions (sad, angry, fearful, happy, disgust, and surprise), two scores were calculated: accuracy of responses and the intensity within the morph at which the correct emotion was first detected (image number). Individuals reporting moderate/severe symptoms of premenstrual dysphoric disorder had more accurate and earlier detection of disgust, regardless of cycle phase. In addition, those with provisional premenstrual dysphoric disorder detected sad emotions earlier. A premenstrual dysphoric disorder group × cycle phase interaction also emerged: individuals reporting premenstrual dysphoric disorder symptoms were more accurate at detecting facial emotions during the premenstrual phase compared to the rest of the cycle, with a large effect size for sad emotions. The findings suggest enhanced facial emotion processing in individuals reporting symptoms of premenstrual dysphoric disorder, particularly for sadness and disgust. However, replication is required with larger samples and prospective designs. This premenstrual dysphoric disorder premenstrual emotion detection advantage suggests an adaptive cognitive mechanism in premenstrual syndrome/premenstrual dysphoric disorder, and challenges stigma surrounding premenstrual experiences.

Recent behavioral and event-related brain potential (ERP) studies have revealed cross-modal interactions in endogenous spatial attention between vision and audition, plus vision and touch. The present ERP study investigated whether these interactions reflect supramodal attentional control mechanisms, and whether similar cross-modal interactions also exist between audition and touch. Participants directed attention to the side indicated by a cue to detect infrequent auditory or tactile targets at the cued side. The relevant modality (audition or touch) was blocked. Attentional control processes were reflected in systematic ERP modulations elicited during cued shifts of attention. An anterior negativity contralateral to the cued side was followed by a contralateral positivity at posterior sites. These effects were similar whether the cue signaled which side was relevant for audition or for touch. They also resembled previously observed ERP modulations for shifts of visual attention, thus implicating supramodal mechanisms in the control of spatial attention. Following each cue, single auditory, tactile, or visual stimuli were presented at the cued or uncued side. Although stimuli in task-irrelevant modalities could be completely ignored, visual and auditory ERPs were nevertheless affected by spatial attention when touch was relevant, revealing cross-modal interactions. When audition was relevant, visual ERPs, but not tactile ERPs, were affected by spatial attention, indicating that touch can be decoupled from cross-modal attention when task-irrelevant.

Functional contributions of the basal ganglia to emotional prosody: Evidence from ERPs

Early processing of the six basic facial emotional expressions

On why Collet's doubts regarding the PCA are misplaced

An ERP investigation on the temporal dynamics of emotional prosody and emotional semantics in pseudo- and lexical-sentence context

IntroductionAmyotrophic lateral sclerosis (ALS) primarily impairs motor abilities but also affects cognition and emotional processing. We hypothesise that subjective ratings of emotional stimuli depicting social interactions and facial expressions is changed in ALS. It was found that recognition of negative emotions and ability to mentalize other’s intentions is reduced.MethodsProcessing of emotions in faces was investigated. A behavioural test of Ekman faces expressing six basic emotions was presented to 30 ALS patients and 29 age-, gender and education matched healthy controls. Additionally, a subgroup of 15 ALS patients that were able to lie supine in the scanner and 14 matched healthy controls viewed the Ekman faces during functional magnetic resonance imaging (fMRI). Affective state and a number of daily social contacts were measured.ResultsALS patients recognized disgust and fear less accurately than healthy controls. In fMRI, reduced brain activity was seen in areas involved in processing of negative emotions replicating our previous results. During processing of sad faces, increased brain activity was seen in areas associated with social emotions in right inferior frontal gyrus and reduced activity in hippocampus bilaterally. No differences in brain activity were seen for any of the other emotional expressions. Inferior frontal gyrus activity for sad faces was associated with increased amount of social contacts of ALS patients.ConclusionALS patients showed decreased brain and behavioural responses in processing of disgust and fear and an altered brain response pattern for sadness. The negative consequences of neurodegenerative processes in the course of ALS might be counteracted by positive emotional activity and positive social interactions.

Perspective taking modulates event-related potentials to perceived pain

Recent studies reported that the detection of changes in the visual stimulation results in distraction of cognitive processing. From event-related brain potentials it was argued that distraction is triggered by the automatic detection of deviants. We tested whether distraction effects are confined to the detection of a deviation or can be triggered by changes per se, namely by rare stimuli that were not deviant with respect to the stimulation. The results obtained comparable early event-related brain potential effects for rare and deviant stimuli, suggesting an automatic detection of these changes. In contrast, behavioral distraction and attention-related event-related brain potential components were confined to deviant stimuli. This finding suggests that deviancy from a given standard adds a genuine contribution to distraction.

Identification of Emotion in a Dichotic Listening Task: Event-Related Brain Potential and Behavioral Findings

Peer relationships become increasingly important during adolescence. The success of these relationships may rely on the ability to attend to and decode subtle or ambiguous emotional expressions that are common in social interactions. However, most studies examining youths' processing and labeling of facial emotion have employed adult faces and faces that depict emotional extremes as stimuli. In this study, 40 adolescents and 40 young adults viewed blends of angry-neutral, fearful-neutral, and happy-neutral faces (e.g., 100% angry, 66% angry, 33% angry, neutral) portrayed by adolescent and adult actors as electroencephalogram (EEG) was recorded. Participants also labeled these faces according to the emotion expressed (i.e., angry, fearful, happy, or neutral). The Late Positive Potential (LPP), an event-related potential (ERP) component that reflects sustained attention to motivationally salient information, was scored from the EEG following face presentation. Among adolescents, as peer-age faces moved from ambiguous (33%) to unambiguous (100%) emotional expression, the LPP similarly increased. These effects were not found when adolescents viewed emotional face blends portrayed by adult actors. Additionally, while both adolescents and young adults showed greater emotion labeling accuracy as faces increased in emotional intensity from ambiguous to unambiguous emotional expression, adolescent participants did not show greater accuracy when labeling peer-compared to adult-age faces. Together, these data suggest that adolescents attend more to subtle differences in peer-age emotional faces, but they do not label these emotional expressions more accurately than adults.

Auditory event-related brain potentials (ERPs) were recorded to tones of different frequencies and locations in a dichotic selective attention task in which Ss responded to occasional deviant tones of a prespecified location and frequency. Attention effects were isolated as negative difference (Nd) waves by subtracting ERPs to tones with no attended features from ERPs to the same tones when they shared target frequency, location, or both cues. The N1/P90 (latency 80-100 ms), originating in a tonotopically organized generator, was enhanced for all tones in the attended ear. Nd waves, beginning at 80 ms and lasting up to 700 ms, were seen to tones with either attended feature. Nd waves to frequency and location features had different scalp distributions consistent with generation in different cortical fields. Conjunction-specific Nds began 30-50 ms after Nds to individual features. The relative timing suggests that feature conjunction began before the analysis of individual features was complete.

Event-related potential studies using affective words have indicated that selective attention to valence can increase affective discrimination at early perceptual stages. This effect most likely relies on neural associations between perceptual features of a stimulus and its affective value. Similar to words, emotional expressions in human faces are linked to specific visual elements. Therefore, selectively attending to a given emotion should allow for the preactivation of neural networks coding for the emotion and associated first-order visual elements, leading to enhanced early processing of faces expressing the attended emotion. To investigate this, we employed an expression detection task (N = 65). Fearful, happy, and neutral faces were randomly presented in three blocks while participants were instructed to respond only to one predefined target level of expression in each block. Reaction times were the fastest for happy target faces, which was accompanied by an increased occipital P1 for happy compared with fearful faces. The N170 yielded an arousal effect (emotional > neutral) while both components were not modulated by target status. In contrast, the early posterior negativity (EPN) arousal effect tended to be larger for target compared with nontarget faces. The late positive potential (LPP) revealed large effects of status and expression as well as an interaction driven by an increased LPP specifically for nontarget fearful faces. These findings tentatively indicate that selective attention to facial affect may enhance early emotional processing (EPN) even though further research is needed. Moreover, late controlled processing of facial emotions appears to involve a negativity bias.