Enhanced N170 to outgroup faces: Perceptual novelty or prejudice?

Correlation of event-related potentials N170 with dysfunctional attitudes in patients with major depressive disorder

BACKGROUND

Cognitive impairment frequently accompanies first-episode major depressive disorder (MDD) in patients. Early detection and intervention for cognitive impairment can enhance the quality of life for individuals with depressive disorders. Impaired emotion recognition may serve as an initial manifestation of cognitive impairment in these patients. This study examines the characteristics of event-related potentials N170 and dysfunctional attitudinal questionnaire total scores, as well as each factor and their correlation, revealing characteristic electroencephalogram (EEG) changes associated with cognitive impairment in first-episode MDD patients.

METHOD

A total of 88 patients experiencing first-episode MDD and 29 healthy volunteers from the same period participated in the study. They underwent event-related potential N170 measures to assess mood recognition function, the 17-item Hamilton depression scale (HAMD-17) to evaluate the severity of depressive disorder, and the Dysfunctional Attitudes Scales(DAS) to appraise cognitive function.

RESULT

The dysfunctional attitude questionnaire's total score and each factor score were higher in the MDD group compared to the healthy control (HC) group. The MDD group exhibited lower amplitudes than the HC group at CZ, PZ, POZ, P7, PO7, P8, and PO8 electrode points. A correlation was identified between the P7 and PO7 electrode points of the event-related potential N170 and cognitive function.

LIMITATION

This study solely considered neutral face emotional stimuli and did not account for depressive disorder subtypes.

CONCLUSION

Differences were observed between the MDD and HC groups in cognitive function and N170 amplitude in the central brain region (CZ, PZ, POZ), left posterior temporal region (P7), left occipitotemporal region (PO7), right posterior temporal region (P8), and right occipitotemporal region (PO8). Additionally, a correlation was found between N170 latency in the left posterior temporal region of the brain (P7) and the left occipitotemporal region (PO7) with cognitive function.

Face motion form at learning influences the time course of face spatial frequency processing during test

Studies that use static faces suggest that facial processing follows a coarse-to-fine sequence; i.e., holistic precedes featural processing, due to low and high spatial frequencies (LSF, HSF) transmitting holistic/global and featural/local information respectively. Although recent studies have focused on the role of facial movement in holistic facial processing, it is unclear whether moving faces have the same processing mechanism as static ones, especially in the time course of processing. The current study uses the event-related potential technique to investigate this issue by manipulating the facial format at study and face spatial frequency during the test. ERP results showed that the P1 amplitude was increased by LSF faces relative to HSF ones, using both moving and static study faces, with the former larger than the latter. The N170 amplitude was more sensitive to HSF than LSF faces when only static study faces were used, while the P2 amplitude was more sensitive to LSF faces regardless of the facial study format. The above results were not modulated by the race of the faces. These results favor the view that regardless of face race, moving study faces promote holistic processing during the earliest stage of face recognition. Furthermore, holistic processing is observed to be the same for both static and moving study faces at a later stage associated with more in-depth processing. It is evident that facial motion should be factored into further studies of face recognition, given the distinctions between holistic and featural processing for moving and static study faces.

Influence of affective verbal context on emotional facial expression perception of social anxiety

Previous studies have shown that the perception of ambiguous facial expressions for individuals with social anxiety was influenced by the affective verbal context. However, it is still unknown how emotional facial expressions are perceived by individuals with social anxiety in the context of the verbal context. In this study, we used event-related potentials (ERPs) technology to examine how individuals with social anxiety perceive emotional facial expressions in positive and negative contexts. The results showed that: (1) Within the negative verbal contexts, the amplitude of P1 induced by facial expressions in the social anxiety group was significantly higher than that induced by the healthy control group; The N170 amplitude induced by facial expressions in social anxiety group was less negative than that in the healthy control group, and was not affected by the context. (2) The social anxiety group had significantly higher LPP in negative contexts elicited by angry expressions than by happy expressions. This study proved that the perception of emotional facial expressions was influenced by top-down information in the early and late stages of visual perception for individuals with social anxiety.

Negative news dominates fast and slow brain responses and social judgments even after source credibility evaluation

Remedies to counter the impact of misinformation are in high demand, but little is known about the neuro-cognitive consequences of untrustworthy information and how they can be mitigated. In this preregistered study, we investigated the effects of social-emotional headline contents on social judgments and brain responses and whether they can be modulated by explicit evaluations of the trustworthiness of the media source. Participants (N = 30) evaluated -and clearly discerned- the trustworthiness of news sources before they were exposed to person-related news headlines. Despite this intervention, social judgments and brain responses were dominated largely by emotional headline contents. Results suggest differential effects of source credibility might depend on headline valence. Electrophysiological indexes of fast emotional and arousal-related brain responses, as well as correlates of slow evaluative processing were enhanced for persons associated with positive headline contents from trusted sources, but not when positive headlines stemmed from distrusted sources. In contrast, negative headlines dominated fast and slow brain responses unaffected by explicit source credibility evaluations. These results provide novel insights into the brain mechanisms underlying the "success" of emotional news from untrustworthy sources, suggesting a pronounced susceptibility to negative information even from distrusted sources that is reduced for positive contents. The differential pattern of responses to misinformation in mind and brain sheds light on the cognitive mechanisms underlying the processing of misinformation and possible strategies to avoid their potentially detrimental effects.

Spatiotemporal Dynamics of Covert Versus Overt Processing of Happy, Fearful and Sad Facial Expressions

Behavioral and electrophysiological correlates of the influence of task demands on the processing of happy, sad, and fearful expressions were investigated in a within-subjects study that compared a perceptual distraction condition with task-irrelevant faces (e.g., covert emotion task) to an emotion task-relevant categorization condition (e.g., overt emotion task). A state-of-the-art non-parametric mass univariate analysis method was used to address the limitations of previous studies. Behaviorally, participants responded faster to overtly categorized happy faces and were slower and less accurate to categorize sad and fearful faces; there were no behavioral differences in the covert task. Event-related potential (ERP) responses to the emotional expressions included the N170 (140-180 ms), which was enhanced by emotion irrespective of task, with happy and sad expressions eliciting greater amplitudes than neutral expressions. EPN (200-400 ms) amplitude was modulated by task, with greater voltages in the overt condition, and by emotion, however, there was no interaction of emotion and task. ERP activity was modulated by emotion as a function of task only at a late processing stage, which included the LPP (500-800 ms), with fearful and sad faces showing greater amplitude enhancements than happy faces. This study reveals that affective content does not necessarily require attention in the early stages of face processing, supporting recent evidence that the core and extended parts of the face processing system act in parallel, rather than serially. The role of voluntary attention starts at an intermediate stage, and fully modulates the response to emotional content in the final stage of processing.