The role of outgroup homogeneity and the neurodynamics of the frontal cortex during beauty comparisons.

The distance effect states that the closer two compared magnitudes (e.g., two numbers, physical attractiveness in two faces), the more difficult the comparison, and the greater the activity of the frontoparietal control network. However, it is unclear whether this network is also recruited to the same extent when we perform ingroup and outgroup beauty comparisons and whether the activation of these networks is tracked by interindividual variation in the perceptions we hold about an outgroup. We recorded brain activity with fMRI, where participants compared the beauty of two women ostensibly either from their ingroup or from an outgroup. Low-distance conditions produced longer response times than the high-distance conditions, and this was found in both the ingroup and outgroup conditions. However, our neuroimaging analyses revealed that the left IFG/anterior insula showed the classic distance effect only during ingroup processing but not during outgroup processing. Notably, interaction-specific activity within the left IFG/anterior insula was related to perceptions of outgroup homogeneity assessed via a questionnaire. This set of findings reveals the dynamic role of the prefrontal cortex and its interplay with perceptions of outgroup homogeneity in shaping ingroup and outgroup decision-making.

Face Perception and Narcissism: Variations of Event-Related Potential Components (P1 & N170) with Admiration and Rivalry.

Previous studies have demonstrated that highly narcissistic individuals perceive themselves as grandiose and devaluate and sometimes overvalue others. These results are mainly based on behavioural data, but we still know little about the neural correlates underlying, such as perceptional processes. To this end, we investigated event-related potential components (ERP) of visual face processing (P1 and N170) and their variations with narcissism. Participants (N = 59) completed the Narcissistic Admiration and Rivalry Questionnaire and were shown pictures of their own face, a celebrity's face, and a stranger's face. Variations of P1 and N170 with Admiration and Rivalry were analysed using multilevel models. Results revealed moderating effects of both narcissism dimensions on the ERP components of interest. Participants with either high Admiration or low Rivalry scores showed a lower P1 amplitude when viewing their own face compared with when viewing a celebrity's face. Moreover, the Self-Stranger difference in the N170 component (higher N170 amplitude in the Self condition) was larger for higher Rivalry scores. The findings showed, for the first time, variations of both narcissism dimensions with ERPs of early face processing. We related these effects to processes of attentional selection, an expectancy-driven perception, and the mobilisation of defensive systems. The results demonstrated that by linking self-report instruments to P1 and N170, and possibly to other ERP components, we might better understand self- and other-perception in narcissism.

Immediate relativity: EEG reveals early engagement of comparison in social information processing.

A wide array of social decisions relies on social comparisons. As such, these decisions require fast access to relative information. Therefore, we expect that signatures of the comparative process should be observable in electrophysiological components at an early stage of information processing. However, to date, little is known about the neural time course of social target comparisons. Therefore, we tested this hypothesis in 2 electroencephalography (EEG) studies using a social distance effect paradigm. The distance effect capitalizes on the fact that stimuli close on a certain dimension take longer to compare than stimuli clearly differing on this dimension. Here, we manipulated the distance of face characteristics regarding their levels of attractiveness (Study 1) and trustworthiness (Study 2), 2 essential social dimensions. In both studies, size comparisons served as a nonsocial control condition. In Study 1, distance related effects were apparent 170 ms (vertex positive potential, VPP) and 200 ms (N2) after stimulus onset for attractiveness comparisons. In Study 2, trustworthiness comparisons took effect already after 100 ms (N1) and likewise carried over to an event-related N2. Remarkably, we observed a similar temporal pattern for social (attractiveness, trustworthiness) and nonsocial (size) dimensions. These results speak in favor of an early encoding of comparative information and emphasize the primary role of comparison in social information processing. (PsycINFO Database Record