Interactions between the perception of age and ethnicity in faces: an event-related potential study

Perception gap of aged facial appearance; self-perception is younger than actual status due to angle of viewing

BACKGROUND

Facial morphology changes with aging, resulting in an aged appearance that is a great matter of concern for people. However, it is not clear whether people perceive their own facial appearance accurately, in part because there are few methods to evaluate this.

AIM

The aim of this study is firstly to establish an evaluation system for the perception gap of aged facial appearance between the self-perceived status and the actual status, and then to use this evaluation system to quantify the perception gap and to clarify the mechanism of this gap METHOD: Thirty-six middle-aged female volunteers were first asked to rate their facial aging-related morphology according to a 6-grade set of photos taken at a 45° angle from the front showing progressive stages of sagging severity, without looking either in a mirror or at photos of themselves (self- or "subjective" perception). Then they were shown photos of their face taken at a 45° angle from the front, and asked again to rate their sagging grade based on these photos ("objective" rating). In addition, facial photos taken from several angles from the front to the side were evaluated for sagging severity by trained evaluators.

RESULTS

This system for analyzing perception gap revealed that the self-perception of aged appearance was significantly younger than the actual situation in three facial areas, namely the cheek, around the eyes and the facial contour, and the gap corresponded to an age difference of as much as 8 years in middle-aged females. Trained evaluators found that the severity of sagging judged from photos taken from a frontal direction was significantly less than in photos of the same subject taken from side angles. This suggests that recognition of sagging is more difficult from the front, which is the direction from which people view their own face in daily life. Indeed, viewing photos taken from the side, a rare viewing angle of one's own face, increased the motivation to improve aged appearance in more than 70% of the subjects in a questionnaire survey.

CONCLUSION

The results suggest that people perceive their own facial appearance as less aged than it actually is. The reason for this appears to be that viewing from the front, the usual viewing angle of one's own face in daily life, results in lower perceived sagging severity, likely due to reduced depth perception.

Effects of Minimal Grouping On Implicit Prejudice, Infrahumanization, and Neural Processing Despite Orthogonal Social Categorizations

Racial prejudice is a pervasive and pernicious form of intergroup bias. However, a mounting number of studies show that re-categorization-even into minimal groups-can overcome the typical consequences of racial and other group classifications. We tested the effects of minimal grouping on implicit prejudice and infrahumanization using a paradigm in which race was orthogonal to group membership. This allowed us to examine whether knowledge of group membership overrides obvious category differences. We found that participants infrahumanized and showed implicit bias toward the minimal out-group, despite the crosscutting presence of race, and in fact did not show any of the usual implicit racial bias. In addition, Event-Related Potentials (ERPs) showed an early race effect followed by distinct reactions on the basis of group as processing continued. This is evidence that arbitrary social classifications can engender in-group preference even in the presence of orthogonal, visually salient categorizations.

Decoding task and stimulus representations in face-responsive cortex

Observers can deliberately attend to some aspects of a face (e.g. emotional expression) while ignoring others. How do internal goals influence representational geometry in face-responsive cortex? Participants watched videos of naturalistic dynamic faces during MRI scanning. We measured multivariate neural response patterns while participants formed an intention to attend to a facial aspect (age, or emotional valence), and then attended to that aspect, and responses to the face's emotional valence, independent of attention. Distinct patterns of response to the two tasks were found while forming the intention, in left fronto-lateral but not face-responsive regions, and while attending to the face, in almost all face-responsive regions. Emotional valence was represented in right posterior superior temporal sulcus and medial prefrontal cortex, but could not be decoded when unattended. Shifting the focus of attention thus alters cortical representation of social information, probably reflecting neural flexibility to optimally integrate goals and perceptual input.