Search asymmetries for threatening faces in chimpanzees (Pan troglodytes)

For primates, the ability to efficiently detect threatening faces is highly adaptive, however, it is not clear exactly how faces are detected. This study investigated whether chimpanzees show search asymmetries for conspecific threatening faces featuring scream and bared teeth expressions. Five adult female chimpanzees participated in a series of touchscreen matching-to-sample visual search tasks. In Experiment 1, search advantages for scream versus neutral targets, and scream versus bared teeth targets were found. A serial search strategy indicated greater difficulty in disengaging attention from scream versus neutral distractors. In Experiments 2a and 2b, search advantages for scream versus neutral targets remained when the mouth was darkened, suggesting that the brightness contrast of the mouth was not critical for the efficient detection of scream targets. In Experiments 3a and 3b, search advantages for inverted scream versus neutral targets disappeared, indicating configural processing. Together, exclusion of the brightness contrast of the mouth as a low-level perceptual confound, and evidence of configural processing, suggested the scream faces may have been perceived as threatening. However, the search advantage for scream faces is most likely explained by the presence of teeth, independently of threat. The study provides further support that an attentional bias towards threatening faces is a homologous trait, which can be traced back to at least the last common ancestor of Old-World monkeys and apes.

Effect of Individual Differences in Fear and Anxiety on Face Perception of Human and Android Agents

People process human faces configurally—as a Gestalt or integrated whole—but perceive objects in terms of their individual features. As a result, faces—but not objects—are more difficult to process when presented upside down versus upright. Previous research demonstrates that this inversion effect is not observed when recognizing previously seen android faces, suggesting they are processed more like objects, perhaps due to a lack of perceptual experience and/or motivation to recognize android faces. The current study aimed to determine whether negative emotions, particularly fear of androids, may lessen configural processing of android faces compared to human faces. While the current study replicated previous research showing a greater inversion effect for human compared to android faces, we did not find evidence that negative emotions—such as fear—towards androids influenced the face inversion effect. We discuss the implications of this study and opportunities for future research.

Does Cross-Race Contact Improve Cross-Race Face Perception? A Meta-Analysis of the Cross-Race Deficit and Contact

Contact with racial outgroups is thought to reduce the cross-race recognition deficit (CRD), the tendency for people to recognize same-race (i.e., ingroup) faces more accurately than cross-race (i.e., outgroup) faces. In 2001, Meissner and Brigham conducted a meta-analysis in which they examined this question and found a meta-analytic effect of r = −.13. We conduct a new meta-analysis based on 20 years of additional data to update the estimate of this relationship and examine theoretical and methodological moderators of the effect. We find a meta-analytic effect of r = −.15. In line with theoretical predictions, we find some evidence that the magnitude of this relationship is stronger when contact occurs during childhood rather than adulthood. We find no evidence that the relationship differs for measures of holistic/configural processing compared with normal processing. Finally, we find that the magnitude of the relationship depends on the operationalization of contact and that it is strongest when contact is manipulated. We consider recommendations for further research on this topic.

Behavioral and neural markers of social vision

Research on face perception has revealed highly specialized visual mechanisms such as configural processing, and provided markers of interindividual differences -including disease risks and alterations- in visuoperceptual abilities that traffic in social cognition. Is face perception unique in degree or kind of mechanisms, and in its relevance for social cognition? Combining fMRI and behavioral methods, we address the processing of an uncharted class of socially relevant stimuli: minimal social scenes involving configurations of two bodies spatially close and face-to-face. We report category-specific activity for facing (vs. non-facing) two-body configurations in visual cortex. That activity shows face-like signatures of configural processing -i.e., stronger response and greater susceptibility to stimulus inversion for facing (vs. non-facing) dyads-, and is predicted by performance-based measures of body-dyad perception. Moreover, individual performance in body-dyad perception is reliable, stable-over-time and correlated with the individual social sensitivity, coarsely captured by the Autism-Spectrum Quotient. Further analyses clarify the relationship between single-body and body-dyad perception. We propose that facing dyads are processed with the same high specialization of the most biologically/socially relevant stimuli: faces. Like face perception, facing-dyad perception can provide a measure of basic (visual) processes that lay the foundations for understanding others, their relationships and interactions.