The influence of flankers on race categorization of faces

Effect of spatial context on perceived walking direction

Contextual modulation occurs for many aspects of high-level vision but is relatively unexplored for the perception of walking direction. In a recent study, we observed an effect of the temporal context on perceived walking direction. Here, we examined the spatial contextual modulation by measuring the perceived direction of a target point-light walker in the presence of two flanker walkers, one on each side. Experiment 1 followed a within-subjects design. Participants (n = 30) completed a spatial context task by judging the walking direction of the target in 13 different conditions: a walker alone in the center or with two flanking walkers either intact or scrambled at a flanker deviation of ±15°, ±30°, or ±45°. For comparison, participants completed an adaptation task where they reported the walking direction of a target after adaptation to ±30° walking direction. We found the expected repulsive effects in the adaptation task but attractive effects in the spatial context task. In Experiment 2 (n = 40), we measured the tuning of spatial contextual modulation across a wide range of flanker deviation magnitudes ranging from 15° to 165° in 15° intervals. Our results showed significant attractive effects across a wide range of flanker walking directions with the peak effect at around 30°. The assimilative versus repulsive effects of spatial contextual modulation and temporal adaptation suggest dissociable neural mechanisms, but they may operate on the same population of sensory channels coding for walking direction, as evidenced by similarity in the peak tuning across the walking direction of the inducers.

An Evaluation of Racial Diversity in Craniofacial Surgery Literature

ABSTRACT

Implicit bias can lead to discrimination of certain populations within healthcare. Representation in medical literature is no exception and it is hypothesized that images with lighter skin tone are more prevalent than darker skin tones in craniofacial literature. Clinical photographs and figure graphics from 5 journals were examined for pre-defined years. Annals of Plastic Surgery, Aesthetic Surgery Journal, Journal of Craniofacial Surgery, Journal of Plastic, Reconstructive and Aesthetic Surgery, and Plastic and Reconstructive Surgery journals were reviewed. All craniofacial-focused articles containing at least one color image depicting human skin were included. 10,477 images and 627 graphics were evaluated using the Fitzpatrick scale as a guide. Most journals trended toward broader inclusion of nonwhite photographs and graphics over time. In 2016, 47% of articles published in Journal of Craniofacial Surgery included nonwhite images compared to Annals of Plastic Surgery (16%), Aesthetic Surgery Journal (40%), Journal of Plastic, Reconstructive and Aesthetic Surgery (25%), and Plastic and Reconstructive Surgery (7%). Comparison of domestic and international publications demonstrated that author's country of origin impacted the percentage of nonwhite clinical photographs for most journals. Comparisons of publications by country demonstrated increased diversity in Asia and the Middle East for clinical photographs but not graphics. The frequency of nonwhite figure graphics was staggeringly low, identified in only 18 articles across all journals and years. Craniofacial literature more commonly reflects white skin tones. The trend over time suggests increasing inclusion of racial diversity in clinical photographs; however, figure graphics remain less racially diverse. Time, country of origin, and publishing journal appear to play a role.

Shining a Light on Race: Contrast and Assimilation Effects in the Perception of Skin Tone and Racial Typicality

Researchers have long debated the extent to which an individual’s skin tone influences their perceived race. Brooks and Gwinn (2010) demonstrated that the race of surrounding faces can affect the perceived skin tone of a central target face without changing perceived racial typicality, suggesting that skin lightness makes a small contribution to judgments of race compared to morphological cues (the configuration and shape of the facial features). However, the lack of a consistent light source may have undermined the reliability of skin tone cues, encouraging observers to rely disproportionately on morphological cues instead. The current study addresses this concern by using 3D models of male faces with typically Black African or White European appearances that are illuminated by the same light source. Observers perceived target faces surrounded by White faces to have darker skin than those surrounded by Black faces, particularly for faces of intermediate lightness. However, when asked to judge racial typicality, a small assimilation effect was evident, with target faces perceived as more stereotypically White when surrounded by White than when surrounded by Black faces at intermediate levels of typicality. This evidence of assimilation effects for perceived racial typicality despite concurrent contrast effects on perceived skin lightness supports the previous conclusion that perceived skin lightness has little influence on judgments of racial typicality for racially ambiguous faces, even when lighting is consistent.

A Meta-Analytic Review of Hypodescent Patterns in Categorizing Multiracial and Racially Ambiguous Targets

Research addressing the increasing multiracial population (i.e., identifying with two or more races) is rapidly expanding. This meta-analysis (k = 55) examines categorization patterns consistent with hypodescent, or the tendency to categorize multiracial targets as their lower status racial group. Subgroup analyses suggest that operationalization of multiracial (e.g., presenting photos of racially ambiguous faces, or ancestry information sans picture), target gender, and categorization measurement (e.g., selecting from binary choices: Black or White; or multiple categorization options: Black, White, or multiracial) moderated categorization patterns. Operationalizing multiracial as ancestry, male targets, and measuring categorization with binary or multiple Likert-type scale outcomes supported hypodescent. However, categorizing multiracial targets as not their lower status racial group occurred for female targets or multiple categorization options. Evidence was mixed on whether perceiver and target race were related to categorization patterns. These results point to future directions for understanding categorization processes and multiracial perception.

Contextual Effects in Face Lightness Perception Are Not Expertise-Dependent

Lightness judgments of face stimuli are context-dependent (i.e., judgments of face lightness are influenced by race classification). Here, we tested whether contextual effects in face lightness perception are modulated by expertise, exploiting well-known other race effects in face perception. We used a lightness-matching paradigm where Chinese and White observers were asked to adjust the lightness of a variable face to match that of a standard face. The context (i.e., race category) of the two faces could be the same or different. Our data indicated that both groups had the smallest matching errors in same-context trials, for which errors did not vary across different racial categories. For cross-context trials, observers made the largest (negative) errors when the reference face was Black, as compared to Chinese and White references, for which matching errors were no different from zero or trended positively. Critically, this pattern was similar for both groups. We suggest that contextual influences in lightness perception are unlikely to be guided by classical mechanisms that drive face perception. We instead speculate that such influences manifest in terms of an interaction between race assumptions (e.g., expected surface reflectance patterns) and traditional mechanisms for reflectance computations.

Children (but not adults) judge similarity in own- and other-race faces by the color of their skin

Both face shape and pigmentation are diagnostic cues for face identification and categorization. In particular, both shape and pigmentation contribute to observers' categorization of faces by race. Although many theoretical accounts of the behavioral other-race effect either explicitly or implicitly depend on differential use of visual information as a function of category expertise, there is little evidence that observers do in fact differentially rely on distinct visual cues for own- and other-race faces. In the current study, we examined how Asian and Caucasian children (4-6 years of age) and adults use three-dimensional shape and two-dimensional pigmentation to make similarity judgments of White, Black, and Asian faces. Children in this age range are capable of making category judgments about race but also are sufficiently plastic with regard to the behavioral other-race effect that it seems as though their representations of facial appearance across different categories are still emerging. Using a simple match-to-sample similarity task, we found that children tend to use pigmentation to judge facial similarity more than adults and also that own-group versus other-group category membership appears to influence how quickly children learn to use shape information more readily. Therefore, we suggest that children continue to adjust how different visual information is weighted during early and middle childhood and that experience with faces affects the speed at which adult-like weightings are established.