A look at the influence of race and emotional context on face perception

Unofficial reports by some media outlets and community outreach organizations that track and document police violence demonstrate that more than any other demographic group, young black males are at a particularly heightened risk for fatal police encounters.

The underlying causes for the reported violent interactions between police and black individuals are likely multifactorial. To shed light on the issue, one approach taken by psychologists and neuroscientists has been to investigate potential behavioral and intrinsic brain-based biases when perceiving black vs. white faces.

One notable study (B. Keith Payne, 2001) reports that brief presentation of black vs white faces as racial cues can actually “prime” a quicker response to weapons or items of danger. The same manipulation increases misidentification of tools as weapons for black, relative to white, face cues. This occurs even if the face cue was flashed so quickly that the participant doesn’t even know it was there.

Several parallel studies have been conducted to investigate the implications of these types of effects on ‘real world’ actions.  These studies use virtual reality games that simulate the police officer’s dilemma of whether to shoot a suspect (criminal vs. innocent) who may be holding a (weapon vs. harmless object) (Correll, et al 2002; Greenwald et al, 2003). The findings from such studies are chilling, and indeed capture the chilling disparity with which people of color fall victim to fatal encounters with police, relative to their white counterparts.

The noted studies show that participants are faster at shooting armed black targets than armed white targets, and faster at deciding not to shoot unarmed white targets relative to unarmed black targets. Similarly, participants show a greater tendency to shoot unarmed targets when those targets are black rather than white.

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The above and similar findings point to race as an important construct that drives perception, which may, at least in part, drive the actions taken by law enforcement. Our research, funded by the MacArthur Foundation Research Network on Law and Neuroscience asks an additional question. Are these types of relationships dependent, or even enhanced, based on the emotional state of the subject making quick decisions?

To investigate the effects of race and emotional context on face perception, our study used black and white faces as stimuli in a functional MRI task (emotional go/no-go task) designed to study impulse control in black and white young adults. Three emotional contexts were induced in a group of African American and European American participants: rewarding, threatening, or neutral contexts. Behaviorally, regardless of their race, participants exhibited greater impulsive actions (more false alarms) to black faces.  This response was enhanced in threat contexts.

The fusiform cortex is a region of the brain implicated in face perception.  Studies show that this region of the brain has a greater neural response to faces of one’s own race relative to other-race faces (Gobly et al. 2001).  In the current study, we hypothesized that emotional context would influence the relative neural activity to own- vs. cross-race faces in the fusiform cortex. Indeed, the functional MRI observations in the fusiform cortex suggest that context influences the functional responses to black vs. white faces, but interestingly, in a manner dependent on the race of the participant. African American participants exhibited similar responses across all contexts.

Specifically, they exhibited higher activity for the same-race, i.e. black, relative to cross-race, i.e. white faces; as would be expected from previous studies.  European American participants exhibited the expected pattern  (higher activity for same-race, i.e. white, relative to cross-race, i.e. black faces) for the neutral and reward contexts, but not for the threat context.  In the threat context, the pattern was reversed.  Instead of responding with increased neural activity to members of the same race, European Americans demonstrated increased activity for black faces.

Our preliminary results demonstrate the importance of emotional context as an essential factor that influences impulsive decision making to racial cues, i.e. faces. Further investigations are underway to uncover the factors underlying the differential effect of context on African American vs. European American participants. The above described and similar investigations should assist in ongoing efforts to increase awareness of racial disparities in law enforcement and ultimately a reduction in preventable violent encounters.

**This post was originally published in June 2017 and has been updated.