Racial Prejudice Affects Representations of Facial Trustworthiness.

What makes faces seem trustworthy? We investigated how racial prejudice predicts the extent to which perceivers employ racially prototypical cues to infer trustworthiness from faces. We constructed participant-level computational models of trustworthiness and White-to-Black prototypicality from U.S. college students' judgments of White (Study 1, N = 206) and Black-White morphed (Study 3, N = 386) synthetic faces. Although the average relationships between models differed across stimuli, both studies revealed that as participants' anti-Black prejudice increased and/or intergroup contact decreased, so too did participants' tendency to conflate White prototypical features with trustworthiness and Black prototypical features with untrustworthiness. Study 2 (N = 324) and Study 4 (N = 397) corroborated that untrustworthy faces constructed from participants with pro-White preferences appeared more Black prototypical to naive U.S. adults, relative to untrustworthy faces modeled from other participants. This work highlights the important role of racial biases in shaping impressions of facial trustworthiness.

A Race-Based Size Bias for Black Adolescent Boys: Size, Innocence, and Threat.

We adopted an intersectional stereotyping lens to investigate whether race-based size bias-the tendency to judge Black men as larger than White men-extends to adolescents. Participants judged Black boys as taller than White boys, despite no real size differences (Studies 1A and 1B), and even when boys were matched in age (Study 1B). The size bias persisted when participants viewed computer-generated faces that varied only in apparent race (Study 2A) and extended to perceptions of physical strength, with Black boys judged as stronger than White boys (Study 2B). The size bias was associated with threat-related perceptions, including beliefs that Black boys were less innocent than White boys (Study 3). Finally, the size bias was moderated by a valid threat signal (i.e., anger expressions, Studies 4A and 4B). Thus, adult-like threat stereotypes are perpetrated upon Black boys, leading them to be erroneously perceived as more physically formidable than White boys.

Social Class and Social Pain: Target SES Biases Judgments of Pain and Support for White Target Individuals.

Social pain, defined as distress caused by negative interpersonal experiences (e.g., ostracism, mistreatment), is detrimental to health. Yet, it is unclear how social class might shape judgments of the social pains of low-socioeconomic status (SES) and high-SES individuals. Five studies tested competing toughness and empathy predictions for SES's effect on social pain judgments. Consistent with an empathy account, in all studies (Ncumulative = 1,046), low-SES White targets were judged more sensitive to social pain than high-SES White targets. Further, empathy mediated these effects, such that participants felt greater empathy and expected more social pain for low-SES targets relative to high-SES targets. Social pain judgments also informed judgments of social support needs, as low-SES targets were presumed to need more coping resources to manage hurtful events than high-SES targets. The current findings provide initial evidence that empathic concern for low-SES White individuals sensitizes social pain judgments and increases expected support needs for lower class White individuals.

Network segregation varies with neural distinctiveness in sensorimotor cortex.

Normal aging is associated with declines in sensorimotor function. Previous studies have linked age-related behavioral declines to decreases in neural differentiation (i.e., dedifferentiation), including decreases in the distinctiveness of neural activation patterns and in the segregation of large-scale neural networks at rest. However, no studies to date have explored the relationship between these two neural measures and whether they explain the same aspects of behavior. To investigate these issues, we collected a battery of sensorimotor behavioral measures in older and younger adults and estimated (a) the distinctiveness of neural representations in sensorimotor cortex and (b) sensorimotor network segregation in the same participants. Consistent with prior findings, sensorimotor representations were less distinct and sensorimotor resting state networks were less segregated in older compared to younger adults. We also found that participants with the most distinct sensorimotor representations exhibited the most segregated sensorimotor networks. However, only sensorimotor network segregation was associated with individual differences in sensorimotor performance, particularly in older adults. These novel findings link network segregation to neural distinctiveness, but also suggest that network segregation may play a larger role in maintaining sensorimotor performance with age.

Michigan Neural Distinctiveness (MiND) study protocol: investigating the scope, causes, and consequences of age-related neural dedifferentiation.

BACKGROUND: Aging is often associated with behavioral impairments, but some people age more gracefully than others. Why? One factor that may play a role is individual differences in the distinctiveness of neural representations. Previous research has found that neural activation patterns in visual cortex in response to different visual stimuli are often more similar (i.e., less distinctive) in older vs. young participants, a phenomenon referred to as age-related neural dedifferentiation. Furthermore, older people whose neural representations are less distinctive tend to perform worse on a wide range of behavioral tasks. The Michigan Neural Distinctiveness (MiND) project aims to investigate the scope of neural dedifferentiation (e.g., does it also occur in auditory, motor, and somatosensory cortex?), one potential cause (age-related reductions in the inhibitory neurotransmitter gamma-aminobutyric acid (GABA)), and the behavioral consequences of neural dedifferentiation. This protocol paper describes the study rationale and methods being used in complete detail, but not the results (data collection is currently underway). METHODS: The MiND project consists of two studies: the main study and a drug study. In the main study, we are recruiting 60 young and 100 older adults to perform behavioral tasks that measure sensory and cognitive function. They also participate in functional MRI (fMRI), MR spectroscopy, and diffusion weighted imaging sessions, providing data on neural distinctiveness and GABA concentrations. In the drug study, we are recruiting 25 young and 25 older adults to compare neural distinctiveness, measured with fMRI, after participants take a placebo or a benzodiazepine (lorazepam) that should increase GABA activity. DISCUSSION: By collecting multimodal imaging measures along with extensive behavioral measures from the same subjects, we are linking individual differences in neurochemistry, neural representation, and behavioral performance, rather than focusing solely on group differences between young and old participants. Our findings have the potential to inform new interventions for age-related declines. TRIAL REGISTRATION: This study was retrospectively registered with the ISRCTN registry on March 4, 2019. The registration number is ISRCTN17266136 .