The Role of Sensory Gating in the Racism/Blood Pressure Relationship A Pilot Study

African Americans bear a disproportionate burden of hypertension with racism postulated as a unique stressor contributing to the noted disparities. Epidemiological studies have found differences in the prevalence of hypertension among African Americans based on the amount of perceived racism reported, and experimental studies have shown increased cardiovascular reactivity to racially-aversive stressors. A difference in individual response to racial stressorsmay create subgroups of African Americans at highest risk for hypertension and its complications. Although sensory gating is the brain's capacity to selectively regulate its sensitivity to environmental sensory stimuli, scant research has been done regarding the role of sensory gating in the stress response, and no research has explored sensory gating with racial stressors. To address this gap, we examined whether P50 sensory gating was associated with cardiovascular and central nervous system responses to an experimentally-induced racial stressor among 15 African Americans. A paired-click paradigm was administered prior to the experimental condition, which involved exposure to a neutral and then a racially-aversive photo stimulus. Participants with weak gating showed a significant within-subjects decrease in alpha-band activity when viewing the racially aversive stimulus and had significantly decreased alpha activity when viewing the aversive stimuli compared to participants with strong gating. Increased cardiovascular reactivity occurred with the aversive stimulus, and gender differences were noted. A gating effect on cardiovascular reactivity could not be determined given the small sample size and the fact that few men qualified as having 'good' gating. Although subjects reported no conscious awareness of distress when viewing the racially-aversive stimulus, both cardiovascular and central nervous system reactions occurred, with the responses varying based on the level of sensory gating. These results suggest sensory gating as a potential physiologic factor that may influence the relationship between perceived racial stressors and health outcomes.