Attitudes and the brain

Evaluative responses appear to involve two seemingly distinct sets of processes: those that are automatically activated and others that are more consciously controlled. Using functional magnetic resonance imaging, we investigate the brain systems associated with automatic and controlled evaluative processing. In one set of studies, participants made either evaluative (good- bad) or nonevaluative (past-present or abstract-concrete) judgments about stimuli. Greater amygdala activity was observed to emotionally valenced stimuli regardless of whether the task directly involved an evaluative judgment (GB) or not (PP or AC). Good-bad judgments resulted in greater medial and ventrolateral prefrontal cortex (PFC) activity than past-present judgments. Additionally, there was greater ventrolateral PFC activity in good-bad judgments marked by greater ambivalence. In another line of research, White participants viewed Black and White faces during event-related fMRI. When the faces were presented for 30 ms, activation in the amygdala was greater for Black than for White faces. When the faces were presented for 525 ms, this difference was significantly reduced, and regions of frontal cortex associated with control and regulation showed greater activation for Black than White faces. Moreover, greater race bias on an indirect behavioral measure was correlated with greater difference in amygdala activation between Black and White faces, and frontal activity predicted a reduction in Black-White differences in amygdala activity from the 30ms to the 525ms condition.  These results provide evidence for neural distinctions between automatic and more controlled processing of social groups, and suggest that controlled processes may modulate automatic evaluation. Together, these findings indicate neural and functional distinctions between processes engaged for automatic and controlled evaluation.