Functional MRI was used to identify the brain areas underlying automatic beliefs about gender and race, and suppression of those attitudes. Participants (n = 20; 7 females) were scanned at 3 tesla while performing the Implicit Association Test (IAT), an indirect measure of race and gender bias. We hypothesized that ventromedial prefrontal cortex areas (PFC) would mediate gender and racial stereotypic attitudes, and suppression of these beliefs would recruit dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC). Performance data on the IAT revealed gender and racial biases. Racial bias was correlated with an explicit measure of racism. Results showed activation of anteromedial PFC and rostral ACC while participants implicitly made associations consistent with gender and racial biases. In contrast, associations incongruent with stereotypes recruited DLPFC. Implicit gender bias was correlated with amygdala activation during stereotypic conditions. Results suggest there are dissociable roles for anteromedial and dorsolateral PFC circuits in the activation and inhibition of stereotypic attitudes.

We assessed political attitudes using the Implicit Association Test (IAT) in which participants were presented faces and names of well-known Democrat and Republican politicians along with positive and negative words while undergoing functional MRI. We found a significant behavioral IAT effect for the face, but not the name, condition. The fMRI face condition results indicated that ventromedial and anterior prefrontal cortices were activated during political attitude inducement. Amygdala and fusiform gyrus were activated during perceptual processing of familiar faces. Amygdala activation also was associated with measures of strength of emotion. Frontopolar activation was positively correlated with an implicit measure of bias and valence strength (how strongly the participants felt about the politicians), while strength of affiliation with political party was negatively correlated with lateral PFC, lending support to the idea that two distinct but interacting networks-one emphasizing rapid, stereotypic, and emotional associative knowledge and the other emphasizing more deliberative and factual knowledge-cooperate in the processing of politicians. Our findings of ventromedial PFC activation suggests that when processing the associative knowledge concerned with politicians, stereotypic knowledge is activated, but in addition, the anterior prefrontal activations indicate that more elaborative, reflective knowledge about the politician is activated.

The ability to read emotions in the face of another person is an important social skill that can be impaired in subjects with traumatic brain injury (TBI). To determine the brain regions that modulate facial emotion recognition, we conducted a whole-brain analysis using a well-validated facial emotion recognition task and voxel-based lesion symptom mapping (VLSM) in a large sample of patients with focal penetrating TBIs (pTBIs). Our results revealed that individuals with pTBI performed significantly worse than normal controls in recognizing unpleasant emotions. VLSM mapping results showed that impairment in facial emotion recognition was due to damage in a bilateral fronto-temporo-limbic network, including medial prefrontal cortex (PFC), anterior cingulate cortex, left insula and temporal areas. Beside those common areas, damage to the bilateral and anterior regions of PFC led to impairment in recognizing unpleasant emotions, whereas bilateral posterior PFC and left temporal areas led to impairment in recognizing pleasant emotions. Our findings add empirical evidence that the ability to read pleasant and unpleasant emotions in other people's faces is a complex process involving not only a common network that includes bilateral fronto-temporo-limbic lobes, but also other regions depending on emotional valence.