Contribution of the anteromedial temporal lobes to the evaluation of facial emotion

Amygdala damage can result in impairments in evaluating facial expressions largely specific to fear. In contrast, right-hemisphere cortical lesions result in a more global deficit in facial emotion evaluation. This study addressed these 2 contrasting findings by investigating amygdala and adjacent cortical contributions to the evaluation of facial emotion in 12 patients with right and 11 patients with left unilateral anteromedial temporal lobectomy (RTL and LTL, respectively) and 23 normal controls. RTL but not LTL patients revealed impaired intensity ratings that included but were not exclusive to fear, with the most severe deficits confined to expressions related to affective states of withdrawal-avoidance. This suggests that affective hemispheric specializations in cortical function may extend to subcortical limbic regions. In addition, the right amygdala and adjacent cortex may be part of a neural circuit representing facial expressions of withdrawal.