Abstract
Bilateral damage to the amygdala can lead to a dramatic impairement in fear recognition through an inability to gaze at and utilize information about the eye region of faces (Adolphs et al., 2005). Here, we extended these findings by applying the Bubbles method, which asks viewers to discriminate happy and fearful faces from randomly sampled small regions of a face, with concomitant gaze tracking, to a group of four rare patients with focal bilateral amygdala damage (including new sessions with SM, the amygdala patient examined in Adolphs et al., 2005) as well as 20 healthy controls. Two of the amygdala patients behaved indiscriminably from healthy controls (JF and BG), while the other two (SM and AB) required an unusually large number of face samples to attain target performance, and neither gazed at nor made use of the eye region. Repeatedly instructing the two impaired amygdala patients to look at the eyes in faces reduced the number of face samples required to reach target performance within the range of healthy controls, and led these patients to gaze at and to use the eye on the right side of the face stimuli. In contrast, this instruction had little impact on the other amygdala patients and on healthy controls. We will argue that these distinct behavioral profiles found in amygdala patients are due to slight differences in their lesions.
Meeting abstract presented at VSS 2013