Article

SM is a patient with complete bilateral amygdala lesions who fails to fixate the
eyes in faces and is consequently impaired in recognizing fear (Adolphs et al.,
2005). Here we first replicated earlier findings in SM of reduced gaze to the
eyes when seen in whole faces. Examination of the time course of fixations
revealed that SM's reduced eye contact is particular pronounced in the first
fixation to the face, and less abnormal in subsequent fixations. In a second set
of experiments, we used a gaze-contingent presentation of faces with real time
eye tracking, wherein only a small region of the face is made visible at the
center of gaze. In essence, viewers explore the face by moving a small
searchlight over the face with their gaze. Under such viewing conditions, SM's
fixations to eye region of faces became entirely normalized. We suggest that this
effect arises from the absence of bottom-up effects due to the facial features,
allowing gaze location to be driven entirely by top-down control. Together with
SM's failure to fixate the eyes in whole faces primarily at the very first
saccade, the findings suggest that the saliency of the eyes normally attract our
gaze in an amygdala-dependent manner. Impaired eye gaze is also a prominent
feature of several psychiatric illnesses in which the amygdala has been
hypothesized to be dysfunctional, and our findings and experimental manipulation
may hold promise for interventions in such populations, including autism and
fragile X syndrome.
CI - Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS