Race, gender, and perceptual asymmetry for faces
Subjects made decisions about two sets of stimuli composed of faces designed to explore if there was an asymmetrical perceptual bias associated with visual field. One set of stimuli required subjects to compare two composites made up of either two left hemifaces or two right hemifaces with an original photograph or its mirror image. A second set of stimuli required subjects to select which of two chimeric photos (a composite half-neutral and half-smiling face paired with its mirror image) looked happier. The models consisted of a roughly equal number of males and females as well as an equal number of Blacks and Whites. Overall, subjects showed a left visual field (right hemisphere) bias for facial perception. Although there was no significant race effect, the patterns of perceptual asymmetry differed significantly between genders. Most males showed a left visual field bias while females displayed more variability both as individuals and as a group. Females were more likely than males to have either a right visual field or no bias, depending on the characteristics of the stimuli.