Facial closure: interrelationship with facial discrimination, other closure tests, and subjective contour illusions

Findings from previous research have argued for the dissociation of two visual-perceptual tasks traditionally thought to be mediated by the nondominant hemisphere (i.e. perceptual closure and facial discrimination). This, primarily methodological, study examined the extent to which the facial closure measure (Mooney closure faces test) involves "closure" and/or facial discrimination. A factor analysis of six visual perceptual measures, carried out separately for left brain damaged (LBDs, n=33) and right brain damaged (RBDs, n=30) patients, resulted in two relatively independent factors (i.e. a closure factor and a facial discrimination factor), with the Mooney closure faces test loading on both. The mixed factorial structure did not aid the facial closure measure's sensitivity to right-sided brain disease. Moreover, age and education intercorrelated differently with the two factors. Results argue for the use of more discrete visual-perceptual measures when examining perceptual functioning and/or right hemisphere integrity, and imply the existence of at least two discrete cortical level visual-perceptual neural systems.