Abstract
Previously, we reported that holistic processing (HP) of faces is reduced by a concurrent face, but not object, working memory load (WML; Gauthier & Cheung, VSS2005). Here, we ask if face discrimination is necessary for such interference. A recent study found that contextual processing of blobs atop bodies engages the fusiform ‘face’ area (FFA) as much as faces themselves, while bodies or blobs alone do not (Cox et al., 2004). HP was measured in a sequential matching task with two face composites, as participants attempted to selectively attend and compare one part of the composites (e.g., the top). HP was defined as a congruency effect, indicating that the to-be-ignored part influences judgments on the attended part. Three types of WML were imposed on this task, always consisting of 3 stimuli: faces on bodies, bodies alone or blurred blobs atop bodies. On face WML trials, different faces were always shown on the same bodies. The body and blob WMLs were identical except that blurred blobs were added atop the bodies. Consistent with prior work, the face WML reduced HP in the main task relative to the body WML. Critically, the blob WML reduced HP compared to the body WML, although the conditions only differed in the presence of undiagnostic blobs and WM performance was comparable. This suggests that the encoding or maintenance of diagnostic facial information is not necessary to interfere with face HP: rather, stimuli without any facial features but which elicit activity in FFA are sufficient.
This work was supported by a grant from the James S. McDonnell Foundation to the Perceptual Expertise Network