Multiple paths to holistic processing: Holistic processing of Gestalt stimuli do not overlap with holistic face processing in the same manner as do objects of expertise.

Holistic processing is often considered to be limited to faces and non-face objects of expertise, with previous studies revealing a specific mechanistic overlap between the holistic processing of these stimuli. However, more recently holistic processing has been demonstrated for untrained, novel stimuli containing salient Gestalt perceptual grouping cues. The relationship between the holistic processing of these novel stimuli and of faces is unclear. Here we examine whether there is a mechanistic overlap between the holistic processing of these two stimulus categories. To do this we used the same two-back interleaved part-matching task previously used to examine the mechanistic overlap between the processing of faces and of objects of expertise. Concurrent holistic processing of these salient Gestalt stimuli did not impact (Experiment 1), nor was it impacted by (Experiment 2), holistic processing of face stimuli. This suggests that the nature of the overlap between holistic processing of faces and of salient Gestalt stimuli may be distinct from that between objects of expertise and faces. We discuss potential mechanistic accounts of this difference.