Holistic Processing Is Not Always a Property of Right Hemisphere Processing- Evidence from Computational Modeling of Face Recognition

Abstract

The hemispheric asymmetry literature traditionally posits that holistic processing (HP) is a property of right hemisphere (RH) processing. Nevertheless, a counterexample was recently found: for Chinese character recognition expertise, studies showed reduced HP (as measured in the composite task) and increased RH lateralization, revealing that these two effects may be separate processes. With a computational model of face recognition, in which we implement a theory of hemispheric asymmetry in perception that posits a low spatial frequency bias in the RH and a high spatial frequency bias in the left hemisphere (i.e., the Double Filtering by Frequency Theory of Ivry and Robertson), here we show that when the face recognition task relies purely on featural information, there is a negative correlation between HP and RH lateralization: HP increases whereas RH lateralization decreases with increasing stimulus dissimilarity. In contrast, when the face recognition task relies purely on configural information, there is a strong positive correlation between HP and RH lateralization: both HP and RH lateralization increase with increasing stimulus dissimilarity. These results suggest that HP and RH lateralization are separate processes that can be influenced differentially by task requirements.