Holistic versus detailed visual processing in body dysmorphic disorder: testing the inversion, composite and global precedence effects.

Individuals with Body Dysmorphic Disorder (BDD) are preoccupied with perceived defects in their appearance that are not visible to others. An excessive focus and processing of details has been proposed as a possible mechanism underlying this distorted self-image in BDD. The nature and extent of visuoperceptual abnormalities in BDD however require further investigation; specifically, it remains unclear whether feature-based processing in BDD is a result of a failure of holistic perceptual processes. The present study evaluated whether BDD is associated with an impairment in global processing. Twenty-five individuals with a primary diagnosis of BDD (15 unmedicated, 10 medicated) and 25 matched healthy controls were administered three robust behavioural tasks that test holistic encoding, namely the face inversion, the composite and the navon tasks. Overall, individuals in the BDD and control groups performed similarly in all aspects of holistic processing tested. Our findings suggest that the excessive focus on specific aspects of appearance in BDD may not be explained by impairments in the global encoding of visual information. Implications of these results and suggestions for future research on visual processing in BDD are discussed.