The eyes or the mouth? Feature salience and unfamiliar face processing in Williams syndrome and autism

Abstract

Using traditional face perception paradigms the current paper explores unfamiliar face processing in two neurodevelopmental disorders. Previous research indicates that autism and Williams syndrome (WS) are both associated with atypical face processing strategies. The current research involves these groups in an exploration of feature salience for processing the eye and mouth regions of unfamiliar faces. The tasks specifically probe unfamiliar face matching by using i) upper or lower face features, ii) the Thatcher illusion and iii) featural and configural face modifications to the eye and mouth regions. Across tasks, individuals with WS mirror the typical pattern of performance; with increased accuracy for matching faces using the upper than lower features, susceptibility to the Thatcher illusion and greater detection of eye than mouth modifications. Participants with autism show a generalised performance decrement alongside atypicalities; deficits for utilising the eye region and configural face cues to match unfamiliar faces.. The results are discussed in terms of feature salience, structural encoding and the phenotypes typically associated with these neurodevelopmental disorders.