Leuven Christmas Applied Vision Association (AVA) Conference location:Leuven, Belgium date:19-20 December 2013
What does an individual with an autism spectrum disorder (ASD) perceive first: the forest or the trees? 30 years of research on local-global visual processing in ASD has led to influential frameworks like the Weak Central Coherence (WCC) theory and the Enhanced Perceptual Functioning (EPF) account. Nevertheless, the exact interplay of local and global visual processing in ASD remains only partly understood. Research findings vary in indicating a local processing bias or a global processing deficit, and results often bluntly contradict each other. Here, we have applied a formal meta-analytic approach, and combined 56 articles on the perception of local and global order in ASD using a wide range of stimuli and tasks. Compared to typically developing (TD) individuals, individuals with ASD show no enhanced local visual processing nor an overall deficit in global visual processing. However, detailed analysis does yield a clear difference in the temporal pattern of the local-global interplay, i.e., slower perception of global order in ASD. Gender, age or IQ of either participant group does not seem to influence performance differentially. Although several important moderator variables have been included in the present study, new experimental research is necessary to identify more clearly which (other) variables are at play and how the temporal pattern of global order perception precisely differs for individuals with ASD compared to TD.