Enhanced visual attention and implicit learning of local context in Autism Spectrum Disorders (ASD)

Background: There is much evidence to suggest that individuals with ASD are characterised by a tendency for attention to details and a processing bias towards featural and local information (Frith, 1989; Happé & Frith, 2006). In visual tasks this cognitive style has been claimed to lead to reduced global/contextual processing, but not when individuals are explicitly required to attend to global information (e.g., Plaisted, Sweetenham & Rees, 1999). Objectives: We aimed to investigate whether individuals with ASD show reduced processing of context (local and global) in visual search tasks, when context learning was either implicit or explicit. Methods: Participants were asked to search for a target which was embedded in a predictive or a non predictive context (Chun & Jiang, 1998) in a series of experiments. Results: Results showed that both individuals with ASD and a control group were able to use predictive contexts whether the context learning was explicit or implicit. It was also found that when the context was implicitly learned, the ASD group outperformed the control group, but only when the local context always predicted the target location. Conclusions: These results suggest that individuals with ASD can attend to and use contextual information both when implicitly and explicitly required to, but they are even better than TD individuals when what they attend and learn is the local context. Results will be discussed in terms of the enhanced perception of individual features hypothesis (Plaisted, Saksida, Alcántara & Weisblatt, 2003).