Visual Search - Effects of Autism

Effects of Autism

In line with previous research, O’Riordan, Plaisted, Driver, and Baron-Cohen showed that autistic individuals performed better and thus with lower RT than matched controls without autism in feature and conjunctive visual search tasks. Several explanations for this phenomenon have been suggested. Firstly, it is suggested that visual search tasks most likely involve exogenous orienting of attention, meaning that attention is guided by an external stimulus. A study by Swettenham, Milne, Plaisted, Campbell, and Coleman reported that autistic individuals had impaired endogenous attention shifts but intact exogenous shifts. Therefore, since visual search tasks emphasize exogenous attention shifting, this explains how autistic individuals can have superior performance on these tasks. A second reason for Autistic individuals’ superior performance on visual search tasks is that they have superior performance in discrimination tasks between similar stimuli and therefore may have an enhanced ability to differentiate between items in the visual search display. A third suggestion is that Autistic individuals may have stronger top-down target excitation processing and stronger distractor inhibition processing than controls. O’Riordan, Plaisted, Driver, and Baron-Cohen.

Keehn, Brenner, Palmer, Lincoln, and Müller used an event-related functional magnetic resonance imaging design to study the neurofunctional correlates of visual search in autistic children and matched controls of typically developing children. Autistic children showed superior search efficiency and increased neural activation patterns in the frontal, parietal, and occipital lobes when compared to the typically developing children. Thus, Autistic individuals’ superior performance on visual search tasks may be due to enhanced discrimination of items on the display, which is associated with occipital activity, and increased top-down shifts of visual attention, which is associated with the frontal and parietal areas.