Poor coherent motion discrimination is the consequence of magnocellular impairment in autism spectrum disorders?

Autism spectrum disorder (ASD) has been associated to poor performance in a coherent dots motion detection task (CDM), a task that measures dorsal-stream sensitivity as well as fronto-parietal attentional processing. To clarify the role of spatial attention in the CDM task, we measured the perception of moving dots displayed in the central or in the peripheral visual field in ASD and typical development children. A dorsal-stream deficit in ASD children should predict generally worse performance in both conditions. However, we show that in ASD children the CDM perception was selectively impaired in the central condition. Moreover, in children with ASD, the central CDM efficiency was predicted by the ability to zoom out the attentional focus, measured combining an eccentricity effect with a cue-size paradigm. These findings suggest that a pure dorsal impairment could not completely explain poor CDM perception in ASD, but that the role of visual spatial attention in integrating the spatiotemporal information should also be taken into account.