A Simon effect induced by induced motion and location: Evidence for a direct linkage of cognitive and motor maps

It has been argued that two distinct maps of visual space are formed: a cog nitive map that is susceptible to illusions, and a motor map that represent s the physical world veridically. In the present study, subjects responded to a nonspatial attribute of a visual target stimulus by pressing a left or right key, while an illusory horizontal displacement of the target was ind uced. A Simon-type effect was obtained to the induced target motion or posi tion shift-that is, responses were faster when the illusory target motion o r location corresponded to the response position. Further experiments indic ated that the observed effects cannot be accounted for by attentional shift s. These results suggest that the content of the cognitive map does not onl y influence perceptual judgments but is also responsible for the automatic activation of response codes. In other words, perception and action seem to be fed by a common, cognitively penetrable, spatial representation.