Influence of visual stimulus mode on transfer of acquired spatial associations.

Associations between corresponding stimulus–response locations are often characterized as overlearned, producing automatic activation. However, 84 practice trials with an incompatible mapping eliminate the benefit for spatial correspondence in a transfer Simon task, where stimulus location is irrelevant. The authors examined whether transfer occurs for combinations of physical-location, arrow-direction, and location-word modes in the practice and transfer sessions. With 84 practice trials, the Simon effect was reduced for locations and arrows, and there was complete transfer across these modes; location words showed little transfer within or between modes. These results suggest that the acquired short-term associations were based on visual-spatial stimulus codes distinct from semantic-spatial codes activated by the words. With 600 practice trials, words showed transfer to word and arrow but not location Simon tasks, suggesting that arrows share semantic-spatial codes with words. Reaction-time distribution functions for the Simon effect showed distinct shapes for each stimulus mode, with little impact of the practiced mapping on the shapes. Thus, the contribution of the short-term location associations seems to be separate from that of the long-term associations responsible for the Simon effect.