STIMULUS-RESPONSE COMPATIBILITY FOR VERTICALLY ORIENTED STIMULI AND HORIZONTALLY ORIENTED RESPONSES - EVIDENCE FOR SPATIAL CODING

It has previously been shown that, when stimuli positioned above or be low a central fixation point (''up'' and ''down'' stimuli) are assigne d to left and right responses, the stimulus-response mapping up-left/d own-right is more compatible than the mapping up-right/down-left for r esponses executed by the left hand in the left hemispace, but this rel ation is reversed for responses executed by the right hand in the righ t hemispace. In Experiment 1, each hand responded at locations in both hemispaces to dissociate the influence of hand identity from response location, and response location was found to be the determinant of re lative compatibility. In Experiment 2 responses were made at the sagit tal midline, and an inactive response switch was placed to the left or right to induce coding of the active switch as right or left, respect ively. This manipulation of relative location had an effect similar to , although of lesser magnitude than, that produced by physically chang ing location of the response switch in Experiment 1. It is argued that these results are counter to predictions of a movement-preference acc ount and consistent with the view that spatial coding underlies compat ibility effects for orthogonally oriented stimulus and response sets.