Influence of handedness on spatial compatibility effects with perpendicular arrangement of stimuli and responses

Abstract

The present study was conducted to determine a possible spatial compatibility effect in absence of any overt correspondence between spatial properties of stimuli and responses, in an experimental situation in which the stimuli were displayed vertically and the responding hands were disposed horizontally. The subjects were requested to make unimanual discriminative key-pressing responses to two light stimuli. The results indicate a preferential association of the dominant hand (right for right-handers and left for left-handers) with upper visual stimuli and the non-dominant hand with lower visual stimuli. This effect can result from a correspondence between the spatial codes associated with the location of the stimulus and the internal representation of the two hands along the vertical dimension, whereby the dominant hand is assigned a ‘higher’ position compared to the non-dominant hand. In this way the position of the two hands along the vertical dimension and the physical position of the two stimuli can be matched according to the same spatial code and producing the spatial compatibility effect reported in the present study.