Difference of S-R compatibility effect in left and right hemispatial response positions between upper and lower limbs

Abstract

The present study was aimed to clarify the hemispatial effect to stimulus-response (S-R) compatibility in upper and lower limb responses, and to determine the difference in S-R compatibility effects in central information processing time and peripheral motor time between upper and lower limbs by measurement of reaction time divided into premotor time and motor time. In order to the either left or right stimulus and the two effectors had been positioned in same hemispace, the 90' head-rotation paradigm had been used. Twelve subjects participated in two experimental conditions (left and right hemispatial conditions). One S-R assign-ment was Compatible (left/left, right/right), and the other assignment was Incompatible (left/right, right/left). The analysis of premotor time showed the S-R compatibility effect for both upper and lower limb responses, but they were not influenced by hemispatial effect. Accordingly, it was suggested that the hemispatial effect was not influenced to S-R compatibility in upper and lower limbs, but the translation time of stimulus to response code was strongly affected. And the analysis of difference in S-R compatibility effect between upper and lower limb was not significant for premotor time, though it was significant for motor time. We concluded that S-R compatibility effect for central information processing time was not different between upper and lower limb, but for motor program respect to peripheral motor control was different in both response effectors.