Difference in stimulus-response compatibility effect in premotor and motor time between upper and lower limbs.

Abstract

The present study assessed differences in stimulus-response compatibility effects during central information processing and peripheral motor control between upper and lower limbs by measurement of times for premotor and motor response to a stimulus presented to one visual hemifield. 16 subjects participated. One stimulus-response assignment was Compatible and the other was Incompatible. In the former, the stimulus presented in the left field required a response from a left limb, and that presented in the right field required a response from a right limb. In the Incompatible condition, assignments were reversed. For both conditions, subjects were required to release the key for the upper or the lower limb as quickly as possible. The analysis of Premotor time showed the stimulus-response compatibility effect for both upper and lower limb responses, although analysis of Motor time indicated the stimulus-response compatibility effect occurred in only a lower limb response. It is concluded that the effect of stimulus-response compatibility for upper limb response was influenced only by central information processing, while the effect for lower limb response was influenced also by peripheral motor control.