NEUROMOTOR PROGRAMMING - BILATERAL AND UNILATERAL EFFECTS ON SIMPLE REACTION-TIME

The effect of unilateral and simultaneous bilateral response requirements on fractionated simple reaction time for finger extension and elbow flexion tasks was examined. Twelve neurologically normal, female subjects participated in two blocks of 20 trials in each of the four conditions. There were no significant differences (p > 0.05) in simple reaction time (SRT) or premotor time (PMT) between unilateral and bilateral elbow flexion responses. In contrast the differences in SRT and PMT between unilateral and bilateral finger extension responses were significant (p < 0.05). A possible explanation in light of the different neural architecture for proximal and distal muscle representation is that elbow flexion responses are able to use a single neuromotor programme for bilateral and/or unilateral responses whereas bilateral finger extension responses require the 'linking' of two separate programmes.