Kirsch, W.
Department of Psychology, University of Wuerzburg, Wuerzburg, Germany
The purpose of the study was to examine the impact of sequence complexity and of visual feedback on the representation acquired during practice of hand movement sequences. The task required the participants to repeatedly hit a series of spatial targets in a fixed order. There were two target conditions and two feedback conditions: (1) a sequence of targets could consist of 5 or 7 elements; (2) during the movements the next target location could visually be presented or had to be retrieved from memory. After some practice blocks a test phase was introduced, in which participants were asked to perform the task with the untrained hand according to the original sequence of stimuli or to a mirrored version of them. We found that transfer to the same spatial locations was significantly better than transfer to the homologues muscles when the sequence was rather complex. For the simple sequence condition, in contrast, the transfer in motor coordinates was comparable to the transfer in visual-spatial coordinates. These results seem to support the view that complex movement sequences are efficiently coded in visual-spatial coordinates, whereas in simple movement sequences motor codes are given more weight.