LAUSR

Motor imagery may be defined as the generation of an image of the acting self that lacks the final execution of a movement. This image is thought to be a simulation of the intended action from a first-person perspective. Recent studies with a Go/NoGo version of the discrete sequence production paradigm, in which a sequence of five finger movements was indicated by visuospatial cues, revealed that both motor imagery and motor preparation induced the learning of a fine hand motor skill. These findings suggest that there may be overlap in the processes activated during motor imagery and motor preparation. Twenty participants took part in an experiment in which they had to prepare, imagine, and execute a sequence of finger movements with the left or right hand. EEG was measured from 128 channels. Wavelet analyses were performed to determine response-side-related lateralizations in the alpha and beta bands. Analyses for the alpha band in the motor imagery condition showed decreased contralateral power with an initial parietal focus that became more occipital at the end of the time interval. A comparable pattern was observed in the motor execution condition. A reversal of this pattern was observed in the motor preparation condition, with an initial occipital focus that became more parietal at the end of the time interval. Comparable results were obtained for the beta bands. The current findings suggest that motor imagery and motor preparation are not equivalent, although they may only differ in the temporal order of the involved processes.