Dynamics of the learning of a morphokinetic movement sequence in humans.

We studied the dynamics of the process through which subjects build a visuomotor representation in memory as they learn a morphokinetic movement sequence presented on videotape. It was hypothesized that recall accuracy is closely tied to the dynamics of the movement-representation process. When analyzed in the form of time series, recall performance should exhibit a deterministic inter-trial relationship reflecting the memorization activity. Twelve subjects divided into two groups recalled a sequence of arm movements 60 times. The model was presented to Group 1 (G1) on all 60 trials, whereas Group 2 only saw the model on the first 30 trials. During these first 30 trials, the analysis of accuracy time series pointed out the short-term historicity of the deterministic inter-trials relationship. For the last 30 trials, this deterministic relationship disappeared in both experimental conditions, except for two subjects of G1, and was replaced by a white-noise process suggesting that a stable representation of the sequence has been built in long-term memory.