Evidence of Neuromuscular Adaptation According to Motor Sequential Learning in the Serial Reaction Time Task

[Purpose] The aim of the current study was to investigate whether or not motor sequential learning leads a reduction in the temporal processing in terms of the onset of muscle activation and movement initiation as well as final motor response in a serial reaction time (SRT) task. [Subjects] We recruited 24 healthy subjects with no history of neurological or orthopedic problems. The subjects were randomly divided into a training group and a control group. [Methods] In response to five visual stimuli, subjects were instructed to move or press a moveable arm/button, and to return it toward the central position as quickly as possible, according to the corresponding stimuli. Kinetic parameters (i.e. onset of muscle activation and movement initiation, reaction time) were analyzed before and after training/controlled sessions over two consecutive days for each group. [Results] Following motor sequential learning, the temporal processing between the visual stimuli and each of three predetermined onsets were significantly declined. There were no significant changes in the control group. [Conclusion] The reduction in the total process to final motor response resulting from motor sequential learning may be attributed to rapid onset of muscle activation and movement initiation. Furthermore, neuromuscular adaptation played an important role in accomplishing rapid temporal processing after motor sequential learning.