Implicit learning of a perceptual-motor skill after stroke

Background and Purpose. A motor skill can be learned implicitly, without aw areness of what is being learned. The purpose of this stud), was to examine the ability of adults who had unilateral stroke to learn implicitly a perc eptual-motor task. Subjects. Subjects were 47 people who were poststroke an d 36 control subjects. Methods. Participants performed sequences of hand mo vements in response to target lights in 2 conditions: a patterned sequence and a random sequence. Participants were not given explicit knowledge of th e presence of the 2 conditions. Those who had stroke performed with the upp er-extremity ipsilateral to the lesion. Results. Subjects who had stroke pe rformed more slowly than control subjects. For both groups,, times decrease d with practice of the patterned sequence, increased with introduction of t he random sequence, and decreased again with reintroduction of the patterne d sequence. Group differences persisted in a retention test given the next day of the patterned sequence, and both groups showed decreased times over the Course of the retention test. Discussion and Conclusion. People with st roke are able to learn a perceptual-motor task even without explicit instru ctions regarding the patterned sequence embedded in the task. [Pohl PS, McD owd JM, Filion DL, et al. Implicit learning of a perceptual-motor skill aft er stroke.