THE INFORMATIONAL ROLE OF KNOWLEDGE OF RESULTS IN MOTOR LEARNING

An experiment is reported that was set-up to examine the informational role of knowledge of results (KR) in the learning of a single-limb mo vement timing task. A group with KR practiced 200 trials a day for 5 d ays prior to receiving a sixth day of practice without KR. The perform ance of this group was contrasted to another group that practiced 200 trials without KR for one day. Traditional movement error and time ser ies analyses revealed that KR serves to calibrate the movement outcome to the task demands and modulate the performance outcome relation bet ween trials. The degree of systematic trial-to-trial modulation was st rongly dependent upon the degree of error exhibited on any given trial , and was enhanced under no-KR conditions. Information in KR has both immediate and persistent influences on learning and performance that a re dependent upon the task constraints and the skill level of the perf ormer.