Frequency and precision of feedback and the adaptive process of learning a dual motor task

Feedback has been considered a fundamental component of the motor learning process (MAGILL, 2007; SCHMIDT & LEE, 2011; SCHMIDT & WRISBERG, 2008). During and after the execution of a movement, the learner normally receives two types of feedback about the performance, intrinsic and augmented. Intrinsic feedback is information that comes from the sensory system and augmented feedback comes from an external source. This external information can be provided by either a teacher or researcher and may focus on the outcome (knowledge of performance KR) or the technique (knowledge of performance KP). By the time closed-loop (ADAMS, 1971) and schema (SCHMIDT, 1975) theories were proposed, the main rule when providing KR was “more is always better” to the formation of cognitive structures (traits and schemas, respectively). These theories have triggered several upcoming studies on KR, especially regarding its schedule (frequency), precision and temporal locus. On the whole, the fi ndings indicate that learning was optimized when KR was integral, that is, frequent, accurate and immediate. However, SALMONI, SCHMIDT and WALTER (1984) detected that most of these studies did not use no-KR transfer tests to tear temporary effects of practice (acquisition), apart from permanent learning effects (KR withdrawal). Since then, an experimental design of KR in acquisition followed by no-KR in transfer was consolidated on the grounds that when KR is withdrawn on transfer tests, the temporary acquisition effects dissipate and, as a result, learning can be inferred. The paper of SALMONI, SCHMIDT and WALTER (1984) can be considered a milestone in the motor learning fi eld because it sparked a flurry of studies (for reviews, see ADAMS, 1987; SWINNEN, 1996; WULF & SHEA, 2004; WULF, SHEA & LEWTHWAITE, 2009) which not only reexamined classical KR factors (i.e., precision, schedules, temporal locus, interpolation of activities during intervals), but also investigated new KR variables (i.e., erroneous, bandwidth, and self-controlled). To date, the examination of KR still remains strong and the fi ndings indicate that integral KR is only effective in very special conditions, for example, on initial stages of learning complex motor skills (GUADAGNOLI & LEE, 2004; SHEA & WULF, 2005). Briefl y, there seems Abstract