Effects of Physical and Observational Practice on Intermanual Transfer.

Some studies have shown that different coordinate systems in the coding of movement sequences develop during observational and physical practice. According to Newell's (Newell, 1986) constraintsled approach, such contradictions could possibly depend on task characteristics. Accordingly, in the present study, two experiments were designed using a five-segment sequence timing task, in which the instructions on how to perform the sequence were different. The task in the first experiment comprised an alternating shift of fast and slow segments, whereas the second experiment involved an incremental procedure from slow to fast. In these experiments, the intermanual transfer of absolute and relative timing through observational and physical practice was examined. Transfer conditions were such that they required the same motor commands (mirror transfer) or the same visual-spatial coordinates (non-mirror transfer) as those in the practice conditions. The first experiment showed that the transfer to the non-mirror condition for relative timing in the physical group was better than that to the mirror condition, while the transfer was similar for both conditions in the observational group, indicating a different pattern of transfer for relative timing. The relative timing transfer pattern in the second experiment was the same for both experimental groups, such that the physical and observational practice resulted in a similar transfer to both mirror and non-mirror conditions. In both experiments, observational and physical practice participants exhibited similar intramanual transfer of absolute timing under both transfer conditions. Thus, the task itself as a constraint was revealed to be an effective factor influencing the behavioral results derived from physical and observational practice.