THE CONTEXTUAL INTERFERENCE EFFECT FOR SKILL VARIATIONS FROM THE SAMEAND DIFFERENT GENERALIZED MOTOR PROGRAMS

Magill and Hall (1990) hypothesized that the contextual interference ( CI) effect is found only when task variations to be learned are govern ed by different generalized motor programs (GMPs). The present experim ents examined their hypothesis by requiring subjects to learn variatio ns of a tapping task that had either different (Experiment 1) or the s ame (Experiment 2) relative timing structure. In each experiment, subj ects (N = 36) performed 270 acquisition trials with knowledge of resul ts (KR) in either a blocked or a serial order. One day later, subjects performed 30 retention trials without KR. In data analyses, errors du e to parameter modifications were dissociated from errors due to GMP c onstruction to examine which process was responsible for the CI effect . In both experiments, parameter learning created a CI effect while GM P learning failed to produce a CI effect. In the light of these findin gs, a modification is proposed to the Magill and Hall (1990) hypothesi s that takes into account these distinct processes in motor learning.