Specificity of motor learning does not deny flexibility

Two experiments are reported that challenge the generalisability of the specificity hypothesis. The first experiment in which subjects (N = 24) were required to make one-handed catches under the condition that they could only see the ball, in an otherwise completely dark room, produced results in line with the hypothesis. However, when the same subjects, after a 3-4 day training period, under the latter condition, were transferred to a condition in which they could see both hand and ball they demonstrated, contrary to what would be predicted by the hypothesis, significant increases in catching performance. In a second experiment subjects (N = 32) were required to catch balls under a variety of conditions in which viewing the hand only, or viewing the hand and ball, were interspersed in a number of ways. The results suggested that subjects who have experience of performing in the presence of both kinds of information (ball only or ball and hand) adopt the particular perception/action coupling appropriate to the situation in which they find themselves and, to this extent, treat the two conditions as different skills. This lead to a reinterpretation of the specificity hypothesis which takes account of the flexibility in performance under changing environmental conditions characteristic of the skilled performer.