The effect of task constraints on the manipulation of visual information and the implications for the specificity of learning hypothesis

The specificity of learning hypothesis predicts that the removal and addition of vision causes a deterioration in aiming performance, and further that this detrimental effect increases as a function of practice (Proteau, 1992). The purpose of this study was to determine the effects of the addition and removal of visual information from a task emphasising the directional component of the movement. Subjects practised the task for a moderate and extensive number of trials in a target-only or normal vision condition. Following each practice phase, subjects were transferred to the other condition. The data indicated that while subjects' directional aiming error increased following the removal of vision, there were no detrimental effects following its addition. In fact, directional error was reduced when transferring to the normal vision condition. These positive effects of the addition of visual information relating to the directional component are not consistent with the present version of the specificity of learning hypothesis.