A study on how concurrent visual feedback affects motor learning of adjustability of grasping force in younger and older adults

In this study, we investigated the differences of the effectiveness from concurrent visual feedback among younger and older adults in learning tasks that require adjustability of grasping force (AGF), as well as the functions related to AGF in each generation. The younger and older adult groups were evaluated for simple visual reaction time as visual-motor speed (VMS) and a 100 g AGF task that reflected the difference between desired performance and actual performance. The main learning task was then practiced using concurrent visual feedback and tested without feedback. The VMS of older adults was slower than that of the younger, and the error in the 100 g AGF task was larger in older adults than in the younger adults. Performance improved from pre-test to retention test in both groups, but the older adult group failed to reach the level of the younger adult group. The results of this study show that concurrent visual feedback is effective for learning the tasks that require AGF in both groups. Indicatively, improvement in performance during practice is insufficient in older people for whom there is a large difference between desired performance and actual performance, or whose VMS is slow.