Abstract
People readily intercept moving targets with a delayed visual representation of their hand. Seeing the representation pass the target is enough to perform better on subsequent trials, so they are not just speeding up in response to the visual representation being less far than they expected. Here we examine the specificity of such sensory-motor adaptation. We examined generalisation to a different task (pursuing a moving dot with the unseen hand), to a new aspect of the same task (moving through a gap on the way to the target), and to slight modifications of the same task (starting the movement at a different position). The pursuit task was measured in separate sessions before and after adaptation. During adaptation, subjects intercepted targets that were moving to the left or right at various speeds. The delay between the position of the hand and that of its representation was gradually increased to 200ms. Delayed visual feedback was provided when the hand started 5 or 20 cm closer than the target’s path. No feedback was provided when it started 10 cm closer. Subjects adapted to the delay. This adaptation transferred to the 10 cm movements. There was no transfer to the pursuit task. In another session, subjects had to pass through a moving gap on their way to intercept the target. They only saw the visual representation of the hand as it passed the target. Nevertheless, they synchronized the delayed feedback with the gap. We propose that our subjects learnt to control the delayed representation of the hand (to use a tool), rather than learning to make specific movements (which would not transfer to a different starting point or to passing through a gap) or adjusting the haptic sensation of their hand to match what they see (which would have transferred to the pursuit task).
Meeting abstract presented at VSS 2013