On the distribution of attention in a visuo-manual adaptation task.

We have observed in a previous study that adaptation to reversed visual feedback in a tracking task is better when subjects are instructed to look at the cursor providing feedback (group C) rather than at the target (group T). Since both groups actually looked at the target, irrespective of their instructions, we suggested that the advantage of group C is not related to their eye movements, but rather to their allocation of spatial attention. The present study scrutinized this view by combining the same adaptation task with a concurrent reaction-time task, designed to spread subjects' attention across the whole display area. Again, subjects were instructed to look at the cursor or at the target, and again, both groups actually looked at the target. Adaptation was similar to group T, and poorer than group C of the previous study. We therefore concluded that adaptation indeed depends on the subjects' allocation of attention: focussing attention mainly on the target, or spreading it across the whole display area, is not as good as distributing attention between target and cursor.