Abstract
During many daily tasks we typically look at an object first and then we reach towards it. It has been shown in monkeys that areas related to hand movement planning integrate information about the current eye and hand position. Similar interactions have been observed using psychophysical studies in humans. In a series of experiments we measured how reaching preferences are updated when eye position is changing. In the first experiment participants were asked to reach to one of two locations in a free choice task, while fixating at different locations on the screen. In accordance with previous studies, we demonstrated that selection of the reaching target is influenced by the current eye position: Participants were more likely to choose targets closer to the current gaze direction. In the second experiment we asked participants to make a saccade to a cued location, and during saccade preparation we briefly flashed two possible reaching targets. The results showed that reaching goal preferences were influenced by the future eye position for targets flashed 100 ms before the eye movement onset, suggesting that reaching target selection takes into account the future eye position before saccade onset. This extends physiological and behavioural findings on eye - hand position interactions by demonstrating updating of reaching preferences before the eye movements.