The relative timing between eye and hand in rapid sequential pointing is affected by time pressure, but not by advance knowledge

Abstract

The present study examined the effect of timing constraints and advance knowledge on eye-hand coordination strategy in a sequential pointing task. Participants were required to point at two successively appearing targets on a screen while the inter-stimulus interval (ISI) and the trial order were manipulated, such that timing constraints were high (ISI = 300 ms) or low (ISI = 450 ms) and advance knowledge of the target location was present (fixed order) or absent (random order). Analysis of eye and finger onset and completion times per segment of the sequence indicated that oculo-manual behaviour was in general characterized by eye movements preceding the finger, as well as 'gaze anchoring' (i.e. eye fixation of the first target until completion of the finger movement towards that target). Advance knowledge of future target locations lead to shorter latency times of eye and hand, and smaller eye-hand lead times, which in combination resulted in shorter total movement times. There was, however, no effect of advance knowledge on the duration of gaze anchoring. In contrast, gaze anchoring did change as a function of the interval between successive stimuli and was shorter with a 300 ms ISI versus 450 ms ISI. Further correlation analysis provided some indication that shorter residual latency is associated with shorter pointing duration, without affecting accuracy. These results are consistent with a neural mechanism governing the coupling of eye and arm movements, which has been suggested to reside in the superior colliculus. The temporal coordination resulting from this coupling is a function of the time pressure on the visuo-manual system resulting from the appearance of external stimuli.

The multiple process model of goal-directed reaching revisited

“…In time-constrained laboratory settings, the limb movement might even begin prior to completing the primary saccade (Binsted et al, 2001), but importantly, the eyes would be stationary on the target for sufficient time to process extra-retinal and retinal input. The same is true when completing a sequence of aiming movements under externally-imposed time constraints (Deconinck et al, 2011;Neggers and Bekkering, 2000;2001). As shown in Figure 2 (panel B), the eye and limb movements to the second target in the sequence occur almost simultaneously but still the eyes are located on the target before the limb reaches peak velocity.…”

Saccadic delays on targets while watching videos

“…In doing a task, active visual search to the target initiates before moving the hand, whereas in watching the task, active visual search is not necessary. Previous studies on goal-directed movement showed that there can be a 100-400 ms delay in time between saccadic eye movement to the target and hand movement [Elliott et al 2010;Deconinck et al 2011]. After noticing the tool movement in video watching, subjects tended to follow the movement of the tool in a smooth pursuit with a reaction time of 200-300 ms [Sailer et al 2005;Deconinck et al 2011].…”

“…Previous studies on goal-directed movement showed that there can be a 100-400 ms delay in time between saccadic eye movement to the target and hand movement [Elliott et al 2010;Deconinck et al 2011]. After noticing the tool movement in video watching, subjects tended to follow the movement of the tool in a smooth pursuit with a reaction time of 200-300 ms [Sailer et al 2005;Deconinck et al 2011]. Adding these times together, we are not surprised to see there is a delay of 600 ms between the onset of saccadic eye movement in "doing" and "watching".…”

Accuracy of Discriminating between Similar Drug Names by Nurses: Effect of Finger-pointing on Error Prevention

“…The effects of finger-pointing can also be explained on the basis of eye movement. The fixation toward the first target was maintained until pointing toward the first target was terminated when participants were instructed to point their finger to two targets consecutively (Carey, 2000;Neggers & Bekkering, 2000, 2002Deconinck, Polanen, Savelsbergh & Bennett, 2011).…”