Attentional Facilitation During Reaches and Saccades in a Cluttered Setting

Abstract

When people make a movement to reach or saccade to an object, there is evidence that attention shifts to the goal of the movement. While eye-hand movements are a crucial part of daily living, research into how attention is deployed during eye-hand movements has focused on sparse arrays. This experiment takes the next step towards documenting the spatiotemporal profile of attentional facilitation during eye and hand movements in the real world by using a design with a complex visual array of multiple targets and distractors to better mimic natural surroundings. Participants made a reach or saccade and reach to one of two targets, presented within an array of seven constantly present distractors, and a probe (contrast increment) was shown at one of these locations on each trial. The stimulus onset asynchrony (SOA) between cue and probe varied from trial to trial. Correct identification of the probe location was used to quantify attention. In line with previous findings, higher probe detection performance was found for the saccade + reach condition compared to the reach alone condition, supporting theories that suggest perceptual benefits with the localisation of overt attention to a target. Reach latencies were generally longer than previously observed in other studies and there was also a higher rate of data exclusion. Altogether, these results suggest the possibility of a different pattern of attentional facilitation across complex versus simple scenes. These findings reaffirm the need for more naturalistically-representative design layouts to be employed in future studies on attentional facilitation.