Abstract
Observers show biases in attention when viewing objects within versus outside of their hands' grasping space. For example, people are faster to detect targets presented near a single hand than targets presented far from the hand (Reed et al., 2006). While this effect could be due to the proximity of the hands alone, recent evidence suggests that visual biases near the hands could be contingent on both the hands' proximity and an observer's affordances for grasping actions (e.g., Thomas, 2015; 2016). The current study examined the role an observer's potential to act plays in biasing attention to the space near the hands. Sixty-one participants completed a standard Posner cueing task in which targets appeared on the left or right side of the display. Across blocks, participants either placed their non-responding hand near one of the target locations or kept this hand in their laps. Half of the participants completed this task with their hands free, creating an affordance for a grasping action. The remaining participants completed the task with their non-responding hand immobilized by a fingerboard, eliminating their potential to grasp. In the hands-free condition, participants showed faster detection of targets presented near the right hand than when targets were presented far from the hand. However, participants in the hands-immobilized condition were no faster to detect targets near the hands than targets appearing far from the hands. These results suggest that improved target detection is contingent not only on the proximity of the hands to a stimulus, but on the ability to use the hands in a grasping action as well.
Meeting abstract presented at VSS 2017