Reduced temporal fusion in near-hand space

Object-substitution masking (OSM) is thought to reflect a failure of object individuation. That is, a briefly presented target surrounded by four dots is perceptually fused with the four-dot mask when the mask is visible after the target has disappeared, thereby obscuring the visibility of the target. If OSM depends on the inability to temporally segregate objects, then increasing the temporal precision of the visual system should reduce OSM. In the study reported here, we manipulated temporal precision by varying the proximity of participants' hands to visual stimuli, because stimuli in near-hand space have been found to enjoy enhanced attentional processing, and attention is known to speed visual processing. Hand placement was indeed found to affect OSM: Placing participants' hands near the visual stimuli reduced the magnitude of the masking. This finding demonstrates that object individuation can be facilitated by increasing the temporal resolution of vision via increasing the proximity of visual stimuli to the hands.