Abstract
Motion-induced blindness (MIB) is an illusion in which peripheral targets perceptually disappear when surrounded by a moving mask (Bonneh et al., 2001). It has recently been proposed that disappearance results from a competition biased towards the transient mask due to stronger sensory adaptation of the stationary target (Gorea et al., 2009). Evidence supporting this adaptation account has primarily emerged from reports of MIB’s increasing magnitude across the trial (Gorea et al. 2009; Wells et al., 2011). However, timecourse effects could be due to changes in attentional or decisional processes over time rather than adaptation. Thus, our goal in the present study was to develop a novel method to test the role of adaptation in MIB. Specifically, we employed the motion aftereffect (MAE) as a measure of adaptation to the moving mask to determine whether motion adaptation could be linked to the reported amount of MIB. The adaptation account predicts that trials with more mask adaptation, or MAE, would yield less MIB. Method: The mask was composed of dots moving to the left or right with 100% coherent motion for 30 sec. In Part 1 of each trial, subjects reported the disappearance of a target. In Part 2, subjects’ MAE was assessed. The procedure involved estimating the direction and coherence of a 0%, 25%, or 50% coherent motion stimulus moving left or right. Results: We found a clear relationship between the magnitude of MIB and the MAE. Specifically, on trials when MIB was low, MAE was strongest, and on trials when MIB was high, MAE was weakest. These findings are consistent with the notion that greater adaptation to the mask is associated with diminished strength of the mask representation, reducing its competitive advantage over the target, and ultimately decreasing disappearance. These findings add novel support for the adaptation account of MIB.
Meeting abstract presented at VSS 2013