Abstract
The present study investigated how attention is distributed over dominant and suppressed stimuli under binocular rivalry. The previous studies have found that the suppressed stimuli can be influenced by attention but did not examine how attentional modulation is allocated to each of the dominant and suppressed stimuli (Shin, Stolte, & Chong, 2009). It is possible that attention preferentially enhances the processing of dominant stimuli at the expense of suppressed ones, or similarly modulates the processing of both dominant and suppressed stimuli. To investigate these hypotheses, we measured the effect of attention on both of the dominant and suppressed stimuli when they were simultaneously attended. We used moving and tilted gratings for dominant and suppressed adapters, respectively, and then measured motion aftereffects (MAEs) and tilted aftereffects (TAEs) for each type of adapter. We presented both types of adapters to the left and the right of the fixation cross, thereby the dominant and suppressed adapters occupying the same location. While adapting to these adapters, participants performed a contrast decrement detection task on one of the MAE adapters, which required spatial attention. For the MAE adapters, which were dominant, we found that there was a larger amount of MAEs at attended locations than at unattended locations. However, spatial attention did not significantly modulate the amount of aftereffects from the suppressed adapters. Although the suppressed adapters were strong enough to produce a significant amount of TAEs, spatial attention enhanced the amount of TAEs only when the suppressed adapters were partially suppressed. These results suggest that spatial attention gives more priority to dominant stimuli over suppressed stimuli.
Meeting abstract presented at VSS 2013