Abstract
Visual attention and awareness are closely related but dissociable processes. One demonstration of the dissociation between attention and awareness comes from attentional allocation toward invisible targets (Jiang, Costello, Fang, Huang, & He, 2006). However, there are multiple subtypes of visual attention, and it is probable that there are differences in the relationship between attention and awareness for different subtypes. Thus, it might be that some aspects of attention, such as orienting to a change in the saliency map of the visual field, demonstrated by Jiang and colleagues (2006), continue to operate without awareness, while other aspects of attention, such as attentional tracking, only occur with awareness. We designed experiments to determine whether attentional tracking can take place without conscious awareness of to-be-tracked moving targets. First, we replicated the result of Jiang and colleagues (2006). We used continuous flash suppression to render images invisible, then measured subjects' performance on a subsequent visible two-alternative forced-choice gabor orientation judgment task in the location of an invisible attentionally salient or non-salient stimulus. We replicated the result that subjects' discrimination of gabor orientation was influenced by the attentionally salient stimuli. We then modified the paradigm to test attentional tracking. We presented an attentionally salient stimulus which morphed into a dot, then moved across the screen to a different location while remaining invisible. We tested subjects' performance on the orientation discrimination task in both the original location of the attentional stimulus and the final location of the associated trackable dot. We found that subjects' performance on the rotation task was influenced in both locations, compared to control locations where a non-salient stimulus and trackable dot appeared. This suggests that attentional tracking can occur without awareness of the tracked stimulus. These data imply that even certain advanced aspects of attention are dissociable from awareness.