Abstract
Successful visual processing involves combining information about object features and their spatial locations. Spatial attention is thought to play an important role in this binding process. However, it has been shown that attention is not only allocated to a specific spatial location (space-based attention) but can also spread across an object (object-based attention). Here we explored whether binding is sensitive to space-based or object-based effects, using a recent finding thought to reflect location binding called the spatial congruency bias (Golomb et al., 2014). The spatial congruency bias shows that when two stimuli are presented in the same location individuals perceive them as more similar in features/identity. We tested whether two stimuli are also perceived as more similar when contained within the same "object" compared to on different objects. Participants fixated at the center of a display with two rectangular frames representing two "objects" (as in Egly et al, 1994). A first stimulus (colored square) was presented on one end of one object and then masked; after a brief delay, a second stimulus was presented and masked. These two stimuli could be presented in the same exact location, a different location on the same object, or a different location on a different object. Importantly, location was irrelevant to the task, which was to judge same or different color. We replicated the spatial congruency bias such that two stimuli presented in the same location were more likely to be judged as the same color. Notably, we also found that participants were more likely to indicate that two stimuli were the same color when they were presented on the same object compared to being presented across different objects. These results suggest that both space-based and object-based effects influence the spatial congruency bias and may play a role in location binding.
Meeting abstract presented at VSS 2016