Abstract
We are constantly exposed to numerous objects vying for limited processing resources. Such competition is thought to be resolved based on bottom-up salience and top-down goals, but a growing body of research suggests that past experience stored in memory can also play an important role in shaping attentional priorities. In a previous fMRI study, we showed that such memory-guided attention is supported by repetition attenuation — the lower fMRI response elicited by repeated vs. novel stimuli. When a repeated scene and a novel scene were presented simultaneously at different locations, the attenuated response for the repeated scene enhanced processing of the novel scene. In the present study, we replicated these findings using a task that allowed for better neural separation between the novel and repeated objects by selecting them from different categories. This also allowed us to generalize from spatial to object-based attention. Each trial began with two presentations of the same face at fixation. In the repeated/novel condition, the face was presented a third time in competition with a surrounding novel scene. The novel/novel condition was identical, except a novel face appeared with the scene instead of the repeated face. We later tested long-term memory for the scenes to index how well they were processed. Two results suggested that repetition attenuation for the face biased processing toward the scene: First, there was a negative correlation across trials between activity in face-selective cortex during the competitive event and subsequent memory for the scene. Second, this relationship was found in the repeated/novel but not the novel/novel condition. Whereas most studies of repetition effects focus on the processing of repeated or similar stimuli, here we show broader consequences for the processing of unrelated stimuli. Specifically, these expressions of perceptual memory automatically bias competitive dynamics in the visual system to highlight new information.
Meeting abstract presented at VSS 2014