Abstract
Priority maps are real-time representations of the behavioral salience of locations in the visual field, which guide the deployment of attention and the planning of saccades. Here, we reconstructed the priority map of faces from BOLD signals in V1 by quantifying the spatial profile of neural activity using population receptive field (pRF) mapping. We used images of upright and inverted faces. Phase-scrambled faces were also used as baseline. In the behavioral experiment, subjects viewed the images and performed a one-back memory task on the stimuli. We recorded the target location of subjects' first saccade for each of the images. In the fMRI experiment, subjects performed a one-back memory task in which subjects needed to attend to the stimuli or a RSVP task on a central letter stream in which their attention was directed away from the stimuli. To reconstruct the priority map, we measured the attention effect size by comparing the BOLD signals in the two task conditions for each voxel in V1 and summated the voxel-wise pRF profiles weighted by the attention effect size measurements. We found that the reconstructed map was highly consistent with the spatial distribution of the target location of the first saccade. Notably, the high-priority regions in the reconstructed map for the upright faces unambiguously corresponded to the facial areas carrying the critical identity information, namely the eyes, the nose, and the mouth, while no such a systematic correspondence was found for the inverted faces. These results suggest that the priority map for natural face stimuli might be located in V1. Our findings thus make headways towards unraveling the neural mechanisms on the generation of the priority map.
Meeting abstract presented at VSS 2016