Abstract
Multi-voxel pattern similarity predicts subsequent memory for visual stimuli (Xue et al., 2010; Ward et al., 2013), suggesting that pattern similarity tracks the stabilization of visual information into familiar, retrievable representations. How consistent are multi-voxel patterns across multiple repetitions of the same visual stimuli? To investigate this question, we scanned 10 participants while they viewed images depicting natural scenes. Each image was repeated four times, allowing us to measure pattern similarity across multiple exposures within three scene-selective regions of interest (ROIs): the parahippocampal place area (PPA), the retrosplenial cortex (RSC), and the occipital place area (OPA). To explore how repeated exposure modulates pattern similarity, we calculated pattern similarity sequentially between each exposure (e.g. between first and second presentation, between second and third presentation, etc.). We found that the overall degree of pattern similarity differed across ROIs, with the OPA showing the highest degree of similarity, followed by the PPA, then by the RSC, which showed the lowest. Additionally, we found that exposure did not modulate pattern similarity in the PPA and the OPA. However, in the RSC we found that pattern similarity was significantly reduced by exposure. Differences in the magnitude of pattern similarity and the modulatory role of exposure across ROIs indicate that these regions may be differentially implicated in behavior, such as visual memory.
Meeting abstract presented at VSS 2014