The Perirhinal Cortex Modulates V2 Activity in Response to the Agreement Between Part Familiarity and Configuration Familiarity

ABSTRACT: Research has demonstrated that the perirhinal cortex (PRC) represents complex object-level feature configurations, and partici-pates in familiarity versus novelty discrimination. Barense et al. [(in press) Cerebral Cortex, 22:11, doi:10.1093/cercor/bhr347] postulated that, in addition, the PRC modulates part familiarity responses in lower-level vis-ual areas. We used fMRI to measure activation in the PRC and V2 in response to silhouettes presented peripherally while participants main-tained central fixation and performed an object recognition task. There were three types of silhouettes: Familiar Configurations portrayed real-world objects; Part-Rearranged Novel Configurations created by spatially rearranging the parts of the familiar configurations; and Control Novel Configurations in which both the configuration and the ensemble of parts comprising it were novel. For right visual field (RVF) presentation, BOLD responses revealed a significant linear trend in bilateral BA 35 of the PRC (highest activation for Familiar Configurations, lowest for Part-Rearrange