Poster D119, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Cortical and subcortical contributions to passive perception of visuospatial changes
Maximilian Hauser1,2, Stefanie Heba3, Tobias Schmidt-Wilcke3, Martin Tegenthoff3, Christian Bellebaum4, Denise Manahan-Vaughan1,2; 1Ruhr-University Bochum, Bochum, Germany, 2International Graduate School of Neuroscience, Bochum, Germany, 3University Hospital Bergmannsheil, Bochum, Germany, 4Heinrich Heine University, Düsseldorf, Germany
In rodents, passive perception of novel configurations of visuospatial stimuli results in robust synaptic plasticity in the hippocampus, in the form of long-term depression (Kemp & Manahan-Vaughan, 2012, Cerebral Cortex, doi: 10.1093/cercor/bhr233). Hippocampal processing of spatial information may be supported by the cerebellum (Rochefort et al., 2011, Science, doi: 10.1126/science.1207403). Here, we explored in humans, hippocampal and cerebellar participation in the processing of passively perceived visuospatial information. First we assessed event-related potentials (ERPs) recorded during passive perception of novel, repeatedly presented, as well as configurationally, or perspectively, changed three-dimensional objects to verify that passive perception occurred. We identified parieto-occipital ERP-components that differentiated between spatially reconfigured, familiar, and novel objects. Using single trial estimation and multivariate approaches, based on rapid event-related fMRI, we then conducted searchlight analyses across the brain, to correlate representational dissimilarity matrices (RDMs) derived from selected regions of interest (ROIs). We observed that the representational profile in the hippocampus significantly correlates with that of the cerebellum across novel, familiar, and spatially changed objects. Looking at the RDMs of our ROIs separately, both the hippocampus and the cerebellar vermis lobules I-V exhibited more unique representations for spatially changed objects. By contrast, vermis lobules VI-X displayed this pattern for all items that displayed some form of novelty. These findings suggest that, during passive visuospatial perception, an evaluative process takes place in the cerebellum that dissociates observer-independent configurational, and observer-related novelty. This process can be expected to support pattern separation in the hippocampus that enables processing of visuospatial change.
Topic Area: PERCEPTION & ACTION: Vision