Abstract
Human observers are experts at extracting summary statistics from a variety of visual features such as orientation and size. Although extensive behavioral studies have documented the existence of such ensemble representations, few studies have addressed the underlying neural mechanism. In this study, using fMRI and multi voxel pattern analysis, we investigated how ensemble orientation is coded in human visual cortex by examining fMRI response patterns in retinotopically defined areas as well as high-level object processing regions. We generated ensemble displays containing Gabor patches with two different orientations (heterogeneous ensembles) as well as ensemble displays containing Gabor patches with a single orientation (homogenous ensembles). Using support vector machine, a linear classifier, we will examine whether heterogeneous and homogenous ensembles sharing the same mean orientation would be represented similarly along the visual processing pathways.
Meeting abstract presented at VSS 2014