Categories and Functional Units: An Infinite Hierarchical Model for Brain Activations.

ABSTRACT: We present a model that describes the structure in the responses of different brain areas to a set of stimuli in terms of stimulus categories (clusters of stimuli) and functional units (clusters of voxels). We assume that voxels within a unit respond similarly to all stimuli from the same category, and design a nonparametric hierarchical model to capture inter-subject variability among the units. The model explicitly encodes the relationship between brain activations and fMRI time courses. A variational inference algorithm derived based on the model learns categories, units, and a set of unit-category activation probabilities from data. When applied to data from an fMRI study of object recognition, the method finds meaningful and consistent clusterings of stimuli into categor

SUBMITTER: Lashkari D 

PROVIDER: S-EPMC4022600 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature