The left fusiform gyrus processes visual, tactile, and auditory features of manipulable objects
Tanja Kassuba, Corinna Klinge, Cordula Hagemann, Hartwig R. Siebner
Poster
Time: 2009-06-29 11:00 AM – 12:30 PM
Last modified: 2009-06-04
Abstract
The aim of this study was to identify brain regions involved in the recognition of object-specific features in the visual, auditory, and tactile modality. 18 right-handed, healthy participants underwent functional MRI while they performed a 1-back working memory task on visual, auditory or tactile stimuli. In different blocks, participants saw pictures of manipulable objects or pictures of surface textures, heard object sounds or sound textures, and touched 3-dimensional objects or surface textures. The order of blocks was pseudorandomized. For each sensory modality, we identified regional increases in blood oxygen dependent (BOLD) signal for object stimuli relative to high-level control stimuli. These contrasts were entered in a conjunction analysis to identify brain regions processing object-specific features across all three sensory modalities. Only a small cluster in the left fusiform gyrus showed increased activity during visual, auditory, and tactile object recognition. The right homologue region was also activated by visual and tactile object features but did not respond to auditory object features. Larger sets of cortical areas displayed object-specific BOLD responses for two out of three modalities. Visual and tactile processing of objects involved the lateral occipital complex and fusiform gyrus bilaterally; auditory and visual object processing only involved the left fusiform gyrus; auditory and tactile object recognition involved the left middle temporal cortex (near V5/MT+), superior parietal cortex, supramarginal, and fusiform gyrus. The present results show that left fusiform gyrus processes unimodal object-specific information in the visual, auditory, and tactile modality. This finding suggests that this region is a key area for multimodal integration of object-specific sensory input.