Crinkling and crumpling: an auditory fMRI study of material properties

Knowledge of an object's material composition (i.e., what it is made of) alters how we interact with that object. Seeing the bright glint or hearing the metallic crinkle of a foil plate for example, confers information about that object before we have even touched it. Recent research indicates that the medial aspect of the ventral visual pathway is sensitive to the surface properties of objects. In the present functional magnetic resonance imaging (fMRI) study, we investigated whether the ventral pathway is also sensitive to material properties derived from sound alone. Relative to scrambled material sounds and non-verbal human vocalizations, audio recordings of materials being manipulated (i.e., crumpled) in someone's hands elicited greater BOLD activity in the right parahippocampal cortex of neurologically intact listeners, as well as a cortically blind participant. Additional left inferior parietal lobe activity was also observed in the neurologically intact group. Taken together, these results support a ventro-medial pathway that is specialized for processing the material properties of objects, and suggest that there are sub-regions within this pathway that subserve the processing of acoustically-derived information about material composition.