Colloquium Series 2014-2015

Melvyn A. Goodale
University of Western Ontario

How We See and Hear Stuff: Visual and Auditory Routes to Understanding the Material Properties of Objects

Almost all studies of object recognition, particularly in brain imaging, have focused on the geometric structure of objects (i.e. ‘things’).  Until recently, little attention has been paid to the recognition of the materials from which objects are made (i.e. ‘stuff’), information that is often signalled by surface-based visual cues (the sheen of polished metal) as well as auditory cues (the sound of water being poured into a glass).  But knowledge about stuff (the material properties of objects) has profound implications, not only for understanding what an object is, but also for the planning of actions, such as the setting of initial grip and load forces during grasping.  In recent years, our lab has made some headway in delineating the neural systems that mediate the recognition of stuff (as opposed to things), not only in sighted people but also in blind individuals who use echoes from tongue clicks to recognize the material properties of objects they encounter.  I will discuss evidence from both neuropsychological and fMRI studies demonstrating that lateral occipital regions in the ventral stream play a critical role in processing the 3-D structure and geometry of objects, whereas more anteromedial regions (particularly areas in the parahippocampal gyrus and collateral sulcus) are engaged in processing visual and auditory cues that signal the material properties of objects.