title: Representation of object weight in human ventral visual cortex.
abstract: Skilled manipulation requires the ability to predict the weights of viewed objects based on learned associations linking object weight to object visual appearance. However, the neural mechanisms involved in extracting weight information from viewed object properties are unknown. Given that ventral visual pathway areas represent a wide variety of object features, one intriguing but as yet untested possibility is that these areas also represent object weight, a nonvisual motor-relevant object property. Here, using event-related fMRI and pattern classification techniques, we tested the novel hypothesis that object-sensitive regions in occipitotemporal cortex (OTC), in addition to traditional motor-related brain areas, represent object weight when preparing to lift that object. In two studies, the same participants prepared and then executed lifting actions with objects of varying weight. In the first study, we show that when lifting visually identical objects, where predicted weight is based solely on sensorimotor memory, weight is represented in object-sensitive OTC. In the second study, we show that when object weight is associated with a particular surface texture, that texture-sensitive OTC areas also come to represent object weight. Notably, these texture-sensitive areas failed to carry information about weight in the first study, when object surface properties did not specify weight. Our results indicate that the integration of visual and motor-relevant object information occurs at the level of single OTC areas and provide evidence that the ventral visual pathway is actively and flexibly engaged in processing object weight, an object property critical for action planning and control.
authors: Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, ON K7L 3N6, Canada. Electronic address: jasongallivan@gmail.com.
authors: Jason P
authors: JP
authors: Gallivan
authors: Department of Psychology, University of Toronto, Scarborough, ON M1C 1A4, Canada.
authors: Jonathan S
authors: JS
authors: Cant
authors: Brain and Mind Institute, University of Western Ontario, London, ON N6A 5B7, Canada; Department of Psychology, University of Western Ontario, London, ON N6A 5C2, Canada.
authors: Melvyn A
authors: MA
authors: Goodale
authors: Centre for Neuroscience Studies, Queen's University, Kingston, ON K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, ON K7L 3N6, Canada. Electronic address: flanagan@queensu.ca.
authors: J Randall
authors: JR
authors: Flanagan
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D011597:Psychomotor Performance; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways; D014892:Weight Perception; D055815:Young Adult