Abstract
When grasping-to-use a familiar tool we often make use of stored information about the functional identity of the tool in order to guide our actions. At present, exactly which brain areas play an important role in representing this information is poorly understood. For example, is information regarding the functional significance of familiar objects stored within those areas mediating object-directed actions or does this information stem from other areas of the brain? During functional magnetic resonance imaging (fMRI), participants viewed short movies depicting different types of grasping actions made towards familiar tools. In one condition, the tool was grasped appropriately such that its function could be performed without further postural adjustments (e.g. a fork was grasped by the handle with the tines facing away from the actor). In the other condition, the tool was grasped inappropriately such that its function could not be performed without further postural adjustments (e.g. a fork was grasped by the handle with the tines facing toward the actor). We hypothesized that the viewing of functionally appropriate grasping actions would resonate more strongly with those areas involved in the processing of object function. Our results showed significantly stronger activity for the viewing of functionally appropriate as compared with inappropriate grasping actions within several brain areas previously implicated in higher-level object perception. In contrast, areas implicated in the control of object-directed actions did not distinguish between the two conditions. These findings suggest that information about the functional significance of objects is stored within areas specialized for object perception and not within areas specialized for object-directed action. Thus, object utilization based on stored knowledge of object function must involve a complex interplay between systems specialized for object perception and those specialized for the control of actions.