Object recognition and action

As humans, we interact with objects in our environment in two ways: by identifying them and by using them. This proposal will study the visual brain mechanisms that underlie these abilities. In particular, comparisons will be made between objects that we can grasp and use like a hammer and those that we cannot like a tree. Is this difference reflected in our learning about and forming memories for objects? Does the ability to grasp and use objects influence our ability to identify them? Does our ability to identify objects influence our ability to use them? Two models of processing object identity and use will be tested. One postulates that we know how to use objects simply based on their visual appearance. Another model postulates that we only know how to use objects after we have identified them. The proposed studies will measure the time and accuracy of our object identification as a function of our ability to use them. Measures of grasping and using objects will also be made. These questions relate to the brain with respect to two major pathways that process visual information. One is involved in object identification and another in reaching and grasping for objects. These pathways have been thought to function independently. The studies proposed here will test that assumption and determine when it holds true and when it does not. Most of the proposed studies will involve testing individuals with normal visual brain function. Some studies will test individuals who have lost the ability to name visually presented objects or functionally use objects to see how the loss of one ability affects the intact ability. This research will help us build more comprehensive models of visual object recognition and brain functioning. These models in turn will guide us in developing better rehabilitation programs for individuals who have lost these functions due to brain damage. They will also be of use in building future machines that interface with our visual and action brain systems and perhaps for the design of autonomous remote robotics.