Grant: Discovery Grants Program - Individual

Our long-term goal is to produce experimental results and theoretical analyses that will yield insight into how visual information from the two eyes is integrated and how this information allows us to interact effectively with objects in our environment. Our short-term goal is to work on four topics, namely, visual direction, binocular eye movements, motion parallax, and visual stability. Visual Direction. We will continue to study how observers judge the directions of objects in the environment with respect to themselves. This is not as simple a question to answer as one might expect, because we have two eyes. That is, an object in front of one eye is not in front of the other eye, and the question is how does the brain integrate the information from the two eyes to judge the directions of objects. Binocular Eye Movements. We will also continue to study how the two eyes move together. It has been known for some time that the eyes do not move independently, and we are examining how they move together in both the same direction (e.g., leftward) and in different directions (e.g., inward). Motion Parallax. We will also continue to study how movements of the head produce what is referred to as motion parallax and how this information contributes to our perception of depth. Although early visual scientists were aware of the usefulness of motion parallax as a cue to depth, the details of what information the brain uses have yet to be worked out. Visual Stability. We will begin a new research project on how the visual world remains stable when we move our head and eyes. With every movement of the eyes, images of stationary objects sweep across the retinae. Despite this, however, the world appears stable. To date this stability or constancy has been studied primarily under conditions in which the head is held stationary and only the eyes are free to move. The stimulus situation we wish to examine is an extension of this traditional one; namely, we wish to examine perceptual stability when both the head and the eyes are free to move.