Results of a previous study (see AD-720 800) suggested that the effect of motion on detecability might be caused entirely by contrast changes as the target moves over a complex background. The test documented in the present study, employing a television display and an artificial background, showed independent effects of both contrast and motion on target detectability. The effects can be accounted for by modifying the exponent in the detection probability function with a linear contrast term and a second-power velocity term. Single-fixation experiments confirmed a larger aperture for moving targets than for static targets, and also demonstrated a gradual increase in the fixation time required to detect a target as a function of its distance from the fixation point. (Author).

The brain's ability to detect movement within the retinal image is crucial not only for determining the trajectories of moving objects, but also for identifying and interpreting image motion resulting from eye and head movements. This book summarizes our knowledge of how information about image motion is encoded in the brain. Key Features * Valuable reference source for those involved in the rapidly expanding area of motion perception * Strong emphasis on integration of physiological, computation, and psychophysical approaches * Topics include: * Principles of local motion detection * Inputs to local motion detectors * Integration of motion signals * Higher-order interpretation of motion * Motion detection and eye movements