Accession Number : ADA277425


Title :   Visual Processing of Object Velocity and Acceleration


Descriptive Note : Annual technical rept. 16 Jan 1993-15 Jan 1994


Corporate Author : SMITH-KETTLEWELL EYE RESEARCH INST SAN FRANCISCO CA


Personal Author(s) : McKee, Suzanne


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a277425.pdf


Report Date : 04 Feb 1994


Pagination or Media Count : 4


Abstract : Human observers can easily detect a signal dot moving, in apparent motion, on a trajectory embedded in a background of random-direction motion noise. A high detection rate is possible even though the spatial and temporal characteristics(step size and frame rate) of the signal are identical to the noise, making the signal indistinguishable from the noise on the basis of a single pair of frames. The success rate for detecting the signal dot was as high as 90% when the probability of mismatch from frame-to-frame, based on nearest neighbor matching was 0.3 control experiments showed that trajectory detection is not based on detecting a 'string' of collinear dots, i.e., a stationary position cue. Nor is a trajectory detected because produces stronger signals in independent 'local' motion detectors. For one thing, trajectory detection improves with increases in duration, up to 250 - 400 msec, a duration longer than the integration typically associated with a single motion detector. Moreover, the signal dot need not travel in a straight line to be detectable. The signal dot was as reliably detected when it changed its direction a small amount (30 deg) each frame. Consistent with this, circular paths of sufficiently low curvature were as detectable as straight trajectories.


Descriptors :   *VISUAL PERCEPTION , *NOISE , *VISUAL SIGNALS , CONTROL , OBSERVERS , DETECTION , DETECTORS , HUMANS , PROBABILITY , PATHS , MOTION , RATES , CIRCULAR , TRAJECTORIES , MATCHING , MOVING TARGETS , CURVATURE , INTEGRATION , STATIONARY , BACKGROUND , TRAVEL , FRAMES


Subject Categories : Anatomy and Physiology
      Infrared Detection and Detectors
      Acoustics


Distribution Statement : APPROVED FOR PUBLIC RELEASE