CYCLOPEAN AND MONOCULAR MOTION PROCESSING

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Cyclopean (cycl.) motion (as in a Julesz cinematogram) will be studied under conditions of conflicting, nonconflicting, and random monocular (mono.) motion to determine properties of mono.-binoc. motion interaction, as described by tuning curves in the relative angle, speed, and spatial frequency domains. Results will have great import on theories of mono.-binoc. information processing, neurophysiology of disparity units, and stereoblindness pathology. Most experiments employ a novel cycl. stimulus: a sinusoidal disparity grating moving vertically in the frontal plane (eg, a horizontal cycl. grating moving upward) formed from mono. fields of random dots moving at a different angle and speed (eg, dots moving quickly to the right). Alternatively, mono. motion can be chosen to be nonconflicting (ie, same vertical speed as cycl. grating), or temporally random (eg, video "snow"). Key experiments include: 1) Cycl. motion aftereffect (CMAE): S's will adapt to a cycl. grating moving vertically formed from temporally random monocular fields. The test speed needed to null the CMAE will be found at various SOA's to determine the decay constant of cycl. response. 2) CMAE with mono. motion in various directions and speeds: Comparing Exp 1 results will show the strength and tunings of suprathreshold mono.-binoc. motion interaction. 3) New contingent aftereffect: Using a McCulloch paradigm, a contingent AE linking vertical cycl. motion to horizontal mono. motion will be sought. The test stimuli will be a) a flat pattern of moving dots, thereby producing an AE of cycl. motion, or b) a drifting cycl. grating, thereby producing an AE of mono. motion. 4) Disparity thresholds for cycl. grating motion detection: Using method of adjustment, disparity thresholds will be found for various mono. conditions to determine whether probability summation or inhibition acts between mono. and binoc. systems. 5) Cycl. motion subchannel independence: Disparity thresholds (Exp 4) for counterphase cycl. gratings will be found. A ratio of disparities 2:1 (counterphase:drifting) will suggest independent cycl. motion subchannels, as shown monocularly by Sekuler. 6) Conditions for coherent motion: If mono. and cycl. vertical speeds are equal, the pattern will move "coherently"--as an apparently single visual entity: for large difference in such speeds, it won't. This range will be found using a 2-choice staircase. 7) Stereomotion blindness: The approximate incidence of stereomotion blindness will be determined and compared with that of standard (static) stereoblindness.