title: Mechanisms of visual motion detection.
abstract: Visual motion is processed by neurons in primary visual cortex that are sensitive to spatial orientation and speed. Many models of local velocity computation are based on a second stage that pools the outputs of first-stage neurons selective for different orientations, but the nature of this pooling remains controversial. In a human psychophysical detection experiment, we found near-perfect summation of image energy when it was distributed uniformly across all orientations, but poor summation when it was concentrated in specific orientation bands. The data are consistent with a model that integrates uniformly over all orientations, even when this strategy is sub-optimal.
authors.affiliation: Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 E. River Dr., Minneapolis, Minnesota 55455, USA. schrater@eye.psych.umn.edu
authors.forename: P R
authors.initials: PR
authors.lastname: Schrater
authors.forename: D C
authors.initials: DC
authors.lastname: Knill
authors.forename: E P
authors.initials: EP
authors.lastname: Simoncelli
mesh_terms: D000222:Adaptation, Physiological; D001676:Biofeedback, Psychology / Q000502:physiology; D003198:Computer Simulation; D003626:Data Display; D005246:Feedback; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D015588:Observer Variation; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D012684:Sensory Thresholds / Q000502:physiology; D013269:Stochastic Processes; D014793:Visual Cortex / Q000502:physiology*