Salamander locomotion-induced head movement and retinal motion sensitivity in a correlation-based motion detector model

    Year:

    2007

    Synopsis

    We report on a computational model of retinal motion sensitivity based on correlation based motion detectors. We simulate object motion detection in the presence of retinal slip caused by the salamander’s head movements during locomotion. Our study o ers new insights into object motion sensitive ganglion cells in the salamander retina. A sigmoidal transformation of the spatially and temporally ltered retinal image substantially improves the sensitivity of the system in detecting a small target moving in place against a static natural background in the presence of comparatively large, fast simulated eye movements, but is detrimental to the direction-selectivity of the motion detector. The sigmoid has insigni cant e ects on detector performance in simulations of slow, high contrast laboratory stimuli. These results suggest that the sigmoid reduces the system’s noise sensitivity.

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