Model of human visual-motion sensing

TLDR

The study proposes a model for how humans perceive the velocity of moving images. The model uses spatial‑frequency‑tuned, direction‑selective linear sensors that exploit the relationship between spatial and temporal frequencies, then resolves velocity components across spatial locations to estimate image motion. The model’s temporal responses encode velocity components, successfully reproduce phenomena such as apparent motion and coherent gratings, and qualitatively match human perception.

Abstract

We propose a model of how humans sense the velocity of moving images. The model exploits constraints provided by human psychophysics, notably that motion-sensing elements appear tuned for two-dimensional spatial frequency, and by the frequency spectrum of a moving image, namely, that its support lies in the plane in which the temporal frequency equals the dot product of the spatial frequency and the image velocity. The first stage of the model is a set of spatial-frequency-tuned, direction-selective linear sensors. The temporal frequency of the response of each sensor is shown to encode the component of the image velocity in the sensor direction. At the second stage, these components are resolved in order to measure the velocity of image motion at each of a number of spatial locations and spatial frequencies. The model has been applied to several illustrative examples, including apparent motion, coherent gratings, and natural image sequences. The model agrees qualitatively with human perception.