Modeling and electronic implementation of directional selectivity

A shunting model of motion detection treatment is proposed and implemented. It is analyzed using a perturbational technique to model the behavior and extract the velocity information including both direction and speed. The model´s properties are illustrated by constructing a simple hardware analogue circuit. Response of the circuit to a variety of stimulus distributions show that the output is sensitive to speed and also is markedly different for movement in opposite directions. In order to analyze the behavior of the model, a perturbational technique is developed which describes the input-output relation in the form of a Volterra integral series. It is shown that the velocity term can be identified with the second order kernel while the second order Volterra operator is a running autocorrelation operator. This is in agreement with alternative methods of motion information analysis