Motion detection and stochastic resonance in noisy environments

Several motion detection schemes are considered and their responses to nois y signals investigated. The schemes include the Reichardt correlation detec tor, shunting inhibition and the Horridge template model. These schemes are directionally selective and independent of the direction of change in cont rast. They function by using spatial information and comparing it at succes sive time intervals. A rudimentary noise analysis is performed on the Reich ardt and inhibition detectors to compare their natural robustness against n oise. Using these detectors, stochastic resonance (SR) is applied, which is characterised by an improvement in response when noise is added to the inp ut signal. It is found that the performance of the detectors degrades with the addition of noise. Employing Stocks' suprathreshold SR, an improvement can be gained when considering a network of detectors. Furthermore, when us ing an incorrect threshold setting for the template model, SR can be displa yed. (C) 2001 Elsevier Science Ltd. All rights reserved.