Abstract
The motion energy sensor (Adelson & Bergen, 1985, JOSA, A2, 284-299) has been shown to account for a wide range of physiological and psychophysical results such as motion direction discrimination (e.g. Georgeson & Scott-Samuel, 1999, Vision Res. 39, 4393-4402). It has become established as the standard computational model for retinal movement sensing in the human visual system. The basic model can be implemented efficiently in Matlab® code. Adaptation effects such as threshold elevation and changes in perceived direction have been extensively studied in the psychophysical literature, but current implementations of the energy sensor do not provide directly for modelling adaptation-induced changes in output. We describe an extension of the model to incorporate changes in output due to adaptation. The extended model first computes a space-time representation of the output to a given stimulus, and then a simple RC gain-control circuit (‘leaky integrator’) is applied in the time domain (van de Grind et al., Vision Res. 44, 2269-2284). Model output shows effects which mirror those observed in psychophysical studies of motion adaptation: A decline in sensor output during continuous stimulation, and changes in the relative outputs of different sensors following this adaptation.
Meeting abstract presented at VSS 2012