Spatio-temporal model for subjective colours based on colour coded ganglion cells.

We propose a mathematical model for the generation of the subjective colour phenomenon through Benham's disk stimuli. The model relates to the spatial and temporal properties of three colour coded retinal ganglion cells: L+/M-, M+/L- and S-/(L+M)+ [or (L+M)-/S+]. It is suggested that the phenomenon is based on both the opponent mechanisms in the cells' receptive fields, and the "rebound response"--a common cell response to turning off of an inhibitory stimulus (nonlinear cell dynamics). A physiological mechanism is suggested for this response. The integrated cell responses to Benham disk-stimuli create imbalances between the colour pathways that are interpreted as actual colours. The model also predicts the shift in the perceived colours when the disk rotation rate is varied.