Interaction between colour and spatial coded processes converging to retinal glanglion cells in goldfish.

1. Extracellular recordings were made from ganglion cell units in the isolated goldfish retina. The discharge patterns of these units are spatial and colour coded.2. Even for weak stimuli these ganglion cell responses are highly distorted. To a first approximation a rectifying element can account for the observed distortion.3. A method is introduced to determine whether the interaction between the spatial and colour-coded processes occurs preceding or after the rectifying stage.4. With various stimulus patterns such as checkerboards, bars, annuli, etc., not only the location of the interaction point but also the mode of operation underlying the colour and spatial interactions has been studied.5. The presented data indicate that for the common phasic ganglion cells in the goldfish retina spatial and colour interaction occurs preceding the rectifying stage. Moreover an algebraic mode of operation governs this interaction.6. The charm of the presented method lies in the fact that no assumptions need to be made about the dynamics of the various retinal transformations converging to the ganglion cells. Neither is a description required for the non-linear (rectifying) element in order to answer the question of the location and the mode of operation of the colour and spatial interaction mechanism.