The luminance and response range of monkey retinal ganglion cells to white light

The responses of single retinal ganglion cells of the monkey to spot stimuli were recorded with extracellular microelectrodes. The stimulus was centered on the receptive field, adjusted in diameter to optimally excite the cell and incremented and decremented from the background level. The response range was defined as the difference between the maximum and minimum response amplitude evoked with a wide range of luminances. The differnce in luminance between the luminances which evoked the maximum and minimum responses was defined as the luminance range for dynamic response. The response amplitude range and luminance range to white light were negatively correlated to one another for the population of cells studied in central vision. The phasic cells had smaller luminance ranges for dynamic responses and a greater response magnitude for small changes in luminance from background than the tonic cells.