TEMPORAL RESPONSE OF GANGLION-CELLS OF THE MACAQUE RETINA TO CONE-SPECIFIC MODULATION

The temporal response of cone inputs to macaque retinal ganglion cells were compared with cone-specific sinusoidal modulation used to isolat e each cone type. For all cell types of the parvocellular (PC) pathway , temporal responsivity was similar for short (S)-, middle (M)-, and l ong (L)-wavelength-sensitive cone inputs, apart from small latency dif ferences between inputs to center and surround. The temporal response resembled that expected from receptor physiology. Responses of cells o f the magnocellular pathway to M- or L-cone modulation showed more com plex properties indicative of postreceptoral processing. Human psychop hysical temporal-sensitivity functions were acquired with S-cone modul ation under conditions similar to those for the physiological measurem ents. Ratios of psychophysical to physiological data from S-cone cells (the only cells that respond to this stimulus) yielded an estimate of the central filter acting upon PC-pathway signals. The filter charact eristic could be described by a four-stage low-pass filter with corner frequency 3-5 Hz.