Figure 3.

Visual response properties of three groups with standard LGN RFs. A, STA spatial RFs for representative units from each group. Scale bar, 10°. B, Temporal response measured by STA for units in A, showing polarity of response (ON/OFF) and biphasic temporal response in transient OFF units (bottom). C, Response to flashing ON (red) and OFF (blue) spots for units in A, showing strong response for preferred polarity and sustained firing throughout spot presentation for sON and sOFF (top, middle) and transient response with large offset response for tOFF (bottom). D, Distribution of RF radius, from Gaussian fit to spatial STA, for the three center-surround groups. E, F, Mean spatial STA amplitude (E) and temporal STA biphasic index (F) across groups illustrate the defining distinctions between ON/OFF and sustained/transient groups. G, Spike rasters for sON unit in A in response to drifting sinusoidal gratings of 2 Hz at preferred spatial frequency (0.04 cpd), showing periodic response to all orientations. H, Spatial frequency tuning curve for unit in G demonstrates bandpass tuning indicative of center-surround organization, as well as preference for 2 Hz temporal frequency. I, Size selectivity measured with flashing spots demonstrates weak response for spots below the RF size, and suppression of response for larger spots, with no response to a full-field flash. J, Size suppression, as measured by fractional reduction in response to full-field flash relative to preferred size, for the three center-surround groups. K, Speed tuning measured for unit in G, measured with moving spots, shows increased response for high speeds. Population data for H, I, and K are shown in Figure 5, for comparison with DS/OS responses.