Figure 4.

The light responses of FPs recorded from lamina cartridges under different conditions of illumination. A, Dark-adapted conditions; responses to a 2 ms flash (left) or a 300 ms pulse (right), increasing progressively in intensity from 500 photons/s (lowest amplitude response) to 10⁶ photons/s (highest amplitude response). B, Light-adapted responses to a background level of 10³ photons/s. Responses to 2 ms flashes and 300 ms pulses with contrasts increasing in 0.2 increments from −1 to +1. C, Light-adapted responses to a background level of 10⁶ photons/s, pulse duration, and contrast as in B.