Figure 11.

When coupling is prevented, the shift to long integration times is impaired at both the behavioral level and the ganglion cell level. This figure reproduces the data in Figure 3 of the main text, but un-normalized. As in the main text, the knockout response fails to make the normal shift in tuning to low temporal frequencies, because the feedback signal is not reduced by the shunt. Note that the un-normalized plots show that at low temporal frequencies, the wild-type response is higher, while at high temporal frequencies, the knockout response is higher. This is predicted by the model (Figure 10, which shows the un-normalized model predictions; lower right of figure). Note also that this crossover (the higher response in the no-feedback state at low frequencies, and the higher response in the high-feedback state at high frequencies) is a well-known phenomenon in light adaptation (Purpura et al., 1990).