Figure 6.

Passive condition. A, PSTH showing the typical response of a neuron to repetitive presentation of backward and forward motion. Conventions are the same as in Figure 2. Note that the general response pattern is preserved over time, leading to essentially constant DIs (0.8, 0.8). B, The DI of the second and third motion cycles (MCs) versus DI of the first MC in the population of MT neurons. Conventions are the same as in Figure 3. For both periods, the vast majority of neurons showed no statistical change of the DI. Of the remaining cells for which a statistically significant change of the DI was computed, some showed an increase of the DI, and a few suffered from decreased direction selectivity.