Figure 3.
Contrast adaptation reduces the difference in contrast gain of P and M cells. Contrast gain (obtained from Eq. 1: G/σc) of 14 P cells (filled symbols) and 18 M cells (open symbols) for gratings of optimal size and spatial frequency, in control conditions (abscissa) and during adaptation to a high-contrast grating of the same configuration (ordinate), is shown. Arrows on the ordinate and abscissa show the geometric mean contrast gain for P cells (filled arrows) and M cells (open arrows). In the control state, this average gain of M cells was 382 imps/s/[unit contrast], and in the adapted state it was 72. For P cells, these values were 72 and 45, respectively.