Figure 3.

Comparing an orientation population code with an “ON” or “OFF” population code. (A) The three different stimulus transitions (rows). All stimulus transitions were also presented after 90° rotation (second column). Under each transition is the group assignment into ON (“up state”) and OFF (“down state”) groups (red curve). (B) All neuronal pairs and all orientations. The combination discriminating best is encircled. Best neuron combination for the “ON” and “OFF” code. (C) The preference of the first and second unit is 45° and 0°, respectively. The horizontal orientation is shown at 45° on the screen. If Rate₁ is larger than Rate₂ the orientation is on (displayed). This rule works for most cases except second row and first column when the stimulus is off (not displayed).