Figure 3. Models of selective integration inconsistent with PFC responses.

Schematic representation of population responses observed in PFC (a) and expected by several models of selective integration (b-d). The models differ from the PFC responses with respect to the relative directions and context dependence of the choice axis (red lines) and the inputs (thick gray arrows; only motion input shown). The relevant input is integrated as movement along the choice axis towards one of two choices (red crosses). A motion input towards choice 1 ‘pushes’ the responses along the direction of the gray arrow (towards choice 2: opposite direction). Same conditions as in Fig. 2a (motion context, top) and Fig. 2d (color context, bottom). As in Fig. 2a and d, a single two-dimensional subspace (which contains the choice axis and motion input) is used to represent responses from both contexts. a, Idealized schematic of the actual PFC trajectories shown in Fig. 2a,d. Both the choice axis and motion input are stable between contexts. The motion input pushes the population response away from the choice axis. b, Early selection model. When relevant (top), the motion input pushes the population response along the choice axis. When irrelevant (bottom), the motion input is filtered out before reaching PFC (no thick gray arrow) and thus exerts no effect on choice. All trajectories fall on top of each other in both contexts, but the rate of movement along the choice axis increases with motion strength only in the motion context (insets show enlarged trajectories distributed vertically for clarity). c, Context dependent input direction. Motion input direction varies between contexts, while the choice axis is stable. Inputs are not filtered out before PFC; rather they are selected based on their projection onto the choice axis. d, Context-dependent output direction. Similar selection mechanism to c, except that the choice axis varies between contexts, while the motion input is stable. The effects of the motion input on PFC responses in both monkeys (schematized in a) and the effects of the color input in monkey A are inconsistent with predictions of the three models in b-d (respectively, Fig. 2a,d; Extended Data Fig. 7a,d; Fig. 2f,c).