Extended Data Figure 8: Simulations of models of selective integration inconsistent with PFC responses.

We simulated population responses mimicking the observed PFC responses (a–c) and alternative responses expected based on the three models of context-dependent selection described in Fig. 3b–d (d–l) (see Supplementary Information, section 8). These simulations are based on a diffusion-to-bound model, unlike the simulations of the recurrent neural network models in Figs 5 and 6 and in Extended Data Figs 9 and 10e–s. Here, single neurons represent mixtures of three time-dependent task variables of a diffusion-to-bound model, namely the momentary motion and colour evidence and the integrated relevant evidence. At the level of the population, these three task variables are represented along specific directions in state space (arrows in a, d, g, j; red, integrated evidence; black, momentary motion evidence; blue, momentary colour evidence). The four simulations differ only with respect to the direction and context dependence of the three task variables. We computed state space trajectories from the population responses using the targeted dimensionality reduction techniques discussed in the main text and in Supplementary Information. The resulting simulated population responses reproduce the schematic population responses in Fig. 3. a–c, Simulated population responses mimicking the observed PFC responses (Fig. 2). a, Response trajectories in the two-dimensional subspace capturing the effects of choice and motion (left) or choice and colour (right) in the motion (top) and colour (bottom) contexts. Same conditions and conventions as in Fig. 2a, c and Fig. 2d, f. The three task variables are represented along three orthogonal directions in state space (arrows). b, Regression coefficients of choice, motion and colour for all simulated units in the population. For each unit, coefficients were computed with linear regression on all simulated trials (top) or separately on trials from the motion or colour context (bottom, context in parentheses). Scale bars represent arbitrary units. Numbers in the inset along each axis represent averages of the absolute value of the corresponding coefficients (±s.e.m., in parentheses). Significant correlations between coefficients are shown in red (P < 0.05, Pearson’s correlation coefficient r. c, Estimated strengths of the motion (top) and colour (bottom) inputs during motion (black) and colour (blue) contexts. Input strength is defined as the average of the absolute value of the corresponding regression coefficients. d–f, same as a–c, for simulated population responses expected from context-dependent early selection (Fig. 3b). When relevant, momentary motion (top) and colour (bottom) evidence are represented along the same direction as integrated evidence (arrows in d). g–i, same as a–c, for simulated population responses expected from context-dependent input directions (Fig. 3c). Integrated evidence is represented along the same direction in both contexts (red arrows in g). The relevant momentary evidence (motion in the motion context, top; colour in the colour context, bottom) is aligned with the direction of integration, whereas the irrelevant momentary evidence is orthogonal to it (black and blue arrows in g). j–l, same as a–c, for simulated population responses expected from context-dependent output directions (Fig. 3d). The momentary motion and colour evidence are represented along the same directions in both contexts (black and blue arrows in j). The direction of integration (red arrows in j) is aligned with the motion evidence in the motion context (top), and with the colour evidence in the colour context (bottom).