Figure 7.
Brain regions coding the decision variable. a, Conjunction map showing the brain regions activated during perceptual decision making in which BOLD activity is negatively modulated by the amount of predictive information conveyed by the last and the penultimate shape. We rendered our map using an uncorrected threshold of p < 0.001 (level of significance used for inference, red voxels) and a threshold of p < 0.005 to show the full extent of the activations (yellow voxels). b, Average parametric response to surprise (u) and predictive information (p1 and p2) in these brain regions. The parametric response to the predictive information conveyed by the last shape (p1) and the penultimate shape (p2) was not significantly different (NS) in any of the regions identified (p1 = p2, orange and red bars; rIPS: p = 0.43; rDLPFC: p = 0.34). There was no parametric response to surprise (u = 0, green bars; rIPS: p = 0.29; rDLPFC: p = 0.8). c, Scatter plots of correspondence between BOLD signal change in the ACC and accumulation's slope average, for each of the brain regions shown in Figure 7a (circled in red; see Materials and Methods, General linear model 3: correlation between BOLD activity and LATER model parameters). Each point represents the BOLD signal change in the ACC and the slope of sensory evidence accumulation estimated using the LATER model averaged over the four levels of predictive information (−0.3, 0.18, 0.72, 1.22 bits) for each subject (see supplemental Fig. S3, available at www.jneurosci.org as supplemental material).