Figure 3. Computational level.

(A) Summary of computations performed by the actor. (B) Sample form of probability distributions. (C) An example of inference of action intensity. In this example the stimulus intensity is equal to $s=1$, the valuation system computes desired reward $R=2$, and the parameters of the probability distributions encoded in the goal-directed and habit systems are listed in the panel. The blue curve shows the distribution of action intensity, which the habit system has learned to be generally suitable for this stimulus. The orange curve shows probability density of obtaining reward of 2 for a given action intensity, and this probability is estimated by the goal-directed system. For the chosen parameters, it is the probability of obtaining 2 from a normal distribution with mean $a$. Finally, the green curve shows a posterior distribution computed from Equation 3.1.