Fig. 1.

Hypothesized direction of brain activity and experimental design. (A) Schematic of proposed flow of oscillatory activity in a hierarchically organized causal inference network. Predictive, beta-band signals (P, red arrows) run in the top down-direction, from the MPFC, via the intermediate TPJ, to the STS. Prediction error signals (E, blue arrows) are conveyed by the gamma-band and flow in the opposite direction, from STS, via TPJ to MPFC. (B) Experimental design. Subjects viewed animations of a bowler throwing a ball that subsequently knocks over a number of pins. Both the kinematic aspect (throwing direction) and outcome aspect (# of pins hit, i.e. score) were manipulated independently from each other, at three probability levels: 10, 30 and 60%. In conjunction, this made up a total of nine possible complete actions, each with a probability that was the product of the separate probabilities of the action’s kinematic and outcome aspects. Thus, these full actions could be presented at frequencies that ranged from 1% (10 × 10%) to a maximum of 36% (60 × 60%). See Supplementary Movies S1–S9 for the video animations and Supplementary Figure S1 for the trial timelines.