Figure 1.

Task design. (A) Sequential two-choice Markov decision task. Participants move from one state to the other with a certain state-transition probability p following a binary choice (left or right) (B) Illustration of the specific goal condition, in which the color of the collecting box (either yellow, blue, or red) should match the color of the coin, and the flexible condition, in which participants are allowed to collect any kind of coin. The high uncertainty condition corresponds to p=(0.5,0.5) and the low uncertainty condition corresponds to p=(0.9,0.1). (C) Illustration of the task. The specific goal block requires participants to rely on a model-based strategy for guiding choices in each state, while, in the flexible goal block, an initial model-based strategy during early experience can give way to a model-free strategy after extensive experience.

See also Figure S2.