Figure 2.

A, Experimental paradigm. The timing of the succession of the events is reported. Each given rule consists of a variable number of colored cards (in which a circle is colored blue) and empty cards in which all circles are presented white. When presented with colored cards, subjects are required to press a button when ready to predict which circle will be colored blue in the next colored card. Immediately after button press, colored cards are replaced with empty cards. During the presentation of empty cards, participants are asked to say aloud the number of the corresponding circle. The next colored card follows an empty card after a variable time (1–3 s). B, Behavioral results during fMRI. The graph reports mean RT of responses (button press) given in the five phases identified in correctly acquired rules. Phase connotation is as follows: (1) SearchPhase1 (SrP1) denotes the first response with a new rule, (2) SearchPhase2 (SrP2) identifies all the responses after SearchPhase1 that precede a successful sequence of correct responses, (3) Discovery (Dsv) corresponds to the first correct response in the successful sequence, (4) FollowingPhase1 (FlP1) denotes the second correct response in the successful sequence, and (5) FollowingPhase2 (FlP2) corresponds to the rest of correct responses (from the third) in the successful sequence until the rule change. Error bars indicate SD.