Fig 2.

The deterministic reversal learning task. a An example of a punishment trial. On each trial, subjects are presented with a face and a landscape. One of the images is surrounded by a black border. The subject had to predict whether the surrounded stimulus was followed by a reward or by a punishment outcome by pressing the associated “reward” or “punishment” button on a keyboard. After the response had been made, the subject saw the actual outcome. b Example of a trial sequence for the unexpected punishment and unexpected reward condition. The reversals are indicated by an unexpected reward or unexpected punishment trial. rw reward prediction, pn punishment prediction, ns-r non-switch reward trial, ns-p non-switch punishment trial, sw-r reversal trial after an unexpected reward, sw-p reversal trial after an unexpected punishment