Fig. 1.

The paradigm rationale. Pairs of numbers were presented horizontal to each other. The numbers corresponded to the amount the subject could win in Norwegian kroner (kr). Each pair was made up of either two similar numbers (i.e. 2–2 or 4–4) or a zero paired with a valuable stimulus (i.e. 2–0, 0–2, 4–0, 0–4). The 0–0 condition was a baseline. The task was to press the response button corresponding to the amount of kr the subject wanted to obtain.