Figure 2.

Illustration of the experimental procedure concerning the first two choices. Each choice could be made just after the presentation of the green slide, but within 12 s (e.g., the interval between choices we selected to allow the detection of a complete hemodynamic response associated with each decision). The black screen was inserted to fill the 12 s inter-choice interval creating an alternation with the green slide, which had to be again presented to allow the next choice. This was repeated for 100 times.