Fig. 1.

Iterated choice task design. A trial, using the same face pair throughout, consisted of an initial choice phase, a manipulated exposure phase, and a final choice phase. To randomize the task, 40% of trials ended after the initial choice. In choice phases, the two faces were presented in sequence, followed by an option to respond. The cycle was repeated, up to five times, until the subject indicated which person they would rather ‘approach and talk to’. In the exposure phase, durations were biased toward the initially unchosen face to subconsciously bias subject preferences.