Goal-Dependent Flexibility In Preferences Formation From Rapid Payoff Sequences

The formation of attitudes or preferences for alternatives that consist of rapid numerical sequences has been suggested to reflect either a summation or an averaging principle. Previous studies indicate the presence of two mechanisms, accumulators (that mediate summation) and population-coding (that mediate averaging), which operate in preference formation tasks of rapid numerical sequences, and are subject to task-demands and individual differences. Here, we test whether participants can flexibly control the preference mechanism they deploy as a function of the reward contingency. Towards this aim, participants in two studies (N-1=21, N-2=23) made choices between the same sequence alternatives in two task-framing sessions, which made the reward dependent on the sequence-sum or sequence-average, respectively. The results demonstrate that although participants show an overall bias in favour of averaging, they are also remarkably flexible in deploying an averaging or a summation type mechanism that matches the reward contingency