Results for the behavioural control experiment. Bars represent regression coefficients (mean ± SEM) obtained from a regression of experimental parameters against subjects' choices. Positive values indicate that the parameter increases the probability to select the option. RP: reward probability, RM: reward magnitude, pO: outcome on previous trial, pC: choice on previous trial, RP × RT: interaction between reward probability and reaction time, RM × RT: interaction between reward magnitude and reaction time.