The effects of a concurrent task on human optimization and self control

Memory deficits have been shown to hamper decision making in a number of populations. In two experiments, participants were required to select one of three alternatives that varied in reinforcer amount and delay, and the effect of a concurrent task on a behavioral choice task that involved making either an impulsive, self-controlled, or optimal response was studied. The studies aimed to see whether or not individuals were capable of optimizing when confronted with a three-alternative choice paradigm, and if a concurrent task could induce over-selectivity toward a self-controlled, or impulsive, choice, rather than an optimal choice. Various factors which could possibly influence optimization were also explored. The results suggest that some, but not all, individuals are capable of optimizing in a three-alternative choice paradigm, especially when there is a great differential between reinforcement rates of optimal versus non-optimal behaviors. Participants with a concurrent task (continuously subtracting seven from a large number) displayed over-selectivity, evidenced by the high proportion of self-controlled responses.