Abstract
A first-person-shooter video game was adapted for the study of probability discounting, in which an outcome decreases in value as its likelihood decreases, and delay discounting, in which an outcome decreases in value as the delay to its occurrence increases. This novel preparation was designed to address a criticism of previous research in the area. Discounting research using humans has been criticized for using hypothetical outcomes and tasks in which the probabilities and delays are not actually experienced. In the video game preparation, participants fired a weapon that could produce an explosion. The longer that they waited, the higher the likelihood that their weapon would function; after 10 seconds, pulling the trigger was guaranteed to produce an explosion. An impulsive person was predicted to shoot sooner with a greater risk of the weapon not firing, whereas a highly self-controlled person was predicted to shoot later in order to ensure a high probability of damage to the target. The advantages of waiting were systematically changed to either encourage or discourage waiting by modifying the way in which the probability increased. Participants who needed more encouragement to wait were judged to be more impulsive than those who waited without significant encouragement. Students also completed a typical probability discounting task, where they were asked to make hypothetical choices between smaller-certain versus larger-uncertain monetary rewards. There were significant individual differences in the task, and participants completed the task less efficiently than they did in an earlier experiment in which outcome magnitude, not probability, increased over time. Behaving impulsively in the video game was detrimental to the progress of the player, which produced less impulsive behavior as the game progressed. Future analyses will examine correlations between behavior in the video game and choices in the typical questionnaire task.