Demand Characteristics in Episodic Future Thinking II: The Role of Cues and Cue Content in Changing Delay Discounting

Episodic future thinking (EFT), or imagining experiencing one's future, reduces discounting of future rewards, but the mechanisms of this effect are unclear. We examined the role of cues to engage in EFT, possible demand characteristics inherent to those cues (prompting awareness of the hypothesized effects of EFT), and changes in temporal horizon (how far one thinks into the future) in these reductions in delay discounting. In Experiment 1, cues prompting participants to engage in EFT during the discounting task were presented or withheld: EFT decreased discounting only when cues were present. In a time-perspective task in which cues were not presented, EFT did not broaden temporal horizon; however, episodic recent thinking (the putative control activity) shortened temporal horizons. In Experiment 2, cues were manipulated in a way designed to make them either more theoretically relevant (prompting episodic thought) or more prone to demand characteristics (prompting attention to the correspondence in delays between EFT and discounting tasks). Only theoretically relevant cues reduced delay discounting. These results do not support the hypothesis that EFT reduces delay discounting because of demand characteristics. Instead, they suggest limitations on the generalizability of EFT effects in uncued contexts and suggest that mechanisms other than temporal horizon may be responsible for its effects. Public Health Significance Prior research indicated that the effects of episodic future thinking (EFT), a method for reducing impulsive choice and addiction-related behaviors, may be due to participants' ability to discern EFT's hypothesized benefits. The present findings suggest awareness of the hypothesis does not account for EFT benefits. Instead, they suggest EFT effects have limited generalizability-something that will need to be addressed in future research. Uncovering mechanisms of EFT may help in developing interventions with more robust clinical utility.