Elsevier

Addictive Behaviors

Volume 66, March 2017, Pages 1-6
Addictive Behaviors

The influence of episodic foresight on delay discounting and demand for alcohol

https://doi.org/10.1016/j.addbeh.2016.11.003Get rights and content

Highlights

  • Imagining the future, known as episodic foresight, may attenuate impulsivity.

  • Episodic foresight reduced delay discounting and alcohol demand intensity.

  • The effect of episodic foresight on impulsivity may extend to alcohol decisions.

Abstract

Background

There is a near-universal tendency to discount the value of delayed rewards relative to those available in the here and now. The rate at which future rewards become devalued over time, delay discounting, is an important individual difference variable related to impulsivity and is elevated in externalising disorders, including alcohol use disorders. Recent research suggests that vividly imagining personally relevant future events (episodic foresight) during an intertemporal choice task can attenuate the rate at which delayed rewards are discounted.

Objectives

The present study sought to extend these findings by examining the effect of episodic foresight on both delay discounting and alcohol-related decision-making.

Methods

Forty-eight college students were administered both modified intertemporal choice and hypothetical alcohol purchase tasks during which personally relevant episodic future event cues or control imagery cues were presented.

Results

Engaging in episodic foresight reduced both the rate at which delayed monetary rewards were discounted and initial alcohol demand intensity (but not other demand indices) relative to control imagery.

Conclusions

Findings suggest that the attenuating effect of episodic foresight on impulsivity may be limited to particular aspects of impulsive choice.

Introduction

Making adaptive decisions often requires a decision-maker to suppress impulses towards immediate gratification in the pursuit of long-term goals. Difficulty doing so has been conceptualized as a key feature of impulsivity, and is characteristic of many behavioural disorders in which immediate gratification becomes highly prioritized over the pursuit of longer-term reinforcement (Bickel and Marsch, 2001, Gullo and Potenza, 2014, MacKillop et al., 2011). Thus, while there is a near-universal tendency to discount the value of future rewards relative to those in the here-and-now, individuals with substance abuse disorders, pathological gambling, obesity, and those who exhibit other risky health behaviours have been consistently found to more rapidly devalue rewards that are delayed in their receipt than healthy controls (Bickel and Marsch, 2001, Dixon et al., 2003, Story et al., 2014). For this reason, responses to intertemporal choices between rewards available immediately and those available only after a delay can act as a ‘behavioural marker’ of addiction-relevant outcomes including the severity, and risk of developing, dependence (for review see Bickel, Koffarnus, Moody, & Wilson, 2014).

Individual differences in discounting rate have been tied to a number of factors, including genetic heritability and early life developmental experiences (Anokhin et al., 2011, Mauro and Harris, 2000, Odum, 2011, Peters and Büchel, 2011). However, the rate at which future rewards are devalued can also vary widely within individuals, as a function of the perceived certainty of a future reward, the framing of the choice question, current affect, alongside other situational or biological variables (for reviews see Gray and Mackillop, 2015, Lempert and Phelps, 2015). One critical set of psychological variables associated with variation in the discounting rate is the manner in which individuals mentally represent or imagine future rewards and the context of their receipt (Bulley, Henry, & Suddendorf, 2016).

A number of recent experimental studies suggest that imagining the future, so-called episodic foresight (Suddendorf and Corballis, 1997, Suddendorf and Corballis, 2007) or episodic future thinking (Atance & O'Neill, 2001), can reduce the rate at which future rewards are discounted in the process of making intertemporal choices. In general, these studies have provided participants with modified intertemporal choice tasks (ICTs) in which a personally relevant future event cue is provided alongside the choice question (Benoit et al., 2011, Daniel et al., 2015, Daniel et al., 2013a, Daniel et al., 2013b, Kwan et al., 2015, Lin and Epstein, 2014, Liu et al., 2013, Palombo et al., 2014, Peters and Büchel, 2010). For example, in Peters and Büchel (2010), participants indicated their preference for either 20€ now, or 35€ in 45 days, while in some trials being simultaneously cued with an actual event they had planned in around 45 days time. In the episodic cue condition, preferences shifted towards longer-term rewards, and the strength of this effect was associated with individual differences in the vividness of mental imagery about the episodic future event.

The effect of episodic foresight has been shown to extend to real-world behavioural indices of impulsive choice. When tempted with unrestricted access to immediately gratifying, densely caloric food, both obese women and children consumed less if concurrently imagining personally relevant future events (Daniel et al., 2015, Daniel et al., 2013b). This effect of episodic foresight on impulsive eating has also recently been demonstrated in college women, such that food-related episodic future thinking led to more restricted consumption of freely and immediately available snacks (Dassen, Jansen, Nederkoorn, & Houben, 2016), and in a sample of obese or overweight women in a real-world food-court experiment (O'Neill, Daniel, & Epstein, 2015).

A large body of evidence suggests that problematic alcohol users tend to show steeper discounting rates than individuals who use alcohol at more moderate or less risky levels (MacKillop et al., 2011, Petry, 2001). While individuals may not be explicitly deciding between payoffs at different times when they choose whether or not to eat unhealthy foods or drink alcohol, there is commonality between the type of decision-processes tapped by the ICT, and the processes employed in such health-related consumption decisions (Yi, Mitchell, & Bickel, 2010). In both cases, the options exist to make either (i) a decision prioritizing immediate gratification (e.g. pleasure) or (ii) a decision that prioritizes longer-term gains (e.g. health). Purchase demand for alcohol is one measure than can be employed to investigate this decision-process, and is predictive of alcohol consumption (Dennhardt et al., 2015, Murphy et al., 2015) as well as problematic alcohol-related behaviours such as driving after drinking (Teeters, Pickover, Dennhardt, Martens, & Murphy, 2014).

Demand for alcohol can be directly assessed with hypothetical ‘alcohol purchase tasks’ (APTs) that ask participants to indicate their willingness to purchase hypothetical drinks at increasing costs (MacKillop et al., 2009, MacKillop et al., 2010, MacKillop and Murphy, 2007, Murphy et al., 2009). There is generally good correspondence between hypothetical tasks of this nature and tasks in which access to alcohol is provided (Amlung, Acker, Stojek, Murphy, & MacKillop, 2012). Given recent studies showing that episodic foresight can reduce not only delay discounting but also ‘impulsive’ eating, in the current study we aimed to explore the effect of episodic foresight on both standard monetary intertemporal choice, as well as alcohol demand using a hypothetical APT. Firstly, we hypothesized that engaging in episodic foresight during the ICT would attenuate the rate at which future rewards were subjectively devalued over time. Secondly, we hypothesized that engaging in episodic foresight would reduce ‘impulsive’ alcohol demand on the hypothetical APT.

Section snippets

Participants

Fifty-two undergraduate students participated in the study for course credit. The study was approved by the relevant university human research ethics committee. Four (7.7%) participants were excluded because they did not attend both experimental sessions. This left a final sample of 48 participants (33 females, 68.8%). The mean age of the sample was 20.67 years (SD = 5.36).

Design and procedure

Participants attended two sessions timed roughly one week apart. In both sessions, participants completed a modified ICT, in

Drinking behaviours of the sample

The mean AUDIT score was 5.73, with 14 (29%) participants scoring above the 8 + cut-off for hazardous drinking specified by Saunders et al. (1993). When asked how often they have a drink containing alcohol, approximately 17% of the sample responded with ‘never’, 38% with ‘monthly or less’, 31% with ‘2–4 times a month’, 13% with ‘2–3 times a week’ and 2% with ‘4 or more times a week’. When asked how many standard drinks they have on a typical day when they are drinking, approximately 56%

Discussion

This experiment investigated the impact of episodic foresight on intertemporal choices and alcohol demand. In line with our initial hypotheses, results demonstrated that imagining personally relevant future events during the monetary ICT attenuated the rate at which delayed rewards were discounted. Furthermore, cued episodic future thinking during the APT led to a small reduction in demand ‘intensity’ (demand at zero cost). However, contrary to our hypotheses, all alcohol demand indices aside

Role of funding source

MJG is supported by a National Health and Medical Research Council of Australia Early Career Fellowship (1036365).

Contributors

AB and MJG conceived the study. AB collected data and ran the analyses, with input from MJG. AB wrote the first draft of the paper, and MJG provided critical revisions. Both authors approved the final manuscript.

Conflict of interest

No conflict declared.

References (68)

  • A.L. Odum

    Delay discounting: Trait variable?

    Behavioural Processes

    (2011)
  • T. O'Hare et al.

    Validating the Alcohol Use Disorder Identification Test with college first-offenders

    Journal of Substance Abuse Treatment

    (1999)
  • E.A. Olson et al.

    Adolescents' performance on delay and probability discounting tasks: Contributions of age, intelligence, executive functioning, and self-reported externalizing behavior

    Elizabeth

    (2007)
  • J. Peters et al.

    Episodic future thinking reduces reward delay discounting through an enhancement of prefrontal-mediotemporal interactions

    Neuron

    (2010)
  • J. Peters et al.

    The neural mechanisms of inter-temporal decision-making: Understanding variability

    Trends in Cognitive Sciences

    (2011)
  • J.M. Thom et al.

    Translational research into intertemporal choice: The western scrub-jay as an animal model for future-thinking

    Behavioural Processes

    (2015)
  • M. Amlung et al.

    Consistency of self-reported alcohol consumption on randomized and sequential alcohol purchase tasks

    Frontiers in Psychiatry

    (2012)
  • M. Amlung et al.

    Understanding the effects of stress and alcohol cues on motivation for alcohol via behavioral economics

    Alcoholism: Clinical and Experimental Research

    (2014)
  • M. Amlung et al.

    Is talk “Cheap”? An initial investigation of the equivalence of alcohol purchase task performance for hypothetical and actual rewards

    Alcoholism: Clinical and Experimental Research

    (2012)
  • A.P. Anokhin et al.

    Heritability of delay discounting in adolescence: A longitudinal twin study

    Behavior Genetics

    (2011)
  • R.G. Benoit et al.

    A neural mechanism mediating the impact of episodic prospection on farsighted decisions

    The Journal of Neuroscience

    (2011)
  • W.K. Bickel et al.

    Toward a behavioral economic understanding of drug dependence: Delay discounting processes

    Addiction

    (2001)
  • A. Bulley et al.

    Prospection and the present moment: The role of episodic foresight in intertemporal choices between immediate and delayed rewards

    Review of General Psychology

    (2016)
  • C. Collodi

    Pinocchio

    (1995)
  • J.B. Daeppen et al.

    Reliability and validity of the Alcohol Use Disorders Identification Test (AUDIT) imbedded within a general health risk screening questionnaire: Results of a survey in 332 primary care patients

    Alcoholism, Clinical and Experimental Research

    (2000)
  • T.O. Daniel et al.

    The future is now: Reducing impulsivity and energy intake using episodic future thinking

    Psychological Science

    (2013)
  • S. Dawe et al.

    Review of diagnostic screening instruments for alcohol and other drug use and other psychiatric disorders

  • A.P. Dempster et al.

    Maximum likelihood from incomplete data via the EM algorithm

    Journal of the Royal Statistical Society: Series B: Methodological

    (1977)
  • A.A. Dennhardt et al.

    Change in delay discounting and substance reward value following a brief alcohol and drug use intervention

    Journal of the Experimental Analysis of Behavior

    (2015)
  • M.R. Dixon et al.

    Delay discounting by pathological gamblers

    Journal of Applied Behavior Analysis

    (2003)
  • J.C. Gray et al.

    Interrelationships among individual differences in alcohol demand, impulsivity, and alcohol misuse

    Psychology of Addictive Behaviors: Journal of the Society of Psychologists in Addictive Behaviors

    (2014)
  • J.C. Gray et al.

    Impulsive delayed reward discounting as a genetically-influenced target for drug abuse prevention: a critical evaluation

    Frontiers in Psychology

    (2015)
  • S.R. Hursh et al.

    Economic demand and essential value

    Psychological Review

    (2008)
  • J.D. Isen et al.

    Predictive validity of delay discounting behavior in adolescence: A longitudinal twin study

    Experimental and Clinical Psychopharmacology

    (2014)
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