Episodic future thinking (EFT) is based on the new science of prospection, which was first identified in a Science publication in 2007 and refers to pre-experiencing the future by simulation. Considerable evidence suggests that prospection is important for understanding human cognition, affect, motivation, and action. Individuals with damaged frontal areas, as well as individuals with alcohol use disorder (AUD), show deficits in planning prospectively. One systematic method to engender prospection is via EFT. EFT, as applied in our prior studies and in this proposal consists of having participants develop positive plausible future events that correspond to several future time frames (e.g., 2 weeks, 1 month, 3 months etc). For each of these timeframes participants are asked to concretize the events (e.g., What are you doing? Who will be there? What will you see, hear, smell, and feel?). We and others have used EFT to decrease delay discounting (DD) in individuals with AUD and smokers, as well as normal weight, overweight, and obese populations when compared to the control condition, control episodic thinking (CET). Consistent with reinforcer pathology, EFT also reduces alcohol valuation in the purchase task among individuals with AUD. However, no study to date has examined whether EFT reduces alcohol self-administration in the laboratory. Moreover, the neural correlates of EFT in AUD are also unknown. In these studies, we propose to test an intervention, EFT, which we hypothesize will decrease reinforcer pathology measures in a bar-like setting in the laboratory; that is, EFT will decrease delay discounting, as well as alcohol self-administration, demand, and craving compared to a control episodic thinking (CET) condition. Moreover, we hypothesize EFT will enhance activation in brain regions associated with prospection (e.g., hippocampus and amygdala) and the executive decision system (e.g., DLPFC). We will also examine the effect of EFT on real-world drinking.
In study 1, participants will be randomly assigned to experimental or control groups, stratified by AUDIT scores, SES, age and sex. Based on our 8 years of experience recruiting this population, we expect approximately 66% retention among eligible participants. Therefore, we will enroll approximately 107 participants in order to conclude with 64 completers. Participants will complete: a baseline assessment (S1), an alcohol self-administration session (S2 or S3), an fMRI session (S2 or S3). The alcohol self-administration session and the fMRI session will be completed in counterbalanced order. At the beginning of S2 and S3, participants in both groups will be prompted to generate positive events and related cues through a researcher-administered interview-based questionnaire. EFT group participants will be asked to think about and describe the most positive event that could realistically happen at each of 7 delays in the future (1 day, 1 week, 1 month, 3 months, 1 year, 5 years, and 25 years). In contrast, participants randomized to the CET condition, will be asked to think about and describe the most positive event that occurred at each of 7 time points from the recent past (last night from 7pm-10pm, yesterday between 4pm-7pm, yesterday between 1pm-4pm, yesterday from 10am-12pm, yesterday between 7am-10am, the night before last between 7pm-10pm, and evening before last between 4pm-7pm). For each time point, the participant will be asked to integrate the event and sensory information into concise textual and/or auditory cues to be used in subsequent behavioral tasks. Cue generation will occur prior to both self administration and fMRI sessions (S2 and S3) to maximize the relevancy of cues at both sessions. In study 2, participants will complete two sessions and undergo a one-week baseline monitoring phase where they provide breath samples to assess for recent alcohol use and report their drinks per day. Following this baseline period, participants will complete an fMRI then be randomized to either the EFT or Control group. Participants will then complete two weeks of monitoring, where they provide a breath sample three times a day and report the number of drinks they consumed. Participants will then come back to the lab to generate new EFT/CET cues, then complete two more weeks of monitoring. After conclusion of the second intervention period, participants will complete a post intervention session and then a one month follow up one month after study completion.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
154
Participants will generate descriptions of vivid positive future events.
Participants will generate descriptions of vivid positive recent past events.
Fralin Biomedical Research Institute at VTC
Roanoke, Virginia, United States
Delay Discounting (DD) Rates (Studies 1 and 2)
DD rates were measured using an adjusting amount task where participants were presented with hypothetical choices between smaller immediate or larger later amounts of money after a range of delays (1 day-25 years). Individual indifference points were calculated for each delay and then used to estimate DD rates for each participant using Mazur's (1987) equation: V = A/(1+kD), where V is the value of the indifference point, A is the amount of the larger delayed reward, k is the discounting rate, and D is the delay. Discounting rates (k) were then natural-logarithmically transformed (ln(k)). Higher ln(k) indicates steeper discounting and greater reward devaluation with increases in delay, while a lower ln(k) reflects shallower discounting and less reward devaluation with increases in delay. Change in ln(k) will be compared within-subjects between S1 and S2, AND between S1 and S3.
Time frame: Pre-intervention (S1; baseline measures; Day 1), Post 1st cue generation: S2 (occurs up to 7 days post S1 in Study 1 and 2-3 weeks post S1 in Study 2), and Post 2nd cue generation: S3 (occurs up to 7 days post S2 in Study 1 and 2 weeks post S2 in Study 2)
Intensity of Alcohol Demand (Study 2)
Participants completed a hypothetical Alcohol Purchase Task in which they indicated how many drinks they would purchase at different prices ($0 to $80 per drink). The number of drinks purchased at $0 was used to calculate the intensity of demand. Changes in intensity of alcohol demand were compared within-subjects between S1 and S2, AND between S1 and S3.
Time frame: Pre-intervention (S1; baseline measure; Day 1), Post 1st cue generation, (S2; approximately 2 weeks post S1), and Post 2nd cue generation (S3; approximately 2 weeks post S2 and 4 weeks post S1)
In-Laboratory Alcohol Consumption (Study 1)
The number of alcoholic beverages purchased/consumed during the self-administration session will be recorded. The average number of drinks consumed will be compared between groups.
Time frame: Self-Administration session will occur at either Session 2 or Session 3 based on counterbalance assignment. S2 occurs up to 7 days post S1 and S3 occurs up to 7 days post S2.
fMRI Hyper-connectivity Decrease During Delay Discounting (Study 1)
Measured using fMRI during delay discounting task. Whole-brain PPI analysis of right DLPFC between EFT and CET participants. We examined the number of participants whose Right DLPFC was negatively correlated with their Left DLPFC after the intervention. We hypothesize that AUD leads to hyperconnectivity (positive correlations) between these two regions as a compensatory decision-making mechanism, and that EFT should reduce or reverse this connectivity relationship
Time frame: fMRI session occurred at either Session 2 or Session 3 based on counterbalance assignment. S2 occurred up to 7 days post S1 and S3 occurred up to 7 days post S2.
fMRI Hyper-connectivity Decrease During Alcohol Purchase Task (Study 1)
Measured using fMRI during the alcohol purchase task. Whole-brain PPI analysis of right DLPFC between EFT and CET participants. We examined the number of participants whose Right DLPFC was negatively correlated with their Left DLPFC after the intervention. We hypothesize that AUD leads to hyperconnectivity (positive correlations) between these two regions as a compensatory decision-making mechanism, and that EFT should reduce or reverse this connectivity relationship
Time frame: fMRI session occurred at either Session 2 or Session 3 based on counterbalance assignment. S2 occurred up to 7 days post S1 and S3 occurred up to 7 days post S2.
Change in Alcoholic Drinks Per Day (Study 2)
Participants self-reported the number of drinks consumed per day via a mobile app during the first five weeks of the study. The first week measured baseline drinking (Pre-intervention), weeks 2-3 measured drinking after the first cue generation (Post 1st cue generation), and weeks 4-5 measured drinking after the second cue generation (Post 2nd cue generation) The number of drinks per day was compared within-subjects and between groups (EFT and CET).
Time frame: Daily during Pre-intervention (week 1); Post 1st cue generation (weeks 2-3); and Post 2nd cue generation (weeks 4-5).
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