Is talk "cheap"? An initial investigation of the equivalence of alcohol purchase task performance for hypothetical and actual rewards

Abstract

Background: Behavioral economic alcohol purchase tasks (APTs) are self-report measures of alcohol demand that assess estimated consumption at escalating levels of price. However, the relationship between estimated performance for hypothetical outcomes and choices for actual outcomes has not been determined. The present study examined both the correspondence between choices for hypothetical and actual outcomes, and the correspondence between estimated alcohol consumption and actual drinking behavior. A collateral goal of the study was to examine the effects of alcohol cues on APT performance.

Methods: Forty-one heavy-drinking adults (56% men) participated in a human laboratory protocol comprising APTs for hypothetical and actual alcohol and money, an alcohol cue reactivity paradigm, an alcohol self-administration period, and a recovery period.

Results: Pearson correlations revealed very high correspondence between APT performance for hypothetical and actual alcohol (ps < 0.001). Estimated consumption on the APT was similarly strongly associated with actual consumption during the self-administration period (r = 0.87, p < 0.001). Exposure to alcohol cues significantly increased subjective craving and arousal and had a trend-level effect on intensity of demand, in spite of notable ceiling effects. Associations among motivational indices were highly variable, suggesting multidimensionality.

Conclusions: These results suggest there may be close correspondence both between value preferences for hypothetical alcohol and actual alcohol, and between estimated consumption and actual consumption. Methodological considerations and priorities for future studies are discussed.

Figure 1

Schematic time line of study procedures. Note. HR/BP, Heart-rate/blood pressure (MAP); Motivation assessments included craving, approach-avoidance, and affect; Hyp-APT, Alcohol purchase task for hypothetical rewards; Actual-APT, Alcohol purchase task for actual rewards; BrAC, breath alcohol level.

Figure 2

Average demand (A) and expenditure (B) curves across all three alcohol purchase task assessments. Price per drink is presented in conventional logarithmic coordinates for proportionality. Individual data points represent mean (+/− standard error).

Figure 3

Relationship between estimated alcohol consumption at a given price (Drinks Provided) and actual consumption (Drinks Consumed) during the one-hour consumption period. The number of participants represented by each datapoint is indicated with subscripts (N = 30).