Can Attribution Bias Improve Preferences for Healthy Drinks? Evidence from a Neuroeconomic Study

The intervention aims to exogenously manipulate subjects' thirst level prior to consumption of a target carbonated drink, with the aim to vary consumption experience across treatments. Participants will be asked to refrain from drinking water or any liquids for five hours prior to the experiment. They will then be randomly assigned to either the treatment or control group using computer-based randomization software. The treatment group will remain thirsty, while the control group will receive a 500 ml bottle of water to offset their thirst. Following thirst manipulation, both groups will be provided with a healthy carbonated drink (e.g., Poppi drink) to consume, after which they will rate their consumption experience. The treatment group is expected to report higher ratings since they consume the drink under an arousal state (thirst), resulting in a better consumption experience than subjects in the control group, who are hydrated before consuming the healthy drink.

2026-06-15

2026-08-15

1. Subjects' bids in a Becker-DeGroot-Marschak (BDM) task will be compared across control and treatment.
2. Frontal Asymmetry Index (FAI) will be calculated from EEG data and compared between control and treatment as subjects view the product in the BDM.
3. Event-Related Potentials (ERPs) will be measured during a cue exposure task and key components (e.g., P1, N1, N2, P3, LPP, RewP) will be compared between control and treatment.

Age, gender, ethnicity, income, education, exercise frequency and intensity, duration since last glass of water, current thirst level, number of glasses of water and any other liquids per day, expected time until next glass of water, and consumption experience.

The experiment is conducted across two days. On the first day, subjects will consume a healthy drink under a control or treatment condition. On day two, they will report their preferences by answering survey questions and completing a BDM task. Neurophysiological indicators of preference will also be collected as subjects evaluate the healthy drink product in the BDM task and during their participation in a cue exposure task.

The experiment is conducted across two days. The first day involves the treatment manipulation, where consumption experience with a healthy drink will be exogenously manipulated between a control and treatment group. The manipulation will be thirst-based, where all subjects will be asked to refrain from drinking water or any liquids for 5 hours prior to arriving at their first-day session. Subjects in the control group will be provided with a 500 ml bottle of water before starting, while those in the treatment group will not. Subjects will then report their thirst levels, which will be used to confirm successful thirst manipulation, after which they will be asked to consume the healthy carbonated drink. During consumption of the healthy drink product, all subjects will first consume the first portion, after which they will answer a very short intermediate questionnaire before consuming the second portion. The intermediate questionnaire will consist of two questions about how tasty the product is and how excited they are to consume the second portion. After consuming both portions of the healthy drink product, subjects will answer a short questionnaire to collect sociodemographic data, as well as behavioral information related to how many glasses of water they typically consume per day, how many glasses of any liquids other than water they typically consume per day, and how often they consume carbonated drinks. The first day’s session will then conclude with measuring subjects’ weight and height to calculate BMI.

The second day’s session will start with a short questionnaire asking subjects to report how much they enjoyed consuming the healthy drink in day 1 and if they would consume the drink again if it were available to them. They will also report if they had consumed the healthy drink/unhealthy equivalent (e.g., Poppi drink and Sprite) between days 1 and 2. Subjects will then complete two tasks in a randomized order to elicit behavioral and psychophysiological indicators of their preferences for the healthy drink consumed on day 1, which will be compared between the control and treatment groups. The first is a BDM task where subjects will view an image of the healthy drink consumed on day 1 then submit a bid for the product with a likelihood of purchase if their bid is greater than or equal to a randomly drawn market price. The second is a cue exposure task, where subjects will be presented with a random sequence of 60 images, consisting of 30 non-food images (e.g., office items) and 30 images of the healthy carbonated drink they consumed in day 1. The images will be presented in a quasi-random order that avoids more than 4 repetitions from the same category.

Participants will be assigned equally to Control and Treatment groups (60 in each). First, each of the 120 participants is labeled with a unique identifier. A random number is then generated for each ID from a uniform distribution. The numbers are ranked from lowest to highest, and the 60 IDs associated with the lowest numbers are placed in the Control group, while the remaining 60 are placed in the Treatment group. This ensures an exact 50–50 split while preserving random assignment.

Individual

No

120 individuals (60 Treatment, 60 Control)

120 individuals

60 individuals control, 60 individuals treatment

WTP outcome minimum detectable effect size: $0.207 (m1=0.953, sd1=0.361, sd2=0.436)