Delay Discounting Task - ABCD

Background

The ABCD Delay Discounting (DD) Task task, under the supervision of James Bjork, is used as part of the Adolescent Brain Cognitive Development Study (ABCD Study®), a decade long longitudinal study on brain development and child health supported by the National Institutes of Health (NIH). The ABCD DD task is run on tablets (in-person testing) and on smartphones (remote testing) which became necessary during the 2020 Pandemic.

The ABCD DD task is a classic monetary DD Task, assessing monetary indifference points to estimate discount rates.

Using the backstory of a "pretend money game", the ABCD DD task tests 7 time points (6h, 1 day, 1 week, 1 month, 3 months, 1 year, and 5 years) and offers a hypothetical reward of $100 at each of these delays. Each delay is tested in a blocked design. Each block uses 6 trials and continuously and systematically adjusts an immediate but smaller amount to estimate the dollar amount at which both options have the same subjective value to the participant. Several safeguards are built into the procedure to increase the validity of the established indifference points. For example, three validity questions of the type "get $100 NOW vs. get $100 in 5 years" are shown at selected time points and it is noted how often a participant chooses the immediate amount (as there is no benefit to waiting 5 years for getting the same pay-off). Furthermore, at the end of the session, it's automatically assessed whether the established indifference points follow a certain logical pattern, e.g. shorter tested delays should produce higher indifference points. Violations to this order may suggest random responding.

It is suggested that the area under the curve formed by the established indifference points can be used to quantify the severity of discounting of the delayed rewards.

Task Procedure

A participant first learns about the basic task in the "pretend money game" and is asked to play this "pretend" game as if they could really win the money. All instructions are presented in visual and auditory format. Then each of the seven time delays is tested separately. For each time delay, the participant answers six questions of the type "which do you like better: get $100 dollar in one month or $50 now?" After pressing on the preferred choice on the screen, the participant has to touch the gray home button that is located between both response options. Only after touching the home button, that forces the participant to return to a neutral response position, the next question appears.

What it Measures

The ABCD DD Task is a behavioral assessment tool of delay discounting and impulsivity in children and adolescents.

Psychological domains

• Inhibitory Control: The ability to withhold a "rash" response for immediate gain in favor of a more valuable future outcome.

Main Performance Metrics

• Indifference Points: Estimated indifference points for various delays

Psychiatric Conditions

Higher discount rates k are linked to the following conditions:

• Addictive Disorders
• Substance Abuse
• Gambling
• Attention Deficit Hyperactivity Disorder (ADHD)
• Bipolar Disorder
• Borderline Personality Disorder (BPD)