5-Trial Adjusting Delay (Temporal Discounting) Task

The 5-trial adjusting delay task was created as a way to quickly assess an individual’s discount rate with the flexibility to be used with a variety of commodities and situations. The task directly measures the ED₅₀ value for a given commodity, a value that is a simple inverse of the discount rate, i.e. the rate at which individuals discount delayed rewards. This is done by presenting the participant with a 2-alternative forced choice between some amount of a delayed commodity and half that amount available immediately.

The task is designed to allow experimenters to set several different parameters, as follows:

• Commodity with unit: e.g. $ or food
• Delayed or probabilistic amount: This is the larger amount for each trial (e.g. Setting this parameter as 1000 would give us a trial presenting $1,000 in 2 weeks as opposed to $500 now)
• Delay or probabilistic discounting: Determines if the commodity is discounted by delay (i.e. gain more later) or by probability (i.e. gain more at a lower probability)
• Gains or losses: Determines whether the task presents gains of a commodity or loss of a commodity
• Future or past events: Only applies to delay discounting (not probabilistic). Can discount future or past events (e.g. earn $500 an hour ago vs. $1000 a week ago)
• Implicit or explicit zero: Implicit presents choices between 2 amounts of money, one immediate and one delayed. Explicit presents the same amounts, but reframes the choice such that the participant receives none of the commodity at the delay not chosen (e.g. earn $500 now and $0 in 2 weeks or $0 now and $1000 now and $0 in 2 weeks)
• Individual, Social Me-Me, Social Me-We, Social We-Me, Social We-We:
  • Individual: Does not modify the task
  • Social Me-Me: Presents participant with the choice of receiving the commodity for “yourself now” or “yourself later”
  • Social Me-We: “Yourself now” or “a group of people later”
  • Social We-Me: “A group of people now” or “yourself later”
  • Social We-We: “A group of people now” or “a group or people later”

The Healthy Brain Network runs the 5-trial adjusting delay task 6 times, with 5 trials per run. The parameters for each task (which are run in random order) are as follows:

Healthy Brain Network 5-Trial Adjusting Delay Protocol
Parameter	Run 1	Run 2	Run 3	Run 4	Run 5	Run 6
Commodity	$	$	$	$	$	Servings of participant's favorite snack
Delayed or probabilistic amount	10	1000	1000000	1000	1000	10
Delay or probabilistic discounting	Delay	Delay	Delay	Delay	Delay	Delay
Gains or losses	Gains	Gains	Gains	Gains	Gains	Gains
Future or past events	Future	Future	Future	Past	Future	Future
Implicit or explicit zero	Implicit	Implicit	Implicit	Explicit	Implicit	Implicit
Individual, Social Me-Me, Social Me-We, Social We-Me, Social We-We discounting	Individual	Individual	Individual	Individual	Individual	Individual

Domains Assessed: Cognitive and Executive Function

Note: The temporal discounting task is administered to all participants.

References: Koffarnus, M. N., & Bickel, W. K. (2014). A 5-trial adjusting delay discounting task: accurate discount rates in less than one minute. Experimental and clinical psychopharmacology, 22(3), 222.

Time to Complete: 5-10 minutes

A complete list of assessments can be found here.