Cognitive Effort Expenditure for Rewards Task (CEEFRT)
Background
The Cognitive Effort-Expenditure for Rewards Task (cEEfRT) is a behavioral task that measures an individual's motivation and willingness to exert mental effort for incentives. The measure was introduced by Paula Lopez-Gamundi and Margaret C. Wardle in 2018 as the analogous cognitive measure to the classic Effort-Expenditure for Rewards Task (EEfRT) that focuses on physical effort. By comparing the two parallel measures, the researchers established cognitive effort as a distinct construct from its physical counterpart.
Like the EEfRT, the cEEfRT gives participants two simple choices: select a easy (cognitive) task and attempt to win some money or select a difficult (cognitive) task and potentially win even more money. The actual cognitive tasks to perform in the cEEFrT are borrowed from Matthew M. Botvinick and colleagues (2009): participants are asked to categorize a single digit as either odd/even (parity judgments) or smaller/greater than 5 (magnitude judgments), depending on the digit's font color. Blue digits signal participants to work on parity judgments; yellow digits signal participants to work on magnitude judgments. When participants select the easy (cognitive) task, they keep working on the same task (no Task switching) whereas when they select the difficult (cognitive) task, they must alternate between parity and magnitude judgments. In addition, the easy task requires 4 judgments within 7 seconds for task completion and provides participants with response reminders, whereas the difficult task provides no response reminders and requires 19 judgments within 21 seconds. Like the EEfRT, the cEEfRT asks participants to make their selection knowingly under 3 different win probability conditions.
Task Procedure
The cEEfRT familiarizes participants with the task during a short practice phase that runs 4 trials. During the first and second trial, participants must choose the easy and difficult task, respectively. For the last two practice trials, participants can choose themselves. If participants fail to choose a task within 5 seconds during practice (and the test), the program randomly chooses a task for them. Practice performance is required to be 100% correct to move on to the test session. If practice performance is below 100%, the practice session is repeated. All participants move to the test session after max. 10 practice rounds.
The actual test phase runs for 20 minutes and participants can work on as many tasks as they can. The number of completed tasks depends on
(a) how fast they make their selection, (b) the type of task they select (with the Difficult task taking 3 times longer) and (c) how fast they complete the task.
The program runs a three 3 reward probabilities (low=0.12, medium=0.5, high=0.88) x 8 different reward magnitudes for the Difficult task ($1.08-$4.30),
within-participant design. The (potential) reward for the Easy Task is always $1. Each level of reward probability (3) is paired with each level of
difficult task rewards (8) twice within every 48 trials in the EEfRT Millisecond implementation. The presentation of the different combinations of
difficult reward tasks x probabilities was randomized for 2 lists of 48 trials and is presentedin fixed order to each participant.
• The expected money for completing 48 trials of the difficult task is = $2.77 * 48 * average(0.12, 0.5, 0.88) = $66.48.
• The expected money for completing 48 trials of the easy task is = $1 * (2 * 48) * average(0.12, 0.5, 0.88) = $48.
A maximum payoff can be set in this script, so that if it's reached, the task is terminated.
Each trial sequence begins with the 'Selection Screen' (max. 5seconds) that explicitly presents the reward probabilities and reward magnitudes for the Easy and the Difficult tasks. After participants make their choice (or after 5s) by pressing one of two keyboard keys, a 'Ready' screen appears for 1second, followed by the task UI that features an empty meter bar whose level rises with each correct response (the height of the meter is determined by the number of required responses). A single digit in either blue font (=> parity judgment) or in yellow font (=> magnitude judgment) is placed right under the meter. For the easy task, the UI also features the response reminder. Once the top of the meter has been reached -or after the assigned task is over (7seconds for the Easy task; 21seconds for the Hard task)- the trial ends, and participants learn if they won the potential reward money (feedback presented for 2seconds). Rewards are only won for successfully completed tasks (by default all required responses have to be correct) and only if the program determines the trial to be a 'win' trial (based on the trial's reward probability).
What it Measures
The cEffort-Expenditure for Rewards Task (EEfRT) measures an individual's motivation and willingness to exert cognitive effort for incentives
Psychological domains
- Anticipatory Motivation: The drive to pursue a reward before it is obtained.
- Effort-Based Decision Making: Weighting the subjective value of a reward against the mental energy required to get it.
- Reward Responsiveness: How much a person's behavior changes when the stakes are raised (e.g., doubling the payout).
- Motivational Anhedonia: The diminished drive, interest, or willingness to exert effort to pursue a reward
- Risk and Probability Assessment: Ability to tolerate risk when energy expenditure is at stake
- Subjective Utility Valuation: Cognitive calculations combining effort costs, probability, and reward magnitude to make an optimized choice.
Main Performance Metrics
- proportion Difficult Choices: Proportion of time participants selects the difficult task; Overall preference metric
Psychiatric Conditions
The cEEfRT is used with the following clinical populations
- Major Depressive Disorder (MDD)
- Schizophrenia
The the Cognitive Effort Expenditure for Rewards Task (cEEfRT) is a measure of reward motivation for cognitive work (Gamundi & Wardle, 2018).
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Cognitive Effort Expenditure for Rewards Task (CEEFRT).
Lopez-Gamundi, P & Wardle, MC (2018). The cognitive effort expenditure for rewards task (C-EEfRT): A novel measure of willingness to expend cognitive effort. Psychol Assess, Sep;30(9):1237-1248. doi: 10.1037/pas0000563. Epub 2018 Apr 5. PMID: 29620381.
Horne, S. J., Topp, T. E., & Quigley, L. (2021). Depression and the willingness to expend cognitive and physical effort for rewards: A systematic review. Clinical Psychology Review, 88, Article 102065. https://doi.org/10.1016/j.cpr.2021.102065
Webber, H. E., Lopez-Gamundi, P., Stamatovich, S. N., de Wit, H., & Wardle, M. C. (2021). Using pharmacological manipulations to study the role of dopamine in human reward functioning: A review of studies in healthy adults. Neuroscience and Biobehavioral Reviews, 120, 123–158. https://doi.org/10.1016/j.neubiorev.2020.11.004