Probabilistic Reversal Learning Task

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Created: January 07, 2018

Last Modified: January 11, 2024 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a Probabilistic Reversal Learning Task, a task of adaptive learning and flexibility in the context of changing stimulus-reward contingencies.

References

Waegeman, A., Declerck, C.H, Boone, C., Seurinck, R. & Parizel, P.M. (2014). Individual Differences in Behavioral Flexibility in a Probabilistic Reversal Learning Task: An fMRI Study. Journal of Neuroscience, Psychology, and Economics, Vol. 7, No. 4, 203–218

Cools R, Clark L, Owen AM, Robbins TW. (2002). Defining the neural mechanisms of probabilistic reversal learning using event-related functional magnetic resonance imaging. J Neurosci. 2002;22:4563–4567.

Like Waegeman et al (2014), this Inquisit script a) uses a timelimit for each of the test blocks. The number of reversals reached during that time reflects how fast a participant learned to adjust behavior

B) attaches explicit rewards (aka points) to 'positive' feedback and punishment for 'negative' feedback (however, the points can be made invisible, see section Editable Parameters) and asks participant to maximize their reward without explicitly alerting participants to the fact that payoff probabilities might change (however, instructions can be easily altered under section Editable Instructions).

C) uses a 80%/20% probability for rewards and punishment (editable under section Editable Parameters)

Duration

30 minutes

Description

Participants are asked to select btw. 2 patterns. One patterns has an 80% probability of a reward and a 20% probability of a loss whereas the probabilities are reversed for the second pattern. Participants are asked to maximize their rewards. After participants have learned to consistently select the pattern with the higher reward probability, the probabilities of the patterns are reversed. A block ends after 9 minutes.

Procedure

(1) Practice:
- the practice phase presents two patterns with the same reward/punishment probabilities as during the test.
- the initial 'lucky' pattern is randomly determined
- The screen position of the two patterns (left vs. right) is randomly determined (random selection with replacement).
- Practice ends after the first reversal is reached.
if the first reversal is not reached within 5 minutes (default), practice is cut short and the script is aborted

(3) Test: 3 blocks
- each of the blocks gets 2 randomly assigned patterns (6 patterns provided)
- one pattern has an 80% probability of reward (20% probability of punishment),
the reward/punishment probabilities are reversed for the second pattern
(the initial 'lucky' pattern is determined randomly)
- The screen position of the two patterns (left vs. right) is randomly determined (random selection with replacement)
- after 10-15 consecutive choices of the 'lucky' pattern (randomly determined), the reward/punishment probabilities are reversed
- each test block is terminated after 9 minutes => the number of reversals will differ
Trial Sequence:
pattern presentation (max. 2000ms or response) -> Feedback (500ms) -> ITI: variable (min: 500ms)
(entire trial takes: 3000ms => every 3s a new pattern is presented)

Stimuli

provided by Millisecond - can be edited under section Editable Stimuli

Instructions

provided by Millisecond - can be edited under section Editable Instructions

Summary Data

File Name: probabilisticreversallearningtask_summary*.iqdat

Data Fields

Raw Data

File Name: probabilisticreversallearningtask_raw*.iqdat

Data Fields

Parameters

The procedure can be adjusted by setting the following parameters.