Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Millisecond thanks Dr. Eric Bijleveld for generously sharing his original e-prime script!
Last Modified: January 26, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements the Unconscious Reward Task. Monetary rewards facilitate performance on cognitive tasks even when these rewards are perceived without conscious awareness but differences in the speed-accuracy only occur with consciously perceived rewards.
Bijleveld, Custers, E.R. & Aarts, H. (2010). Unconscious reward cues increase invested effort, but do not change speed–accuracy tradeoffs,Cognition, 115, 330-335,
15 - 20 minutes
Participants work on simple addition equations (3 + 2 + 6 = 13) and have to decide whether the suggested solution is correct or incorrect. For correct evaluations, they can earn two types of rewards, either a low reward (max. 1cent) or a high reward (max. 50cents) with the caveat that rewards get smaller the longer is takes to respond.
The take-home reward further depends on the overall accuracy of the participants' responses: the extra money can only be earned if 90% or more of all responses were correct. Half the trials present the reward cues subliminally (at 17ms duration); half the trials present the reward cues supraliminally (at 300ms).
Test: 56 trials
- 28 trials with reward 1 (14 presented at 17ms (7 correct), 14 presented at 300ms (7 correct));
28 trials with reward 2 (14 presented at 14 ms (7 correct), 14 presented at 300ms (7 correct))
- trial order is random
- the math problem is randomly (without replacement) selected from the pool of pre-generated 56 problems
Trial Sequence:
-> precue fixation (3000ms)
-> precue mask (400ms)
-> cue (17ms vs. 300ms)
-> postCue mask (583ms vs. 300ms)
-> postCue fixation (1500ms)
-> generic equation cue (1500ms): 'x+x+x=xx'
-> math equation (until response): actual problem presented
-> performance feedback (3000ms): participants learn whether a) they were correct or incorrect and b) how much they earned
-> cumulative earnings feedback (2000ms): participants learn their accumulated earnings
-> iti
(one break after 28 trials)
Reward Calculations: the promised reward decreases by ~14% per s responding
- the rewards per trial (for correct responses) are calculated using the following formula:
actual reward = max. rewardvalue - (max. rewardValue * response time in ms/7000)
=> responses given after 7000ms earn an actual reward value of 0 (same as incorrect responses)
• 56 addition problems generously provided by Dr. Eric Bijleveld (see section Editable Stimuli)
- each problem contains 3 digits (1-9) (repeated digits ok)
- no two of the digits add up to 10
• coins and mask generously provided by Dr. Eric Bijleveld (see section Editable Stimuli)
generously provided by Dr. Eric Bijleveld and translated to English by Millisecond
(see section Editable Instructions)
File Name: unconsciousrewardtask_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| propCorrectOverall | Proportion correct responses across all 56 trials |
| totalRewardAmount | The cumulative reward amounts |
| takeHomeReward | The take home reward (depends on performance (90% correct or higher) and totalRewardAmount) |
| propCorrectReward1Duration1 | Proportion correct responses for reward 1 (here: 1cent) presented for the short (superliminal) duration (here: 17ms) |
| meanRTReward1Duration1 | Mean response time (in ms) of correct responses for reward 1 (here: 1cent) presented for the short duration (here: 17ms) that were < 7000ms (at 7000ms and above no reward can be earned) |
| propCorrectReward1Duration2 | Proportion correct responses for reward 1 (here: 1cent) presented for the long (supraliminal) duration (here: 300ms) |
| meanRTReward1Duration2 | Mean response time (in ms) of correct responses for reward 1 (here: 1cent) presented for the long duration (here: 300ms) that were < 7000ms (at 7000ms and above no reward can be earned) |
| propCorrectReward2Duration1 | Proportion correct responses for reward 2 (here: 50cents) presented for the short (superliminal) duration (here: 17ms) |
| meanRTReward2Duration1 | Mean response time (in ms) of correct responses for reward 2 (here: 50cents) presented for the short duration (here: 17ms) that were < 7000ms (at 7000ms and above no reward can be earned) |
| propCorrectReward2Duration2 | Proportion correct responses for reward 2 (here: 50cents) presented for the long (supraliminal) duration (here: 300ms) |
| meanRTReward2Duration2 | Mean response time (in ms) of correct responses for reward 2 (here: 50cents) presented for the long duration (here: 300ms) that were < 7000ms (at 7000ms and above no reward can be earned) |
File Name: unconsciousrewardtask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| countTrials | Counts the number of trials run |
| cueStim | 1 = selects the reward coin with itemnumber 1 (here: 1 cent) 2 = selects the reward coin with itemnumber 2 (here: 50 cents) |
| rewardValue | Stores the value of the reward (here: 1 vs. 50) |
| cueDuration | Stores the duration (in ms) of the reward cue (here: 17ms vs. 300ms) |
| mathProblem | Contains the assembled math problem |
| corrSolution | The correct solution to the math problem |
| providedSolution | The computer suggested solution to the math problem |
| corrResponse | 1 = the suggested solution is correct 0 = the suggested solution is incorrect |
| response | The participant's response: scancode of response key 18 = E ('correct') 23 = I ('incorrect') |
| resp | 1 = the suggested solution is accepted as correct 0 = the suggested solution is not accepted as correct |
| correct | Accuracy of response: 1 = correct response (participant selected correct response key); 0 = otherwise |
| latency | The response latency (in ms); measured from: onset of math problem until response |
| rewardAmount | The calculated earned reward amount for the current trial |
| totalRewardAmount | The cumulative reward amounts |
| takeHomeReward | The take home reward (depends on performance (90% correct or higher) and totalRewardAmount) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| pauseTrial | A rest trial is presented after 28 (default) trials Duration Parameters | |
| readyDuration | The duration (in ms) of the 'get-ready' trial | 3000ms |
| preCueFixationDuration | The duration (in ms) of the precue fixation cross | 3000ms |
| preMaskDuration | The duration (in ms) of the precue mask | 400ms |
| shortCueDuration | The duration (in ms) of the short reward cue | 17ms |
| longCueDuration | The duration (in ms) of the long reward cue | 300ms |
| combinedCueMaskDuration | The duration (in ms) of the combined cue and postCue mask the post-cue mask will be longer for the short cue duration | 600ms |
| postCueFixationDuration | The duration (in ms) of the postCue fixation cross | 1500ms |
| genericEquationCueDuration | The duration (in ms) of the (X+X+X=XX) stimulus before actual math problem is presented | 1500ms |
| performanceFeedbackDuration | The duration (in ms) of the performance feedback | 3000ms |
| earningFeedbackDuration | The duration (in ms) of the total earnings feedback | 2000ms |
| iti | The duration (in ms) of the intertrial interval | 3000ms |
| pauseDuration | The duration (in ms) of the rest/pause trial Stimulus Sizing Parameters | 10000ms |
| cueSize | The proportional (to canvas) size of the reward cue | 30% |
| fixationSize | The proportional (to canvas) size of the fixation cross | 8% |
| problemSize | The proportional (to canvas) size of the math problem Response Key Assignment | 5% |
| leftResponseKey | The left response key label (here: E) | |
| rightResponseKey | The right response key label (here: I) | |
| correctResponseKey | The correct response key label (here: the left response key) | |
| incorrectResponseKey | The correct response key label (here: the right response key) |