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										Unconscious Reward Task
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 08-13-2018
last updated:  03-12-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Millisecond Software thanks Dr. Eric Bijleveld for generously sharing his original e-prime script!

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BACKGROUND INFO 	
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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.

Reference:

Bijleveld, Custers, E.R. & Aarts, H. (2010). Unconscious reward cues increase invested effort, 
but do not change speed–accuracy tradeoffs,Cognition, 115, 330-335,

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TASK DESCRIPTION	
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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).

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DURATION 
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the default set-up of the script takes appr. 15-20 minutes to complete

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DATA FILE INFORMATION 
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The default data stored in the data files are:

(1) Raw data file: 'unconsciousrewardtask_raw*.iqdat' (a separate file for each participant)*

build:								The specific Inquisit version used (the 'build') that was run
computer.platform:					the platform the script was run on (win/mac/ios/android)
date, time, 						date and time script was run 
subject, group, 					with the current subject/groupnumber
script.sessionid:					with the current session id

blockcode, blocknum:				the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: 				the name and number of the currently recorded trial (built-in Inquisit variable)
										Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those
										that do not store data to the data file such as feedback trials. Thus, trialnum 
										may not reflect the number of main trials run per block. 
										
values.countTrials:					counts the number of trials run		
																
values.cueStim:						1 = selects the reward coin with itemnumber 1 (here: 1 cent)
									2 = selects the reward coin with itemnumber 2 (here: 50 cents)
									
values.rewardValue:					stores the value of the reward (here: 1 vs. 50)	
values.cueDuration:					stores the duration (in ms) of the reward cue (here: 17ms vs. 300ms)
values.mathProblem:					contains the assembled math problem
values.corrSolution:				the correct solution to the math problem
values.providedSolution:			the computer suggested solution to the math problem

values.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')
									
values.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

expressions.rewardAmount:			the calculated earned reward amount for the current trial
values.totalRewardAmount:			the cumulative reward amounts
expressions.takeHomeReward:			the take home reward (depends on performance (90% correct or higher) and totalRewardAmount)

(2) Summary data file: 'unconsciousrewardtask_summary*.iqdat' (a separate file for each participant)*

computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)
									
expressions.propCorrect_overall:			proportion correct responses across all 56 trials
values.totalRewardAmount:					the cumulative reward amounts
expressions.takeHomeReward:					the take home reward (depends on performance (90% correct or higher) and totalRewardAmount)

expressions.propCorrect_reward1duration1:		proportion correct responses for reward 1 (here: 1cent) presented for the short (superliminal) duration (here: 17ms)
expressions.meanRT_reward1duration1:			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)
									
expressions.propCorrect_reward1duration2:		proportion correct responses for reward 1 (here: 1cent) presented for the long (supraliminal) duration (here: 300ms)
expressions.meanRT_reward1duration2:			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)

expressions.propCorrect_reward2duration1:		proportion correct responses for reward 2 (here: 50cents) presented for the short (superliminal) duration (here: 17ms)
expressions.meanRT_reward2duration1:			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)
									
expressions.propCorrect_reward2duration2:		proportion correct responses for reward 2 (here: 50cents) presented for the long (supraliminal) duration (here: 300ms)
expressions.meanRT_reward2duration2:			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)

* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions

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EXPERIMENTAL SET-UP 
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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)

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STIMULI
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* 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)

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INSTRUCTIONS 
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generously provided by Dr. Eric Bijleveld and translated to English by Millisecond Software
(see section Editable Instructions)

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EDITABLE CODE 
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check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code 
to further customize your experiment.

The parameters you can change are:

/pauseTrial:					a rest trial is presented after 28 (default) trials

Duration Parameters:

/readyDuration:					the duration (in ms) of the 'get-ready' trial (default: 3000ms)
/precue_fixationDuration:		the duration (in ms) of the precue fixation cross (default: 3000ms)
/premaskDuration:				the duration (in ms) of the precue mask (default: 400ms)
/shortcueDuration:				the duration (in ms) of the short reward cue  (default: 17ms)
/longcueDuration:				the duration (in ms) of the long reward cue  (default: 300ms)
/combinedCueMaskDuration:		the duration (in ms) of the combined cue and postcue mask (default: 600ms)
									Note: the post-cue mask will be longer for the short cue duration
									
/postcue_fixationDuration:		the duration (in ms) of the postcue fixation cross (default: 1500ms)
/genericEquationCueDuration:	the duration (in ms) of the (X+X+X=XX) stimulus before actual math problem is presented (default: 1500ms)
/performanceFeedbackDuration:	the duration (in ms) of the performance feedback (default: 3000ms)
/earningFeedbackDuration:		the duration (in ms) of the total earnings feedback (default: 2000ms)
/iti:							the duration (in ms) of the intertrial interval (default: 3000ms)
/pauseDuration:					the duration (in ms) of the rest/pause trial (default: 10000ms)

Stimulus Sizing Parameters:

/cueSize:						the proportional (to canvas) size of the reward cue (default: 30%)
/fixationSize:					the proportional (to canvas) size of the fixation cross (default: 8%)
/problemSize:					the proportional (to canvas) size of the math problem (default: 5%)


Response Key Assignment:

/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)