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							ABCD Adjusting Amount Discounting Procedure
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 04-28-2017
last updated:  01-02-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 01-02-2020 Millisecond Software

This script has been made available to the Millisecond Software Library by the ABCD Research Consortium.
The script was designed to be run on ipads.

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BACKGROUND INFO 	
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This script implements an Adjusting Amount Discounting Procedure 
to assess the hypothetical reward amounts at which people start to discount higher monetary rewards
in favor of shorter wait periods. 

This script is based on an Python script written by Dr. Mikhail Koffarnus and
generously shared by the ABCD Consortium.

Koffarnus, M.N. & and Warren K. Bickel, W.K. (2014). A 5-Trial Adjusting Delay Discounting Task:
Accurate Discount Rates in Less Than One Minute. 
Experimental and Clinical Psychopharmacology, 22, No. 3, 222–228

Rule Violations described in:
Johnson and Bickel (2008, Experimental and Clinical Psychopharmacology, 16, 264-274). 

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TASK DESCRIPTION	
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Participants have to make a choice between 2 amounts of moneys with different delays:
a delayed amount (here: $100) for delay1 (e.g. "in a year") compared to an immediate amount (e.g. $50)
right now. Seven delays ("6hours", "1 day", "1 week", "1 month", "3 months", "1 year", "5 years")
are tested in this script to determine 7 indifference points. Each delay is tested with 6 trials. 
Depending on the participant's choice the immediate amount is adjusted up (when delayed amount is selected) 
or down (when immediate amount is chosen.)

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DURATION 
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the default set-up of the script takes appr. 5 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: 'abcdadjustingamountdiscounting_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. 
																				
countDelays:						counts the number of delays tested
delayIndex:						index of delay (in ascending order)
delay:							stores the current delay tested: ("6 hours from now", "1 day", "1 week", "1 month", "3 months", "1 year", "5 years")
Delay_indays:					stores the current delays in unit 'day' (numbers from original Phython program)
countTrials:						counts the number of adjustment trials run per block
delayedReward:					the delayed amount in $ (here: 100)
immediate:						stores the currently tested 'immediate' amount

delayedLocation:					1 = delayed amount is presented on the left; 
								2 = delayed amount is presented on the right
								
stimulusitem:						the presented stimuli in order of trial presentation
text.delayed.timestamp:			the elapsed script time when 'Delayed' text was presented
choiceRT: 						the response latency (in ms) of the choice
response:						the participant's response (for test trials: immediate vs. delayed)
Adjust Amount:					stores the adjust amount of the next immediate amount
nextimmediate:					stores the next 'immediate' amount
lastImmediateChosen:				stores the last immediate amount chosen
lastImmediateRejected:			stores the last immediate amount rejected
IndiffPoint:						Indifference point (absolute indifference point as the midpoint of values.last ImmediateChosen and values.lastImmediateRejected)
percent_IndiffPoint	: 			percentage indifference point (relative to standard amount)

immediateChoiceValidity:			immediate choice validity questions after: 3 months, 1 year, 5 year
								("get $100 NOW" vs. "get $100 in 5 years")
								each immediate choice receives 1 point: max points 3
	
(2) Summary data file: 'abcdadjustingamountdiscounting_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)

parameters.delayedRewardAmount:			the delayed amount in $ (here: 100)
testedDelays:								a string variable that stores all tested delays in the order tested

immediateChoiceValidity:			immediate choice validity questions after: 3 months, 1 year, 5 year
								("get $100 NOW" vs. "get $100 in 5 years")
								each immediate choice receives 1 point: max points 3


Indif_Point_6h-
Indif_Point_5years:				store the absolute Indifference Points (IP) for the 7 specific delays tested in this script

percentage indifference points (relative to standard amount)
percent_Indif_Point_6h-
percent_Indif_Point_5years

Johnson & Bickel (2008)-test for rule violations:
Consistent_per_JBcriterion1: 		no: at least one indifference point is larger than the preceding one by 20% of delayed amount (here: $100)
								yes: otherwise
								
violations_JBcriterion1:			stores the number of rule violations of JB criterion 1 based on the six individual indifference point checks 
									(Range: 0 - 6)
									
Consistent_per_JBcriterion2: 		no: the difference btw. first and last indifference point (set relative to delayed amount) is smaller than 10% of the delayed standard amount
								yes: otherwise
								
meanRT_allChoices:				mean latency (in ms) of all choices
medianRT_allChoices:				median latency (in ms) of all choices
meanRT_immedChoices:			mean latency (in ms) of 'immediate' choices			
medianRT_immedChoices:			median latency (in ms) of 'immediate' choices	
meanRT_delayedChoices:			mean latency (in ms) of 'delayed' choices	
medianRT_delayedChoices:		median latency (in ms) of 'delayed' choices	

* 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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* 7 delays ("6hours", "1 day", "1 week", "1 month", "3 months", "1 year", "5 years") are tested within-participants in a blocked design
Note: the delays can be adjusted under section Editable Lists (names of IP values will then have to be adjusted under section VALUES)
* the order of the delays is determined randomly
* 6 trials per delays
* the delayed amount can be set under Editable parameters. By default, it's $100
* the starting immediate amount is set as half of the delayed amount

Trials:
* left or right screen location of the delayed and immediate amount are randomly determined for each trial
* participants makes a choice via a button press: the left key refers to selecting the choice on the left,
the right key refers to selecting the choice on the right
* participants have an unlimited time to make a choice
* depending on choice

Adjustment Algorithm of the Immediate Amount:
First Trial: half of the difference of delayed and immediate amount
Example: delayed amount = 100; immediate amount = 50; adjustment = (100-50)/2 = 25

if participants chooses delayed amount (100) -> the next immediate amount tested is = 50 + 25 = 75
if participant chooses immediate amount (50) -> the next immediate amount tested is = 50 - 25 = 25

Subsequent Trials: half of the previous used adjustment 
Example: previous adjustment = 25 => the next adjustment will be 12.5


Algorithm to calculate Indifference Points (P):
at the end of each delay, the computer calculates the indifference point for the tested delays 
as the midpoint of last 'immediate' amount chosen and last 'immediate' amount rejected.
Notes: 
a) if participant always rejects the immediate amount, the IP will be the midpoint between the
delayed amount and the last immediate amount rejected.
b) if participant always rejects the delayed amount, the IP will be the midpoint between
0 and the last immediate amount chosen

Rule Violation Algorithms (Johnson & Bickel, 2008):
Johnson and Bickel (2008, Experimental and Clinical Psychopharmacology, 16, 264-274). 

JB Rule1: if a later indifference point (absolute) is larger than the preceding one by 20% of the delayed standard amount=> rule violation
JB Rule2: if the difference btw. first and last indifference point (absolute) is smaller than 10% of the standard amount => rule violation

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INSTRUCTIONS 
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provided by ABCD Research Consortium - can be edited under 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:

/delayedRewardAmount:	the delayed amount in $ (here: 100)

/starttrialDuration:	the duration (in ms) of the start trial in each block (the announcement of the particular delay) (default: 2000ms)

/leftx:					the proportional screen position of the left amount (here: 25% of the width of the canvas) note: 0% is the very left of canvas
/rightx:					the proportional screen position of the right amount (here: 75% of the width of the canvas): 100% is the very right of canvas