Return to the Delay Discounting Task with Money and Food page
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									Money / Food Delay Discounting Task
									(in French)
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Script Author: David Nitz for Millisecond Software
last updated:  11-08-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 11-08-2019 Millisecond Software

Millisecond Software thanks Dr. Sylvain Iceta for sharing his French translations!

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BACKGROUND INFO 	
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This script implements the Money/Food Delay Discounting Task, an adjusting delay discounting task
to assess the reward amounts at which people start to discount higher monetary/food rewards
in favor of shorter wait periods. 

The implemented procedure is based on:
	
Odum, A.L., Baumann, A.A.L., Rimington, D.D. (2006). Discounting of delayed hypothetical money and food: 
Effects of amount. Behavioural Processes, 73, 278-284.

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TASK DESCRIPTION	
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Participants are asked to select btw. 2 options: one option presents a higher value but with a delay (7 different ones),
the second option presents a lower value but with an immediate pay-off. The lower value continuously
decreases or increases (decrease/increase tested in blocked format).
The options tested are 'Money' and 'Food'.

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DURATION 
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the default set-up of the script takes appr. 15 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: 'ddt_moneyfood_french_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:							with current subject number
 
group:								assigned group number
									4 different experimental groups (assignment by groupnumber)
										1: Money-> Food, desc -> asc 
										2: Money-> Food, asc -> desc
										3: Food -> Money, desc -> asc
										4: Food -> Money, asc -> desc

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. 
										

blockcount:						The number of blocks run
blocktype:						Type of current block: “money” or “food”
order:								Current order of values "descending" vs “ascending”
trialcount:						Discounttrials run in the current block

response:							Participant’s response (choice trials: ‘delayed’ or ‘immediate’)
latency:							Response latency for the current trial in ms
delay:								The currently selected delay

parameters.delayedreward:		The set amount for a delayed reward ($10)
immediatereward:					The currently selected immediate reward
delayedresponsestreak:			Tracks the number of consecutive delayed responses per block
immediateresponsestreak:		Tracks the number of consecutive immediate responses per block
ip_desc:							The indifference point found in the descending blocks of a consecutive pair of money/food blocks for a given delay
ip_asc:								The indifference point found in the ascending blocks of a consecutive pair of money/food blocks for a given delay
ip:									The overall estimated indifference point of a pair of money/food blocks: average of the ip_asc and ip_desc of a consecutive pair of money/food blocks for a given delay


(2) Summary data file: 'ddt_moneyfood_french_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 number
									4 different experimental groups (assignment by groupnumber)
										1: Money-> Food, desc -> asc 
										2: Money-> Food, asc -> desc
										3: Food -> Money, desc -> asc
										4: Food -> Money, asc -> desc
										
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.delayedreward:		The set amount for a delayed reward ($10)

ip_delay1_M-
ip_delay7_F:						the IPs for the 7 different delays for food (F) and money (M) blocks
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EXPERIMENTAL SET-UP 
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2 options (food, money: tested in blocked format) x 2 orders (ascending, descending: tested in blocked, consecutive format) x 7 delays (tested in blocked format, in ascending order);
tested within subjects

4 different experimental groups (assignment by groupnumber)
	1: Money-> Food, desc -> asc 
	2: Money-> Food, asc -> desc
	3: Food -> Money, desc -> asc
	4: Food -> Money, asc -> desc

Indifference Point Calculations:
For each of the 7 temporal delays 2 indifference points are assessed: one for ascending order and one for descending order.
Indifference points are reached when participants switches response pattern 'consistently':
-> descending order: after 2 choices of the delayed option
-> ascending order: after 2 choices of the immediate option
The final indifference point for a delay is the midpoint of these 2.
	
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STIMULI
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see section EDITABLE STIMULI

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INSTRUCTIONS 
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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:

/ pretrialdelay:					pretrialpause (default: 0ms)
/ posttrialdelay:					posttrialpause (default: 500ms)
/ delayedreward:					the default value to use for the delayed reward (here: $10.00)

/delay1-
/delay7:							the proposed 7 delays tested
								(defaults: "1 day", "2 days", "1 week", "2 weeks", "1 month", "6 months", "2 years")