___________________________________________________________________________________________________________________ Money / Food Delay Discounting Task (German translations) ___________________________________________________________________________________________________________________ Script Author: David Nitz for Millisecond Software last updated: 05-30-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 05-30-2023 Millisecond Software German translation by K. Borchert for Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ 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. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ 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'. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 15 minutes to complete ___________________________________________________________________________________________________________________ DATA OUTPUT DICTIONARY ___________________________________________________________________________________________________________________ The fields in the data files are: (1) Raw data file: 'ddt_moneyfood_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 session: 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 ipDesc: The indifference point found in the descending blocks of a consecutive pair of money/food blocks for a given delay ipAsc: 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_summary*.iqdat' (a separate file for each participant) inquisit.version: Inquisit version run computer.platform: the platform the script was run on (win/mac/ios/android) startDate: date script was run startTime: time script was started subjectId: assigned subject id number 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 sessionId: assigned session id number elapsedTime: time it took to run script (in ms); measured from onset to offset of 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) ipDelay1M- ipDelay7F: the IPs for the 7 different delays for food (F) and money (M) blocks ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 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. ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ see section EDITABLE STIMULI ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ see section EDITABLE INSTRUCTIONS ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ 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")