___________________________________________________________________________________________________________________ MILLISECOND (CAMBRIDGE) GAMBLING TASK ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 03-06-2014 last updated: 01-19-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 01-19-2023 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements the Millisecond Gambling Task (MGT), a decision-making and risk-taking behavioral task similar to the Cambridge Gambling Task (CGT). The implemented procedure is based on: Rogers, R.D., Everitt, B.J., Baldacchino, A., Blackshaw, A.J, Swainson, R., Wynne, K., Baker, N.B., Hunter, J., Carthy, T., Booker, E., M. London, M., Deakin, J.F.W., Sahakian, B.J., & Robbins, T.W. (1999). Dissociable Deficits in the Decision-Making Cognition of Chronic Amphetamine Abusers, Opiate Abusers, Patients with Focal Damage to Prefrontal Cortex, and Tryptophan-Depleted Normal Volunteers: Evidence for Monoaminergic Mechanisms. NEUROPSYCHOPHARMACOLOGY, 20, 322–339. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are given 10 boxes. Some of these boxes are red, the others are blue. They are told that a yellow token is hidden under one of these boxes and they have to guess the color of the box under which the yellow token is hidden. Once they decide on the color, they are asked to bet points on this choice: the computer provides the bets in either ascending (bets get bigger) or descending order (bets get smaller) and participants are asked to click on a bet when they want to bet this number of points. If they win, the bet number is added to their total points. If they lose the bet number is taken away from their total points. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 20 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'millisecondgamblingtask_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 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 such as feedback trials. Thus, trialnum may not reflect the number of main trials run per block. conditionorder: 1 = ascending-descending 2 = descending-ascending count_sequence: counts sequences per condition counttrials_sequence: counts trials in a sequence counttrials_condition: counts trials per conditions counttrials_total: counts trial across conditions ratio: stores the current ratio rednumber: stores the number of the current red boxes bluenumber: stores the number of the current blue boxes bestchoice: stores the best choice (either 'red' or 'blue' depending on which color has more boxes) tokenbox: stores the number of the token box (1-10) betorder: 1 = ascending; 2 = descending rt_selectcolor: latency in ms to select the color (measured from time the interface appears on screen until the color box is clicked) selectedcolor: stores the selected color (red vs. blue) select_bestchoice: 1 = participant selected best choice (= more probable to win); 2 = participant did not select best choice p_reward: probability of reward for picking this color given the number of the boxes with that color (Example: there are 3/10 red boxes and participant picked red -> p_reward = 0.3) rt_selectbet: the time it cumulatively took to pick a bet (measured from start of displaying first bet until bet was selected or time for betting was up) percent_bet: percentage of totalpoint that is picked to display current bet bet: currently displayed bet (calculated by values.percent_bet x values.totalpoints) selectbet: 1 = participant did select a bet; 2 = participant did NOT select a bet (and therefore last bet was taken as default) result: 1 = participant wins; 2 = participant loses totalpoints: the number of totalpoints at the end of the current trialsequence (2) Summary data file: 'millisecondgamblingtask_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 id number 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) conditionorder: 1 = ascending-descending 2 = descending-ascending counttrials_ascending: number of trials run in ascending condition counttrials_descending: number of trials run in descending conditions totalpoints_ascending: final totalpoints in ascending condition totalpoints_descending: final totalpoints in descending condition //best Choices made: Quality of Decision making by betOrder and ratio prop_bestChoices_19_asc: proportion of bestChoice (higher probability color) selection for trials with "1:9" ratio in ascending bet trials prop_bestChoices_28_asc: proportion of bestChoice (higher probability color) selection for trials with "2:8" ratio in ascending bet trials prop_bestChoices_37_asc: proportion of bestChoice (higher probability color) selection for trials with "3:7" ratio in ascending bet trials prop_bestChoices_46_asc: proportion of bestChoice (higher probability color) selection for trials with "4:6" ratio in ascending bet trials prop_bestChoices_asc: proportion of bestChoice (higher probability color) selection in ascending bet trials (across ratios) prop_bestChoices_19_desc: proportion of bestChoice (higher probability color) selection for trials with "1:9" ratio in descending bet trials prop_bestChoices_28_desc: proportion of bestChoice (higher probability color) selection for trials with "2:8" ratio in descending bet trials prop_bestChoices_37_desc: proportion of bestChoice (higher probability color) selection for trials with "3:7" ratio in descending bet trials prop_bestChoices_46_desc: proportion of bestChoice (higher probability color) selection for trials with "4:6" ratio in descending bet trials prop_bestChoices_desc: proportion of bestChoice (higher probability color) selection in descending bet trials (across ratios) prop_bestChoices_19: proportion of bestChoice (higher probability color) selection for trials with "1:9" ratio (across ascending and descending bet order) prop_bestChoices_28: proportion of bestChoice (higher probability color) selection for trials with "2:8" ratio (across ascending and descending bet order) prop_bestChoices_37: proportion of bestChoice (higher probability color) selection for trials with "3:7" ratio (across ascending and descending bet order) prop_bestChoices_46: proportion of bestChoice (higher probability color) selection for trials with "4:6" ratio (across ascending and descending bet order) prop_bestChoices: proportion of bestChoice (higher probability color) selection in bet trials (across ratios and across ascending and descending bet order) //deliberationRT by betOrder and ratio meanDeliberationRT_19_asc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "1:9" ratio in ascending bet trials meanDeliberationRT_28_asc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "2:8" ratio in ascending bet trials meanDeliberationRT_37_asc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "3:7" ratio in ascending bet trials meanDeliberationRT_46_asc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "4:6" ratio in ascending bet trials meanDeliberationRT_asc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection in ascending bet trials (across ratios) meanDeliberationRT_19_desc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "1:9" ratio in descending bet trials meanDeliberationRT_28_desc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "2:8" ratio in descending bet trials meanDeliberationRT_37_desc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "3:7" ratio in descending bet trials meanDeliberationRT_46_desc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "4:6" ratio in descending bet trials meanDeliberationRT_desc: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection in descending bet trials (across ratios) meanDeliberationRT_19: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "1:9" ratio (across ascending and descending bet order) meanDeliberationRT_28: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "2:8" ratio (across ascending and descending bet order) meanDeliberationRT_37: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "3:7" ratio (across ascending and descending bet order) meanDeliberationRT_46: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection for trials with "4:6" ratio (across ascending and descending bet order) meanDeliberationRT: mean DeliberationRT (in ms) of bestChoice (higher probability color) selection in bet trials (across ratios and across ascending and descending bet order) //riskPercentage (only for trials in which the best choice was selected) //Risk Taking //by betOrder and ratio meanRiskPercent_bestChoiceOnly_19_asc: mean risk percentage* in bestChoice (higher probability color) selection trials for trials with "1:9" ratio in ascending bet trials meanRiskPercent_bestChoiceOnly_28_asc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "2:8" ratio in ascending bet trials meanRiskPercent_bestChoiceOnly_37_asc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "3:7" ratio in ascending bet trials meanRiskPercent_bestChoiceOnly_46_asc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "4:6" ratio in ascending bet trials meanRiskPercent_bestChoiceOnly_asc: mean risk percentage in bestChoice (higher probability color) selection trials in ascending bet trials (across ratios) meanRiskPercent_bestChoiceOnly_19_desc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "1:9" ratio in descending bet trials meanRiskPercent_bestChoiceOnly_28_desc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "2:8" ratio in descending bet trials meanRiskPercent_bestChoiceOnly_37_desc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "3:7" ratio in descending bet trials meanRiskPercent_bestChoiceOnly_46_desc: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "4:6" ratio in descending bet trials meanRiskPercent_bestChoiceOnly_desc: mean risk percentage in bestChoice (higher probability color) selection trials in descending bet trials (across ratios) meanRiskPercent_bestChoiceOnly_19: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "1:9" ratio (across ascending and descending bet order) meanRiskPercent_bestChoiceOnly_28: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "2:8" ratio (across ascending and descending bet order) meanRiskPercent_bestChoiceOnly_37: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "3:7" ratio (across ascending and descending bet order) meanRiskPercent_bestChoiceOnly_46: mean risk percentage in bestChoice (higher probability color) selection trials for trials with "4:6" ratio (across ascending and descending bet order) meanRiskPercent_bestChoiceOnly: mean risk percentage in bestChoice (higher probability color) selection trials in bet trials (across ratios and across ascending and descending bet order) mean risk percentage* = risk percentage in bet box at time of bet placing //riskPercentage (all selections = across bestChoice and worstChoice selections) //overall proportion bet //by betOrder and ratio meanRiskPercent_all_19_asc: mean risk percentage* all selection trials for trials with "1:9" ratio in ascending bet trials meanRiskPercent_all_28_asc: mean risk percentage all selection trials for trials with "2:8" ratio in ascending bet trials meanRiskPercent_all_37_asc: mean risk percentage all selection trials for trials with "3:7" ratio in ascending bet trials meanRiskPercent_all_46_asc: mean risk percentage all selection trials for trials with "4:6" ratio in ascending bet trials meanRiskPercent_all_asc: mean risk percentage all selection trials in ascending bet trials (across ratios) meanRiskPercent_all_19_desc: mean risk percentage all selection trials for trials with "1:9" ratio in descending bet trials meanRiskPercent_all_28_desc: mean risk percentage all selection trials for trials with "2:8" ratio in descending bet trials meanRiskPercent_all_37_desc: mean risk percentage all selection trials for trials with "3:7" ratio in descending bet trials meanRiskPercent_all_46_desc: mean risk percentage all selection trials for trials with "4:6" ratio in descending bet trials meanRiskPercent_all_desc: mean risk percentage all selection trials in descending bet trials (across ratios) meanRiskPercent_all_19: mean risk percentage all selection trials for trials with "1:9" ratio (across ascending and descending bet order) meanRiskPercent_all_28: mean risk percentage all selection trials for trials with "2:8" ratio (across ascending and descending bet order) meanRiskPercent_all_37: mean risk percentage all selection trials for trials with "3:7" ratio (across ascending and descending bet order) meanRiskPercent_all_46: mean risk percentage all selection trials for trials with "4:6" ratio (across ascending and descending bet order) meanRiskPercent_all: mean risk percentage all selection trials in bet trials (across ratios and across ascending and descending bet order) mean risk percentage* = risk percentage in bet box at time of bet placing //Risk Adjustment: Participants typically gamble more if the odds are in their favor (for ratios 1:9 and 2:8) //than when they are not (ratios 3:7 and 4:6) //The Risk Adjustment measure is calculated by //(2 * meanRiskPercent_19 + 1* meanRiskPercent_28) - (2*meanRiskPercent_46 + 1* meanRiskPercent37) //'bestChoice' selection trials only riskAdjust_asc: risk Adjustment for ascending trials riskAdjust_desc: risk Adjustment for descending trials riskAdjust: risk Adjustment across ascending and descending trials //Delay Aversion by ratio //Unwillingness to wait is calculated by the difference between meanRiskPercent in descending and ascending order //The assumption is that people who don't like to wait bet at higher percentage in descending order (because //they come up faster) than in the ascending order (where they have to wait longer) //calculation: delayAversion = meanRiskPercent_bestChoiceOnly_desc - meanRiskPercent_bestChoiceOnly_asc delayAversion_19: delay Aversion in "1:9" ratio trials delayAversion_28: delay Aversion in "2:8" ratio trials delayAversion_37: delay Aversion in "3:7" ratio trials delayAversion_46: delay Aversion in "4:6" ratio trials delayAversion: delay Aversion in across the four ratio trials ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 4 ratios of blue/red (as well as red/blue) boxes are tested within participants: 1/9, 2/8, 3/7, 4/6 (a) Practice Block: selection of box color (the color of the box that hides token) only * 5 trials with a fixed order of blue/red ratios (see LISTS -> list.rednumbers_practice) and fixed order of token position (see LISTS -> list.tokenbox_practice) counterbalanced order (by groupnumber) of (b) and (c) => odd groupnumbers run Ascending -> Descending => even groupnumbers run Descending -> Ascending (b) Ascending Bet Block: after selection of box color, bets are offered to participants * by default: 4 blocks with 9 trial sequences aka "displays" each (see Rogers et al, 1999); participants start with 100 points at the beginning of each block (values.totalpoints- editable value) (Note: according to Rogers et al, 1999, the trial sequence for one block is prematurely aborted if the total points go below 2, the total points reset to 100 and the next block is started) * displays (ratios) are presented in fixed order: order was pseudo-randomly determined by Millisecond Software. In this script all 4 ratios are sampled 9 times across all 36 trials; half the time there are more red, half the time there are more blue boxes -> to change the fixed order go to LISTS -> list.rednumbers_ascending * fixed order of token position: the order of the token position (box1-10) was pseudo-randomly determined by Millisecond Software. In 1/6 of all trials the better choice (based on probability) leads to a loss (see LISTS -> list.tokenbox_ascending) * 5 bets are provided in fixed order of proportions of current total points (see LISTS -> list.betpercentages_asc). * bets are starting small and get bigger (each bet is presented for parameters.betduration, default 5s); sounds accompany each bet (the higher the sound, the higher the bet) * if no bet is selected the last bet is selected by default (b) Descending Bet Block: * bets are starting big and get smaller * different fixed orders for ratios/token position => no other differences to Ascending Bet Blocks ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are not original to the task. They are provided by Millisecond Software as htm/html pages and can be edited by changing the provided htm/html files. To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac) or Notepad (Windows). ___________________________________________________________________________________________________________________ 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: