___________________________________________________________________________________________________________________ Four Choice Reaction Time Task - Mouse/Touchscreen Input ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 04-11-2017 last updated: 02-22-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-22-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a version of a 4 Choice Reaction Time Task similar to the one described in: Armstrong et al (2012). Mild Dehydration Affects Mood in Healthy Young Women. The Journal of Nutrition: Ingestive Behavior and Neurosciences. Feb;142(2):382-8. doi: 10.3945/jn.111.142000. Epub 2011 Dec 21 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ 4 boxes are presented on the screen in a horizontal array. After a fixed amount of time, one of the boxes turns red and participants are asked to click on/press the red box as fast as possible. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 2.5 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'fourchoicereactiontimetask_mi_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. totalTrialcount: number of test trials run position: 1, 2, 3, or 4 => screen position of the stim from left to right response: the participant's response (selected box - left to right: box1, box2, box3, box4) selectedPosition: the selected position based on keyboard press latency: the response latency (in ms) measured from start of trial (onset of the 4 gray boxes) rt: stores the latency measured from onset of red box (Note: negative latencies => response was made before ONSET of red box) prematureError: 1 = premature error was made (premature error: rt < parameters.prematureErrorWindow) 0 = otherwise; timeoutError: 1 = a timeout error was made; (timeout error: rt > parameters.timeoutErrorWindow) 0 = otherwise; incorrectChoice: 1 = a valid (neither premature nor timeout response) but incorrect response was made; 0 = otherwise ACC: the correctness of the response 1 => valid (no premature response nor late response) AND correct choice of response button 0 => otherwise countPrematureErrors: counts incorrect premature responses (responses made BEFORE appearance of red box and those made AFTER within the prematureErrorWindow) countTimeoutErrors: responses made after parameters.timeoutErrorWindow countIncorrectChoices: counts the number of valid responses (neither premature nor late) that are incorrect response choices (2) Summary data file: 'fourchoicereactiontimetask_mi_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) totalTrialcount: number of test trials run propCorrect: proportion correct responses (correct in terms of response button and timing of response) meanRT: the average reaction time (in ms) of correct responses SD: the standard deviation of correct response reaction times propPrematureErrors: proportion of Premature Errors relative of total number of trials propTimeoutErrors: proportion of Timeout Errors relative of total number of trials propIncorrectChoices: proportion of IncorrectChoices (otherwise valid) relative of total number of trials * separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section "DATA" and follow further instructions ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 1. Practice Block: 10 practice trials with feedback by default, the positions of the red box is randomly determined with replacement (see section Editable Lists) error feedback provided 2. Testblock: 100 trials (default; can be adjusted under section Editable Parameters) by default, the positions of the red box is randomly determined with replacement (see section Editable Lists) Trial Sequence: 4 gray boxes (default: 500ms; parameters.SOA; fixed)-> onset of red box -> waits for response to continue Two latencies recorded: 1) 'latency' measured from onset of trial (with onset of the 4 gray boxes) 2) values.RT measured from onset of red box Error Categories: premature Errors: all responses with values.rt < parameters.prematureErrorWindow (measured from onset of red box) If participant responds BEFORE red box appears, values.rt will be negative and automatically scored as a prematureError. timeoutErrors: all responses with values.rt > parameters.timeoutErrorWindow (measured from onset of red box) incorrectChoiceErrors: all responses that are valid (aka: no premature Error nor a timeoutError) BUT the incorrect response button was pressed ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Millisecond Software - can be edited under 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: Interface: /pos1_x: the first horizonal box position from the left in canvas width percentages (0% at the far left of canvas - 100% far right of canvas) /pos2_x: the second horizonal box position from the left in canvas width percentages /pos3_x: the third horizonal box position from the left in canvas width percentages /pos4_x: the fourth horizonal box position from the left in canvas width percentages /stimHeight: height of the boxes in canvas height percentages (default: 5%) Duration Parameters (in ms): /SOA: Response Stimulus Interval in ms (interval between onset of gray boxes and onset of red box) (default: 500ms) /prematureErrorWindow: responses made before the end of this window (measured in ms from onset of red box) are scored as premature errors (default: 100) (Note: ALL responses BEFORE appearance of red box are automatically considered premature) /timeoutErrorWindow: responses made after this response window (measured from onset of red box in ms) are considered 'timeOut Errors' (default: 1000ms) Example: if a response is made 1000ms AFTER onset of red box, the response is scored as a timeout error. /readyDuration: duration (in ms) of getting ready trial (default: 5000ms) /feedbackDuration: duration (in ms) of feedback during the practice trials (default: 1000ms) Trial Numbers: /maxTrials: number of trials to run (default: 100)