___________________________________________________________________________________________________________________ LETTER MEMORY TASK (written input) ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC (reusing some interface code by David Nitz) Date: 10-26-2016 last updated: 02-24-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-24-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements the Letter Memory Task, a test of executive functioning focusing on continuously updating working memory representations. The implemented procedure is similar to the one outlined by: Friedman, N. P., Miyake, A., Young, S. E., DeFries, J. C., Corley, R. P., & Hewitt, J. K. (2008). Individual differences in executive functions are almost entirely genetic in origin. Journal of Experimental Psychology: General, 137, 201–225. Note: this script collects written input at the end of each trial ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants view series of letters (5, 7, 9), one at a time in the middle of the computer screen. Whenever a new letter comes on screen, they have to rehearse out loud the last 3 letters in the series. After the last letter disappears, they have to enter the last 3 letters by selecting the correct letters from a provided letter matrix. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 10 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'lettermemorytask_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. currentsetsize: the current set Size used (default: 5, 7, or 9) presentedLetters: stores the presented letters (in the order they were presented) recallDuration: stores the duration (ms) of the recall (= difference in Start and End Time of recall screen) response: the participant's response in the recorded trial last3: stores the last 3 letters (in the order they were presented) recalledletters: stores a string of 3 recalled characters (if more than 3 are selected, they get ignored by computer) ACC: the correctness of the response 1 = correct (here: all letters were correctly recalled; order not important); 0 = otherwise countCorrectLetters: stores the number of letters correctly recalled for the current trial (min: 0 - max: 3) (2) Summary data file: 'lettermemorytask_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) only test trials considered: propCorrect: proportion correct test trials (proportion of trials where all 3 letters were correctly recalled -in any order) mean_correctLetters: mean number of letters correctly recalled per test trial (across set sizes) * 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 ___________________________________________________________________________________________________________________ 3 set sizes tested: 5, 7, 9 (controlled by list.setSize under Editable Lists) 1. Practice: 3 practice trials (one per set size), order of set sizes randomly determined (change number of trials under section BLOCKS) 2. Test: 12 trials (4 per set size), order of set sizes randomly determined with the constraint that every set size appears once every 3 trials (change number of trials under section BLOCKS) Trial Sequence: Fixation (1000ms) -> 5-9 letters (2500ms per letter, letters randomly selected without repeat) -> recall screen (until response) -> feedback (until response) -> ITI (0ms) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ - 21 English consonants - size can be controlled via editable parameters ___________________________________________________________________________________________________________________ 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: /fixationDuration: the duration (in ms) of the fixation cross (default: 1000ms) /letterDuration: the duration (in ms) of each letter (default: 2500ms) /stimSize: the size of each letter in proportion of the canvas height (default: 8%) /ITI: the duration of the intertrial interval (in ms) presented after feedback (default: 0)