Return to the Visual Letter Number Sequencing Test page
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MILLISECOND LETTER-NUMBER-SEQUENCING TEST (VISUAL)
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 03-31-2016
last updated: 03-10-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 03-10-2020 Millisecond Software
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BACKGROUND INFO
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This script implements a computerized version of a Letter-Number-Sequencing Test to test visual Short Term Memory
Capacity and Attention similarly to the one used in the Wechsler Adult Intelligence Scale (WAIS).
This script presents randomly generated letter-number sequences visually and accepts written input.
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TASK DESCRIPTION
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Participants receive growing series of alternating letters and digits (set sizes: 2-8).
In this script, the sequences always start with a letter.
2 Recall Conditions:
LNS-Forward: Participants have to recall the letters and digits in the order presented
LNS-Reordered: Participants have to recall first the digits from smallest to largest and then the letters in alphabetical order
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DURATION
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upper duration for the LNF task: about 8 minutes
upper duration for the LNR task: about 10 minutes
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DATA FILE INFORMATION
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The default data stored in the data files are:
(1) Raw data file: 'msletternumbersequencingtest_visual_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
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 such as feedback trials. Thus, trialnum
may not reflect the number of main trials run per block.
values.condition: "LNF" vs "LNR"
values.setSize: number of stimuli in the current sequence (2-8)
values.attempt: number of attempts at a given set size (max. 3)
values.presentedSequence: stores the presented sequence of letters and numbers
values.length: length of presented stimuli (debug check)
values.correctResponse: stores the correct response
response: built-in Inquisit response variable: the participant's entered response
values.currentResponse: custom response variable:
stores the response after 'cleanup'
(after removal of possible empty spaces, comas or semicolons;
lower case letters are converted to upper case letters)
correct: the correctness of the response (1 = correct; 0 = incorrect)
values.setACC: 1 = at least one correct response for the current set size; 0 = otherwise
latency: the response latency (in ms)
values.TotalPoints_LNF: sums up all the points for condition LNF (Range: 0-21)
values.TotalPoints_LNR: sums up all the points for condition LNR (Range: 0-21)
expressions.totalPoints: combined total points across the two tasks (Range: 0-42)
(2) Summary data file: 'msletternumbersequencingtest_visual_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 id number
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)
values.maxSetSize_LNF: stores the last successful set size for condition LNF
values.maxSetSize_LNR: stores the last successful set size for condition LNR
values.TotalPoints_LNF: sums up all the points for condition LNF (Range: 0-21)
values.TotalPoints_LNR: sums up all the points for condition LNR (Range: 0-21)
expressions.totalPoints: combined total points across the two tasks (Range: 0-42)
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EXPERIMENTAL SET-UP
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* 2 conditions: LNF, LNR: order is counterbalanced (determined by groupnumber).
odd groupnumbers: LNF -> LNR
even groupnumbers: LNR -> LNF
By default, each condition runs one practice/demo trial with 4 characters and receives performance feedback
(practice set size can be edited).
* Set Sizes tested: 2-8 stimuli; every stim is presented for 1000ms (editable parameter)
* 3 trials at each level (1 point per correct response for a maximum of 21)
* needs to get at least 1 correct to advance to next set size
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STIMULI
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letters: all 26 letters of the English alphabet (change selection under section Editable Stimuli)
digits: 1-9 (change under section Editable Stimuli) Note: 0 was excluded due to its resemblance with 'O'
The size of the letters can be set under section Editable Parameters.
Sequence Generation:
* the letters and digits are randomly drawn for each sequence (no repeats)
* letters and digits alternate and sequences always start with a letter
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INSTRUCTIONS
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Instructions are provided by Millisecond Software. They can be edited under section "Instructions"
and in the provided html-instruction files.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).
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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:
/stimDuration: the presentation duration (in ms) of each stimulus (default: 1000ms)
/stimSize: the stim Size in canvas height percentages (default: 10%)
/SRI: the interval (in ms) between offset of last stim and onset of recall textbox (default: 1000ms)
/ITI: intertrial interval (in ms); time btw. last response and onset of next sequence (default: 1000ms)
/practiceSetSize: the setSize used for demo/practice trial (default: 4)
/debugmode: true (1): the sequence is presented for debugging purposes
false (0): the sequence is not presented (default)