Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 31, 2016
Last Modified: January 01, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
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.
8 minutes
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
• 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
letters: all 26 letters of the English alphabet (change selection under section Editable Stimuli)
digits: 1-9 (change under section Editable Stimuli) 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
Instructions are provided by Millisecond. 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).
File Name: msletternumbersequencingtest_visual_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| maxSetSizeLNF | Stores the last successful set size for condition LNF |
| maxSetSizeLNR | Stores the last successful set size for condition LNR |
| totalPointsLNF | Sums up all the points for condition LNF (Range: 0-21) |
| totalPointsLNR | Sums up all the points for condition LNR (Range: 0-21) |
| totalPoints | Combined total points across the two tasks (Range: 0-42) |
File Name: msletternumbersequencingtest_visual_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject, group, | With the current subject/groupnumber |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| condition | "LNF" vs "LNR" |
| setSize | Number of stimuli in the current sequence (2-8) |
| attempt | Number of attempts at a given set size (max. 3) |
| presentedSequence | Stores the presented sequence of letters and numbers |
| length | Length of presented stimuli (debug check) |
| correctResponse | Stores the correct response |
| response | Built-in Inquisit response variable: the participant's entered response |
| 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) |
| setAcc | 1 = at least one correct response for the current set size; 0 = otherwise |
| latency | The response latency (in ms) |
| totalPointsLNF | Sums up all the points for condition LNF (Range: 0-21) |
| totalPointsLNR | Sums up all the points for condition LNR (Range: 0-21) |
| totalPoints | Combined total points across the two tasks (Range: 0-42) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| stimDuration | The presentation duration (in ms) of each stimulus | 1000ms |
| stimSize | The stim Size in canvas height percentages | 10% |
| sri | The interval (in ms) between offset of last stim and onset of recall textbox | 1000ms |
| iti | Intertrial interval (in ms); time btw. last response and onset of next sequence | 1000ms |
| practiceSetSize | The setSize used for demo/practice trial | 4 |
| debugmode | True (1): the sequence is presented for debugging purposes false (0): the sequence is not presented (default) |