Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 03, 2019
Last Modified: January 09, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a Missing Scan Test (MST) procedure based on the procedure described by Buschke (1963).
In general the MST procedure presents lists of randomly ordered items (mostly numbers) of well known sets (Example: set 1-16) that leave out one set member (e.g. 5). Participants then have to name the missing set member.
The MST procedure is believed to test item short term memory retention that is less subject to retrieval effects than recall/recognition tests. According to Bushke the MST method does not require retrieval by recall or recognition as it depends mainly on prior (well versed) knowledge of class membership. In order to correctly report the missing class member of such a well-known class, however, retention of all presented class members is still necessary and thus the MST can be used as a capacity measure for short term memory.
Usually, the MST methodology uses lists of items that are greater in length than is used in digit span tests (e.g. N=13) and use items that are well-known such as lists of consecutive numbers.
Disclaimer: the procedure implemented is a best guess effort by Millisecond.
Buschke, H. (1963). Retention in Immediate Memory Estimated without Retrieval. Science, New Series, Vol. 140, No. 3562 (Apr. 5, 1963), pp. 56-57 https://www.jstor.org/stable/1710736
25 - 30 minutes
This script runs an MST task and Digit Span (DS) task* (optional). Order of task is determined by selected groupnumber. Both tasks are using the same stimuli lists which are generated at the beginning of each script run. By default, only the MST task is set to be run (see editable parameters).
Participants are given a class of consecutive numbers of varying lengths (4, 6, 8, 10, 12, 14). The classes are taken from the numbers 1-16. Example class: '4, 5, 6, 7, 8, 9 ' Then participants hear a random order of these elements. However, one of the items is missing. Example presentation: "seven", "four", "five", "eight", "nine"
MST: participants are asked to name the missing number (by default, the missing number is selected from a number dial) DS: participants are asked to name all the numbers that were presented, order is not important (by default, numbers are selected from a number dial)
•the DS task is simplified: participants get the same stimuli lists as in the MST task and recalling the order of the items is not important (see Buschke, 1963)
This script is set up to run a Missing Scan Test (MST) and a Digit Span (DS) Assessment by default.
The order of the tasks is counterbalanced by groupnumber:
odd groupnumbers will run MST -> DS; even groupnumbers will run DS -> MST
( parameters.runDSAssessment controls whether the DS Assessment is run)
Stimuli Preparation:
At the beginning of the script, the script generates all the stimuli that are used for the MST/DS task:
- the script generates stimuli for 90 trials: 15 trials for each of the 6 levels (4, 6, 8, 10, 12, 14) tested
- the script randomly selects a level (4, 6, 8, 10, 12, 14) and randomly (without replacement)
selects the missing number for the current level (1-15) ( each level runs numbers 1-15 once as the missing number)
Example: level 4, missing number 5
- an algorithm randomly selects a suitable class/sequence for the selected level and selected missing number
and randomizes the order of the numbers for presentation purposes.
the missing number is never 'a limiting number of the class' (Buschke, 1963) which
Millisecond interpreted to be the highest number of the class.
Example: class generated: '3, 4, 5, 6' => presentation class: '04050306' (the missing number '05' will not be presented)
- the information is then added to several level specific lists
(e.g. list.level4Class, list.level4_missingNumber, list.level4PresentationNumbers), so that MST and DS assessment
run the very same stimuli for each level
Response Format:
By default, the stimuli are presented orally at 1 number per second and the response is collected in 'written' format
(the numbers are selected from a number dial).
parameters.responseFormat can be set to collect oral responses.
Numbers 1-16, presented orally (using voiceover feature of text elements)
provided by Millisecond - can be edited under section Editable Instructions
File Name: missingscantestSummary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| 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 |
Missing Scan Test Data |
|
| mst | Retention span for the Missing Scan Test |
Performance Performance Metrics By Level 4,6,8,10,12,14 |
|
| mstPropCorrectLevel4 | Stores the proportion correct responses for level 4 MST trials |
| mstMeancorrRTLevel4 | Stores the mean reaction time for level 4 MST trials (correct trials only) |
(Simplified) Digit Span Test |
|
| ds | Retention span for the (simplified) Digit Span Test |
Performance Performance Metrics By Level 4,6,8,10,12,14 |
|
| dsPropCorrectLevel4 | Stores the proportion correct responses for level 4 DS trials |
| dsMeancorrRTLevel4 | Stores the mean reaction time for level 4 DS trials (correct trials only) |
File Name: missingscantest_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| level | The currently tested level (length of sequence) |
| missingNumber | The selected missing Number of the currently tested sequence (e.g. 6) |
| class | The selected class (e.g. '5, 6, 7, 8') |
| startNumber | The first class member |
| lastNumber | The last class member |
| presentationClass | The selected class in the randomly ordered presentation (e.g. 05080706) |
| presentedNumbers | Lists the presented numbers in order of presentation (missing number is not presented) |
| enteredResponse | All the entered responses in the order entered (including those respones that might have been deleted) |
| finalResponse | The final response given for the current trial for DS trials the final values.finalResponse contains the ordered sequence of entered numbers (thus it may not reflect the order in which the items were named) |
| correctResponse | The correct response for the current trial ( for DS trials it contains the ordered response) |
| correct | Accuracy of response: 1 = correct response; 0 = otherwise |
| rt | The cumulative response time (in ms) of all trials that collected a number until the submit button is pressed/'done' measured from onset of first reponse collecting trial |
Mainly Used For Debugging |
|
| debugMode | For data collection purposes this value should be 0 (if it's 1 participants will be able to see correct responses on the screen) |
| sequenceLength | Stores the length of the sequence (should be equal to values.level) |
| theoreticalPresentedNumbers | The theoretically presented numbers (should be equal to values.presentedNumbers) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Design |
||
| debugMode | True: the missing number as well as (verbal) numbers are presented on screen false: the missing number is not presented and the verbal numbers are 'hidden' (=> test mode) | false |
| responseFormat | Select btw. written ("written" => select number from a number dial) or verbal response ("verbal") | "written" |
| runDSAssessment | True = script runs DS assessment in addition to MST assessment false = only MST assessment is run if DS assessment is run, order of assessment types can be counterbalanced by groupnumber | false |
| skipSummaryFeedback | True: the summary feedback (Span Feedback) is skipped false: summary feedback (Span Feedback) if provided at the end | false |
Timing Parameters |
||
| numberPresentationDelay | The delay (in ms) of presenting the first oral number after pressing start button | 500 |
| numberPresentationDurationMS | The presentation duration (in ms) of the verbally presented numbers | 1000 |
| responseDelay | The delay (in ms) of the response collecting trials after offset of last oral number | 0 |
| iti | Intertrial interval (in ms); blank screen in between trials | 1000 |