Keep Track Task

Technical Manual

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond

Created: December 07, 2017

Last Modified: April 21, 2026 by K. Borchert (katjab@millisecond.com), Millisecond

Background

This script implements a 'Keep Track Task'; a test of executive functioning focusing on continuously updating working memory representations.

The implemented procedure is similar to the one outlined by Friedman et al (2008).

References

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.

The Friedman et al (2008) task is in turn based on: Yntema, D. B. (1963). Keeping track of several things at once. Human Factors, 5, 7–17.

Duration

15 minutes

Description

Participants need to mentally update the state of key categories while watching a sequence of 15 words that belong to 6 different categories. Before the presentation, participants are told the specific categories to keep track of and these target categories are displayed on screen throughout the presentation. The number of target categories to keep track of (of the 6 possible) varies from round to round (default in this script: 2-4). At the end of each round, participants are asked to enter the last item presented for each of the target categories.

Procedure

1. Practice Session

• by default, the practice session runs 3 rounds with difficulty level increasing from 2-4
=> number of rounds as well as their difficulty level can be adjusted by editing list.difficulty_practice
under section Editable Lists
• per round:
• target categories are sampled randomly for each round (no balancing across rounds)
• each category is presented at least twice and at most three times within the 15 word presentations
(it's randomly determined for each round which category is represented three times - no balancing across rounds);
order of category presentation is randomized
• the particular exemplars presented for each category are sampled at random from the 6 provided options
(constraint: no repeats within the same round)
• after recall, participants receive detailed feedback of their responses
• by default, practice session can be repeated if no more than parameters.maxNumberOfPracticeSessions (default: 2) have been run yet
(change settings under section Editable Parameters)

2. Test Session

• by default, the test session runs 12 rounds with difficulty levels 2, 3, 4 (each difficulty level is repeated 4 times,
levels are randomly selected)
=> Total words that need to be recalled: 2x4 + 3x4 + 4x4 = 36
=> number of rounds as well as their difficulty levels can be adjusted by editing list.difficulty_test
under section Editable Lists
• per round:
• target categories are sampled randomly for each round (no balancing across rounds)
• each category is presented at least twice and at most three times within the 15 word presentations
(it's randomly determined for each round which category is represented three times - no balancing across rounds);
order of category presentation is randomized
• the particular exemplars presented for each category are sampled at random from the 6 provided options (see Editable Stimuli)
(constraint: no repeats within the same round)
• after recall, participants receive detailed feedback of their responses by default. However, feedback can easily be
turned off by setting parameters.skipTestFeedback to 'true' (default setting is 'false', see section Editable Parameters)

Note on Accuracy Checks of entered Responses:
1) all entered responses as well as target items (e.g. India) are converted to lower-case letters for comparisons
Example: presented item: India; entered item: india (evaluated as correct)
Example: presented item: bear; entered item: BEAR (evaluated as correct)
2) empty characters are removed from all entered responses before comparisons
Example: presented item: 'brother'; entered item 'brother ' (evaluated as correct)
Example: presented item: 'gold'; entered item ' g o ld ' (evaluated as correct)

Trial/Round Sequence (Default Settings):

presentation of target categories until spacebar is hit -> 500ms delay ->
word presentation 1 (1500ms) -> isi (0ms) -> word presentation 2 (1500ms) -> etc. ->
word presentation 15 (1500ms) -> isi (0ms) -> recall delay (0ms) ->
recall until 'submit' button is pressed -> iti (default: 1000ms)

this script provides the code to run any difficulty level btw. 1-6.
To change the number of rounds run and/or the levels of difficulty levels run, simply
change list.difficulty_practice and/or list.difficulty_test under section Editable Lists

Stimuli

categories: Friedman et al (2008)
exemplars: provided by Millisecond

By default, this script runs with 6 exemplars per category. That reduces the chance to guess
the correct exemplar (per category) at the end of each trial to p ~ 0.17.

specific categories as well as exemplars can be edited under section "Editable Stimuli"
in script 'keeptracktask_instructions_inc.iqjs'

Instructions

provided by Millisecond - can be edited under section Editable Instructions
in script 'keeptracktask_instructions_inc.iqjs'

Summary Data

File Name: keeptracktask_summary*.iqdat

Data Fields

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
countPracticeSessions	Running total of practice sessions requested
roundCount	Final count of test rounds run
totalCorrect	Stores the number of correctly recalled items across all test rounds
totalWordsRecalled	Stores the total number of words that needed to be recalled across all test rounds
propCorrect	The proportion correct of all possible test round responses (= number of correct responses across all test rounds / total number of responses = X/36 in this script)
meanPropCorrect	Mean proportion correct per round; based on propCorrect for each round (Example: 0.25 => on average, participant got 25% of all responses correct per test round, regardless of level of difficulty)
meanPropCorrect1	Mean proportion correct for level 1 trials
meanPropCorrect2	Mean proportion correct for level 2 trials
meanPropCorrect3	Mean proportion correct for level 3 trials
meanPropCorrect4	Mean proportion correct for level 4 trials
meanPropCorrect5	Mean proportion correct for level 5 trials
meanPropCorrect6	Mean proportion correct for level 6 trials

Raw Data

File Name: keeptracktask_raw*.iqdat

Data Fields

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)
countPracticeSessions	Running total of practice sessions requested
roundCount	Running total of the trials/rounds run; resets after each practice session
difficulty	Level of difficulty ( = number of categories to keep track of)
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.
stimulusItem	The presented stimuli in order of trial presentation
currentTargetCategory	Stores the currently presented target category in digits 1-6
targetCategory1	Stores the label of the randomly selected target category1
category1Last	Stores the last item presented for target category1
targetCategory2	Stores the label of the randomly selected target category2
category2Last	Stores the last item presented for target category2
targetCategory3	Stores the label of the randomly selected target category3
category3Last	Stores the last item presented for target category3
targetCategory4	Stores the label of the randomly selected target category4
category4Last	Stores the last item presented for target category4
targetCategory5	Stores the label of the randomly selected target category5
category5Last	Stores the last item presented for target category5
targetCategory6	Stores the label of the randomly selected target category6
category6Last	Stores the last item presented for target category6
response	The participant's response
latency	The response latency (in ms) recall trials: measured from: onset of recall-trial until all textbox responses are submitted via 'submit' button
countCorrect	Counts the number of correctly items per round (across all target categories)
propCorrect	Stores the proportion correctly recalled items per round (= countCorrect/difficulty)
correctCategory1	1 = last item of target category 1 was correctly recalled; 0 = otherwise
correctCategory2	1 = last item of target category 2 was correctly recalled; 0 = otherwise
correctCategory3	1 = last item of target category 3 was correctly recalled; 0 = otherwise
correctCategory4	1 = last item of target category 4 was correctly recalled; 0 = otherwise
correctCategory5	1 = last item of target category 5 was correctly recalled; 0 = otherwise
correctCategory6	1 = last item of target category 6 was correctly recalled; 0 = otherwise

Parameters

The procedure can be adjusted by setting the following parameters.

Name	Description	Default
Design
maxNumberOfPracticeSessions	Maximum number of times participants can repeat the practice session if they choose to do so the script will run at least 1 practice session regardless of parameter setting	2
skipTestFeedback	True(1): participants only receive performance feedback after each round during practice (but not the test) false(0): participants receive performance feedback after each round during practice AND test	false
Sizing Parameters
exemplarSize	Proportional (to canvas height) size of exemplars	8%
Timing Parameters
stimDelay	The delay (in ms) of the first exemplar presented after hitting spacebar	500
stimDuration	Duration (in ms) of examplars on screen	1500
stimISI	The duration (in ms) of a blank screen presented after each stimulus and before the next	0
recallDelay	Additional delay (on top of stimISI) (in ms) of the recall trial after the last exemplar is presented	0
iti	Intertrial interval (in ms) in between each round	1000
Debugging
debugmode	True(1): the script is run in debugmode; a stimulus with all correct responses is presented with the textboxes during each recall trial false (0): the script is NOT run in debugmode	0

Keep Track Task

Technical Manual

Background

References

Duration

Description

Procedure

1. Practice Session

2. Test Session

Trial/Round Sequence (Default Settings):

Stimuli

Instructions

Summary Data

Data Fields

Raw Data

Data Fields

Parameters

Design

Sizing Parameters

Timing Parameters

Debugging