Motor Praxis Test

Technical Manual

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

Created: January 03, 2023

Last Modified: August 20, 2026 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements Millisecond's version of the Motor Praxis Task (MPT) described by Taylor et al (2019). The Motor Praxis Task tests psychomotor speed and visual tracking.

Researchers can select to run the task with an absolute screen size to ensure that distances stay the same across devices. The default setting is to use proportional sizing. Go to section Defaults for more information.

References

Taylor, Y., Merat, N., & Jamson, S. (2019). The Effects of Fatigue on Cognitive Performance in Police Officers and Staff During a Forward Rotating Shift Pattern. Safety and Health at Work, 10(1), 67–74. https://doi.org/10.1016/j.shaw.2018.08.003

Gur, R. C., Richard, J., Hughett, P., Calkins, M. E., Macy, L., Bilker, W. B., Brensinger, C., & Gur, R. E. (2010). A cognitive neuroscience-based computerized battery for efficient measurement of individual differences: Standardization and initial construct validation. Journal of Neuroscience Methods, 187(2), 254–262. https://doi.org/10.1016/j.jneumeth.2009.11.017

Duration

2 minutes

Description

Participants are asked to quickly touch a series of blue dots as they appear on the screen in random locations. The dots continuously get smaller in size on each new trial. This script allows test administrators to set the start and end size of the dots as well as the number of trials to run. Based on these three variables (number of trials, start- and end size), the script calculates the size adjustment rate per trial.

Procedure

1. Practice: 5 Trials (Editable Parameter)
During the practice trials, the dot stays the same size.
The Dot appears randomly somewhere on the active canvas. Participants are instructed to touch
the dot as fast as possible. If no response occurs within the first 3se, a reminder text
stimulus appears on screen.

2. Test: 20 Trials (Editable Parameter)
During the test trials, the dot gradually decreases in size (see Editable Parameters for size
settings). The Dot appears randomly somewhere on the active canvas. Participants are instructed to touch
the dot as fast as possible. No reminder text appears on screen if participants fail to respond.

Number of Trials in practice/test blocks as well as their color and size can be adjusted under
section Editable Parameters.

Stimuli

provided by Millisecond
The color of practice and test dots as well as sizes can be adjusted
under section Editable Parameters.

Instructions

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

Summary Data

File Name: motorpraxistest_summary*.iqdat

Data Fields

NameDescription
startDate Date the session was run
startTime Time the session was run
subjectId Participant ID
groupId Group number
sessionId Session number
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
elapsedTime Session duration in ms
completed 0 = Test was not completed
1 = Test was completed
numberOfTrials The set number of test trials to run
meanRT The mean response latency (in ms)
sdRT The standard deviation of the response latencies (in ms); measure of variability
medianRT The median response latency (in ms)
speedDifferential Difference of the response time (ms) to the first dot (largest and easiest to hit dot), R1,
and the last dot (smallest and hardest to hit dot),RL, relative to R1
(R1-RL)/R1

Raw Data

File Name: motorpraxistest_raw*.iqdat

Data Fields

NameDescription
date Date the session was run
time Time the session was run
subject Participant ID
group Group number
session Session number
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
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)
trial.searchEnd currently stores the summary of a target search.
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.
response The response of participant during current trial
latency Response latency (in ms); measured from onset of dot
Custom Variables
trialCounter Counts the number of trials run
xPct Horizontal coordinate of the current dot (in %)
yPct Vertical coordinate of the current dot (in %)
stimSizeAdjust The percentage height adjustments done per trial
stimHeightPct The height of the current in %of active canvas
stimHeightMM The height of the current in mm

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
Design
numberOfTrials Set the number of test trials to run
the script calculates the adjustment rate based on those
three variables (see expressions.stimSize_adjust)
20
numberOfPracticeTrials Set the number of practice trials to run5
stimColorPractice The color of the practice dotsblue
Color Parameter
canvasColor Display color of the actively used portion of the screen (the 'canvas')
if set to a color other than the screenColor, the active canvas
appears 'anchored' on the screen regardless of monitor size
black
screenColor Color of the screen not used by the canvas ('inactive screen')black
defaultTextColor Default color of text items presented on active canvaswhite
stimColorTest The color of the test dotsblue
Sizing Parameters
startSizePct Set the startSize (diameter) of the circle in percent (size during trial1)15%
endSizePct Set the endSize of the circle in percent (size during last trial)3%