Mental Arithmetic Task

Technical Manual

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

Created: January 18, 2014

Last Modified: January 08, 2023 by K. Borchert (katjab@millisecond.com), Millisecond

Script Copyright © Millisecond Software, LLC

Background

This script implements a computerized performance-adaptive Math Task as described in:

Girdler, S. S., Turner, J. R., Sherwood, A., & Light, K. C. (1990). Gender differences in blood pressure control during a variety of behavioral stressors. Psychosomatic Medicine, 52, 571- 591.

And

Turner, J. R., Hewitt, J. K., Morgan, R. K., Carroll, D., Sims, J., & Kelly, K. A. (1986). Graded mental arithmetic as an active psychological challenge. International Journal of Psychophysiology, 3, 307-309.

Duration

4 minutes

Description

Participants work on 40 (default) subtraction problems. Each problem consists of the presentation of the problem for 2s (default); the presentation of an "=" sign (default) for 1s (default), and the presentation of an answer to the problem for 1s (default).

Participants have to press one key (SPACEBAR) if the presented answer is the correct answer and simply wait if the presented answer is an incorrect answer. The subtraction problems are divided into 5 levels of difficulty (Turner et al, 1986). If participants make the correct choice, they move up a level of difficulty. If participants make an incorrect choice (or don't answer fast enough), they move down a level of difficulty.

Procedure

- subtraction problems are divided into 5 levels of difficulty (Turner et al, 1986; only subtraction problems):
Level1: 1digit - 1 digit problems (e.g. 7 - 5)
Level2: 2digits - 1 digit problems (e.g. 28 - 4)
Level3: 2digits - 2digits problems (e.g. 56 - 23)
Level4: 3digits - 2digits problem (e.g. 487 - 67)
Level5: 3digits - 3digits problem (e.g. 359 - 128)

- problems are randomly generated for each levels
- participants work on 40 subtraction problems starting with a problem of midlevel difficulty (3).
- depending on performance they move up (correct decision) and down levels (incorrect decision)
- half the presented solutions are correct; the other half are incorrect foils

Trial Sequence:
a) Presentation of Problem for 2s (default) ->
b) presentation of '=' sign for 1s (default) ->
c) presentation of a solution (correct or incorrect) for 1s (Participants have entire time to make the choice whether
the answer is the correct solution to the problem or not)
d) immediate feedback for 500ms (to change feedback duration go to section TRIALS and follow further instructions)

Foil Creation: (Neither Girdler et al nor Turner et al provide an algorithm of how their foils were created)
Because a random generation of foils could potentially ending in very simple problems (mostly one would only have
to be able to pay attention to the last digits), a somewhat more complicated algorithm was used in this script:
- if subtrahend has only 1 digit OR correctsolution has only 1 digit => presented foil = correctsolution +/- 1
- if subtrahend has more than 1 digit AND correctsolution has more than 1 digit => presented foil = correctsolution +/- 10

Stimuli

math problems are randomly generated

Instructions

Instructions are provided by Millisecond. They are not original to Girdler et al (1990) nor
to Turner et al (1986). Go to section Editable Instructions for more details.

Summary Data

File Name: mathtask_summary*.iqdat

Data Fields

NameDescription
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
list.accOverall.itemCount Tracks the number of math problems run
propCorrect Proportion correct responses (across all levels)
propDiff1 Proportion of level1 problems (relative to all mathproblems)
propCorrectDiff1 Proportion of level1 problems correctly solved (of the number of level 1 problems given)
propDiff2 Proportion of level2 problems (relative to all mathproblems)
propCorrectDiff2 Proportion of level2 problems correctly solved
propDiff3 Proportion of level3 problems (relative to all mathproblems)
propCorrectDiff3 Proportion of level3 problems correctly solved
propDiff4 Proportion of level4 problems (relative to all mathproblems)
propCorrectDiff4 Proportion of level4 problems correctly solved
propDiff5 Proportion of level5 problems (relative to all mathproblems)
propCorrectDiff5 Proportion of level5 problems correctly solved

Raw Data

File Name: mathtask_raw*.iqdat

Data Fields

NameDescription
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
difficulty Stores the level of difficulty of the current math problem
solutionAcc 1 = presented answer is correct
2 = presented answer is incorrect
mathProblem Stores the math problem in a string without white spaces (for evaluation purposes)
correctSolution Stores the correct solution to the the problem
presentedSolution Stores the presented solution (either correct or foil)
response The participant's response
correct The correctness of the response
latency The response latency (in ms)
list.acc1.itemCount-
list.acc5.itemCount Counts the number of problems worked on for each level of difficulty

Parameters

The procedure can be adjusted by setting the following parameters.

NameDescriptionDefault
correctResponseKey The correct response key " " -> spacebar
fontSizeStims Size of the math problem, equal sign and presented answer in % of canvas height
mathProblemDuration Presentation duration of the mathproblem in ms 2000ms
equalSignDuration Presentation duration of the equal sign in ms 1000ms
mathAnswerDuration Presentation duration of the answer to the mathproblem in ms
participants have the entire duration to respond
1000ms
iti Intertrial duration: pause inbetween problems
runOperation 1 = runs only addition problems
2 = runs only subtraction problems (default)
3 = runs mixed problems per level
maxnrMathProblems The number of math problems to run 40