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									COMPUTERIZED MATH TASK
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 09-18-2014
last updated:  03-10-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-10-2020 Millisecond Software

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BACKGROUND INFO 	
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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.

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TASK DESCRIPTION	
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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.

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DURATION 
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the default set-up of the script takes appr. 4 minutes to complete

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DATA FILE INFORMATION 
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The default data stored in the data files are:

(1) Raw data file: 'mathtask_raw*.iqdat' (a separate file for each participant)

build:							The specific Inquisit version used (the 'build') that was run
computer.platform:				the platform the script was run on (win/mac/ios/android)
date, time, 					date and time script was run 
subject, group, 				with the current subject/groupnumber
script.sessionid:				with the current session id

blockcode, blocknum:			the name and number of the current block (built-in Inquisit variable)
trialcode, trialnum: 			the name and number of the currently recorded trial (built-in Inquisit variable)
										Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those
										that do not store data to the data file such as feedback trials. Thus, trialnum 
										may not reflect the number of main trials run per block. 
									
values.difficulty:				stores the level of difficulty of the current math problem

values.solutionACC:				1 = presented answer is correct; 
								2 = presented answer is incorrect
									
values.mathproblem:				stores the math problem in a string without white spaces (for evaluation purposes)
values.correctsolution:			stores the correct solution to the the problem
values.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.ACC_1.itemcount-
list.ACC_5.itemcount:			counts the number of problems worked on for each level of difficulty


(2) Summary data file: 'mathtask_summary*.iqdat' (a separate file for each participant)

computer.platform:				the platform the script was run on (win/mac/ios/android)
script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				assigned subject id number
script.groupid:					assigned group id number
script.sessionid:				assigned session id number
script.elapsedtime:				time it took to run script (in ms); measured from onset to offset of script
script.completed:				0 = script was not completed (prematurely aborted); 
								1 = script was completed (all conditions run)
							
list.ACCoverall.itemcount:		tracks the number of math problems run
expressions.propCorrect:		proportion correct responses (across all levels)

expressions.prop_diff1:			proportion of level1 problems (relative to all mathproblems)
expressions.propCorrect_diff1:	proportion of level1 problems correctly solved (of the number of level 1 problems given)

expressions.prop_diff2:			proportion of level2 problems (relative to all mathproblems)
expressions.propCorrect_diff2:	proportion of level2 problems correctly solved

expressions.prop_diff3:			proportion of level3 problems (relative to all mathproblems)
expressions.propCorrect_diff3:	proportion of level3 problems correctly solved

expressions.prop_diff4:			proportion of level4 problems (relative to all mathproblems)
expressions.propCorrect_diff4:	proportion of level4 problems correctly solved

expressions.prop_diff5:			proportion of level5 problems (relative to all mathproblems)
expressions.propCorrect_diff5:	proportion of level5 problems correctly solved

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EXPERIMENTAL SET-UP 
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- 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

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STIMULI
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math problems are randomly generated

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

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EDITABLE CODE 
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check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code 
to further customize your experiment.

The parameters you can change are:

Response Keys:
/correctresponsekey:						the correct response key (default: " " -> spacebar)		

/fontsize_stims:							size of the math problem, equal sign and presented answer in % of canvas height

/mathproblemduration:						presentation duration of the mathproblem in ms (default: 2000ms)
/equalsignduration:							presentation duration of the equal sign in ms (default: 1000ms)

/mathanswerduration:						presentation duration of the answer to the mathproblem in ms (default: 1000ms)
												Note: participants have the entire duration to respond
												
/iti:										intertrial duration: pause inbetween problems

/runoperation:								1 = runs only addition problems
											2 = runs only subtraction problems (default)
											3 = runs mixed problems per level

/maxnr_mathproblems:						the number of math problems to run (default: 40)