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									*STERNBERG MEMORY TASK*
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last updated:  06-15-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 06-15-2020 Millisecond Software

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BACKGROUND INFO 	
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This script implements the classic Sternberg Memory Task paradigm to test working memory with strings of digits.

Reference:
Sternberg, S. (1966). High speed scanning in human memory. Science, 153, 652-654.

Note: script tests set sizes of 2-7 (see list.setsize)

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TASK DESCRIPTION	
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Participants are given a series of digits (2-7 digits long) before being prompted with a digit
that was either part of the series (IN) or not (OUT). Participants have to decide
whether the probe was IN or OUT by pressing 2 different keys on the keyboard.

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DURATION 
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the default set-up of the script takes appr. 5 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: 'sternbergmemorytask_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. 

response:							the participant's response (scancode of response button)
										33 = f
										36 = j
										
values.responseCategory:			the interpreted key response: "in" vs. "out"
										
correct:							the correctness of the response (1 = correct; 0 = incorrect)
latency: 							the response latency (in ms); measured from onset of target digit

values.setsize:						the currently tested set size

values.first-
values.seventh:						contain digit1 to digit7 (depends on current set size)

values.target:						stores the currently presented target

stimulusitem:						the currently presented trial stimulus

individual counts per set sizes:
values.count2/values.countcorrect2,
values.count3/values.countcorrect3,
values.count4/values.countcorrect4,
values.count5/values.countcorrect5,
values.count6/values.countcorrect6,
values.count7/values.countcorrect7

(2) Summary data file: 'sternbergmemorytask_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)
									
expressions.propcorrect2-
expressions.propcorrect7:			proportion correct responses by setsize

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EXPERIMENTAL SET-UP 
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1 Testblock with 18 trials: 3 repetitions of setsizes 2, 3, 4, 5, 6, 7
* set sizes randomly selected
* 9 trials are randomly selected to be in-trials (the probe digit was part of the list) and 
9 trials are selected to be out trials (the probe digit was not part of the list)

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INSTRUCTIONS 
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see section Editable Instructions

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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:

learninginterval:			interstimulusinterval (in ms), how fast a new letter is presented					
probepause:					pause (in ms) before probe is presented