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									Lexical Decision Task
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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 simple Lexical Decision Task to investigate semantic memory and lexical access.
The implemented procedure is based on:
	
Lepore & Brown (2002), The Role of Awareness: Divergent Automatic Stereotype 
Activation and Implicit Judgment Correction, Social Cognition, 20 (4), pp 321-351.
	
This script uses placeholders for actual stimuli.

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TASK DESCRIPTION	
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Participants are asked to categorize words into words and nonwords by pressing the E-key (non words)
or I-key (words) as fast as possible when a word/nonword stimulus appears on screen.

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DURATION 
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the default set-up of the script takes appr. 3 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: 'lexicaldecisiontask_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.condition:				"Category Word", "Neutral Word", "Non Word"										
values.presentedStim:			the currently presented word or non-word										
										
response:						the participant's response (scancode of response button)
										18 = E (non word)
										23 = I (word)
										57 = spacebar
										 
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms); latency measured from onset of stimulus


(2) Summary data file: 'lexicaldecisiontask_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.PropCorrect:		overall proportion correct across all testtrials
expressions.MeanRT:				overall mean latency of correct responses across all correct testtrials
expressions.STD:				overall standard deviation of correct latencies
expressions.MedianRT:			overall median latency of correct responses across all correct testtrials

expressions.PropCorrect_CatW:	proportion correct of responses to category words
expressions.MeanRT_CatW:		mean latency of correct responses to category words
expressions.STD_CatW:			standard deviation of correct responses to category words
expressions.MedianRT_CatW:		median latency of correct responses to category words

expressions.PropCorrect_NeutralW	proportion correct of responses to neutral words
expressions.MeanRT_NeutralW:	mean latency of correct responses to neutral words
expressions.STD_NeutralW:		standard deviation of correct responses to neutral words
expressions.MedianRT_NeutralW:	median latency of correct responses to neutral words

expressions.PropCorrect_NonW:	proportion correct of responses to non words
expressions.MeanRT_NonW:		mean latency of correct responses to non words
expressions.STD_NonW:			standard deviation of correct responses to non words
expressions.MedianRT_NonW:		median latency of correct responses to non words


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EXPERIMENTAL SET-UP 
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3 types of words (category words, neutral words, nonwords) tested within participants in a mixed design

1 Practice Block: 6 trials (3 neutral words, 3 nonwords; order randomly selected)
1 Test Block: 52 trials (13 category words, 13 neutral words, 26 non words; order and stimuli randomly selected)

Trial Sequence:
* (for 700ms) -> stimulus (250ms) -> blank screen until response (latency measured from onset of stimulus)
(Durations can be edited under section Editable Parameters)

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STIMULI
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are spaceholders - actual stimuli can be easily inserted under section Editable Stimuli

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INSTRUCTIONS 
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can be edited under 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:

/fixationDuration:			the duration (in ms) of the fixation stimulus presented at the start of each trial (default: 700ms)
/stimDuration:				the duration (in ms) of the presented word/nonword in ms (default: 250ms)

/stimSize:					the proportional height (to active canvas) of the stimuli (default: 5%)