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						Single Category Implicit Association Test (SC-IAT) - with images
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Main Inquisit programming: Sean Draine (seandr@millisecond.com)
last updated:  02-25-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 02-25-2020 Millisecond Software

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BACKGROUND INFO 	
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The SC-IAT script is based on:

Karpinski, A. & Steinman, R.B. (2006). The Single Category Implicit Association Test as a Measure of Implicit
Social Cognition. Journal of Personality and Social Psychology, 91, 16–32.

and the general IAT.iqx script published by Millisecond Software LLC

Differences btw. this script and Karpinski & Steinman (2006)
- error responses in this script need to be corrected before moving on
- no response window:
stimuli stay on screen until a correct response is given. A reminder to "respond more quickly" is
optional if latencies exceed a certain limit (see section "Editable Parameters" for more info)
- no error response correction necessary for d-score calculation as error responses needed to be corrected
before moving on (therefore an error penalty was added automatically to each error latency)


IAT-Background Info:

The Implicit Association Task (Greenwald, McGhee, & Schwartz, 1998) is a widely-used cognitive-behavioral paradigm
that measures the strength of automatic (implicit) associations between concepts in people’s minds relying 
on latency measures in a simple sorting task.
 
The strength of an association between concepts is measured by the standardized mean difference score of 
the 'hypothesis-inconsistent' pairings and 'hypothesis-consistent' pairings (d-score) (Greenwald, Nosek, & Banaji, 2003). 
In general, the higher the d-score the stronger is the association between the 'hypothesis-consistent' pairings 
(decided by researchers). Negative d-scores suggest a stronger association between the 'hypothesis-inconsistent' pairings.

Inquisit calculates d-scores using the improved scoring algorithm as described in Greenwald et al (2003). 
Error trials are handled by requiring respondents to correct their responses according to recommendation (p.214).
This differs slightly from Karpinski & Steinman (2006) who removed noresponse trials from d-score calculations and 
replaced error responses with the mean latency + 400ms penalty.

D-scores obtained with this script:
positive D-scores: positive attitude towards animals
negative D-scores: negative attitude towards animals

References:
Greenwald, A. G., McGhee, D. E., & Schwartz, J. K. L. (1998). Measuring individual differences in implicit cognition: 
The Implicit Association Test. Journal of Personality and Social Psychology, 74, 1464-1480.

Greenwald, A. G., Nosek, B. A., & Banaji, M. R. (2003). Understanding and Using the Implicit Association Test: 
I. An Improved Scoring Algorithm. Journal of Personality and Social Psychology, 85, 197-216.

Karpinski, A. & Steinman, R.B. (2006). The Single Category Implicit Association Test as a Measure of Implicit
Social Cognition. Journal of Personality and Social Psychology, 91, 16–32.

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TASK DESCRIPTION	
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Participants are asked to categorize attributes (e.g. "joyful"; "tragic") and insect pictures
into predetermined categories via keystroke presses. The basic task is to press a left key (E) if an item (e.g. "joyful")
belongs to the category presented on the left (e.g. "Animal OR Good") and to press the right key (I) if the word (e.g. "tragic") 
belongs to the category presented on the right ("Bad") . Pairings are reversed for a second test: 
press a left key (E) if an item (e.g. "joyful") belongs to the category presented on the left (e.g. "Good") and to press 
the right key (I) if the word (e.g. "tragic") belongs to the category presented on the right ("Animal OR Bad").
The order of the pairings is counterbalanced by groupnumber.				  

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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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(1) Raw data file: 'singlecategorypictureiat_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
										Note: odd/even groupnumbers balance the order in which 
										hypothesis-compatible/incompatible blocks are run
										odd = compatible - incompatible
										even = incompatible - compatible
										
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
										
conditionOrder:						c-ic: consistent -> inconsistent
									ic-c: inconsistent -> consistent
																													
responsetext:						the response key pressed (e.g. 'E' or 'I')										
									Note: script saves the final and -by design- correct response for each trial
										
correct:							the accuracy of the initial response
										0 = initial response was incorrect and needed to be corrected
										1 = initial response is correct
										
latency:							the latency of the final (correct) response in ms; measured from onset of stim
stimulusnumber:						the number of the current stimulus
stimulusitem:						the currently presented item


(2) Summary data file: 'singlecategorypictureiat_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)
									
conditionOrder:						c-ic: consistent -> inconsistent
									ic-c: inconsistent -> consistent									
								
expressions.m1:						mean latencies (in ms) of correct responses in compatible block
expressions.sd1:					standard deviation of latencies of correct responses in compatible block
expressions.m2:						mean latencies (in ms) of correct responses in compatible block
expressions.sd2:					standard deviation of latencies of correct responses in compatible block
expressions.latdiff:				difference between mean latencies in incompatible and compatible block

expressions.d:						d-score; main DV

									Suggested Interpretation:

											D-score <= -0.65 => "a strong" preference for hypothesis-NONconforming pairings
											D-score < -0.35 => "a moderate" preference for hypothesis-NONconforming pairings
											D-score < -0.15 => "a slight" preference for hypothesis-NONforming pairings																						
											-0.15 <= D-score <= 0.15 "little to no" preference
											D-score > 0.15 => "a slight" preference for hypothesis-conforming pairings
											D-score > 0.35 => "a moderate" preference for hypothesis-conforming pairings
											D-score >= 0.65 => "a strong" preference for hypothesis-conforming pairings

expressions.percentcorrect:       	the overall percent correct score of initial responses in test trials of D-score qualifying latencies
expressions.propRT300:				the proportion of response latencies < 300ms

expressions.excludeCriteriaMet:		1 = yes, exclusion suggested by Greenwald et al (2003, p.214, Table 4):
										More than 10% of all response latencies are faster than 300ms
									0 = otherwise
									
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EXPERIMENTAL SET-UP 
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a) Block Practice Compatible* (24 trials); responses not counted towards D-score
b) Block Compatible (72 trials)
c) Block Practice InCompatible (24 trials); responses not counted towards D-score
d) Block InCompatible (72 trials)

*order compatible - incompatible counterbalanced by groupnumber
=> one D-score is determined 

TRIALS
After a pretrialpause of 250ms (default, editable), stimuli are presented until correct response is given. 
In contrast to Karpinski & Steinman (2006), participants have to correct error responses and stimulus stays 
on screen until response is corrected. 
If latencies exceed a certain limit, a reminder to "respond more quickly" is optional in this script 
(see Editable Values for more info).

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STIMULI
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- 21 words for Attribute Categories Good/Bad
- 8 words for target category (here: insects)

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INSTRUCTIONS 
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Instructions 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:

/showsummaryfeedback:					set parameter showsummaryfeedback = true to display summary feedback to participants at the end (default)
										set parameter showsummaryfeedback = false if no summary feedback should be presented to participants

/pretrialpause:							pause before stimuli presentation (default: 250ms)
/showreminder:							true = shows a reminder to respond faster if latencies exceeds a predetermined latency
														Note: Karpinsky & Steinman (2006) call using a reminder "largly window dressing" but that the response window (in this script: a pseudo response window) might create a "sense of urgency" (p.18)
										false = does not show reminder to respond more quickly (default in this script)
/reminderRT:							if response latency is larger than reminderRT, a reminder is presented to respond faster (if parameters.showreminder = true)
											Note: error responses have to be corrected in this script; this will add ms to their response latencies
/reminderduration:						time that the reminder to respond more quickly stays on the screen (default: 500ms)