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Single Target Implicit Association Test (ST-IAT)
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Main Inquisit programming: Sean Draine (seandr@millisecond.com)
last updated: 02-23-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-23-2022 Millisecond Software
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BACKGROUND INFO
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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).
D-scores obtained with this script:
Positive d-scores: support a stronger association between 'Animals-Good' than 'Animals-Bad'
Negative d-scores: support a stronger association between 'Animals-Bad' than 'Animals-Good'
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.
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TASK DESCRIPTION
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Participants are asked to categorize attributes (e.g. "joyful"; "tragic") and animal names
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. 3.5 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: 'singletargetiat_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
session: 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
response: the response key pressed (e.g. 18=E or 23=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
Only meaningful for the last row of data in the raw data file (upon completion of IAT):
latdiffa: difference in mean latencies of the first blocks (first compatible and first incompatible block)
latdiffb: difference in mean latencies of the second blocks (second compatible and second incompatible block)
latdiff: overall difference in mean latencies between compatible and incompatible blocks
da: d-score of the first short blocks
db: d-score of the second long blocks
d: overall d-score (non-weighted mean of the 2 d-scores); 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
percentcorrect: the overall percent correct score of initial responses in test trials of D-score qualifying latencies
propRT300:: the proportion of response latencies < 300ms
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
(2) Summary data file: 'singletargetiat_summary*.iqdat' (a separate file for each participant)
inquisit.version: Inquisit version run
computer.platform: the platform the script was run on (win/mac/ios/android)
startDate: date script was run
startTime: time script was started
subjectid: assigned subject id number
groupid: assigned group id number
sessionid: assigned session id number
elapsedTime: time it took to run script (in ms); measured from onset to offset of 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
latdiffa: difference in mean latencies of the first blocks (first compatible and first incompatible block)
latdiffb: difference in mean latencies of the second blocks (second compatible and second incompatible block)
latdiff: overall difference in mean latencies between compatible and incompatible blocks
da: d-score of the first short blocks
db: d-score of the second long blocks
d: overall d-score (non-weighted mean of the 2 d-scores); 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
percentcorrect: the overall percent correct score of initial responses in test trials of D-score qualifying latencies
propRT300:: the proportion of response latencies < 300ms
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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Hypothesis-consistent pairings vs. hypothesis-inconsistent pairings; tested within-subjects
=> order is counterbalanced by groupnumber assignment
Sequence:
Sequence:
1. Attribute sorting training
2. 1. Test Block of hypothesis-consistent* pairings with 20 trials (half the participant start with inconsistent pairings)
3. 2. Test Block of hypothesis-consistent pairings with 40 trials
4. 1. Test Block of hypothesis-inconsistent pairings with 20 trials
5. 2. Test Block of hypothesis-inconsistent pairings with 40 trials
In all Test Blocks:
* attributes as well as targets are randomly selected without replacement
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STIMULI
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Stimuli can be edited under section Editable Stimuli
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INSTRUCTIONS
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* start instruction page is provided as an html page. It automatically adapts to different category labels UNLESS
the number of attributes and/or targets have been changed. In this case, changes have to be
made to file "intro_stiat.htm", so that the correct number of items are presented in the overview table.
Example: instead of 8 words for target A, only 5 should be presented:
in file "intro_stiat.htm":
change:
<td><%item.targetA.item(1)%>, <%item.targetA.item(2)%>, <%item.targetA.item(3)%>, <%item.targetA.item(4)%>,
<%item.targetA.item(5)%>, <%item.targetA.item(6)%>, <%item.targetA.item(7)%>, <%item.targetA.item(8)%>
</td>
To:
<td><%item.targetA.item(1)%>, <%item.targetA.item(2)%>, <%item.targetA.item(3)%>, <%item.targetA.item(4)%>,
<%item.targetA.item(5)%>
</td>
* item.instructions under section 'Editable Instructions' contains the the trial instructions
The instructions adapt automatically if different attributes and targets are used.
TASK DURATION
the default set-up of the script takes appr. 3.5 minutes to complete
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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
/ISI: interstimulus interval (in ms) (default: 250ms)
