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*Reaction Time Concealed Information Test (RT-CIT)*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 03-24-2021
last updated: 10-06-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 10-06-2023 Millisecond Software
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BACKGROUND INFO
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This script implements a 'Reaction Time Concealed Information Test' (RT-CIT), a procedure
to detect information a person tries to conceal (Suchotzki et al, 2021).
The RT-CIT compares 'no' reaction time responses to probe and control items.
The RT-CIT effect describes that people who deceptively deny recognizing information (the probes,
e.g. crime relevant information) respond slower to the probe items than to control items
(crime irrelevant information), particularly if a response timeout is built into the task
which seems to reduce faking abilities (Suchotzki et al, 2021).
Reference
Suchotzki, K., Verschuere, B., & Gamer, M. (2021)
How Vulnerable is the Reaction Time Concealed Information Test to Faking?,
Journal of Applied Research in Memory and Cognition,
https://doi.org/10.1016/j.jarmac.2020.10.003.
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TASK DESCRIPTION
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The task involves responding to target, probe, and control items as soon as possible.
The target items are the items to which participant should respond "Yes, I know them".
The probe and control items are words to which participant should respond "No, I don't know them".
The 5 target ('Yes') items are learned at the beginning of the test.
Probe items are items that are relevant to the task (e.g. crime-relevant information).
Control items are items that task irrelevant.
The order of the items during the reaction time portion of the test are presented
in random order.
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DURATION
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the default set-up of the script takes appr. 8 minutes to complete
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DATA OUTPUT DICTIONARY
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The fields in the data files are:
(1) Raw data file: 'reactiontimeconcealedinformationtest_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
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.
trialCounter: tracks the number of trials run during the test
word: stores the currently presented word
itemNumber: stores the currently presented itemnumber of the word
response: the participant's response (scancode of response buttons)
30 = A
38 = L
57 = space
responseText: the label of the pressed response key (Note: it appears empty for space)
correct: accuracy of response: 1 = correct response; 0 = otherwise
latency: the response latency (in ms); measured from: onset of word
//learning phase:
recall1: the 1. recalled item (in 'cleaned' format)
recall2: the 2. recalled item (in 'cleaned' format)
recall3: the 3. recalled item (in 'cleaned' format)
recall4: the 4. recalled item (in 'cleaned' format)
recall5: the 5. recalled item (in 'cleaned' format)
targetStorage: stores all the target words (in 'cleaned' format)
countCorrectRecall: tracks the number of correctly recalled items
(2) Summary data file: 'reactiontimeconcealedinformationtest_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)
learningBlockCounter: tracks the number of learning rounds run
countCorrectRecall: the number of correctly recalled items after the last learning round
learningPass: 1 = the learning criterium was reached; 0 = otherwise
//Note: no response time 'cleaning' was done for the following summary statistics:
propCorrectTargets: proportion correctly categorized targets (as YES)
nrTargets: the number of No responses to target items within the allotted response timeout
meanHitRTTargets: mean response time (in ms) of correctly categorizing targets
propCorrectProbes: proportion correctly categorized probes (as NO)
nrProbes: the number of No responses to probe items within the allotted response timeout
meanCRRTProbes: mean response time (in ms) of correctly categorizing probes
propCorrectControls: proportion correctly categorized controls (as NO)
nrControls: the number of No responses to control items within the allotted response timeout
meanCRRTControls: mean response time (in ms) of correctly categorizing controls
sdCRRTControls: standard deviation of response times of correctly categorizing controls (in ms)
rtdiff: the response time difference of ('mean response time (in ms) of correctly categorizing probes' - 'mean response time (in ms) of correctly categorizing controls')
rtCITEffect: 1: participant was on average slower to categorize probe items compared to control items
0: everything else
* separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section
"DATA" and follow further instructions
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EXPERIMENTAL SET-UP
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(1) Learning Phase: (see section Editable Parameters for 'Learning Phase' parameter settings)
By default, at least 3 learning rounds are run. If participants have recalled all five items
correctly after the last round, they move on to the test phase. Otherwise, another learning
round is added (up to 10, see section Editable Parameters).
- Learning screen: all 5 items are presented on screen for 30s
- Recall screen: 5 textboxes to enter the five items (in any order)
The computer compares the recalled items to the target items and counts the
number of correctly recalled items.
Note: the algorithm implemented converts all items to lower case letter and removes empty spaces
commas and periods. However, spelling errors will still be identified as 'errors'.
(2) Test Phase:
- 5 target items repeated 6 times (30 trials)
- 5 probe items repeated 6 times (30 trials)
- 20 control items repeated 6 times (120 trials)
=> total of 180 trials, order is randomized (after 90 trials, a break trial is presented)
Trial Sequence:
word (Max: 800ms or until response)* -> variable iti (randomly selected from 500ms-1000ms in 100ms increments)
* if no response was made within 800ms: a 'too slow' message was presented for 1000ms before the iti.
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STIMULI
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provided by Millisecond Software as template stimuli only - can be edited under section Editable Stimuli
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INSTRUCTIONS
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provided by Millisecond Software - 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:
