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*Chimeric Faces*
- used by the Behavioural Laterality Battery-
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 01-06-2021
last updated: 03-19-2024 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 03-19-2024 Millisecond Software
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BACKGROUND INFO
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This script implements a Chimeric Faces Procedure similar to the one used by the Behavioural Laterality Battery
(Parker et al, 2020).
The Chimeric Face Task assesses the lateralisation of emotion processing in faces.
References:
//Behavioural Laterality Battery:
Adam J. Parker , Zoe V. J. Woodhead , Paul A. Thompson & Dorothy V. M.
Bishop (2020): Assessing the reliability of an online behavioural laterality battery: A pre-registered
study, Laterality, DOI: 10.1080/1357650X.2020.1859526
To link to this article: https://doi.org/10.1080/1357650X.2020.1859526
https://gorilla.sc/openmaterials/104636
//chimeric faces:
Burt, D. M. & Perrett, D. I. (1997).
Perceptual asymmetries in judgements of facial attractiveness, age, gender, speech and expression.
Neuropsychologia, 35, 685-693.
https://doi.org/10.1016/S0028-3932(96)00111-X
Innes, R. B., Burt, D. M., Birch, Y. K. & Hausmann, M. (2016).
A leftward bias however you look at it: Revisiting the emotional chimeric face task as
a tool for measuring emotion lateralization.
Laterality, 21, 643-661.
https://doi.org/10.1080/1357650X.2015.1117095
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TASK DESCRIPTION
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Participants view chimeric faces (different emotion on left and right side of face) for a short duration
and have to select from 4 possible emotions (anger, disgust, happiness, sadness) which emotion was
the strongest emotion displayed.
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DURATION
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the default set-up of the script takes appr. 10 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: 'chimericfaces_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
heightFaceImagesMM: the height of the face images used (if screen allows, the image height should be -by default- 70mm)
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.
testBlockCounter: counts the test blocks run
index: the currently selected itemnumber of the presented image Note: 0-based selection
(first item has index = 0)
stim: the presented image
leftEmotion: the left emotion in the presented image
rightEmotion: the right emotion in the presented image
chimericCategory: 1 = control condition (both sides show the same image)
2 = chimeric condition (different emotions on left and right side)
response: the selected response button (no response = 0)
selectedEmotion: the selected emotion (no response = 0)
selectedFaceSide: left, right, none (= for incorrect emotion selections as well as no responses)
Note: by default, if participants select the correct emotion for control (=only one emotion) images
'selectedFaceSide' will be 'left'
correct: 1 = either one of the presented emotions was selected; 0 = otherwise
latency: the response latency (in ms); measured from: onset of image
(2) Summary data file: 'chimericfaces_summary*.iqdat' (a separate file for each participant)*
inquisit.version: the Inquisit build/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)
heightFaceImagesMM: the height of the face images used (if screen allows, the image height should be -by default- 70mm)
propCorrectOverall: the proportion of correct emotion selections
(correct = either one of the presented emotions was selected) across all test trials
meanCorrRTOverall: the mean response time of selecting a correct emotion across all test trials
//chimeric faces
countChLR: counts the number of times the left emotion in the presented image was selected
countChRR: counts the number of times the right emotion in the presented image was selected
countChIR: counts the number of times an unrelated emotion for the presented image was selected
countChNR: counts the number of times a no response was collected
//separate for each emotion:
countChangerLeftLR: counts the number of times the left emotion ('anger') in the presented angerleft-image was selected
countChangerLeftRR: counts the number of times the right emotion (not anger) in the presented angerleft-image was selected
countChangerLeftIR: counts the number of times an unrelated emotion was selected for an angerleft-image
countChangerLeftNR: counts the number of times no response was made for an angerleft-image
(same for disgustleft, happyleft, sadleft images)
//control faces (show the same emotion on both sides)
countCtrlCR: counts the number of times the correct emotion was selected
countCtrlIR: counts the number of times the incorrect emotion was selected
countCtrlNR: counts the number of no responses collected
//separate for each emotion:
countCtrlAngerCR: counts the number of times the emotion 'anger' was selected for anger control images
countCtrlAngerIR: counts the number of times an incorrect emotion was selected for anger control images
countCtrlAngerNR: counts the number of times no responses were selected for anger control images
(same for disgust, happy, sad control images)
* 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) Intro*
(2) Practice: 8 trials
- 8 different images using 'surprise' and 'fear' as the emotions
- order of images randomly determined
(3) Test: 4 test blocks (see Editable Parameters)
- 16 images (4 per emotion: angerleft, disgustleft, happyleft, sadleft) are run twice per block = 32 trials
- order of images randomly determined (Note: the same image can be run consecutively)
Trial Sequence:
-Fixation Cross for 1000ms (editable parameter)
-image for 500ms (editable parameters)
-max response time: 10000ms (editable parameters)
*Note: the Inquisit script does NOT run a sizing procedure for the stimuli as done by Parker et al (2020)
The images are presented with a 7cm height (as based on the height the images roughly appeared
in the Parker et al, 2020, Chimeric Demo task after completion of the resizing procedure).
If the current screen is NOT big enough to present the image with these default dimensions,
the largest possible size for the current screen is created (the image size used is noted in the data files).
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STIMULI
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the stimuli are provided by the Behavioural Laterality Battery (Parker et al 2020)
and can be downloaded at:
https://osf.io/4bqe6/
Note: if used, please cite reference articles.
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INSTRUCTIONS
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provided by Millisecond Software. The instructions are based on the ones used by
the Behavioural Laterality Battery (Parker et al 2020).
The instructions can edited in the provided htm-files.
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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:
