Return to the Behavioural Laterality Battery Dichotic Listening Task page
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										*Dichotic Listenting Task*
										- used by the Behavioural Laterality Battery-
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 01-19-2021
last updated:  02-01-2021 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 02-01-2021 Millisecond Software

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BACKGROUND INFO 	
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This script implements a Dichotic Listening Task similar to the one used by the Behavioural Laterality Battery
(Parker et al, 2020). 
This task assesses the lateralisation of language processing.

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


//Dichotic Listening Tasks:

Bless, J. J., Westerhausen, R., Arciuli, J., Kompus, K., Gudmundsen, M., & Hugdahl, K. (2013). 
Right on all Occasions?” – On the Feasibility of Laterality Research Using a Smartphone Dichotic Listening Application.
Frontiers in Psychology, 4, 42.
https://doi.org/10.3389/fpsyg.2013.00042

Hugdahl, K., & Andersson, L. (1986). 
The “Forced-Attention Paradigm” in Dichotic Listening to CV-Syllables: A Comparison Between Adults and Children.
Cortex, 22, 417-432.
https://doi.org/10.1016/S0010-9452(86)80005-3 

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TASK DESCRIPTION	
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Participants hear two syllables (selected from: ba, da, ga, ka, pa, ta) through their left and right ear
and are asked to indicate which syllable their heard best.

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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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The default data stored in the data files are:

(1) Raw data file: 'blb_dichoticlistening_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. 
										
										
										
										
/index:								itemnumber of the selected soundfile 
/soundfile:							the selected soundfile 
/leftSound:							the sound played through the left ear 
/rightSound:						the sound played through the right ear 

/dualSound:							1 = the left sound is different than the right sound
									0 = the same sound is played in both ears
																		
response:							the participant's response (selected response button)

choice:								left/right/other (= the selected ear; if an incorrect sound was selected it says 'other')
									(in case of mono sounds: if the correct sound was selected it will always say 'left')

correct:							accuracy of response: 	
									1 = correct response (either the left or right sound was selected)
									0 = otherwise (a different sound was selected)
									
latency: 							the response latency (in ms); measured from: onset of sound
									Note: the soundfiles are ~500ms long. 
									Any latencies smaller than that => participant responded before the entire soundfile was played


(2) Summary data file: 'blb_dichoticlistening_summary*.iqdat' (a separate file for each participant)*

inquisit.build:						the Inquisit build/version run
computer.platform:					the platform the script was run on (win/mac/ios/android)
inquisit.build:						the version/build of Inquisit
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)
							
							
* 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 + Demo
- all 6 mono sounds are introduced, order is determined randomly
- each sound can be played multiple times

(2) Practice: 9 trials
- all 6 mono sounds + (da-ba, ga-ta, ka-pa); order is randomly determined
=> each sound is played equally often during practice

(3) 4 test blocks (see Editable Parameters) of 36 trials
- order of trials is randomly determined for each block
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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 for Dichotic Listening Task as given above.
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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: