Return to the Auditory Oddball Task (no markers) page
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AUDITORY ODDBALL TASK
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last updated: 10-17-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 10-17-2019 Millisecond Software
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BACKGROUND INFO
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This script implements the Auditory Oddball Task, an auditory go/nogo task to measure
attention and cognitive control.
The implemented procedure is based on:
Williams, L.M., Simms, E., Clark, C.R., & Paul, R. H. (2005). The test-retest reliability of a
standardized neurocognitive and neurophysiological test battery: "neuromarker".
International Journal of Neuroscience, 115, 1605-30.
The script uses baseline tones of 500hz and oddball tones of 1000hz.
There are no markers set in this script.
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TASK DESCRIPTION
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Participants listen to a random sequence of 2 different beeps. They are asked to press
the Spacebar whenever they hear the high tone (go trial) and refrain from doing anything
if they hear the low tone (nogo trial).
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DURATION
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the default set-up of the script takes appr. 4 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: 'auditoryoddballtask_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
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. Thus, trialnum
may not reflect the number of main trials run per block.
values.lasttrial: the name of the trial
stimulustitem.1: the presented sound file
response: the participant's response: scancode of key response
57 = spacebar
0 = no response
values.responseCategory: hit: pressing spacebar for oddball sounds (targets)
omission error: not pressing spacebar for oddball sounds (targets)
corrReject: not pressing spacebar for baseline sounds (nontargets)
commission error: pressing spacebar for baseline sounds (nontargets)
correct: the correctness of the response (1 = correct; 0 = incorrect)
latency: the response latency (in ms); measured from onset of sound file
=> for no responses, the latency is the max response timeout = 900ms
list.FAs.mean: proportion of commission errors (pressing spacebar for a non oddball event)
(2) Summary data file: 'auditoryoddballtask_nomarkers_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)
list.ACC.mean: the overall proportion correct
expressions.numberGoTrials: number of Go trials ('oddball') in the test block
expressions.numberNogoTrials: number of Nogo trials ('baseline') in the test block
list.hitRTs.mean: mean hit latency (in ms)
*Adjustments to z-scores as recommended by:
Gregg, A. & Sedikides, C. (2010). Narcissistic Fragility:
Rethinking Its Links to Explicit and Implicit Self-esteem, Self and Identity, 9:2, 142-161 (p.148)
expressions.hitrate: calculates the hitrate (proportion of correctly hitting the spacebar for oddball-trials)
expressions.FArate: calculates the commission error rate (proportion of incorrectly hitting the spacebar for baseline-trials)
expressions.z_hitrate*: calculates the z-score for the hitrate. Adjustments are made if the hitrate = 0 (increased to 0.005) or 1 (decreased to 0.995)*
expressions.z_FArate*: calculates the z-score for the false alarm rate. Adjustments are made if the FArate = 0 (increased to 0.005) or 1 (decreased to 0.995)*
expressions.dprime: Computes d' (parametric measure of discriminability btw. signals and noise)
=> Range (in this script):
-5.1516586840152740479 <= dprime <= 5.1516586840152740479 (=perfect performance)
=> The higher the value, the better signals (oddballs) were overall distinguished from noise (baseline)
(d' = 0: chance performance; negative d-primes: participant treated nontargets as targets and targets as nontargets)
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EXPERIMENTAL SET-UP
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1 Testblock of 200 trials: 24 oddball signals (go trials), 176 baseline (nogo trials)
-> order is randomized (constraint: no consecutive oddball trials, if at all possible)
-> trials last 1000ms (default, editable value) with 100ms of that time dedicated to trialCleanUp (default, editable value)
(thus the effective response timeout is: 1000ms-100ms = 900ms)
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STIMULI
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oddball signal: 1000Hz sound
baseline signal: 500Hz sound
sound files can be edited under section Editable Stimuli
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INSTRUCTIONS
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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:
/trialduration: the trial duration in ms (default: 1000ms) => every 1s, a new sound file is started
/trialCleanupTime the duration at the end of the trial duration (in ms) explicitly allocated
to stimulus clean-up etc. (default: 100ms)
=> the effective response timeout is = trialduration - trialCleanupTime = 1000ms - 100ms = 900ms