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AUDITORY ODDBALL TASK
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last updated: 02-25-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-25-2022 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.
TTL Marker signals indicating stimulus onset, type of stimulus, and response times are sent to the
parallel port for purposes of synchronizing with EEG/ERP measures.
Marker Values:
1 = onset of oddball signal
2 = onset of baseline signal
3 = onset of response (if any)
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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
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. Thus, trialnum
may not reflect the number of main trials run per block.
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
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_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)
list.ACC.mean: the overall proportion correct
numberGoTrials: number of Go trials ('oddball') in the test block
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)
hitrate: calculates the hitrate (proportion of correctly hitting the spacebar for oddball-trials)
FArate: calculates the commission error rate (proportion of incorrectly hitting the spacebar for baseline-trials)
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)*
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)*
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
