___________________________________________________________________________________________________________________ AUDITORY ODDBALL TASK ___________________________________________________________________________________________________________________ last updated: 10-04-2024 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 10-04-2024 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ 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) ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ 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). ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 4 minutes to complete ___________________________________________________________________________________________________________________ DATA OUTPUT DICTIONARY ___________________________________________________________________________________________________________________ The fields 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) missRate: the calculated missrate (1-hitrate) faRate: calculates the commission error rate (proportion of incorrectly hitting the spacebar for baseline-trials) corrRejectRate: the calculated correct rejection rate (1-commission rate) 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) c: c-criterion in signal detection:The absolute value of c provides an indication of the strength of the response bias/response style negative: participant more likely to report that signal (go stims) is present (liberal response style); may favor faster responding in speed-accuracy trade-off response paradigms positive: favoring caution (conservative response style) ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 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) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ oddball signal: 1000Hz sound baseline signal: 500Hz sound sound files can be edited under section Editable Stimuli ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ can be edited under section Editable Instructions ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ 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