___________________________________________________________________________________________________________________ *PSYCHOMOTOR VIGILANCE TEST* ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 06-07-2017 last updated: 02-01-2024 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-01-2024 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a Psychomotor Vigilance Test, a basic simple response time test. The implemented procedure is based on: Thomann, J.; R. Baumann, C.R.; Landolt, H.-P.; & Werth, E (2014). Psychomotor Vigilance Task Demonstrates Impaired Vigilance in Disorders with Excessive Daytime Sleepiness. Journal of Clinical Sleep Medicine, Vol. 10, 1019-1024. Mathias Basner, MD, PhD, MSc, David F. Dinges, PhD, Maximizing Sensitivity of the Psychomotor Vigilance Test (PVT) to Sleep Loss, Sleep, Volume 34, Issue 5, 1 May 2011, Pages 581–591, https://doi.org/10.1093/sleep/34.5.581 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are instructed to press the <Spacebar> as fast as possible after a red stopwatch appears on screen. A valid response (response occurs after stopwatch appears) is followed by reaction time feedback. An invalid response (response occurs before stopwatch appears) is followed by a brief error message. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 12 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'psychomotorvigilancetest_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. ISI: the currently randomly selected interstimulus interval in ms (randomly sampled from 2-10s) response: the participant's response (scancode of response button): 57 = spacebar press responseCategory: "false start" (= response before target occurs) vs. "no lapse" (= valid response with latency <= 500ms) vs. "lapse" (= valid response with latency > 500ms) vs. "lapse-overrun" (= valid response with latency >= parameters.) clock.target.stimulusonset: the onset time of the clock measured from onset of trial (in ms) latency: the response latency (in ms); measured from onset of trial rt: stores the latency of the response measured from onset of target stim (calculated as the difference btw. latency - clock.target.stimulusonset) countFalseStarts: counts the number of times an invalid (early) response is made in the current block (2) Summary data file: 'psychomotorvigilancetest_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) ///Summary Variables for Test Block only (excludes Habituation Phase): (see Thoman et al, 2014, p.1020) meanRT: mean valid response latency (in ms; measured from onset of target) reciprocalMeanRT: its reciprocal (see Thoman et al, 2014, p.1020) medianRT: median valid response latency (in ms; measured from onset of target) maxRT: the maximum valid response latency (in ms; measured from onset of target) minRT: the minimum valid response latency (in ms; measured from onset of target) meanRT500: mean valid response latency of responses with latencies <= 500ms (in ms; measured from onset of target) reciprocalMeanRT500: its reciprocal (see Thoman et al, 2014, p.1020) medianRT500: median valid response latency of responses with latencies <= 500ms (in ms; measured from onset of target) maxRT500: the maximum valid response latency of responses with latencies <= 500ms (in ms; measured from onset of target) minRT500: the minimum valid response latency of responses with latencies <= 500ms (in ms; measured from onset of target) 10thpercentile: in this script: the 10th percentile RT is taken as the value that sits at the 10%index (rounded to the nearest integer) in the sorted RT list Example: the sorted RT list (from slowest to fastest) contains 120 values; the 10th percentile would be the value sitting at index 12 (120*10%) of this sorted list 90thpercentile: in this script: the 90th percentile RT is taken as the value that sits at the 90%index (rounded to the nearest integer) in the sorted RT list Example: the sorted RT list (from slowest to fastest) contains 120 values; the 90th percentile would be the value sitting at index 108 (120*90%) of this sorted list rangeRT: the difference in ms betw. 10th percentile RT and 90th percentile RT 10thpercentile500: in this script: the 10th percentile RT is taken as the value that sits at the 10%index (rounded to the nearest integer) in the sorted RT list of valid latencies <= 500ms 90thpercentile500: in this script: the 90th percentile RT is taken as the value value that sits at the 90%index (rounded to the nearest integer) in the sorted RT list of valid latencies <= 500ms rangeRT500: the difference in ms btw. 10th percentile RT and 90th percentile RT of valid latencies <= 500ms numberOfLapses: stores the total number of lapses (responses with latencies > 500ms) during the test block transformedNumberOfLapses: numberOfLapses transformed with (sqrt(numberOfLapses) + sqrt(numberOfLapses+1)) (see Thoman et al, 2014, p.1020) meanLapseRT: the average lapse in ms (average ms above 500ms for lapses) cumulativeLapseRT: the sum of all lapse times during the test block countFalseStarts: counts the number of false starts during the test block falseRT: ratio of 'number of times participant responded BEFORE target appeared' to 'the number of times participant responded AFTER target appeared' this ratio is presented as a percentage. * separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section "DATA" and follow further instructions ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 1. Habituation Phase: ~1 min (Block is terminated after the last trial cycle within the designated timeframe) - same task as actual test but performance is not used for summary statistics Note: the Habituation Phase seamlessly turns into the Test Phase without giving participants any further warning. During the first trial only, a reminder to press spacebar is presented on screen. 2. Test Phase: ~10 min (Block is terminated after the last trial cycle within the designated timeframe) Trial Sequence: ISI (randomly selected from 2-10s)-> target stim until response-> RT feedback (1000ms) Note: If a response is made before the target stim appears, a short error message is flashed onto the screen and a new trial is started. ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ target stimulus is a red stopwatch counter (counts in milliseconds) ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Millisecond Software - 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: