___________________________________________________________________________________________________________________ *Number Vigilance Task* (subtest of COGDRAS) ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 09-08-2020 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 a computerized Number Vigilance Task, a measure of attention and cognitive control. The Number Vigilance Task is used as a subtest of the Cognitive Drug Research Computerized Assessment System (COGRAS). The Number Vigilance Task is a type of go/no go task with digits. The implemented procedure is similar to the one published in: Nicholl, C.G. et al (1995). The the Cognitive Drug Research Computerized Assessment System in the evaluation of early dementia- is speed of the essence? INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, VOL. 10: 199-206 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants view a stream of digits presented in the middle of the screen, one at a time. A new digit is presented ~750ms (for a presentation Rate of: 80 words/minute). Whenever the digit is the same as the target digit (which is presented on the right of the screen throughout the task), they have to press the 'Yes' key (here: Q-key). Otherwise they are instructed to not do anything but stay vigilant and wait for the next digit. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 3 minutes to complete Note: the test can easily be aborted by pressing "Ctrl+Alt+A" ___________________________________________________________________________________________________________________ DATA OUTPUT DICTIONARY ___________________________________________________________________________________________________________________ The fields in the data files are: (1) Raw data file: 'numbervigilance_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. digitType: 1 = target digit (current digit = target digit); 2 = foil digit (current digit <> target digit) targetDigit: the randomly selected target digit that is presented at the right of the screen currentDigit: the currently randomly selected digit that is presented in the center of the screen response: the participant's response (scancode of response button) 16 = yes-key was pressed; 0 = no response responseLabel: "yes" vs. "" (empty) responseCategory: "Hit" (pressed yes-key for a target) "Miss" (did not press yes-key for a target) = omission error "CR" (did not press yes-key for a nontarget) = correct rejection "FA" (pressed yes-key for a nontarget) = commission error correct: accuracy of response: 1 = correct response; 0 = otherwise latency: the response latency (in ms); measured from: onset of center digit (2) Summary data file: 'numbervigilance_summary*.iqdat' (a sepaRate file for each participant)* inquisit.version: the Inquisit build/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) numberOfDigits: the number of digits presented (targets and nontargets) numberOfTargets: the number of targets presented numberOfFoils: the number of foils presented propCorrect: proportion correct responses (across targets and nontargets) vigHit: the number of hit responses (pressing spacebar for target digits) vigFA: the number of false alarms (pressing spacebar for foil digits) vigAcc: the hitRate (proportion of targets that were correctly responded to) in Number Vigilance Test vigMissRate: the miss rate (proportion of targets that were not responded to) vigFARate: the false alarm Rate (proportion of non targets that were responded to) vigCrRate: the correct rejection rate dPrime: d' = sensitivity index calculated as difference btw. z score of hit rate and z-score of false alarm rate => Range (in this script): -5.1516586840152740479 <= dprime <= 5.1516586840152740479 (=perfect performance) => The higher the value, the better signals (=targets) were overall distinguished from noise (=nontargets) and thus the better participant paid attention (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) //response Times: vigRT: the mean response time (in ms) of correctly responding to a target in Number Vigilance Test ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ Target Digit: is sampled randomly at the start of the script. The same target is throughout the test. 1. Test Block: - number of test trials can be set under section Editable Parameters (default: 90) - proportion of target trials can be set under section Editable Parameters (default: 30%) - order of target and foil trials is random (constraint: first trial is a foil trial) - selection of foil digits is random with replacement - SOA and digit presentation duration can be set under section Editable Parameters (SOA: 750ms; digit presentation duration: 750ms) Trial Sequence: * target is presented throughout the blocks to the right on the screen * each block starts with the target presented alone for duration SOA current digit presentation (750ms), response window = SOA = 750ms ->current digit presentation ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ target = randomly determined digit from 0 to 9, presented in black font on the right side of the screen current digit = digit from 0 to 9, presented in black font in the center of the screen both digits are equal in size (size can be set under section Editable Parameters) ___________________________________________________________________________________________________________________ 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.