___________________________________________________________________________________________________________________ CONTINUOUS PERFORMANCE TEST (CPT) ___________________________________________________________________________________________________________________ last updated: 02-21-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-21-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements the Continuous Performance Test, a test of sustained and selective attention. Reference: Rosvold, H.E., Mirsky, A., Sarason, M., Bransome, E.D., Jr., and Beck, L.H. A Continuous Performance Test of brain damage. Journal of Consulting Psychology, 20, 343 (1956). Even numbered participants are assigned the longer adult version Odd numbered participants are assigned the shorter child's version ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants get presented a sequence of letters (one-by-one). Task1: press the Spacebar whenever the letter is an X Task2: press the Spacebar whenever the letter is an X that follows an A. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ short version: the default set up takes appr. 15min to run long version: the default set up takes appr. 25min to run ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'cpt_rosvold_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. phase: current phase of the procedure: "x practice" vs. "x test", "ax practice" vs. "ax test" blockcount_xpractice: counts the number of practice blocks run for phase X blockcount_xtest: counts the number of test blocks run for phase X blockcount_axpractice: counts the number of practice blocks run for phase AX blockcount_axtest: counts the number of test blocks run for phase AX previousLetter: the letter presented in the previous trial currentLetter: the letter presented in the current trial response the scancode for the key that was pressed (if any) 57 = spacebar press; 0 = noresponse correct whether the response was correct: 1 = correct; 0 = error latency the response time in milliseconds; measured from onset of letter (2) Summary data file: 'cpt_rosvold_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) blockcount_xpractice: counts the number of practice blocks run for phase X blockcount_xtest: counts the number of test blocks run for phase X blockcount_axpractice: counts the number of practice blocks run for phase AX blockcount_axtest: counts the number of test blocks run for phase AX xtestsignaltrialcount: counts all signal (=target) trials during Phase X xtestomissionerrorcount : number of errors when X was presented but no response was given during Phase X xtestomissionerrorrate : omission rate during Phase X xtestnoisetrialcount: counts all non-signal (= non target) trials during Phase X xtestcomissionerrorcount: number of false alarms during Phase X xtestcomissionerrorrate: commission rate during Phase X axtestsignaltrialcount: counts all signal (=target) trials during Phase AX axtestomissionerrorcount: number of errors when X was presented but no response was given during Phase AX axtestomissionerrorrate: omission rate during Phase AX axtestnoisetrialcount: counts all non-signal (= non target) trials during Phase AX axtestcomissionerrorcount: number of false alarms during Phase AX axtestcomissionerrorrate: commission rate during Phase AX ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ long version (even groupnumbers)/short version (odd groupnumbers) (1) phase "X": - 2 blocks practice - 10 (short version)/20 (long version) test blocks (duration of test blocks: ~ 5min total for short version/ ~10 min total for long version) - each blocks runs 31 letters with 8 targets (order is randomly determined) - the no-target letters are selected randomly WITH replacement from item.xletters (2) phase "AX" - 2 blocks practice - 10 (short version)/20 (long version) test blocks - each block runs 31 letters with: 6 targets (target = letter X that follows an A) ~ 5min total for short version/ ~10 min total for long version) - the no-target letters are selected randomly WITH replacement from item.axletters (with the constraint that no A is followed by an X) Note: in this script, any letter can precede an X (including X itself); any letter can follow an A (including A itself); the number of 'no-signal As' as well as 'no target Xs' are randomly determined per block Trial Sequence: letter (690ms)-> ISI: blank screen (230ms)-> letter.... response is accepted until end of letter duration (trial timings can be edited under section Editable Parameters) ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ see 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: /resttime: the time of the rest duration in ms (default: 120000ms => 2 min) /letterDuration: duration of the letters in ms (default: 690ms) (time to respond) /isi: interstimulus interval (= blank screen) in ms (default: 230ms) /letterHeight: the size (proportional to canvas height) of the the letters (default: 8%)