___________________________________________________________________________________________________________________ AX Continuous Performance Task (AX-CPT) ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 07-15-2015 last updated: 05-24-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 05-24-2023 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements the AX-CPT procedure, a test of sustained and selective attention. Reference: Marcora, S.M, Staiano, W. & Manning, V. (2009). Mental fatigue impairs physical performance in humans. J Appl Physiol, 106: 857–864 ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants view sequences of letters: cue-distractor-distractor-probe and have to decide if the probe is a target (cue = A, probe = X) or not. If the probe is a target, participants press the 'E'; if it's not a target they press the 'I' key. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 20 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'ax_cpt_rawdata.iqdat' (a separate script 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 nr_trials: number of trials to run in the predetermined time with the predetermined stimulus durations nr_targettrials_AX: number of AX trials to run for the predetermined duration (default: for 20 minutes nr_targettrials_AY: number of AY trials to run for the predetermined duration (default: for 20 minutes) nr_nontargettrials_BX: number of BX trials to run for the predetermined duration (default: for 20 minutes) nr_nontargettrials_BY: number of BY trials to run for the predetermined duration (default: for 20 minutes) phase1trials: last trial run for critical phase 1 time period (default: trials run in the first 5 minutes) Note: for a 20 minutes task (200 trials) -> trials 1-50 are counted towards phase 1 phase3trials: trial numbers higher than this number count towards trials run for critial phase 3 (default: trials run in last 5 minutes) Note: for a 20 minutes task (200 trials) -> trials 151-200 are counted towards phase 3 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. counttrials: count of the trialsequences trialtype: 1 = AX (target); 2 = AY; 3 = BX; 4 = BY phase: 1 = trials run in the first 5 minutes (default; see parameters.targetphaseduration_min) 2 = trials run in the middle 3 = trials run in the last 5 minutes (default; see parameters.targetphaseduration_min) cue: stores the letter presented as the cue probe: stores the letter presented as the probe distractor1: stores the letter presented as the distractor1 distractor2: stores the letter presented as the distractor2 stimulusitem: the presented stimuli in order of trial presentation Note: only statically presented items response: the participant's response (scancode of response key) 18 = E = target 23 = I = nontarget correct: the correctness of the response (1 = correct; 0 = incorrect) latency: the response latency (in ms); measured from onset of probe (2nd red letter) (2) Summary data file: 'ax_cpt_summary.iqdat' (Inquisit Lab: one data file for all participants) 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) countcorrect: counts all correct responses percentcorrect: overall percent correct meanRT: overall mean latency of correct responses probHits: proportion hits overall propHits_phase1: proportion hits in phase1 (first 5 minutes, default; see parameters.targetphaseduration_min) propHits_phase2: proportion hits in phase2 propHits_phase3: proportion hits in phase3 (last 5 minutes, default; see parameters.targetphaseduration_min) nr_trials: number of trials to run in the predetermined time with the predetermined stimulus durations nr_targettrials_AX: number of AX trials to run for the predetermined duration (default: for 20 minutes) nr_targettrials_AY: number of AY trials to run for the predetermined duration (default: for 20 minutes) nr_targettrials_BX: number of BX trials to run for the predetermined duration (default: for 20 minutes) nr_targettrials_BY: number of BY trials to run for the predetermined duration (default: for 20 minutes) phase1trials: last trial run for critical phase 1 time period (default: trials run in the first 5 minutes) Note: for a 20 minutes task (200 trials) -> trials 1-50 are counted towards phase 1 phase3trials: trial numbers higher than this number count towards trials run for critial phase 3 (default: trials run in last 5 minutes) Note: for a 20 minutes task (200 trials) -> trials 151-200 are counted towards phase 3 feedbacktrialinterval: number of trials that are run before feedback is given for the predetermined feedback interval ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ (I) Task: 20minutes; each trialsequences takes 6000ms => Total of 200 trials (target: 140; notarget= 3 x 20) => order of the trialsequences is randomly determined NOTE: the task duration in this script is determined by the number of trial sequences that span the predetermined taskduration_min (e.g. 20 min) given the default letterduration (300ms) and ISI (1200ms) (each trial sequence: cue -> distractor -> distractor -> probe => 6000ms). Trialnumber instead of timing is used to determine the length of the task to ensure that the predetermined probability of targettrials and nontargettrials is indeed run. (II) Types of Trials: 70% Target Trial Sequences AX 10% NoTarget Trial Sequences AY 10% NoTarget Trial Sequences BX 10% No target Trial Sequences BY (III) Default Trial Sequence: Cue (300ms)-> ISI(1200ms)->Distractor(300ms)->ISI(1200ms)->Distractor(300ms)->ISI(1200ms)->Probe(300ms)->ISI(1200ms) => Response measured from onset of Probe; time to respond until end of ISI. Probe is presented for 300ms even if response occurs before probe is erased. To be able to give errorfeedback immediately (or almost immediately) following the response; the ISI after the probe is handled by a separate trial. If no response occurs, the error feedback adds about 50ms to the trialduration (IV) Performance Feedback: Performance Feedback is presented after every 10min (default) -> after every 100 trials Target Phases (counts hits for first and last 15 minutes of the test): Phase 1 (for 20 minutes test): first 5 minutes -> trials 1-50 Phase 3 (for 20 minutes test): last 5 minutes -> trials 151-200 ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Letters: * Default Font: Arial * Size: can be set under section Editable Parameter (Size is proportional to monitor height) * Cue and Probe letters: red on black * Distractors: white on black Errorfeedback: 50ms beep (can be edited under section Editable Stimuli) ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are provided by Millisecond Software. They 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: