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						AX Continuous Performance Task (AX-CPT)
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 07-15-2015
last updated: 08-15-2016 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 08-15-2016 Millisecond Software

BACKGROUND INFO

											*Purpose*
This script implements the AX-CPT procedure described in:

Marcora, S.M,  Staiano, W. & Manning, V. (2009). Mental fatigue impairs physical performance in humans.
J Appl Physiol, 106: 857–864

											  *Task*
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.


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:							Inquisit build
date, time, subject, group:		date and time script was run with the current subject/groupnumber 
blockcode, blocknum:			the name and number of the current block
trialcode, trialnum: 			the name and number of the currently recorded trial
									(Note: not all trials that are run might record data; by default data is collected unless /recorddata = false is set for a particular trial/block) 
/counttrials:					count of the trialsequences
/trialtype:						1= AX (target); 2 = AY; 3 = BX; 4 = BY
/phase:							1 = trials run in the first 15 minutes (default)
								2 = trials run in the middle
								3 = trials run in the last 15 minutes (default)
/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)
correct:						the correctness of the response (1 = correct; 0 = incorrect)
latency: 						the response latency (in ms)

(2) Summary data file: 'AX_CPT_summary.iqdat' (Inquisit Lab: one data file for all participants)

script.startdate:				date script was run
script.starttime:				time script was started
script.subjectid:				subject id number
script.groupid:					group id number
script.elapsedtime:				time it took to run script (in ms)
/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
/prophits: 						proportion hits overall
/prophits_phase1: 				proportion hits in phase1 (first 15 minutes, default)
/prophits_phase2:				proportion hits in phase2
/prophits_phase3:				proportion hits in phase3 (last 15 minutes, default)
/nr_trials:						number of trials to run in the predetermined time with the predetermined stimulus durations
/nr_targettrials_AX:			number of AX trials
/nr_nontargettrials_BX:			number of BX trials 
/nr_nontargettrials_BY:			number of BY trials
/nr_nontargettrials_AY:			number of AY trials
/phase1trials:					last trial run for critical phase 1 time period (default: trials run in the first 15 minutes)
									Note: for a 90 minutes task (900 trials) -> trials 1-150 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 15 minutes)
									Note: for a 90 minutes task (900 trials) -> trials 751-900 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: 
A) 90minutes; each trialsequences takes 6000ms => Total of 900 trials (target: 630; notarget= 3 x 90)
B) 60 minutes; each trialsequence takes 6000ms => Total of 600 trials (target: 420; notarget= 3 x 60)
=> 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. 90 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(1200ms)->ISI(1200ms)->Distractor(1200ms)->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 30min (default) -> after every 300 trials 

Target Phases (counts hits for first and last 15 minutes of the test):
Phase 1 (for 90 minutes test): first 15 minutes -> trials 1-150
Phase 3 (for 90 minutes test): last 15 minutes -> trials 751-150

Phase 1 (for 60 minutes test): first 15 minutes -> trials 1-150
Phase 3 (for 60 minutes test): last 15 minutes -> trials 451-600

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
are presented in the form of an html file. The html file can be edited directly to change
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:

/taskduration_min:						duration of task in minutes
/feedbackintervals_min:					feedback intervals in min (default: every 30 minutes)
/targetphaseduration_min:				the duration of the critical phases in minutes (default: first 15 minutes and last 15 minutes)
/letterduration_ms:						the duration of the letters in ms (default: 300ms)
/isi_ms:								the duration of the interstimulusintervals (offset of one letter to onset of next) in ms (default: 1200ms)

!NOTE: 
the duration of this script is determined by the number of trial sequences that span the predetermined taskduration_min (e.g. 90 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.

Taskduration_min should be chosen carefully for the specified trialdurations (letterduration and ISI) to
ensure that integer values are obtained for total number of trials and number of targettrials and non-targettrials.

This script is set up for taskduration = 90min and taskduration = 60 min for the default letterduration (300ms) and ISI (1200ms)
and the default probabilities of target (0.7) and nontarget trials (0.1 x 3)

/prob_targettrials_AX:					frequency of targettrials AX
/prob_nontargettrials_BX:				frequency of BX no target trials
/prob_nontargettrials_BY:				frequency of BY no target trials
/prob_nontargettrials_AY:				frequency of AY no target trials

/letterheight:							sets the letterheight in proportion of the canvas height (default: 5%)
/performancefeedbackduration:			sets the duration of the performance feedback in ms (default: 5000ms)

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