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								PERCEPTUAL VIGILANCE TEST
SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
last updated: 01-17-2018 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Copyright © 01-17-2018 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script runs a simple visual reaction time task similar to the one described by:

Wilkinson, R. T., & Houghton, D. (1982). Field test of arousal: A portable reaction timer with data storage. Human Factors, 24, 487-493.

This script adapts the procedure to computers.


											  *Task*
Participant are asked to click the mouse/touchthescreen as soon as they see a circle appearing on screen.
Afterwards, their reaction is displayed for 1.5s (default). The test is timed and stops after 10min (default).


DATA FILE INFORMATION: 
The default data stored in the data files are:

(1) Raw data file: 'PerceptualVigilanceTask_raw*.iqdat' (a separate file for each participant)

build:							Inquisit build
computer.platform:				the platform the script was run on
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) 
parameters.targetcolor:			the current color of the target circle
parameters.targetsize:			the current color of the target circle
parameters.targetx:				the x-coordinate of the target circle
parameters.targety:				the y-coordinate of the target circle
parameters.fixed:				0= fixed position of target; 1 = random position of target

/stiminterval:					determines how long the focus stimulus is shown before the target stimulus is presented
/trialStart:					script.elapsedtime (in ms) at start of trial (script.elapsedtime measured from start of script)
shape.targetcircle.timestamp:	script.elapsedtime (in ms) of last circle appearance
/lastCircleTimestamp:			stores the script.elapsedtime of the circle appearance in the previous trial
									Note: if response was made BEFORE the appearance of a new circle, lastCircleTimestamp = shape.targetcircle.timestamp otherwise
									they differ
response:						the mouse button pressed	
/rt_elapsed:					script.elapsedtime (in ms) at time of response
/rt:							stores the current response latency (in ms); calculated as the difference of elapsedtime of response and elapsedtime of circle
								Note: if response was made BEFORE onset of circle values.rt = "early response"

/EarlyResponse:					1 = the response was given before the circle appeared
								0 = the response was given after the circle appeared
								
/countEarlyResponses:			count of all early responses									
/countResponses:				running count of the number of responses made (excluding the first)	


(2) Summary data file: 'PerceptualVigilanceTask_summary*.iqdat' (a separate file for each participant)

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)
computer.platform:				the platform the script was run on
/completed:						0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
/meanRT:						mean response latency in ms (for trials that were responded to)
/Std:							standard deviation of the response latencies (for trials that were responded to)
/medianRT:						median latency in ms (for trials that were responded to)
/minrt:							minimum response latency (in ms)
/maxrt:							maximum response latency (in ms)
/countEarlyResponses:			count of all early responses									
/countResponses:				the total number of responses made during the test (excluding the first from trial.start)	
/proportionEarlyResponses: 		proportion early responses (in relation to total number of responses made)


EXPERIMENTAL SET-UP
(a) By default, the target stimulus appears in the center of the screen. Changes can be made under 
"Editable Values", including changing the script so that the target stimuli appear randomly in one of 9 screen positions.

(b) By default, the time intervals are randomly chosen  (with replacement) from 1000ms, 2000ms, 3000ms, 4000ms, 5000ms, 6000ms, 7000ms, 8000ms, 9000ms, 10000ms
Changes can easily be made under "Editable Lists"

(c) By default, the test runs for 10 Minutes. Changes can be made under "Editable Values -> parameters.testduration"

(d) By default, the color of the circle is red. Changes can be made under "Editable Values"

(e) By default, the color of the screen background is white. Changes can be made under "VALUES"

Procedure:
Task starts with the presentation of a red circle (this response latency not considered for summary statistics).
Immediately after the left or right mouse button response, the next trial starts randomly selecting one of the 10 possible stimintervals.
If a response is made prior to the appearance of the red circle, the trial terminates and a new trial starts.
The number of early responses are counted.


INSTRUCTIONS
The instructions can be easily changed under "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:

/targetcolor:							sets the color of the circle; the default is red
/targetsize:								sets the size of the circle; the default is 10% of the vertical screen
/targetx:								sets the x-coordinate of  the target circle ; the default is the center (50%)
/targety:								sets the y-coordinate of the target circle , the default is the center (50%)
/screencolor:							sets the background color of the screen
/feedbackheight:						height of feedback text stimulus (relative to canvas height) (default: 5%)
/fixed:									determines whether to use the fixed coordinates for the target stimulus (= 0) or to select
										randomly from 9 different screen positions (=1) ;  default is 0

/testduration:							duration of test: recommended minimum time is 600000ms => 10 min
/presenttrialfeedback:					true = after each trial the response latency is reported (default)
										false = no trial response latencies are reported
/rtfeedback_duration:					duration of feedback (default: 500ms)
											Note: feedback duration is counted towards taskduration

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