Return to the Sustained Attention to Response Task page
																						   
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								*SUSTAINED ATTENTION TO RESPONSE TASK (SART)*
								(with optional "Mindwandering Probes")
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-15-2013
last updated:  03-11-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-11-2020 Millisecond Software

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BACKGROUND INFO 	
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This script implements the Sustained Attention to Response Task (SART), a go/nogo task with
infrequent nogo signal to measure attention.

The implemented procedure is based on:

Robertson, I. H., Manly, T., Andrade, J., Baddeley, B. T., & Yiend, J. (1997). ‘Oops!’: Performance correlates of 
everyday attentional failures in traumatic brain injured and normal subjects. Neuropsychologia, 35(6), 747–758.

and 

Cheyne, J.A., Solman, G.J.F., Carriere, J.S.A., & Smilek, D. (2009). Anatomy of an error: 
A bidirectional state model of task engagement/disengagement and attention-related errors. Cognition, 111, 98–113.


!NOTE: This script includes an optional "Mindwandering Probe" addition for the SART.iqx.
The code is provided in helper script "SART_MindWanderingProbeAddition.iqx". More info about
the mindwandering probe in the additional script.
To run the probe addition, go to section Editable Parameters and set 
parameters.run_mindwanderingprobe = true (default is false)

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TASK DESCRIPTION
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Participants are presented with a single digit 1-9 in the middle of the screen in varying fontsizes.
The digit disappears after a short while and is replaced with a mask (circle with an X).
Participants are asked to press the SPACEBAR if any digit other than 3 is presented and to withhold the response
if digit 3 presented.

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DURATION 
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the default set-up of the script takes appr. 6 minutes to complete

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

(1) Raw data file: 'sart.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
script.sessionid:					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. 
										
expressions.trialcount:				counts all test trials
parameters.digitpresentationtime:	digit duration in ms (default: 250ms)
parameters.maskpresentationtime:	mask duration in ms (default: 900ms)

values.trialtype:					"Go" (digit !=3); "NoGo" (digit == 3)
values.digit:						contains the currently selected digit
values.fontsize:					contains the currently (randomly) selected fontsize

response:							the participant's response
									SART trials: 0 for no response or 57 for Spacebar
									Probe trials (if run): the selected anchor digit
										
correct:							the correctness of the response (1 = correct; 0 = error)

values.RT:							the latency of the response in ms: 
									trial latency unless no response was given; 
									no response = empty
										
latency: 							the trial latency in ms (if no response, trial latency shows the trialduration)

values.latencytype:					0 = no response given (suppression); 
									1 = anticipatory latency (< parameters.anticipatoryresponsetime);
									2 = ambiguous latency; 
									3 = valid latency  (>= parameters.validresponsetime)
									Note: independent of Go-NoGo trialtype
									
values.responsetype:				"NoGo Success": correctly suppressed response to NoGo trial (digit 3)
									"Omission": incorrectly suppressed response to a Go trial (digit other than 3)
									"NoGo Failure": any response to a NoGo trial
									"Go Anticipatory": anticipatory response for Go trials with latencies < parameters.anticipatoryresponsetime
									"Go Ambiguous": ambiguous response for Go trials
									"Go Success": valid response for Go trials with latencies >= parameters.validresponsetime
									
values.count_anticipatory:			counts the number of times a Go-latency was faster than parameters.anticipatoryresponsetime
values.correctsuppressions:			counts number of correct suppressions (-> no response to digit 3)
values.incorrectsuppressions:		counts number of incorrect suppressions (-> no response to digit other than 3)
values.count_NoGo:					counts NoGo trials (digit 3)
values.count_Go:					counts Go trials (digits other than 3)
values.count_validgo:				counts Go trials with a correct response and latencies >= parameters.validresponsetime
values.countprobes:					counts the number of probes run



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

computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)
																
radiobuttons.difficulty.response:	response to the difficulty question
radiobuttons.interest.response:		responses to the posttask survey questions (if run)

dropdown.age.response:				response to the age question at the end of the task (if run)
values.ageGroup:					the assigned age group (1-6) based on age response. (used for reporting z-scores and percentiles)
									!Note: age groups correspond to the age cohorts used by Carriere et al (2010), table 2, p. 572

expressions.nr_commissions:			absolute number of commission errors in NoGo trials (=NoGo failures; also reported as SART errors)				
expressions.percent_commissions:	percentage of commission errors in NoGo trials (=NoGo failures; also reported as SART errors)
values.z_commission:				z-value of number of Commission errors based on Carriere et al (2010), table 2 (SART errors), p. 572
values.percentile_commission:		percentile of Commission z-value based on Carriere et al (2010), table 2 (SART errors), p. 572

expressions.nr_omissions:			absolute number of omission errors in Go trials (=omission of response)
expressions.percent_omissions:		percentage of incorrect suppressions in Go trials (=omission of response)
values.z_Omission:					z-value of number Omission errors based on Carriere et al (2010), table 2, p. 572
values.percentile_Omission:			percentile of Omission z-value based on Carriere et al (2010), table 2, p. 572

values.count_anticipatory:					counts the number of times a Go-latency was faster than parameters.anticipatoryresponsetime
values.z_AnticipatoryResponses:				z-value of number Anticipatory Responses based on Carriere et al (2010), table 2, p. 572
values.percentile_AnticipatoryResponses:	percentile of Anticipatory Responses z-value based on Carriere et al (2010), table 2, p. 572

expressions.meanRT_go:						mean latency (in ms) of valid and correct Go trials (latencies >= parameters.validresponsetime)
expressions.stdRT_go:						estimated standard deviation (STD) of valid and correct Go trials
values.z_goRT:								z-value of mean go latency based on Carriere et al (2010), table 2, p. 572
values.percentile_goRT:						percentile of goRT z-value based on Carriere et al (2010), table 2, p. 572

expressions.CV_go:							coefficient of variablity (CV = STD/Mean) => a measure of variability independent of mean differences
values.z_CV:								z-value of CV based on Carriere et al (2010), table 2, p. 572
values.percentile_CV:						percentile of CV z-value based on Carriere et al (2010), table 2, p. 572

Mean RTs are calculated for the correct consecutive (not interrupted either by a NoGo or by an omission trial) last four Go- trials (digit other than 3) preceding successful NoGo trial
Mean RTs are calculated for the correct consecutive (not interrupted either by a NoGo or by an omission trial) last four Go- trials (digit other than 3)  preceding preceding failed NoGo trial
!!!!Note: in this script any 4 correct Go trials are counted irrespective of values.latencytype

expressions.meanRT_GObeforesuccessNOGO:		mean latency (in ms) of consecutive 4 correct trials before correct suppression of response to digit 3
													(=> a measure of speed before successful NoGo trials)
													
expressions.meanRT_GObeforefailedNOGO:		mean latency (in ms) of consecutive 4 correct trials before incorrect response of response to digit 3
													(=> a measure of speed before failed NoGo trials)
											
NORMS:
z-value and percentile calculations use data published by:

	Carriere, J.S.A., Cheyne, J.A., Solman, G.J.F. & Smilek, D. (2010). 
	Age Trends for Failures of Sustained Attention. Psychology and Aging, 25, 569–574.
	
Carriere et al (2010) grouped data by 6 age groups (no separate data for gender norms provided)	
Check helper script SART_Norms.iqx for more details.

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EXPERIMENTAL SET-UP 
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*9 digits, each of them presented 25 times = 225 trials
*in 5 fontsizes, each of them randomly selected 45 times (distribution across digits is randomly determined)
*in this script the digit order is semi-random, predetermined 
no special constraints were used to determine the order (only constraint: each digit is presented 25 times)
* List properties can be edited to change the order from a pre-fixed one to a random one. Further instructions under
(see section Editable Lists -> list.digitsequence for more information)

Trial Sequence:
digit (250ms) -> mask (900ms) ->  -> digit.....

=> Response latencies are measured from onset of digit and can therefore catch anticipatory responses 
	(latencies faster than parameters.anticipatoryresponsetime) (see discussion in Cheyne et al, 2009)

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STIMULI
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- digits 1-9 presented in fontstyle "Symbol" (if available on computer) 
- in 5 fontsizes
	=> fontsizes in this script are based on screen percentages and can be customized under 
	section Editable Lists -> list.fontsizes
- a picture mask (circle with an X) section Editable Stimuli -> picture.mask
- stimuli/mask presented in white on a black background

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INSTRUCTIONS 
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Instructions are not original to the task. They are provided by Millisecond Software
as htm/html pages and can be edited by changing the provided htm/html files.
To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac)
or Notepad (Windows).
	
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EDITABLE CODE 
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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:

/digitpresentationtime:				digit duration in ms (default: 250ms)
/maskpresentationtime:				mask duration in ms (default: 900ms)
/ITI:								intertrial interval in ms (default: 0 => digit SOA is therefore 1150ms)

/responsekey:						the response key (here: " " -> Spacebar)

	
/maskheight:						the height/size of the mask (default: 20%)
									Note: Robertson et al (1997): mask size on their screen ~29mm
									
/anticipatoryresponsetime:			by default, latencies (in ms) are measured from digit onset
									latencies faster than anticipatoryresponsetime are interpreted as anticipatory
									as opposed to ambiguous/true responses to the digit (default: 100ms)
									(-> Cheyne et al, 2009)
								
/validresponsetime:					latencies (in ms) that are at or above validresponsetime are considered true 
									responses to the digits (default: 200ms)
									(-> Cheyne et al, 2009)

Minderwandering Probe Addition:
/run_mindwanderingprobe:			true: script runs the mindwandering probe addition
									false: script does not run the mindwandering probe addition  (default)
								
/postprobeduration:					intertrial pause between probe and re-start of SART (in ms)