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SHORT ATTENTION NETWORK TEST (short ANT) - Adult Version
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 02-21-2013
last updated: 12-09-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 12-09-2019 Millisecond Software
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BACKGROUND INFO
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This script implements the Short Attention Network Test (ANT), a behavioral measure of orienting and
executive attention. In contrast to the original ANT, the short ANT does not provide a measure of the
alerting attention network.
The implemented procedure is based on:
This script implements the short Attention Network Test (shortANT) as shared by Dr. Fan:
http://people.qc.cuny.edu/Faculty/Jin.Fan/Pages/Downloads.aspx
the original ANT was published in:
Fan, J., McCandliss, B. D., Sommer, T., Raz, A., & Posner, M. I. (2002). Testing the efficiency and independence
of attentional networks. Journal of Cognitive Neuroscience, 14, 340–347.
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TASK DESCRIPTION
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Participants are presented arrows either directly above or below a fixation cross. Arrows are flanked by other
arrows that point in the same (congruent) or opposite direction (incongruent).
Participants have to decide whether the central arrows point right or left.
Several cue conditions (3) (may) alert the participants that the targets are about to come on screen
and potentially where on the screen (above or below the fixation cross).
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DURATION
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the default set-up of the script takes appr. 12 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: 'shortant_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
script.sessionid: with the current session id
values.blockcount: counts the number of experimental blocks run
blockcode: the name and number of the current block
values.trialcount: counts the number of trials run (resets after practice)
trialcode: the name and number of the currently recorded trial
values.practice: 1 = practice trial; 0 = test trial
parameters.completetrialDuration: the complete duration (in ms) of one trial sequence (default: 4000ms)
values.fixation1_duration: The actual duration (in ms) of the first fixation cross (400ms +)
parameters.cue_duration: the duration (in ms) of the cue presentation (default: 100ms)
parameters.ISI_cuetarget: the duration (in ms) of the fixation cross after cue presentation and before target (default: 400ms)
parameters.target_duration: the maximal duration (in ms) of the target/flanker presentation (default: 1700ms)
Note: equals the response window
values.ITI_duration: the current intertrial interval (in ms)
values.cuecondition: the current cue condition (1 = no cue; 2 = center cue; 3 = spatial cue)
values.flankercongruence: the current flanker condition (1 = neutral; 2 = congruent; 3 = incongruent)
values.targetposition: position of target relative to fixation (1 = above fixation; 2 = below fixation)
values.targetdirection: the direction of the target (1 = right; 2 = left)
picture.flanker1.currentitem/
picture.flanker4.currentitem: stores the images presented for targets and flankers
Variables that contain x/y coordinates for cues, targets, flankers:
/target_x
/target_y
/flanker1_x
/flanker1_y
/cue_x
/cue_y
response: the response of participant (scancode of response button: 18 = left E; 23 = right I; 57 = spacebar)
correct: correctness of response (1 = correct, 0 = error)
latency: response latency (in ms); measured from onset of target until response is made or trial times out
(2) Summary data file: 'shortant_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)
expressions.overallpropcorrect: overall proportion correct across all testblock trials
expressions.meanrt_correct: overall mean RT (of correct responses) for test trials
Main Effects:
expressions.propCorrect_noCue: proportion correct responses in nocue condition
expressions.meanrt_noCue: mean response time (in ms) of correct responses in nocue condition
expressions.propCorrect_centerCue: proportion correct responses in centercue condition
expressions.meanrt_centerCue: mean response time (in ms) of correct responses in centercue condition
expressions.propCorrect_spatialCue: proportion correct responses in spatialcue condition
expressions.meanrt_spatialCue: mean response time (in ms) of correct responses in spatialcue condition
expressions.propCorrect_congruent: proportion correct responses in trials with target-congruent flankers (flankers that point in the same direction as target)
expressions.meanrt_congruent: mean response time (in ms) of correct responses in trials with target-congruent flankers (flankers that point in the same direction as target)
expressions.propCorrect_incongruent: proportion correct responses in trials with target-incongruent flankers (flankers that point in the opposite direction as target)
expressions.meanrt_incongruent: mean response time (in ms) of correct responses in trials with target-incongruent flankers (flankers that point in the opposite direction as target)
Interactions:
expressions.propCorrect_congruentNC: proportion correct responses in trials with target-congruent flankers in No Cue Condition
expressions.meanRT_correctCongruentNC: mean response time (in ms) of correct responses in trials with target-congruent flankers in No Cue Condition
expressions.propCorrect_incongruentNC: proportion correct responses in trials with target-incongruent flankers in No Cue Condition
expressions.meanRT_correctIncongruentNC: mean response time (in ms) of correct responses in trials with target-incongruent flankers in No Cue Condition
(same for CC= center condition; SC = spatial condition)
Expressions that use above expressions and calculate the 2 attentional network effects (Fan et al, 2002, p.342/343)
expressions.orientingeffect = expressions.meanrt_correctcentercue - expressions.meanrt_correctspatialcue => Effect of orienting attention towards a specific location of information
expressions.conflicteffect = expressions.meanrt_correctincongruent - expressions.meanrt_correctcongruent =>
Effect of resolving conflict between several possible responses (executive function)
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EXPERIMENTAL SET-UP
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3 cue conditions (no cue, center cue, spatial cue) x 2 flanker conditions (congruent, incongruent)
within-subjects design
A) 1 Block of 12 Practice trial sequences with feedback
B) 1 Blocks of 120 trial sequences each - no feedback
EXPERIMENTAL BLOCKS:
120 trial sequences: 5 (repetitions) x 3 (cue conditions) x 2 (flanker conditions) x 2 (target positions) x 2 (target directions)
Trial Sequence (one sequence for each cue condition) - randomly selected
fixation (randomly chosen presentation time: 400ms +) -> cue (100ms) -> fixation (400ms) -> target (1700ms)-> intertrialinterval (depends: complete trialduration = 4s)
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STIMULI
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Size of Stimuli:
Fan et al (2002) give specific dimensions of the size and distance of targets/flankers (p.345/346)
=> distance participant/screen: 65 cm
=> single line arrow : 0.55 degree visual angle
=> distance flankers/target: 0.06 degree visual angle (area covered by all: 3.08 degree visual angle)
=> distance target/fixation cross: 1.06 degree visual angle
This script does NOT attempt to replicate these dimensions as different monitors require different fontsizes etc.
Fine-tune fontsize of stimuli, distance of flanker to target, and position of target above and below
fixation cross under section EDITABLE PARAMETERS
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INSTRUCTIONS
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Note: Instructions are modelled after the instructions generously made available by Dr. Fan
Instructions can be edited under section EDITABLE INSTRUCTIONS
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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:
Stimuli Dimension/Placement:
/fontsize_fixation: regulates the size of the fixation cross, in canvas height percentage (default: 3%)
/cueSize: regulates the size of the cues, in canvas height percentage (default: 5%)
/arrowSise: regulates the size of the target/flanker, in canvas height percentage (default: 5%)
/flankerdistance: the relative screen distance between stimuli, in canvas width percentage (default: 5%)
/top_y: the y-coordinate of the target above the fixation cross (default: 40%)
/bottom_y: the y-coordinate of the target below the fixation cross (default: 60%)
Trial Durations:
/completetrialDuration: sets the complete duration (in ms) of one trial sequence (default: 4000ms)
/minfixation1_duration: sets the minimum duration (in ms) of the first fixation cross in a trial sequence. The actual duration
contains the addition of a random component: a randomly selected number between 0-1200ms is added to
this fixation duration. (default: 400ms)
/cue_duration: sets the duration (in ms) of the cue presentation (default: 100ms)
/ISI_cuetarget: sets the duration (in ms) of the fixation cross after cue presentation and before target (default: 400ms)
/target_duration: sets the maximal duration (in ms) of the target/flanker presentation (default: 1700ms)
Note: equals the response window
/practicefeedback_duration: sets the duration (in ms) of the feedback trial during practice (default: 2000ms)
/readyDuration: duration (in ms) of the get-ready trial (default: 5000ms)
Response Keys:
/responsekey_left: scancode for the left response key (default: "E", 18)
/responsekey_right: scancode for the right response key (default: "I", 23)