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								ATTENTION NETWORK TEST (ANT) - Adult Version

SCRIPT INFO

Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date:	02-21-2013
last updated:  08-15-2016 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Copyright ©  08-15-2016 Millisecond Software


BACKGROUND INFO

											*Purpose*
This script implements the Attention Network Test (ANT) as described 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.

The original ANT for adults and the child ANT as well as all stimuli used are generously shared by 
the original authors/Sackler Institute at:  http://www.sacklerinstitute.org/cornell/assays_and_tools/


											  *Task*
Participants are presented arrows either directly above or below a fixation cross. Arrows may be flanked by other 
stimuli  (3 flanker conditions). Participants have to decide whether the arrows point right or left. 
Several cue conditions (4)  (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).

Differences in mean reaction times in the different cue/flanker conditions are used to calculate
the following three Attentional Network Effects:
* Alert Effect: Effect of achieving and maintaining alertness
* Orienting Effect: Effect of orienting attention towards a specific location of information
* Conflict Effect: Effect of resolving conflict between several possible responses


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

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

build:									Inquisit build
computer.platform:						the platform the script was run on
date, time, subject:					date and time script was run with the current subjectnumber 
/blockcount:							counts the number of experimental blocks run
blockcode:								the name and number of the current block
/trialcount:							counts the number of trials run (resets after practice)
trialcode: 								the name and number of the currently recorded trial
/cuecondition:							sets the current cue condition (1 = no cue; 2 = center cue; 3 = double cue; 4 = spatial cue)
/flankercondition:						sets the current flanker condition (1 = neutral; 2 = congruent; 3 = incongruent)
/targetposition:						sets position of target (1 = above fixation; 2 = below fixation)
/targetdirection:						sets the direction of the target (1 = right; 2 = left)
text.flanker1.currentitem-
text.flanker4.currenitem:				stores the items used as flanker1-flanker4


Variables that contain x/y coordinates for cues, targets, flankers:
/target_x
/target_y
/flanker1_x
/flanker1_y
/cue1_x
/cue1_y

response:								the response of participant (scancode of response button: 18 = left; 23 = right)
correct:								correctness of response (1 = correct, 0 = error)
latency:								response latency (in ms)

Variables to help calculate mean reaction times (RT) for the different cue/flanker conditions (only correct responses),
needed to calculate the Alert Effect, Orienting Effect and Conflict Effect
/count_correctNoCue-
/sumRT_correctInCongruent
Expressions that calcuate the mean reaction times (RT) for the different cue/flanker conditions
/meanRT_correctNoCue -----
/meanRT_correctInCongruent 

(2) Summary data file: 'ANT_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)
/overallpercentcorrect:			%correct across all testblock trials
/meanRT_correct:				overall mean RT (of correct responses) for test trials

Variables to help calculate mean reaction times (RT) for the different cue/flanker conditions (only correct responses),
needed to calculate the Alert Effect, Orienting Effect and Conflict Effect (see EXPRESSIONS)
/count_correctNoCue-
/sumRT_correctInCongruent

Expressions that calcuate the mean reaction times (RT) for the different cue/flanker conditions
/meanRT_correctNoCue -----
/meanRT_correctInCongruent 

Expressions that use above expressions and calculate the 3 attentional network effects (Fan et al, 2002, p.342/343)
/AlertingEffect = expressions.meanrt_correctnocue - expressions.meanrt_correctdoublecue => Effect of achieving and maintaining alertness
/OrientingEffect = expressions.meanrt_correctcentercue - expressions.meanrt_correctspatialcue => Effect of orienting attention towards a specific location of information
/ConflictEffect = expressions.meanrt_correctincongruent - expressions.meanrt_correctcongruent => Effect of resolving conflict between several possible responses




EXPERIMENTAL SET-UP
4 cue conditions (no cue, center cue, double cue, spatial cue) x 3 flanker conditions (neutral, congruent, incongruent)
within-subjects design

A) 1 Block of 24 Practice trial sequences with full feedback, including summary feedback of speed and accuracy
B) 3 Blocks of 96 trial sequences each - no feedback
	EXPERIMENTAL BLOCKS:
	96 trial sequences: 2 (repetitions) x 4 (cue conditions) x 3 (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) -> cue (100ms) -> fixation (400ms) -> target (1700ms)-> intertrialinterval (depends: complete trialduration = 4s)

STIMULI
A) Type of Stimuli: This script uses a simple black dot as the cue as opposed to a * (see Fan et al (2002))

B) 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

INSTRUCTIONS
Note: Instructions are modelled after the instructions generously made available on:
http://www.sacklerinstitute.org/cornell/assays_and_tools/
Instructions can be edited under section EDITABLE INSTRUCTIONS

EDITABLE CODE:
check under EDITABLE CODE 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%)
/fontsize_cue:							regulates the size of the cues, in canvas height percentage (default: 5%)
/fontsize_target:						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:
/completetrial_duration:				sets the complete duration of one trial sequence (default: 4000ms)
/cue_duration:							sets the duration of the cue presentation (default: 100ms)
/fixation2_duration:					sets the duration of the fixation cross after cue presentation (default: 400ms)
/target_duration:						sets the maximal duration of the target/flanker presentation (default: 1700ms)
/practicefeedback_duration:				sets the duration of the feedback trial during practice (default: 750ms)

Response Keys:
/responsekey_left:						scancode for the left response key (default: "E", 18)
/responsekey_right:						scancode for the right response key (default: "I", 23)


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