CRSD-ANT

Background

The Attention Network Test (ANT) was developed by Jin Fan and Michael Posner. More information about it can be obtained from Fan's website.

In 2009, we published an article introducing the ANT to researchers and clinicians with an interest in driving. At that time, we were using the Java version of the ANT, downloaded free of charge from Fan's website. But it takes approximately 20 minutes to complete, which is too long for our purposes. Therefore, we developed a shorter version of the ANT, called the CRSD-ANT. It was programmed by Luke Docksteader and Kris Scott, and takes about 10 minutes to complete. We are currently working on an article that reports very strong correlations between measures from the CRSD-ANT and Fan & Posner's Java ANT. Anyone interested in trying the CRSD-ANT can download it (free of charge) below.

License

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California 94105, USA.

Any original or modified version of this software must attribute the original work to the following (original) authors, and include a hyperlink (or at very least a URL reference) to their respective Web sites:

• Luke Docksteader - http://docksteaderluke.com
• Kris Scott - http://krssctt.com

Installation

Download the source files

Click on the "Zip" link in the sidebar above or simply click here.

Extract the archive

Extract the archive using the zip utility of your choice. Once the archive has been extracted a new folder named "CRSD-ANT" should now exist.

Running the CRSD-ANT software

Inside of the newly created "CRSD-ANT" folder there should be a file named "index.html". Open this file with the Firefox Web browser and follow the on-screen instructions.

You can use a URL query to pre-populate some of the fields (ID, Session Number, Study ID, Group ID, and Age). This is done in the following format, where 'x' indicates a value:

index.html?ID=x&sessionNumber=x&studyID=x&groupID=x&age=x

The index.html page will extract the values if they are present and pre-populate the main.html page with those values, marking the text boxes as read-only. If one or more values are not present in the URL query, then the text boxes will will not be pre-populated and will be editable.

URL Query	Element Name
ID	ID
sessionID	Session #
studyID	Study ID
groupID	Group ID
age	Age

Important Note: The CRSD-ANT program will run in any browser, but timing accuracy is not guaranteed in all browsers, and importantly, it is known to be faulty in Internet Explorer. If you do not have Firefox, you can download it here.

Changing Keys to Press

Under default operation, the left and right arrow keys are used. If you wish to change these (for example, changing them to E and I) you will need to do the following.

1. open trial.js
2. under the stage4Interrupted function, locate and change the following key values:

• Left key:

if (e.keyCode == 37) {

• Right key:

if (e.keyCode == 39) {

• Change these values to the desired key values.

3. Either update the main.html page instructions to reflect these changes, or advise the participant of the change in keys.

Adding new stimulus images

1. Find image with an aspect ratio of 1:1, preferably 100x100 pixels. Images must be of type .png to allow for transparency.
2. Create a second version of the image facing the opposite direction.
3. Place both images in the images/targets folder and rename them to "NAMELeft.png" and "NAMERight.png". For example: a horse picture would become "HorseLeft.png" and "HorseRight.png".
4. Add a reference to the image file on line 1 of the config/targetTypes.js file:

var stimList = ["Arrow", "Truck", "Hand", "Airplane", "Car", "Horse"];

Modifying the number of test blocks

1. Open js/navigation.js in the text editor of your choice.
2. Near the top of the file, change the following line, replacing "4" with the desired number of blocks:

var numberOfTestBlocks = 4;

Data files

Description of Data Files Saved by the CRSD-ANT.

Table 1: Variables in the summary data file.

Variable Name	Description	Source
uniqueID	Alphanumeric string (with no spaces)	Entered by user
studynum	Alphanumeric string (with no spaces)	Entered by user
ANTversion	Numeric version code	Entered by user
TargFile	Name of graphics file for target stimulus	User selects file at startup
ANTdate	Date of data collection	Read from system
ANTtime	Time of day	Read from system
SessionDur	Length of session in seconds (start of practice -> end of last test block)	Computed
Session	Session number	Entered by user
Age	Age of participant (years)	Entered by user
Sex	Sex of participant (M or F)	Entered by user (checkbox?)
Group	Alphanumeric group code	Entered by user
ANT.N	Total number of trials (excluding practice)	Computed
med.all	Median RT for all test block trials[1]	Computed
mean.all	Mean RT for all test block trials	Computed
sd.all	Standard deviation of all RT for all test block trials	Computed
min.all	Minimum RT for all test block trials	Computed
max.all	Maximum RT for all test block trials	Computed
alert	NOCUE – DOUBLE	Computed
orient	CENTRE – SPATIAL	Computed
conflict	INCONG – CONG	Computed
pc.all	Percent correct over all test trials[2]	Computed
e.all	Percent errors over all test trials	Computed
nocue	Mean(med.C1T1, med.C1T2)	Computed
double	Mean(med.C2T1, med.C2T2)	Computed
centre	Mean(med.C3T1, med.C3T2)	Computed
spatial	Mean(med.C3T1, med.C3T2)	Computed
cong	Mean(med.C1T1, med.C2T1, med.C3T1, med.C4T1)	Computed
incong	Mean(med.C1T2, med.C2T2, med.C3T2, med.C4T2)	Computed
med.C1T1	Median RT: No Cue × Congruent	Computed
med.C1T2	Median RT: No Cue × Incongruent	Computed
med.C2T1	Median RT: Centre Cue × Congruent	Computed
med.C2T2	Median RT: Centre Cue × Incongruent	Computed
med.C3T1	Median RT: Double Cue × Congruent	Computed
med.C3T2	Median RT: Double Cue × Incongruent	Computed
med.C4T1	Median RT: Spatial Cue × Congruent	Computed
med.C4T2	Median RT: Spatial Cue × Incongruent	Computed
mean.C1T1	Mean RT: No Cue × Congruent	Computed
mean.C1T2	Mean RT: No Cue × Incongruent	Computed
mean.C2T1	Mean RT: Centre Cue × Congruent	Computed
mean.C2T2	Mean RT: Centre Cue × Incongruent	Computed
mean.C3T1	Mean RT: Double Cue × Congruent	Computed
mean.C3T2	Mean RT: Double Cue × Incongruent	Computed
mean.C4T1	Mean RT: Spatial Cue × Congruent	Computed
mean.C4T2	Mean RT: Spatial Cue × Incongruent	Computed
e.nocue	% Errors : All No Cue trials	Computed
e.double	% Errors : All Double Cue trials	Computed
e.centre	% Errors : All Centre Cue trials	Computed
e.spatial	% Errors : All Spatial Cue trials	Computed
e.incong	% Errors: All Incongruent trials	Computed
e.cong	% Errors: All Congruent trials	Computed
pc.C1T1	% Errors: No Cue × Congruent	Computed
pc.C1T2	% Errors: No Cue × Incongruent	Computed
pc.C2T1	% Errors: Centre Cue × Congruent	Computed
pc.C2T2	% Errors: Centre Cue × Incongruent	Computed
pc.C3T1	% Errors: Double Cue × Congruent	Computed
pc.C3T2	% Errors: Double Cue × Incongruent	Computed
pc.C4T1	% Errors: Spatial Cue × Congruent	Computed
pc.C4T2	% Errors: Spatial Cue × Incongruent	Computed

[1] Note: For all summary statistics that are computed based on response times, only correct responses with RTs between 100 and 1500 ms are used. RT < 100 ms is considered anticipatory, and so is excluded; and the maximum display duration for the target is 1500 ms, so that is also the maximum possible RT.

[2] A trial is considered correct if the subject correctly indicated the direction of the target arrow, and if the RT was within the range 100 to 1500 ms.

Table 2: Variables in the raw data file.

Variable Name	Description	Source
uniqueID	Alphanumeric string (with no spaces)	Entered by user
StudyNum	Alphanumeric string (with no spaces)	Entered by user
age	Age of participant (years)	Entered by user
sex	Sex of participant (M or F)	Entered by user (checkbox?)
group	Alphanumeric group code	Entered by user
Date	Date of data collection	Read from system
block	Block number (0=practice; 1 & 2 for test blocks)
trial	Trial number
CueType	Numeric (1 = No Cue; 2 = Centre Cue; 3 = Double Cue; 4 = Spatial Cue)
TargLoc	String (UP or DOWN)
TargDirection	String: L or R
Congruency	String: Congruent or Incongruent
TrialStartTime	Time at start of trial
targetOnTime	Time at target onset
firstFix	Duration of first fixation (panel 1 in Fig 1)
Response	Subject’s response (L, R, or None)
Correct	1=correct, 0 = incorrect[3]
RT	Response time to nearest millisecond
LowRT	Set to 1 if RT < 100 ms, 0 otherwise

[3] Set variable CORRECT to 1 if the subject’s response matches the correct response, and if the RT is in the range 100 to 1500 ms. Otherwise, CORRECT = 0.