EyeLink II User Manual version 2.12
(07/02/2006)
©
2002-2006 SR Research Ltd.
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the display visible. This also has the advantage of making the trial code more
general: almost any stimulus can be displayed given its bitmap.
C. Picture
The template “Picture” is almost identical to “Text”, except that images are
loaded from BMP or JPEG files and displayed instead of text.
D. EyeData
This template introduces the use of the link in transferring gaze-position data.
This data can be used for gaze contingent or gaze control type paradigms. Gaze
position data can be transferred in real time, or played back after recording has
ended, which helps to separate recording from analysis.
The “Eyedata” template uses link data to display a real-time gaze cursor. The
data is then played back after the trial, drawing the saccade paths and fixation
points to the screen. The bitmap for the trial is a grid of letters.
E. GCWindow
The most useful real-time experiment is a gaze-contingent display, where the
part of the display the subject is looking at is changed, or where the entire
display is modified depending on the location of gaze. These require high
sampling rates and low delay, which the EyeLink II tracker can deliver through
the link.
This template demonstrates how to use the link’s real-time gaze-position data to
display a gaze-contingent window. This is an area centered on the point of gaze
that shows a foreground image, while areas outside the window show the
background image. You supply full-screen sized bitmaps for these, which are
stored in the bmp folder. You can use different images by replacing the one
provided with the experiment with an image of your own with the same name.
F. Control
This template implements a computer interface that is controlled by the
subject’s gaze. The participant can select one of a grid of letters by fixating on
it. The template contains code to support many rectangular selection regions,
but can be simplified if gaze in a single region is all that needs to be detected.
The image for the trial is a grid of letters.
G. Dynamic
