Drift Correction - SR Research EyeLink 1000 Installation Manual

from within the scanner room if a fiber optic response device is available. Please see the
Experiment Builder online help for the "Camera Setup" action, paying particular attention to
"Customized Calibration Positions" and mention of "External Control".
7.10.1.2 Simple Horizontal or Vertical Scaling of Target Positions
A quick and easy to implement approach for simply scaling the horizontal or vertical extent of
the calibration area is to use the calibration_area_proportion, and
validation_area_proportion commands to set the proportion of the X and Y display area to
use during calibration and validation. This can help when less than the entire display is
viewable by subjects and is much quicker than redefining all of the calibration positions as it
will scale the existing positions. Hence this approach is particularly useful when first trying to
calibrate the eye tracker in a non-standard setting.
By changing these simple commands' X and Y values one can easily shrink the dispersion of
the points in the horizontal or vertical dimension respectively. The commands as used below
shrink to 88% of the X dimension of the display and 53% of the Y dimension of the display.
Simply include these lines in your EYELINK:\ELCL\EXE\FINAL.INI or send them over the link
as EyeLink commands from Experiment Builder or your favorite programming method. Note
that default values for this command are 0.88 for X and 0.83 for Y.
calibration_area_proportion 0.88 0.53
validation_area_proportion 0.88 0.53
7.10.2

Drift Correction

The standard configuration of the EyeLink 1000 for behavioral laboratory use comes with Drift
Correction disabled. When the EyeLink 1000 is used with the Long Range mount, small
changes in pupil size or head position can translate to larger absolute inaccuracies given the
larger eye-to-camera distances typically used. For this reason enabling drift correction may be
desirable with the Long Range mount.
The EyeLink 1000 User Manual gives detailed information about enabling Drift Correction in
several ways. Of particular interest for MEG.MRI users is online drift correction, whereby drift
correction can be undertaken while recording is underway.
Please consult Section 3.11 of the User Manual for Drift Correction options.
Long Range Mount Installation
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