User manual

If automatic sequencing has been enabled, targets will be presented and

fixations collected without further intervention. Each time a new target is

displayed, the subject quickly makes a saccade to it. The EyeLink 1000 system

detects these saccades and the fixation following, producing an automated

sequencing system.

NOTE: Sequencing may halt if the setup of the eye causes pupil loss or noise at

the target position. If this happens, adjust the threshold and restart the

calibration by pressing the ‘ESC’ key. Press it twice (once to restart and again to

exit) to return to the Setup menu.

Even though the calibration is automatic, watch the Host PC’s display carefully.

Note the position of the cross-shaped pupil position markers: these should form

a grid shape for the 9-point calibration. Lapses of subject attention will be

clearly visible in the movements of this cursor. Also visible will be any

difficulties the subject has in fixating targets, and most camera setup problems.

The following figure illustrates a good calibration (left panel) and a poor

calibration (right panel).

Good Calibration

Poor Calibration

Figure 3-19. Calibration Grid

For some subjects (especially those with neurological conditions) short fixations

or lapses of attention can make the automated procedure unusable. A manual

calibration mode can be used for these subjects, where the ↵ (ENTER) key must

be pressed to collect each fixation. Pressing the ‘M’ key switches automatic

calibration off. It may be switched back on by pressing the ‘A’ key.

In addition, the “Backspace” key may be used in the middle of a calibration

sequencing to backtrack the calibration sequence. With each press of this key,

the data collected for the last point in the calibration sequence is erased and

new calibration data can then be collected. This can be used to improve

calibration accuracy for one or few selected points without having to restart the

calibration procedure. This is especially helpful for those subjects whose

calibration data is hard to get.

An EyeLink 1000 Tutorial: Running an Experiment