SR Research
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Gaze Contingent and Gaze Control Paradigms

In Gaze Contingent paradigms a stimulus change is delivered based on eye movement behaviour. For instance, as soon as a saccade is launched, while the input to the retina and brain is awash with a smear of signals, the objective stimulus can be changed and the resulting effect on behaviour studied.

Gaze Contingent paradigms push technological limits, and SR Research has long been recognized as the world leader in enabling this important technique. EyeLink 1000 eye trackers have the highest sampling rate, the fastest access to eye sample data, and most importantly, the lowest variability in sample data of any eye tracking system in the world.

End-to-End Delay is the time between an actual eye position change until the signal arrives at the computer that will update the stimulus. The table below shows the mean, median and standard deviation (in milliseconds) from the time an artificial eye rapidly changed position until the position change was registered on a Windows XP Display PC. From the table, at 2000 Hz there is a mean delay of 1.35 msec per sample with standard deviation under 0.36 msec.

EyeLink 1000 End-to-End Delay and Variability in Milliseconds

Hz No Filter 1 Sample Filter Active 2 Sample Filter Active
mean
delay		 median
delay		 1 SD mean
delay		 median
delay		 1SD mean
delay		 median
delay		 1SD
2000 1.35 1.38 0.36 1.79 1.76 0.58 2.40 2.35 1.52
1000 1.77 1.79 0.60 2.80 2.79 1.18 3.88 3.78 1.67
500 2.79 2.79 1.13 4.87 4.79 2.32 6.94 6.81 2.45

Common Gaze Contingent research using the EyeLink includes Boundary Crossing, Moving Window, Gaze Control and Saccade Contingent paradigms.
Click here for a list of over 70 peer-reviewed publications involving Gaze Contingent and Gaze Controlled Paradigms using EyeLink hardware and software.

Suggested EyeLink Hardware

  1. EyeLink 1000 Core System (ELM-CORE)
    The Core System is the heart of the EyeLink 1000 system's extendible modular design. The core system includes the standard EyeLink 1000 High-speed Camera, a Host Computer with Monitor, the EyeLink Software Development Kit, 24 month hardware warranty and perpetual technical support.
  2. EyeLink 1000 Desktop Mount (ELM-DESK-89)
    When used with a chin or forehead rest, the EyeLink 1000 Desktop Mount enables high temporal and spatial resolution monocular and binocular recording. By adding the Remote Camera Upgrade (ELM-RMT-UP), the mount can also be used to achieve 500 Hz monocular Remote recording without head stabilization.
  3. SR Research Head Support (SR-HDR)
    This is a sturdy, yet comfortable, chin and / or forehead rest that clamps to a table top for ultimate stability. Great care was taken to design the head support so that there is no interference with the users knees or legs.
  4. 2000 Hz Camera Upgrade (ELM-2K-UP)
    Upgrading the EyeLink 1000 camera to 2000 Hz provides the world's fastest sample rate and access time. This upgrade also enables 1000 Hz recording of each eye when recording binocularly.
  5. SR Research Experiment Builder and Data Viewer Software Bundle (EL-DVEB)
    Experiment Builder and Data Viewer enable easy implementation of most experimental paradigms and provide simple access to the features of the EyeLink eye tracker.

Other Common Options

  1. Tower Mount (ELM-TWR-91)
    The Tower Mount provides a large monocular eye tracking range and is useful for tasks that require the participant to use their hands to touch the display screen. This mount includes the SR Research Head Support.
  2. EyeLink Installation and Training (EL-INS)
    Get your EyeLink experience off to a great start with an expert introduction to the system and software, tailored to your particular research interests. This service includes travel expenses, one-half day installation and one day of training.
For a personalized consultation or quotation, including special solution bundle pricing,
please contact us.