SR Research
Fast, Accurate, Reliable Eye Tracking

Gaze Contingent and Gaze Control Paradigms

Gaze Contingent paradigms push technological limits, and SR Research has long been recognized as the world leader in enabling this important technique with a 2000 Hz sampling rate first introduced over a decade ago in 2006!

With low variability and fast end-to-end delays, EyeLink systems have been at the forefront of this technique. Every new EyeLink Portable Duo and the EyeLink 1000 Plus include the ability to sample binocularly at up to 2000 Hz.

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.

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 Display PC. From the table, at 2000 Hz there is a mean delay of 1.34 msec per sample with standard deviation under 0.20 msec.

EyeLink 1000 Plus and Portable Duo
End-to-End Delay and Variability with Filtering Off

  EyeLink 1000 Plus EyeLink Portable Duo
  Mean (msec) 1 SD (msec) Mean (msec) 1 SD (msec)
Head Stabilized
     2000 Hz Monocular
1.34 0.20 1.34 0.18
     2000 Hz Binocular
1.37 0.19 1.38 0.17
     1000 Hz Monocular
1.97 0.39 1.88 0.36
     1000 Hz Binocular
2.28 0.40 2.32 0.36
Remote Head Free-to-Move
     1000 Hz Monocular
2.19 0.30 2.10 0.37
     1000 Hz Binocular
2.42 0.32 2.34 0.38
      500 Hz Monocular
3.29 0.58 3.21 0.61
      500 Hz Binocular
3.60 0.59 3.60 0.64

Common Gaze Contingent research using the EyeLink includes Boundary Crossing, Moving Window, Gaze Control and Saccade Contingent paradigms.

Suggested EyeLink Hardware

  1. EyeLink 1000 Plus Core System (ELP-STD-CORE or ELP-LAP-CORE)
    The Core System is the heart of the EyeLink 1000 Plus system's extendible modular design. The core system includes the standard EyeLink 1000 Plus High-speed Camera, a Host Computer with Monitor, the EyeLink Software Development Kit, 24 month hardware warranty and perpetual technical support.
  2. EyeLink 1000 Plus Desktop Mount (ELP-DESK-89)
    When used with a chin or forehead rest, the EyeLink 1000 Plus Desktop Mount enables high temporal and spatial resolution monocular and binocular recording. By adding the Remote Camera Upgrade (ELP-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 (ELP-2K-UP)
    Upgrading the EyeLink 1000 Plus 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 (ELP-TWR)
    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.