OpenIrisDPI: An open-source digital dual Purkinje image eye tracker for visual neuroscience

Area of Science:

• Neuroscience
• Vision Science
• Psychology

Background:

• Video-based eye trackers are crucial in vision science, psychology, and neurophysiology.
• Traditional pupil center and corneal reflection (P-CR) methods often lack the precision required for demanding applications.
• Existing P-CR systems can be costly and imprecise for critical research.

Purpose of the Study:

• Introduce OpenIrisDPI, an open-source plugin for high-precision dual Purkinje image (DPI) eye tracking.
• Enable simultaneous pupillography alongside DPI tracking for direct signal comparison.
• Provide a more accessible and accurate eye-tracking solution for research.

Main Methods:

• Developed OpenIrisDPI as an open-source plugin for the OpenIris framework.
• Implemented dual Purkinje image (DPI) tracking.
• Enabled simultaneous pupillography and DPI tracking for comparative analysis.

Main Results:

• The P-CR method was found to overestimate fixational drift compared to DPI tracking in macaque monkeys.
• DPI signal accuracy was validated using high-density extracellular recordings in the lateral geniculate nucleus.
• Using DPI signals for compensation resulted in sharper neuronal receptive field estimates than P-CR signals.

Conclusions:

• OpenIrisDPI provides the research community with accessible, high-precision eye tracking.
• The system is particularly suitable for visual neuroscience applications requiring precise retinal image data.
• OpenIrisDPI is the first eye tracker to combine pupillography and DPI tracking.