Related Experiment Video
Updated: Jul 2, 2026
11:28
3D Orbital Tracking in a Modified Two-photon Microscope: An Application to the Tracking of Intracellular Vesicles
Published on: October 1, 2014
Tracking in 3-D space under natural viewing condition
H A Rambold1, T Sander, A Sprenger
1Department of Neurology, University of Lübeck, Lübeck, Germany. ramboldh@nei.nih.gov
Progress in Brain Research
|August 23, 2008
Summary
Human eye movements in 3-D space rely on the conjugate pursuit and vergence systems, not a disjunctive pursuit system. This finding clarifies how the brain processes visual information for accurate depth tracking.
Area of Science:
- Ophthalmology
- Neuroscience
- Vision Science
Background:
- Tracking small visual targets in three-dimensional (3-D) space requires coordinated eye movements.
- Two hypotheses exist: a disjunctive pursuit system using individual eye motion without disparity, or a combined conjugate pursuit and vergence system.
Purpose of the Study:
- To investigate the neural mechanisms underlying 3-D visual target tracking.
- To determine whether disparity signals are essential for accurate depth tracking.
Main Methods:
- Recorded eye movements in five healthy subjects using the scleral search-coil method.
- Presented dim laser stimuli in various horizontal and depth directions (convergence/divergence).
- Compared binocular (fusible), prism-induced unfused, and monocular viewing conditions.
Main Results:
- Tracking in depth was severely impaired under unfused and monocular conditions compared to binocular viewing.
- Horizontal tracking remained unaffected across all viewing conditions.
- These results indicate that disparity signals are crucial for depth tracking.
Conclusions:
- The findings support the hypothesis that the conjugate pursuit and vergence systems, rather than a disjunctive pursuit system, are responsible for 3-D eye movement tracking.
- Disparity information is critical for accurate eye movements in depth.
