Active vision in freely moving marmosets using head-mounted eye tracking.

Area of Science:

• Neuroscience
• Primate Vision
• Active Sensing

Background:

• Understanding primate vision during active navigation is limited due to head-restrained experimental setups.
• The impact of combined motor actions (eyes, head, posture) on visual perception in natural environments is largely unknown.

Purpose of the Study:

• To develop an innovative system for studying active vision in freely moving primates.
• To investigate how natural movements influence visual perception and gaze stability.

Main Methods:

• Developed CEREBRO (Chair-free Eye-Recording using Backpack mounted micROcontrollers), a wireless head-mounted eye-tracking system for small mammals.
• Utilized a segmentation artificial neural network for robust pupil tracking under dynamic lighting conditions.

Main Results:

• Freely-moving marmosets exhibit predictable gaze patterns, higher than head-fixed subjects.
• Gaze stabilization remains steady during locomotion due to increased Vestibulo-Ocular Reflex (VOR) gain.
• Compensatory eye movements in marmosets are comparable to other primates, including humans.

Conclusions:

• The CEREBRO system enables novel insights into primate visuo-motor control during natural behavior.
• Primates possess efficient mechanisms for maintaining stable foveal vision while actively exploring their environment.
• Active sensing and motor planning are crucial for high-resolution vision in dynamic, real-world scenarios.