Pupillometry indexes ocular dominance plasticity

Area of Science:

• Neuroscience
• Vision Science
• Perceptual Psychology

Background:

• Short-term monocular deprivation (MD) in humans causes a temporary shift in ocular dominance, favoring the deprived eye.
• Previous studies documented this effect using perceptual tests or physiological recordings, but not concurrently.

Purpose of the Study:

• To introduce an objective physiological index of ocular dominance plasticity using pupillometry.
• To concurrently measure physiological responses and perceptual effects of MD using an integrated binocular rivalry paradigm.

Main Methods:

• Combined binocular rivalry with pupillometry in 10 participants.
• Measured pupil diameter and perceptual rivalry dynamics before and after 2 hours of MD via a translucent patch.
• Compared rivalry dynamics and pupil size changes pre- and post-deprivation.

Main Results:

• Monocular deprivation boosted the deprived eye's signal, increasing ocular dominance, consistent with prior research.
• Pupil size modulations tracked rivalry alternations and increased in amplitude after MD.
• Increased pupil modulation amplitude correlates with the post-deprivation boost in ocular dominance.

Conclusions:

• MD impacts the effective strength of monocular visual stimuli, affecting both perception and unconscious pupil regulation.
• The combined binocular rivalry and pupillometry paradigm offers new insights into deprivation-induced plasticity mechanisms.
• Pupillometry serves as a viable physiological index for ocular dominance plasticity.