Oculomotor challenges in macular degeneration impact motion extrapolation

Area of Science:

• Ophthalmology
• Neuroscience
• Perception

Background:

• Macular degeneration (MD) significantly impacts central vision, affecting visual acuity and oculomotor control.
• Understanding motion perception deficits in MD is crucial for developing visual aids and rehabilitation strategies.

Purpose of the Study:

• To investigate how scotoma-related factors influence motion extrapolation in individuals with Macular Degeneration (MD).
• To differentiate the effects of target occlusion, position uncertainty, and oculomotor noise on motion estimation in MD.

Main Methods:

• A motion extrapolation task (perceptual baseball task) was used to assess judgments of a moving target's trajectory.
• Participants with MD and controls with simulated scotomata performed fixation and smooth pursuit tasks.
• Eccentric viewing using preferred retinal loci (PRL) for MD patients and foveal fixation for controls was employed.

Main Results:

• Simulated scotomata impaired motion extrapolation accuracy in controls, confirming the impact of target occlusion.
• MD participants with eccentric PRLs showed poorer motion extrapolation compared to controls with matched scotomata.
• Occlusion and target eccentricity significantly degraded motion extrapolation during pursuit in MD.

Conclusions:

• Scotoma-induced occlusion and the use of eccentric viewing significantly challenge motion extrapolation in Macular Degeneration.
• These findings highlight the complex visual processing difficulties faced by individuals with MD, impacting their ability to track moving objects.