Detection, eye-hand coordination and virtual mobility performance in simulated vision for a cortical visual...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Ophthalmology

Background:

• Cortical prosthesis development aims to restore vision for individuals with blindness.
• Previous studies demonstrated adaptation to phosphene maps, but used artificial patterns (square/hexagonal).
• This research simulates expected phosphene patterns from intracortical electrode arrays for realistic visual prosthesis assessment.

Purpose of the Study:

• To evaluate visual performance and adaptation to a realistic, gaze-locked dotted phosphene image in normally sighted and low-vision subjects.
• To assess the impact of varying phosphene dot density (electrode dropout) on task performance.

Main Methods:

• Subjects performed visual inspection, eye-hand coordination, and way-finding tasks using a head-mounted system projecting gaze-locked dotted phosphene images.
• Image resolution was varied by simulating electrode dropout (0%, 25%, 50% of 650 dots).
• Performance was measured by task completion accuracy and time.

Main Results:

• All subjects demonstrated learning and improved performance across tasks with practice, even under a 50% dot dropout condition (325 dots).
• Adaptation to the dotted phosphene visual input was successful, indicating potential for functional vision restoration.
• Task performance improved despite significant reduction in visual information density.

Conclusions:

• Individuals may adapt to and utilize low-resolution dotted images generated by cortical prostheses for functional tasks.
• Successful adaptation suggests that cortical visual prostheses could provide meaningful visual capabilities to blind individuals.
• Practice and learning are key factors in adapting to prosthetic vision, even with limited resolution.