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Sequence of visual cortex stimulation affects phosphene brightness in blind subjects
Michelle Armenta Salas1, Joseph Bell1, Soroush Niketeghad1
1Department of Neurosurgery, University of California Los Angeles, USA.
Brain Stimulation
|April 4, 2022
Summary
Sequential stimulation of visual cortex in blind subjects using visual cortical prostheses (VCP) can alter phosphene brightness perception. This suggests temporal interactions influence visual perception, a key finding for VCP development.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Ophthalmology
Background:
- Visual cortical prostheses (VCP) offer potential vision restoration for the blind.
- Feasibility testing of VCPs allows for novel characterization of visual cortex stimulation.
Purpose of the Study:
- To investigate if sequential electrode stimulation in the visual cortex creates a bias in perceived phosphene brightness.
- To understand temporal interactions in visual perception during VCP use.
Main Methods:
- Three blind subjects with Orion VCPs were stimulated using sequences of two and three electrodes.
- Interval forced-choice paradigms assessed perceived phosphene brightness.
- Stimulation parameters, including amplitude, were systematically varied.
Main Results:
- Two subjects showed a significant bias, perceiving later stimuli as brighter (p < 0.001).
- This effect was consistent across electrode locations and amplitudes within subjects.
- The third subject exhibited non-significant trends in the opposite direction.
Conclusions:
- Temporal interactions significantly influence phosphene brightness perception in VCP users.
- These interactions are subject-specific but consistent across stimulation parameters.
- Findings are crucial for optimizing VCP stimulation strategies for more naturalistic vision.
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