Why Neuralink’s Blindsight and brain implants to restore sight won't work like human eyesight

🌈 Abstract

The article discusses the limitations of Elon Musk's claims about Neuralink's "Blindsight" cortical implant to restore vision, and the challenges in accurately reproducing natural vision through cortical stimulation.

🙋 Q&A

[01] Limitations of Cortical Implants for Vision Restoration

1. What are the key limitations of using cortical implants to restore vision?

• Neurons in the visual cortex do not represent tiny dots or pixels like a screen, but have specific receptive fields that determine what visual stimuli can activate them.
• Electrically stimulating a single neuron only produces a blob of light, not a clear pixel.
• To accurately reproduce natural vision, the implant would need to replicate the complex pattern of neuronal responses, which requires knowing the precise location, orientation, and size of each neuron's receptive field - a feat that has not yet been achieved.
• Even reproducing the visual experience of a single star would require thousands of electrodes and precise knowledge of each neuron's receptive field properties.

2. What does the computational model developed by the authors suggest about the quality of vision from cortical implants?

• The model shows that even with a very high-resolution cortical implant of 45,000 electrodes, the resulting visual experience would be blurry and lack many details of the original scene.
• This is because the blob-like stimulation of individual neurons cannot accurately recreate the complex neural patterns underlying natural vision.

[02] Challenges in Developing Effective Cortical Implants

1. What are the key challenges in developing effective cortical implants for vision restoration?

• Determining the receptive field properties (location, orientation, size) of each individual neuron in a patient's visual cortex, which is necessary to accurately reproduce natural vision.
• Replicating the complex pattern of neuronal responses that occurs in natural vision, which goes beyond just having a high number of electrodes.
• The human brain's complexity often defeats companies trying to develop these technologies, leaving patients with failed or orphaned devices.

2. What recommendations do the authors make for regulating cortical implant development?

• The FDA could mandate that companies developing cortical implants have failure plans to minimize harm to patients, such as requiring technology escrow agreements and insurance to ensure continued care if the company goes bankrupt.
• This would help protect patients from being left stranded with failed technologies implanted in their brains.