The Science Behind Elon Musk’s Neuralink Brain Chip

[Narrator] Neuralink, Elon Musk's brain chip company,

recently pushed back on claims

that it violated animal welfare laws a few years ago

while testing on monkeys.

This year, the company plans to test on human subjects.

But when it does,

what would this major step mean for brain implant science?

Academics like me have conducted clinical trials

in people with brain implants.

[Narrator] Dr. Paul Nuyujukian

is a professor of bioengineering and neurosurgery.

He directs the Brain Interfacing Laboratory at Stanford.

For about 20 years now,

academic research brain implants, up until this point,

more or less have almost exclusively been with wires.

The difference that the N1 has with Neuralink,

it's fully implantable, it is battery-powered,

it is wireless.

All of this is being done over Bluetooth protocol.

[Narrator] Let's dive into the science behind Neuralink

to understand how exactly human brain chips work.

[electronic music]

The science behind how these implants work

is not that different from how

you would go about trying to measure

the energy from a AA battery.

It's the same principle that we're doing

with these brain implants.

This is called neuro electrophysiological recording.

When you move your arm to the right,

certain sets of neurons are activated in a certain pattern.

Listening in to that activity and that pattern,

you can predict very quickly

which direction the arm is going to move.

These are the neurons that are directly wired

to your muscle.

[Narrator] Unless that pathway

from the brain to the spinal cord to the muscle is damaged,

the way it is in patients with paralysis.

That pathway is damaged, then the neuro signals,

their signals from their brain,

aren't gonna get down to move the muscles.

But in many cases,

the signals are still present in the brain.

They're just not getting out.

So, if you reach in and put something that listens in

to those neurons,

then you know what's happening to the muscle

[Narrator] And that's the goal of a brain implant.

Now, let's look at a timeline

of brain interface breakthroughs over the years.

Scholars have long been interested in how the brain works.

So, it's important to view these new developments

at Neuralink as a culmination of breakthroughs

by brain machine interface researchers,

especially in the last few decades.

For example, in 2002, the first demonstration

of real-time cursor control in monkeys took place.

2008, a monkey controlling a robotic arm

in three dimensions fed itself.

2012, the first brain-controlled robotic arm by a human.

2017, a human controlled a cursor mentally

to type out words and sentences.

Dr. Nuyujukian was part of the study,

as well as the one in 2018,

where a human subject mentally controlled a tablet

to do things like browse the web, send emails,

and play games or music.

All that's been done with a couple hundred electrodes.

[Narrator] But in 2019, Neuralink, a private company,

changed the game when it unveiled a pig named Gertrude

with a wireless implant that monitored

about a thousand neurons.

The neurons are like wiring.

And you kind of need an electronic thing

to solve an electronic problem.

That was a very interesting moment

because it signaled to the community

that they're serious, they're investing,

they're building hardware from scratch,

and they're putting it in large animals.

For the pig, the electrodes were implanted

in somatosensory cortex,

allowing them to measure sensory activity,

like that of taking a step.

Every time that that particular neuron

they were listening to fired,

you would hear this little pop or click

from the audio channel.

And so, the moment I heard it, right,

it's like, oh yeah, they got neurons.

You just recognize it instantly.

You know what neurons sound like

if you've been listening to them for decades.

And that's what they were communicating, right?

They were telling the field,

We've got neurons, pay attention.

[Narrator] And overnight,

it seemed the industry took notice.

Then in April of 2021,

Neuralink released the so-called mind Pong video.

Pager was the name.

It's a rhesus macaque, which is the type of monkey

that is very commonly used in this field.

Implanted with two of the N1 devices, the Neuralink devices,

performing brain control of a cursor on a screen.

That's extremely significant because here,

Neuralink is showing their new hardware,

their new device in their hands works in a monkey.

That's the level that's necessary

to convince the scientific community,

to convince the FDA,

that you're ready to go into human clinical trials.

That's the evidence the FDA is looking for.

[Narrator] The recording power of the N1 device in Pager

was eyeopening because of the sheer number

of individual electrodes that had been implanted.

There was definitely a lot of clever engineering

that went into that,

to build a device that can transmit 2,048 electrodes-worth

of spiking information, right,

of digital ones and zeros of spikes,

over a radio wirelessly.

And when you have that many channels,

the performance that you should be able to get

should eclipse what we've been able to do

in the academic field.

The maximum number of electrodes I've ever recorded from

is 200 to 300.

[Narrator] So, with all those electrodes,

how does a device like the N1 get implanted

in a subject's brain?

Make no mistake, this is neurosurgery.

It is not a joke.

This requires cutting the skin, getting down to skull,

drilling a hole in the skull.

Exposing what's called the dura,

which is this protective layer of tissue

that surrounds the brain.

Cutting the dura, folding it back to expose the brain.

And then, you get to the surface of the brain,

where you can implant the electrodes.

The biggest risks with these types of techniques

are infection, bleeding, and tissue damage.

[Narrator] So, what would it take for the FDA to approve

clinical trials in humans?

The Neuralink device

are called Class III medical devices.

They are implantable,

and they're going into very sensitive body cavities.

That is the highest level of scrutiny

that the FDA assigns to medical devices.

They don't have a predecessor.

There's no previous example that's approved.

And so, very appropriately, they got a high bar

they have to cross in order to get it approved.

So, what Neuralink has to do next

is prepare a very long and technical document

with all of the evidence from animal studies

that their device is safe and effective.

This document is submitted to the FDA,

who has 90 days to review and give them an answer.

If the FDA says yes, then their clinical trial is approved,

and Neuralink can enroll and recruit human participants.

We are on the cusp of a complete paradigm shift.

This type of technology has the potential

to transform our treatments,

not just for stroke, and paralysis,

and degenerative disease, motor degenerative diseases,

but also for pretty much every other type of brain disease,

from Parkinson's to epilepsy, to dementias, Alzheimer's,

and even psychiatric disease.

Seeing Neuralink and the other companies in this space

start an industry around neuroengineering

brain machine interfaces, neuro prosthetics,

has been a tremendous amount of validation

for neuroscientists and engineers

who've been working in this space for decades.

How much happier could the scientific community be

than to give birth to an industry?

[Narrator] So, will this industry someday lead

to the creation of cyborg humans

with superhuman intelligence?

There's all sorts of wild speculation in our field.

I think science fiction is wonderful

at telling very creative and captivating stories

about all sorts of things,

including brain machine interfaces.

The reality is we are in such early stages of this space,

right, where we are just barely able to record

from neurons that control muscles

and try to interpret something,

glean meaningful information out of that.

We're gonna be in that space for decades.

That's where I will focus much of my career,

is understanding what's going on with these neurons,

and the circuits that they are working on.

That's where the last 15 years of my work has been.

And the coming several decades of my work

will focus in on this space

because that's gonna be the forefront of neuroscience.

The rest, I think, is fun to think about,

but I don't see how that's going to be

in the foreseeable future.

[electronic music]