Neurosurgeon Answers Brain-Computer Interface Questions

I'm Ben Rapoport.

I'm an electrical engineer and neurosurgeon.

And I'm here today to answer your questions

from the internet.

This is Brain-Computer Interface Support.

[upbeat music]

WinnieCherian asks,

How does brain-computer interface technology work?

Brain-computer interface technology uses the fact

that the brain communicates with itself

and with the outside world using electrical signals.

And so brain-computer interfaces are implants

that use tiny little electrodes that touch the brain

and transform the electrical signals from the brain

into ways of interacting with computers

and external devices.

That translation of electrical signals

into useful means of communication with the outside world

takes place using machine learning algorithms

that transform the digitized bitstreams

from brain electrical data

into means of communication with computers, smart devices,

and in some cases, robotics.

Inskigator asks, Could somebody, anybody,

explain to me why a human being would even want

a brain-computer interface implanted in him/her?

I only ask 'cause it's happened.

Well, I think it's important to understand

that one of the early uses

of brain-computer interface technology

is especially for people with disorders of the brain

and nervous system,

and I'm talking about people

with spinal cord injury, stroke,

and some forms of neurodegenerative disease such as ALS,

conditions that paralyze people

and leave people with totally functioning mind,

unable to interact with the world

in the ways that many of us take for granted.

The first generation of brain-computer interface technology

is really geared towards enabling people

with those kinds of conditions

to interact with other people, with the outside world,

return to work and have a sense of dignity, independence

that many of us take for granted.

Guavault asks, Can you move a cursor in your mind

or draw using a cursor?

That's how BCIs for blind people work right now.

Everything needs to be drawn, AKA sequential,

instead of all at once.

Let me try to unpack this question.

How do you move a cursor with your mind?

Or how do people with brain-computer interfaces

learn to move a cursor using their mind?

For each person who's had this experience,

it's a little bit different.

At the beginning, we usually provide an instruction,

think about moving a joystick

or think about moving your hand

or think about moving your arm.

At first it's very laborious

and eventually the brain just connects to the cursor.

Like you learn to use a tool, a pencil, a baseball bat,

or riding a bicycle,

so that the brain-computer interface

is a tool like any other.

And we're still really learning what that experience is like

and how the brain accomplishes it.

But that is the subjective experience

that people who've used this technology explain,

that it sort of clicks at some point

and it starts to feel like magic.

You know, when we interact with the real world,

we don't realize it, but there's actually a delay

between what our brain thinks and tells the body to do

and when the body does it.

I.n a brain-computer interface

where the interaction takes place

directly between the brain and electrode,

we can bring that latency down to individual milliseconds.

That's why people feel like the experience

is almost like the interface is predicting their thought.

There's another question that's packed in here.

Can brain-computer interfaces

manifest a fully formed thought?

That gets to the question

of how we subjectively feel like we're thinking.

Very often we imagine something or we have a feeling

or a picture or a concept in our brains,

and we don't right now have a way of expressing

that fully formed thought

other than through drawing a picture

or speaking in paragraph form.

But we do have this subjective sense

that thoughts exist in a fully formed way.

And there's this question that I think Guavault is asking,

which is, will brain-computer interfaces allow us

to transmit thoughts in that fully formed way?

I have a feeling that the technology will allow us

to travel in that direction

probably even faster than we can imagine,

even if we can't say exactly how right now.

Pesh909x asks, Will BCIs ever be able

to record our dreams and psychedelic trips to video?

And the answer is yes.

Brain-computer interfaces already

can see activity in the visual cortex,

which is the part of the brain

that processes visual information.

And there has been some work showing that actually

some of that information can be decoded

to recreate the visual scene.

There is some evidence that that kind of visual replay

happens during our dreams,

and so it may be possible in the future

just as some of these studies have begun to show

that brain-computer interfaces can record, replay,

process the information that occurs

during imagined visual activity and dreams.

Stephen_Roto asks, The first human patient

with a brain-computer implant

used the technology to successfully play Mario Kart?

If that isn't the definition of a '90s kid,

I don't know what is.

It is true that the first Neuralink patient

used his implant to play Mario Kart

and seems to have had a great time doing it.

That wasn't the first human patient

with a brain-computer implant,

but he did use it to play Mario Kart.

And I think that points to the fact

that people are gonna use brain-computer interfaces

to do all the sorts of things that we take for granted

and know and love can be done in the digital world.

Fashion Savage asks, Will BCI lead to security issues

of hacking or reprogramming people's brains?

This is a really important question.

It's one that many people have asked,

which is, given the sensitivity of neural information,

will BCI technology lead to issues involving hacking

or compromising the security of people's private thoughts?

Certainly in the first generation

of brain-computer interfaces,

we're really interacting

with the parts of the conscious brain

that move the body and move the hands, move the arms,

move the face and the muscles that control speech.

And these are not really areas of the brain

that we consider private thought activity,

and furthermore, patients, when you ask them,

would you be concerned about a privacy issue,

in this context, many of the people

who stand to benefit from this technology

would trade a little bit of privacy

for the ability to interact smoothly with the outside world,

but that doesn't minimize the possibility

of real security and privacy issues

when neural data is being transmitted wirelessly

outside of the body.

So we and others involved in the industry

have taken real care to try to encrypt

and secure any neural data streams that leave the body.

RealEditor6 asks, I was wondering

if ever a human brain merged with an LLM

via a brain-computer interface,

what would the AI experience?

What would that person experience?

Is anyone connected already?

The answer is a qualified yes

because people with brain-computer interfaces

now certainly have the ability

using the same means that we do

of textually querying an LLM.

And so that interaction is definitely happening.

I haven't asked the AI what the AI's experience is,

but certainly we can do that.

I look forward to that question.

What would that person experience

I think is actually very similar

in the current form of the technology

to what you and I experience when we query the AI.

Those interactions right now are textual in nature.

The AI's output is not fed back

directly into the user's brain just yet.

So the BCI users have an experience

that's similar to what every other user of an LLM has.

But I get the question is asking towards a future state

in which there's a more symbiotic meld

between artificial intelligence and humans

through brain-computer interfaces.

And I think this is the direction of travel,

and it's hard to predict exactly what it's gonna look like.

James Rosen-Birch asks,

What part of the brain is the BCI interfacing with?

Many brain-computer interfaces to date

spend a lot of time in and around the motor cortex,

which is this area of the brain.

This is the hand motor area, this is the leg motor area,

this is the face motor area involved in speech.

Those motor areas are really important

for current-generation brain-computer interfaces

because they perform the computations in the brain

that allow us to interact with the world physically.

When we think about things like typing or moving our hands

or walking or speaking,

those are the parts of the brain

that serve those functions most directly.

But there certainly are future directions

of brain-computer interface technology.

We can think about connecting to

and interfacing with other areas of the brain

and other areas of the nervous system,

so areas that control sensation, decision-making, memory,

even parts of the brain stem and spinal cord

that are involved in other types of neurological disease.

Our friends at g.tec medical engineering,

How many electrodes are needed

to run the brain-computer interface?

The answer to that is in the hundreds or thousands,

and that just gets us off the ground.

I think it's hard to say

what the upper limit is to functionality.

So many of us are familiar in the world of communication

that basically the higher the speed of your connection,

the more sophisticated the applications you can run,

or in the world of images,

the more pixels or megapixels you have in your display,

the higher fidelity the graphics you can render.

And the same is true in brain-computer interfaces.

The more detailed and the higher resolution

the picture of brain activity you can generate,

the more smooth and sophisticated

the real-time interaction you can have with the brain.

Right now we're seeing that brain-computer interfaces

with around a thousand electrodes get us off the ground

to incredibly high levels of functionality

that include things like controlling a cursor,

performing the sorts of tasks that we take for granted

in everyday interactions with computers,

but we can see a path towards many thousands of electrodes

and even orders of magnitude higher

in which smooth, intuitive connections between the brain

and the outside world will be even higher performance.

Ok-Hunter-8210 asks,

Considering recent developments

in brain-computer interfaces,

I'd love to hear from experts or enthusiasts

about potential applications

in assisting individuals with severe paralysis or ALS.

Have we made sufficient strides

toward leveraging BCI technology

for rehabilitation purposes?

Yes.

Severe paralysis and ALS are really the first conditions

that have received a tremendous amount of attention

for brain-computer interface technology.

There's quite a few examples of patients in clinical studies

who have had tremendous benefit from their implants

quite apart from being part of the clinical studies,

and it's exactly these individuals

with severe paralysis from spinal cord injury,

certain forms of stroke and ALS

will be among the first to benefit from the technology.

A Reddit user in the singularity thread asks,

Is there a concrete pathway

to non-invasive BCI technology?

Mostly no in the way that we think of,

but also yes to the implied question of,

is there a use for non-invasive neural interfaces?

So when I think about brain-computer interfaces,

I think about systems that are being used

to drive real-time interactions

between the brain and the outside world.

And that kind of high-bandwidth,

sophisticated, smooth, high-speed interactions

between the brain and the outside world

that really happen at the speed of thought,

that requires implanted technology.

There's no way that we know of around the need

to actually be touching the brain in some way

to get that kind of high-bandwidth, high-speed interaction.

Non-invasive techniques and technologies

have captured scientists' and neuroscientists' imagination

for a long time,

and there definitely is a use for non-invasive technologies.

They can detect brain state,

they can manipulate brain state,

and they can be used to treat certain forms of disease,

but not to manipulate at high fidelity

and high resolution in real time.

@HowardG69263 asks,

Brain-computer interfaces sound cool,

but kind of scary too.

Like, what if it malfunctions or something?

So many important technologies

have these sorts of questions attached to them,

whether it's cars or airplanes

or gene sequencing or artificial intelligence.

There's always this question of,

it's magical when it works well

and what if it doesn't work well or what if it malfunctions?

It is important,

as in the development of all kinds of technology,

to have ways of fixing things when they go wrong.

You know, Murphy's law is real.

Anything that can go wrong will happen in some way,

and so we need to try to anticipate failure modes

and plan for how to fix them.

We've developed electrodes that interact with the brain

in a way that doesn't damage the brain,

and so these electrodes can be moved, removed, replaced,

and upgraded as necessary in the future,

and other components of the system

can be modularly changed out over time.

For example, the battery or the wireless

or certain forms of tunneled connectors

that are implanted under the skin.

So understanding the way things obsolesce or change

or may need to be switched out in the future is important

to ensuring that we can safely repair a device

and plan for all eventualities.

QueenGwenevere asks,

Imagine what happens when an implant becomes obsolete,

is no longer supported,

and becomes increasingly vulnerable to hacking

the longer it remains installed,

and you can't uninstall it without surgery.

Like, imagine if you had the equivalent

of Flash implanted in your brain.

This is actually a really deep question,

and it gets to the notion that all technologies have a cycle

and you wanna be able to plan for upgrades

and plan against obsolescence.

At Precision, one of the ways

that we've thought about this question of obsolescence

and the potential need for replacement

is to develop an electrotechnology

that's based on thin films.

This is the Precision electrode array.

If I turn it on its side in this way,

you can see it's incredibly thin.

This film coats the brain's surface with electrodes

rather than penetrating the brain.

The idea is that those electrodes

could be removed or upgraded over time

and that other components of the implant

also can be removed or swapped out.

This notion that something

can't be uninstalled without surgery is an important notion,

but I would also just point out that surgery itself

is not necessarily such a huge barrier.

Actually, almost everyone over the course

of their life in the United States will have a surgery,

if not more than one surgery.

So really it's a question of making sure

that it can be done in a safe manner

rather than the concept of a surgery itself.

Dckill97 asks, Why can brain-computer interface technology

only read from the brain and not write to it?

The short answer is that brain-computer interface technology

can both read from and write to the brain.

Reading really means

recording neural activity and decoding it,

recording the electoral signals

that the brain uses to communicate

and transforming those into command and control signals

and ways of interaction with digital technology, computers,

and the outside world.

So that's really a translation problem.

The other side of the coin

is what people sometimes call writing into the brain,

and that really means stimulating the brain in some way.

In the context

of current-generation brain-computer interfaces,

that stimulation takes place

using electrical pulses, electrical stimulation.

Those kinds of stimulation have been used

to restore a sense of sensation, touch, vision,

and also to stimulate the brain in other ways.

Most of current generation

brain-computer interface technology

really is focused on the read and decode side of things.

Reading and writing or recording and stimulating

are actually quite different problems.

You can't just sort of reverse the decoding into an encoder

that writes information into the brain.

It's not that simple.

The field of genomics is one good example of this

in which the early 2000s saw an explosion

in our ability to record

or read and decode the human genome,

and it wasn't until years later really using almost

a completely different form of technology,

things like CRISPR for gene editing,

that allowed gene modification

in a scalable and programmatic way.

Ulteriorkid324 asks,

How do you get a brain chip into the brain?

Is the surgery long?

The surgery is a relatively short surgery.

General anesthesia will not always be required.

It involves making a small incision in the scalp

and an incision in the bone,

but not necessarily removing a significant amount of bone.

It will be an incision right about here.

The electrode array itself, you can see it's very thin

and it gets slipped through an incision in the bone

onto the surface of the brain.

Right now, that whole process takes about an hour or two.

In the future, it probably will be a little bit quicker.

We foresee a future in which this can be done

as a same-day surgery,

much as a lot of surgery across the country is done.

PiyushKThisSide asks, Think of a future

where thoughts and feelings can be completely shared

through a brain-computer interface,

surpassing the current limits of language.

Will such a future be better or worse?

I think we will eventually get to that future

and I think it will be a better future.

I don't exactly know how we'll get there,

and I'm sure there'll be trade-offs,

but just like many forms of technology

where you can't exactly predict what's gonna happen,

I think that's the case with brain-computer interfaces.

Olydriver asks, Is anybody using AI

to create a better brain-computer interface?

Definitely, yes.

Actually, all brain-computer interfaces today

use forms of artificial intelligence

as a core part of how the interface works.

It's important to understand that basically

the problem of translating neural data

into actions and interactions with digital technology,

that is a translation problem.

And that translation between neural code and digital code

requires artificial intelligence and machine learning.

But there's so many other applications

of how artificial intelligence is involved in BCI.

It's an extremely important and exciting area.

Chrome_Plated asks, How can I get involved

in brain-computer interfaces and neurotechnology?

There are a number of ways to get involved,

but especially if you're a talented engineer,

especially if you're a software engineer

or have experience in modern machine learning techniques,

I would invite you to apply to work

with any of the companies

that are working in the space today.

Many of them are hiring.

All right, that's it. That's all the questions.

Hope you learned something. Until next time.