
Six Paths to the Nonsurgical Future of Brain-Machine Interfaces - lgats
https://www.darpa.mil/news-events/2019-05-20
======
lgats
The Battelle team, under principal investigator Dr. Gaurav Sharma, aims to
develop a minutely invasive interface system that pairs an external
transceiver with electromagnetic nanotransducers that are nonsurgically
delivered to neurons of interest. The nanotransducers would convert electrical
signals from the neurons into magnetic signals that can be recorded and
processed by the external transceiver, and vice versa, to enable bidirectional
communication.

The Carnegie Mellon University team, under principal investigator Dr. Pulkit
Grover, aims to develop a completely noninvasive device that uses an acousto-
optical approach to record from the brain and interfering electrical fields to
write to specific neurons. The team will use ultrasound waves to guide light
into and out of the brain to detect neural activity. The team’s write approach
exploits the non-linear response of neurons to electric fields to enable
localized stimulation of specific cell types.

The Johns Hopkins University Applied Physics Laboratory team, under principal
investigator Dr. David Blodgett, aims to develop a completely noninvasive,
coherent optical system for recording from the brain. The system will directly
measure optical path-length changes in neural tissue that correlate with
neural activity.

The PARC team, under principal investigator Dr. Krishnan Thyagarajan, aims to
develop a completely noninvasive acousto-magnetic device for writing to the
brain. Their approach pairs ultrasound waves with magnetic fields to generate
localized electric currents for neuromodulation. The hybrid approach offers
the potential for localized neuromodulation deeper in the brain.

The Rice University team, under principal investigator Dr. Jacob Robinson,
aims to develop a minutely invasive, bidirectional system for recording from
and writing to the brain. For the recording function, the interface will use
diffuse optical tomography to infer neural activity by measuring light
scattering in neural tissue. To enable the write function, the team will use a
magneto-genetic approach to make neurons sensitive to magnetic fields.

The Teledyne team, under principal investigator Dr. Patrick Connolly, aims to
develop a completely noninvasive, integrated device that uses micro optically
pumped magnetometers to detect small, localized magnetic fields that correlate
with neural activity. The team will use focused ultrasound for writing to
neurons.

~~~
mrfusion
None of those sound non invasive. How do they get light through the skull?

~~~
brian_spiering
Typically, it is not wavelengths from the visual light spectrum. It is common
to use infrared. For example, high-power infrared light can penetration at
least 3 cm into the brain.

~~~
gimmeThaBeet
Uhh, I'm sure it's fine, but how high power are we talking? Just when you say
"high-power infrared light" my brain thinks "cooking an egg"

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b_tterc_p
A lot of commenters seem fearful of this tech. But I don’t see a problem is it
is strictly read only and not connected to the internet. There are ways to
make this bad, but it’s not fundamentally bad.

One thing I was surprised to learn recently was that mentally controlled
prosthetics are simply machine learning algorithms trained to interpret the
electrical signals and produce physical outcomes. In hindsight that seems
obvious but before that I had assumed something more complicated. I think a
lot of great stuff could come from this. Especially art. Either generating
things that the device observes you find enjoyable or generating music you’re
mentally composing could be awesome. Imagery could be great.

~~~
0xDEFC0DE
A malicious firmware update that commands the prosthetic to punch you in the
face on an infinite loop will still be a threat. Updates will likely be
necessary for a while as the ML stuff gets tuned, though it's not impossible
to get the other parts of the controlling software correct the first time and
make those read-only.

Also I expect the medical device manufacturers will most likely join this
market eventually and they have a less-than-stellar record of security with
their devices. Some company is going to connect it to the internet and
regulation will be too glacially slow to stop it.

~~~
b_tterc_p
That fear feels overblown to me. This isn’t some autonomous vehicle, it’s a
learned mapping of electrical signals to specific motions. I don’t see a need
for over the air firmware updates. And the model can’t generalize because
everyone’s brain works differently so you’ll need to retrain every single
time.

Perhaps I wasn’t clear but that technology already exists and is in use. It’s
much easier to do prosthetics because you can just hook it up to the nerves on
former limb stub.

~~~
whatshisface
> _I don’t see a need for over the air firmware updates._

There isn't a need, but if the same thing happens here that happened
everywhere else in the tech industry, there will be a _motivation_ for over-
the-air firmware updates. If the average person won't install adblock because
they don't realize the end result of ad network tracking, why would they
object to a prosthetic that records their every move? Time and time again, the
public has shown that they have no practical aversion to being creeped on and
abused in ways that don't immediately translate to pain or lost money.

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sametmax
This is why SF should be mandatory reading in high school. People can't even
grasp the consequences of tracking cookies and we are going to sell them stuff
to plug in their head.

~~~
jdpigeon
What is SF?

~~~
supergauntlet
Science fiction. The poster you're responding to I think means that the common
philosophical issues brought up in science fiction aren't being thought of by
the creators of this technology in advance.

Basically, they're too preoccupied with whether they could, and not thinking
about whether they should.

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needlesurgeon
As a clinician, this news is extraordinarily exciting. Here's why.

A brain computer interface is something that records neural activity in a
person, and then decodes that neural activity to allow them to control objects
in their environment. When we think about sources of neural information, it's
useful to divide them into non-invasive (EEG, fMRI, MEG, NIRS) technology, and
to invasive technology (intracortical electrodes, SEEG, ECoG) systems.

Fundamentally, the DARPA grant is about acquiring new sources of neural
information. As the article points out, the latter category is happening
almost exclusively as people are hanging out in epilepsy monitoring units with
nothing better to do, or as part of early clinical trials looking at safety
profiles of implanted devices.

Simply speaking, the divide between invasive and non-invasive systems is about
the signal-to-noise ratio of neural information. The closer you get to single
neurons, the closer you get to the source of neural activity, the higher the
signal quality you get to decode with. Consider that EEG systems (the most
commonly used non-invasive methods) average neural activity over the range of
several 10^-3 to 10^-2 meters, through the attenuation of spinal fluid, dura
mater, skull, five scalp layers, and the electrode interface. Electrodes used
in modern intracortical BCI systems are 10^-5 meters in diameter.

To my mind, the DARPA announcement is extraordinary -- these technologies have
the possibility of upping the SNR for non-invasive methods, and acquiring
fundamentally different sources of neural activity. Importantly, the methods
seem to have the ability to work at the bedside, without needing very large
and very expensive devices (e.g. fMRI, MEG).

Here are some reasons why this would be important:

1) Someone has been admitted to the intensive care unit, and needs a breathing
tube on a ventilator for life saving purposes. Some people in this situation
are awake and alert. Literature suggests that being intubated and awake is
incredibly scary, since you're aware but can't communicate. Having a non-
invasive beside method that could decode your thoughts would be a dramatic
increase to the person's quality of life, given their temporary stay. Note
that eye-trackers may not be feasible, given the amount of stuff in the ICU
room, the fact that they're lying down, etc.

2) If you ask people with locked in syndrome them about their priorities for
improving their quality of life, the biggest need is improving their ability
to communicate (as opposed to spelling boards, or looking up/down to
communicate). Note these people cannot use eye-trackers, due to their
neurologic condition.

3) Ongoing clinical trials have had volunteers undergo implantation of
electrodes into their brain. The devices implanted have been percutaneous
(i.e. had a portion go through their skin). These devices have allowed some
participants to feed themselves, either using muscle stimulation or through
robotic arm control. Not only would having a non-invasive method obviate the
need for a surgery, but having a method for "writing into" the brain would
provide closed-loop control of the arm/robotic limb they were controlling,
putatively increasing the quality of control.

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return1
These are all interesting approaches. I m surprised there is nothing related
to optogenetics, but i guess that is considered too invasive. In reality once
we are inside the brain it might prove to be easier to deliver signals,
because our brains can learn to "read" a specific sense. This is essentially
about creating a sixth sense to humans which can deliver information in new
forms to the brain.

~~~
Amygaz
You would need to engineer cells for optogenetic. So unless you do it at the
embryo stage, or have very efficient and robust delivery and editing
mechanisms, it will not work.

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unixhero
As long as I can avoid synaptic seepage!

~~~
samirm
Is this a reference to something cyberpunky?

~~~
unixhero
Certainly is! :)

[https://en.wikipedia.org/wiki/Johnny_Mnemonic_(film)](https://en.wikipedia.org/wiki/Johnny_Mnemonic_\(film\))

[http://www.subzin.com/quotes/M1282877de/Johnny+Mnemonic/Syna...](http://www.subzin.com/quotes/M1282877de/Johnny+Mnemonic/Synaptic+seepage+can+kill+you+in+2+or+3+days).

~~~
samirm
thank you!

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graycat
Let's see, for such communications we already have eyes, ears, fingers, and
voice with all or nearly all of these well proven from most mammals from the
smallest mouse to the largest elephant with development time 65+ million
years.

And with those _systems_ given, DARPA is going to try to do better, just
externally, by using sound, optics, magnetic fields, etc.?

They are NOT going to put one of their devices anywhere near MY head!

Ah, DARPA has done some good stuff -- they are allowed some big losers!

Old Advice: The first step in good research is to pick a good problem!

~~~
civility
If you like science fiction at all, give Accelerando a read. Of course it's
just a story, but it feels like a possible real future (at least the first
section). In it, there is definitely a place for people who reject integrating
with technology, but that place is in the back and left behind. Instant access
to all of digital knowledge, unlimited storage for every thought or experience
that interests you, performing complicated calculations, visualizing higher
dimensions, and so on. Your fingers, ears, and voice aren't that quick, and
your eyes are limited to 2D and only have decent resolution around the center.
There is certainly room for improvement over what evolved in mammals (or any
animal).

It probably won't be real before I die of old age, and I'd certainly let the
early adopters find the bugs, but sign me up for version 3.0 or later if I'm
still around.

~~~
chrisweekly
> "Accelerando"

Singularity book 3 by Stross?

~~~
maxander
By Stross, yes. And it’s online: [http://www.antipope.org/charlie/blog-
static/fiction/accelera...](http://www.antipope.org/charlie/blog-
static/fiction/accelerando/accelerando-intro.html)

