What baseline would be needed for this to work? My motor cortex and pre-motor cortex are mostly dead. Isn't that what the EMG and EEG are reading? Is this better than action observation?
https://www.pcmag.com/news/359198/how-virtual-avatars-help-stroke-patients-improve-motor-funct
I am hooked up to a 16-channel brain machine interface with 12 channels of EEG on my head and ears and four channels of electromyography (EMG ) on my arms. An Oculus Rift occludes my vision.
Two inertial measurement
units (IMU) are stuck to my wrists and forearms, tracking the
orientation of my arms, while the EMG monitors my electrical impulses
and peripheral nerve activity.
Dr. Sook-Lei Liew, Director of USC's Neural Plasticity and Neurorehabilitation Laboratory ,
and Julia Anglin, Research Lab Supervisor and Technician, wait to
record my baseline activity and observe a monitor with a representation
of my real arm and a virtual limb. I see the same image from inside the
Rift.
"Ready?" asks Dr. Liew. "Don't move—or think."
I stay still, close my eyes, and let my mind go blank.
Anglin records my baseline activity, allowing the brain-machine
interface to take signals from the EEG and EMG, alongside the IMU, and
use that data to inform an algorithm that drives the virtual avatar
hand.
"Now just think about moving your arm to the avatar's position," says Dr. Liew.
I don't move a muscle, but think
about movement while looking at the two arms on the screen. Suddenly,
my virtual arm moves toward the avatar appendage inside the VR world.
Something happened just because I thought about it!
I've read tons of data on how this works, even seen other people do it,
especially inside gaming environments, but it's something else to
experience it for yourself.
"Very weird isn't it?" says David Karchem, one of Dr. Liew's
trial patients. Karchem suffered a stroke while driving his car eight
years ago, and has shown remarkable recovery using her system.
"My stroke came out of the blue and it was terrifying,
because I suddenly couldn't function. I managed to get my car through an
intersection and call the paramedics. I don't know how," Karchem says.
He gets around with a
walking stick today, and has relatively normal function on the right
side of his body. However, his left side is clearly damaged from the
stroke. While talking, he unwraps surgical bandages and a splint from
his left hand, crooked into his chest, to show Dr. Liew the progress
since his last VR session.
As a former software engineer, Karchem isn't fazed by using
advanced technology to aid the clinical process. "I quickly learned, in
fact, that the more intellectual and physical stimulation you get, the
faster you can recover, as the brain starts to fire. I'm something of a
lab rat now and I love it," he says.
REINVENT Yourself
Karchem is participating in Dr. Liew's REINVENT
(Rehabilitation Environment using the Integration of Neuromuscular-based
Virtual Enhancements for Neural Training) project, funded by the
American Heart Association, under a National Innovative Research Grant.
It's designed to help patients who have suffered strokes reconnect their
brains to their bodies.
"My
PhD in Occupational Science, with a concentration in Cognitive
Neuroscience, focused on how experience changes brain networks,"
explains Dr. Liew. "I continued this work as a Postdoctoral Fellow at
the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, before joining USC, in my current role, in 2015.
"Our main goal here is to enhance neural plasticity or
neural recovery in individuals using noninvasive brain stimulation,
brain-computer interfaces and novel learning paradigms to improve
patients' quality of life and engagement in meaningful activities," she
says.
Here's the science bit:
the human putative mirror neuron system (MNS) is a key motor network in
the brain that is active both when you perform an action, like moving
your arm, and when you simply watch someone else—like a virtual
avatar—perform that same action. Dr. Liew hypothesizes that, for stroke
patients who can't move their arm, simply watching a virtual avatar that
moves in response to their brain commands will activate the MNS and
retrain damaged or neighboring motor regions of the brain to take over
the role of motor performance. This should lead to improved motor
function.
"In previous occupational therapy sessions, we found many
people with severe strokes got frustrated because they didn't know if
they were activating the right neural networks when we asked them to
'think about moving' while we physically helped them to do so," Dr. Liew
says. "If they can't move at all, even if the right neurological
signals are happening, they have no biological feedback to reinforce the
learning and help them continue the physical therapy to recover."
For many people, the knowledge that there's "intent before
movement"—in that the brain has to "think" about moving before the body
will do so, is news. We also contain a "body map" inside our heads that
predicts our spacetime presence in the world (so we don't bash into
things all the time and know when something is wrong). Both of these
brain-body elements face massive disruption after a stroke. The brain
literally doesn't know how to help the body move.
What Dr. Liew's VR platform has done is show patients how
this causal link works and aid speedier, and less frustrating, recovery
in real life.
From the Conference Hall to the Lab
She got the idea while geeking out in Northern California one day.
"I went to the Experiential Technology Conference
in San Francisco in 2015, and saw demos of intersections of
neuroscience and technology, including EEG-based experiments, wearables,
and so on. I could see the potential to help our clinical population by
building a sensory-visual motor contingency between your own body and
an avatar that you're told is 'you,' which provides rewarding sensory
feedback to reestablish brain-body signals.
"Inside VR you start to map the two together, it's
astonishing. It becomes an automatic process. We have seen that people
who have had a stroke are able to 'embody' an avatar that does move,
even though their own body, right now, cannot," she says.
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