The Mind-Bending Qualities of VR Might Also Be Used to Heal
Neuroscientists are tapping the power of virtual reality to improve recovery from a stroke.
When you strap on a virtual reality headset, your brain is instantly convinced that it’s in a real environment. The immersion is so complete that during tests at the Virtual Human Interaction Lab at Stanford University, participants refused to step off a VR bridge even though they knew that the drop was 100-percent digital.
VR clearly messes with your mind, but can it also be used to heal it? A Swiss company called MindMaze recently won FDA approval to introduce a VR-based therapy in the United States that uses virtual avatars and gamification to trick a stroke patient’s brain into recovering faster.
Nearly 800,000 Americans a year suffer a stroke, which is caused by a blocked artery cutting off oxygen to parts of the brain. Without oxygen, brain cells in the affected region will die, often resulting in partial or full paralysis of one side of the body. Damage in the right hemisphere of the brain results in loss of movement on the left side, and vice versa.
If post-stroke rehabilitation is initiated quickly and effectively, some patients can recover movement in paralyzed limbs and facial muscles by rerouting neural pathways to undamaged parts of the brain. The best hope is to activate brain cells in the penumbra, the area directly surrounding the damaged cells. But how do you stimulate new brain activity if the corresponding limb is paralyzed?
One classic rehab method is called mirror therapy. Holding a mirror down the center of a patient’s body, the patient is prompted to move their healthy arm or leg, making it appear like the opposite limb is moving. When neurologists track the brain activity of healthy subjects, it’s clear that the mirror trick triggers brain activity in the opposite hemisphere. The hope is that it can also spark new brain connections in stroke victims.
Now MindMaze has developed a new rehab device that brings the mirror method into the VR age. The machine, called the MindMotion Pro, is like a hospital-grade Wii. Equipped with a 3D motion-tracking camera, the MindMotion Pro captures a stroke patient’s movements and displays them on a realistic virtual avatar. The device takes advantage of the unique mind-bending power of VR, coupled with game-like exercises, to deliver recovering times that are 35 percent faster on average than conventional therapy.
Tej Tadi, CEO of MindMaze, said his decade-old company has always seen virtual reality and augmented reality as gateways to neuroscience, because they are such powerful catalysts of brain activity.
“You’re able to present stimuli in a way that’s ecologically valuable,” said Tadi. “It’s the difference between a physical therapist asking you to imagine a cursor on the screen as your hand, versus actually seeing a virtual hand that really moves like your hand. Your brain says, ‘Listen, that’s my hand.’”
This is particularly true with the mirror therapy exercise. In the MindMotion Pro version, there’s no actual mirror, just the patient’s avatar on a flatscreen display in front of them. The game, let's say for a patient with a paralyzed left arm, is to reach out and touch a glowing green circle in the center of the screen. He reaches for the ring with his right arm, but it’s the avatar’s left arm that moves. The action is so simultaneous and convincing that the brain doesn’t have time to realize it’s being tricked into action.
The virtual mirror therapy can be repeated across many different types of actions — reaching, pointing, grabbing, squeezing — each prompted by a different game-like interface. Since the device can be rolled up to a patient’s bed or wheelchair, treatments can begin just four days post-stroke.
“The neuroscience is in the content,” said Tadi, referring to the gamified therapy exercises developed by an in-house team. “There are so many ways to trigger those neural pathways, but the exercises must be tailored to the patient.”
The MindMotion Pro was first introduced in Europe in 2013 and is now being used in three dozen hospitals and clinics across the continent. Tadi said the device is popular with physical therapists because it provides a level of quantitative feedback that’s missing from conventional post-stroke therapy.
Therapists can access detailed performance data measuring both time and accuracy of exercises. Also, by equipping patients with small, motion-capture sensors, therapists can isolate and track specific movements like the range of motion of a wrist or the bend of an elbow.
A hospital in Lausanne, Switzerland conducted a small study in 2015 to gauge the efficacy of the MindMotion Pro and came back with some interesting results. Over several days of therapy, patients made modest gains in range of motion and reported decreased pain, but the biggest impact was on motivation. The gamification of post-stroke therapy, reported the study, resulted in 90 percent of patients reporting a greater desire to do their therapy, and full 100 percent saying that they “forgot they were in a hospital.”
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