Reimagining Rehabilitation: The Impact of Brain-Computer Interfaces on Motor Functions

Picture yourself in this scenario:

You were in the midst of a basketball game, and while you weren’t looking around, someone ran head-first into you, causing you to fall on the ground with a blow to the brain. You go unconscious.

After a few minutes, your coach and your teammates are surrounding you, checking if you’re okay. You’re trying to tell them you’re fine, but you stutter when you speak and you have a lot of grammatical errors. Your teammates don’t understand you well but know that you’re trying your best. You’ve just suffered damage in your Broca’s Area (The part of the brain that deals with speech production).

How does this scenario make you feel?

Not great, right? If you felt something else, here’s another scary scenario.

You’re the leading linebacker on the Pittsburgh Steelers (A NFL Team based in Pennsylvania) and you go in to tackle the Wide Receiver who has just received possession of the football. You run in headfirst and clutch the tight end by the chest, bringing him down. After the tackle, you’re on the ground, unable to move your legs. You’ve just suffered a spinal contusion in the lower back.

Imagine not being able to move your legs. Pretty scary, right?

And to top it off, this is a real story.

Pittsburgh Steelers Linebacker Ryan Shazier (#50) is carted off the field after a spinal injury.

This is not to say that these injuries can only happen in sports. These can happen anywhere, and it’s based on the prevalent circumstances. Surprisingly, spinal cord injuries are more prevalent outside of professional sports that deal with it.

For Ryan Shazier, the recovery period consisted of a lot of stress and frustration. He had to work to reframe the injury because this wasn’t your typical football injury. He’d create smaller positive moments to establish “progress” while in rehab, which he did for 2 hours a day, 5 days a week. He used this as a way to eliminate the stressors and focus on regaining activity. Exactly 2 months after the injury, he walked with assistance from a cane. After 4 months he walked onto the NFL Draft Stage. And on May 3rd, 2019, he danced with his wife, Michelle Rodriguez, at their wedding.

NFL player dances at his wedding 17 months after spinal injury

Now this dealt with a lot of rehabilitation work to allow the brain to naturally send signals down to the body, which took about 6 months. He only relied on this as his method to get back to walking, which had taken a toll on his daily life and routine. He didn’t use Brain-Computer Interfaces in his recovery, as they weren’t widely available at the time of his injury. However, BCIs have emerged as a revolutionary technology in recent years, allowing individuals such as Ann Johnson to make remarkable progress in communication and movement.

This is Ann Johnson. When she was 30 years old, she suffered a stroke that gave her the Locked-In Syndrome (LIS). Her speech production is fully damaged, and she is paralyzed from the neck down.

Just a month ago, she was able to “speak” to her loved ones with her brain signals and particular facial movements (Notice the brain implant on her head). The system made predictions based on such data and produced it using an avatar of her speaking. She was wired to the system and the data was taken directly from the brain.

How does this work?

BCIs (Brain-Computer Interfaces) are at the root of this groundbreaking solution. BCIs meld a computer with a person’s brain, allowing researchers to track the data of the brain in real time. By placing electrodes either on the scalp or in the person’s brain, researchers can send in electrical signals, manipulate the magnetic activity, and help create wireless connections between the brain and the particular body part.

Firstly, we’ll have to know why brains would require magnetic or electrical activity, or why brains even have them in the first place. Here’s a quick 101 about the brain’s activity.

Our neurons consist of dendrites and axons. The dendrites receive the messages from incoming neurons through their receptors, and the axons send the signals out of the cell to other neurons through their terminal branches. The dendrites receive messages through neurotransmitters, which bind to the receptors, transmitting a chemical message.

The dendrites receive the message from an adjacent neuron. This is processed into an electrical message that is sent out through the axon terminal.

The reason that electrical signals are being fired is because of the distribution of the ions within the neuron (Which makes the electrical signal also a chemical signal). When these neurotransmitters bind to the receptor, ion channels are opened, and this allows ions (Positively or negatively charged ions) to flow through. Considering the number of dendrites in the cell, there are a lot of ion channels that open, allowing for an influx of tons of ions. When a neuron is in action potential, there are more positive Sodium ions entering the cell, allowing it to reach the required charge to send the message.

The green region is when the neuron is at its action potential. The sodium ions are flowing into the cell, allowing it to gain a net positive charge.

After an action potential, the ion distribution is reset, with the cell gaining a net negative charge after the positive Sodium ions are cast out of the cell. This is the neuron’s resting phase.

The yellow region is when the neuron is at its resting potential. It is gaining a net negative charge so the membrane potential decreases.

BCIs technically build a “communication bridge” between the human brain and the external world by manipulating this ion distribution and movement. It allows people to control the movement and function of external devices using their brain. For example, warfighters might be able to control their war drones hands-free as a result of BCIs, allowing disabled war troopers to help out.

As a result of this electrical firing, magnetic environments are created within the brain, which are specific to varying source characteristics. There can be weaker magnetic activity in one neuron and greater in the other neuron, and this would be dependent on if the neuron is firing, the spread of the neurotransmitter, and the level of brain tissue (micro, meso, or macroscales of generation) among other sources.

This improves human-computer interactions as well. Think of it as your external and controllable corpus callosum!

For instance, researchers at the University Of Texas at Austin have recently utilized BCIs on a VR headset to track brain activity during immersive VR games. This includes games such as driving, and jumping off highboards, among others. This allowed them to predict what the participants would do in a real-life situation by simulating it with a BCI so that the correct precautions could be taken. This allowed the participants to create interactions with a computer and control the movement of devices.

Nanshu Lu, professor at The University of Texas at Austin Biomedical Engineering , utilizes the Meta VR headset while playing a driving game to track brain activity.

“It gives the user a more realistic experience, and our technology enables us to get better measurements of how the brain is reacting to that environment ” — Nanshu Lu

To be honest, that’s as close as I can get to really swinging like Spider-Man. I’d honestly get the feeling of puking after every somersault and swing. How does Peter Parker do that? Anyways, back to the topic.

The UT Austin researchers mapped out the brain activity while people were in the immersive environment through an EEG system. What’s that? you may ask. This is the mapping technology that researchers use within BCIs to accurately get the data and encode it into something that the computer can read.

BCIs have a lot of applications but are no good if the mapping technology doesn’t accurately get the data. Here’s a comprehensive list of the different brain mapping techniques, and their certain functions that make them distinguishable.

• EEG — Electroencephalogram (EEG) is a non-invasive (Nothing is implanted into the brain) technique that utilizes sensors on the scalp of the participant’s head to measure brain wave activity and electrical shifts in the brain. This would be optimal when trying to measure neural firing and sleep.
• PET — A Positron Emission Tomography (PET) Scan injects a small amount of radioactive glucose into the body so that researchers can map out how that glucose is being used by the brain. This is usually used to diagnose diseases, which range from heart diseases, tumors and other brain-related disorders.
• CT — A Computer Tomography (CT) Scan combines multiple X-ray images from different angles of your body and uses computer processing to create cross-sectional images of these different body parts. It’s used to help people who’ve had a lot of internal injuries or trauma.
• fMRI — The functional Magnetic Resonance Imaging (fMRI) scan helps with identifying which parts of your brain are the most active. You can correlate this information to what you were doing at that time to see which parts of your brain “light up” while you do that activity. It’s mostly used for planning surgeries or other similar procedures that would involve the brain and its functionality.
• MRI — The Magnetic Resonance Imaging (MRI) scan also uses the brain’s magnetic activity to investigate or diagnose conditions that usually affect soft tissue. The parts of the brain and muscles are seen a lot more clearly with MRIs than X-rays, making it a suitable tool to identify the parts of the brain.

These techniques allow researchers to experiment and work around different conditions, with specific techniques for each one. Thanks to this, we can conduct sleep research, operate things with our brains, and create better applications for best-use case systems.

With all these mapping techniques come numerous applications and advantages of BCIs:

• Assistive technology: BCIs can control devices, allowing users to operate computers, wheelchairs, and other assistive technologies using only their thoughts.
• Neurorehabilitation: BCIs are used in neurorehabilitation to enhance recovery from brain injuries and stroke by providing real-time feedback to patients.
• Research and Diagnostics: BCIs help researchers study brain activity and diagnose neurological conditions by interpreting and monitoring neural signals and impulses.
• Cognitive Enhancement: BCIs can be utilized to identify and even enhance cognitive abilities, such as attention, memory, and learning. These can be employed to create systems that can allow people to work to their capabilities in cognitive functions.

These advantages pose a dual phenomenon, allowing people to use their brains to program something, while researchers measure people’s activities.

This makes me think that even something as sci-fi as Darth Vader using the force can become a reality.

Having discussed the advantages of BCIs, it’s important to delve into how these technologies are being harnessed for the benefit of humanity. Let’s see how it worked for Ann Johnson:

• Ann’s stroke damaged the brainstem of her brain, especially the Pons region. The brainstem is very important for the connection between her brain and spinal cord, and it also helps with involuntary body functions (Heart rate, digestion, breathing, etc.). This stroke caused her to lose most of her motor function and her speech production as well.
• In Ann’s case, an invasive BCI system was rooted deep into the brainstem of the brain. This would decode brain signals into full words that would appear as text on a screen.
• The system helps capture neural activity, where advanced algorithms help process these signals. This is what allows the researchers to identify Ann’s brain activity and interact with it.
• The researchers created advanced algorithms that helped process the brain signals and facial movements into predicted speech, which was displayed on a computer for the receiving person in the conversation to see. They also added an associated avatar to mimic the predicted speech that was decoded from the brain signals.

Now, while still going through ongoing treatments, Ann’s journey demonstrates the potential and exciting advancements coming to this field. Her journey is a testament to the numerous advancements of BCIs.

When I built one of my first Github projects, titled ‘CuriosityIndicator,’ I thought I was helping the world by knowing how to attempt to track curiosity (Alright maybe not that bold, but I was still super stoked). Curiosity is super subjective, and being able to try to track that, is what I thought was out of this world. Once I found out about all the other advancements happening to BCIs, such as prosthetics and newer communication systems, my mind was blown. Take a look for yourself:

1. Neuralink

Founded by Elon Musk, Neuralink aims to develop advanced BCIs to enable direct communication between the brain and external machines. They have been actively working on implantable brain-computer interfaces and look toward human trials for it as well.

A key system that they developed was Link (Neuralink V2).

• This was a smaller, more refined version of their original implant known as Link. This was devised to be less invasive and more durable, allowing for higher data transfer rates and allowing for bidirectional communication. This has potential for various applications, including control of external technologies and assisting individuals with neurological conditions.

Above is Neuralink V2 and how it’d look inside a machine.

2. Kernel

Kernel, led by Bryan Johnson, is focused on building neuroprosthetics and BCIs. They are working on non-invasive and invasive technologies to address neurological conditions and enhance human capabilities.

Their main focus, being on better data and precision neuroscience, allows them to create state-of-the-art technology to deal with biological issues that directly correlate to the brain. This would help accelerate treatment discovery and adjustment, improve patient outcomes, and transform the neuro medicine industry. This is one of their precision technology that helps with understanding the data transfer.

This is one of Kernel’s technologies for precision neuroscience and data delivery. This can help transform treatments and remediations. Credit: Next Big Future

Putting a BCI to the test

Now that you know the relative ins and outs of BCIs, let’s see how they can potentially be used to help with motor dysfunctions. Going back to scenario 2 (Ryan Shazier’s injury), let’s look at how a BCI might be used to help him diagnose the condition and regain his motor functions, with shorter and more efficient rehab.

Step 1: Diagnosis through brain mapping

Firstly, the spinal cord has a natural curvature. When Ryan went to tackle the player, his position caused him to straighten up the spinal cord, causing it to take on heavier stressors and loads than what it’s used to. As a result, Ryan suffered an injury in the Lumbar Vertebrae of his spinal cord. This part of the spine helps with sensory information and voluntary motor functions in his legs. As a result of the injury, no sensory information from the legs can be processed by the brain, and no voluntary motor functions can be conducted by the legs.

The Lumbar (5) is the region of the spine where Ryan got injured. Credit: Teach Me Anatomy

As a result, an fMRI scan would be plausible to identify the type of contusion he faced by mapping out the function of the brain in real time concerning the flow of blood within the body. Because his legs are paralyzed, the body has lost control over the blood vessels, which causes them to widen. This would cause the blood to collect in other parts of the body that don’t necessarily require it. There would be a significant drop in blood flow when looking at the fMRI scans on his brain and sensory information to his legs. This is what the fMRI should not be able to detect:

The fMRI wouldn’t be able to detect activity in the toes, knee, leg, and hip region as shown by the homunculus above. Credit: Britannica

Step 2: Regular EEG Testing

With the current state of EEGs right now, it is plausible for him to take regular EEG tests to identify shifts in electrical and brain wave activity at the affected brain regions. This process of neurorehabilitation will enhance the recovery process and allow patients to learn more about their condition. This will allow him to track progress and have his doctor adjust treatments based on real-time data.

Step 3: Creating wireless connections

With consent from Ryan, brain implants will be placed in his motor and somatosensory cortex, with wireless receivers in his lumbar vertebrae. In that way, the thought of him moving will stimulate electrical activity, which then sends wireless signals in the form of sensory-motor feedback through and from his brain and spinal cord, allowing his legs to regain function quickly and adaptively. Simply, the brain implants are allowing the neurons to send impulses in areas that they couldn’t because of the paralysis.

In what we can call a “digital bridge,” these implants do so much more than just regain electrical communication and function. With the brain getting used to these new forms of electrical communication with the body, it rewires, allowing Ryan to do certain movements with his legs with the implant turned off. In the early days of treatment, these new nerve connections would require the support of a cane or crutches to allow him to walk without the implant’s influence.

Step 4: Rehab and Training

With these new electrical connections, Ryan would have to get used to thinking about the movement in certain ways so that the artificial algorithms can process it to send that signal to the Lumbar Vertebrae. This would have Ryan under supervision for a good amount of time, but it wouldn’t take long for him to get used to it as it is only for the legs.

And here’s our patient:

Looking fresh, right? Just like nothing ever happened.

(Note that this is how BCIs would regain function for the person considering their condition. This would have a lot of ethical concerns that I did not mention for the sake of this demonstration.)

As this technology continues to advance, the boundaries between human and machine interaction will become non-existent, and it’s only a matter of time before we consider both the possibilities and the questions about the evolution of this technology.

And a Star Wars dream of using the force.