A gust of wind. She looks up the sheer slope as she brushes the hair out of her eyes. No use looking down, the climb down would be more work anyway. One more reach, one more step. And another, and another. She pauses. Sometimes you forget to drink water in the frigid air.
Gasp.
Her handhold breaks, causing her footing to slip. Her water bottle falls, and she slams her metal arm into the mountainside, praying for a grip.
The bottle smashes against stone below, echoing up the slope. Though she is safe. Oh yes, the mountain has taken names, but that doesn’t faze her. She would take its name.
The girl returns from her moment of imagination, and peers out the window from her room. She shifts closer to the windowsill, reaches, and pulls herself up to get a better view out into the night sky. She places both forearms onto the sill, one of skin and bone, the other of metal and plastic. She loses her thoughts into the dark sky again.
“Maybe some day.”
Prosthetics and more specifically cybernetics have been quite the buzz lately due in part to the release of the hit new videogame: Cyberpunk 2077. It presents a high tech future dystopia where such body modifications are common place. The genre piqued my interest, and like the girl from the story dreaming of climbing mountains, I wonder what capabilities we’ll see in the future. How do we stack up and where is the technology leading? Let’s explore.
There are a variety of prosthetic limbs on the market, some more advanced than others. Two, in particular, have shown impressive movement functionality. The Modular Prosthetic Limb (MPL) from Johns Hopkins University, and the Chalmers UOT prosthetic arm (3) are both designed to mount directly onto bone. Electrodes embedded in muscle tissue further up the arm are signal sources that are triggered by the mind. They offer the same number of degrees of freedom of the human arm. Though is the functionality truly the same? Consider you day to day movements like the act of walking up the stairs. Do you think about your body, and the instructions you give when you walk up/down them? Of course not, our mind is trained to do those things automatically, without deeper thought. The focus is on the concept of stair walking, not of each specific degree of freedom our leg must move in sequence. When training motor abilities, it’s just as much about training the mind, as it is training the body, so that it becomes a natural, both for optimized muscle recruitment as well as basic motor needs. What this means is that these kinds of prosthetics are not truly analogous to how our bodies function, because they still rely on continuous thinking of the electrode contacts points to recruit smooth motor abilities. However, the significance of the mind should be the hint.
Neuroprosthetics are the next frontier that we are hoping to breach. They are defined as supplemental channels to nervous system input/outputs and have been explored to help in bypassing neural deficiencies as well as potentially raising the bar of our physical capabilities. Should the mind not recruit muscles properly, it wouldn’t matter if you had those muscles available to you or not. It all still relies on a good signal. Electrodes placed on the scalp are the first and least invasive way to recruit them. Other ways include on top of the brain, in the spine, inside the brain tissue. It’s fascinating to note that the brain shows shifts in signal frequency during the act of opening and closing the hand. If you can map that accurately to the brain, you ought to be able to investigate more refined movements.
This is where the philosophy of science begins to enter the fold. In the Chalmers UOT video, Rickard (the patient) described how he finally feels “one” with his prosthetic arm. That’s certainly a testament to its quality, but there are other nagging questions that arise. Max Ortiz (the project lead) stated specifically that enhancement was beyond his ambitions, all he wanted to do was return the body to its standard capability. His comments are a chilling reminder to the philosophy that we approach as we explore these topics.
Prosthetics were actually conceived long ago as static replacements to body parts things such as peg legs, iron hands, and the like. They’ve evolved into mechanically optimized parts with some very simple robotics, and now move toward the dawn of seamless mind-body integration and beyond. In this rabbit hole we arrive at the blurred lines of “when can it no longer be considered human?”. 2020 had us all spending more time with ourselves; in introspection, in contemplation. So perhaps like the considerations between “what is man vs what is machine?”, you too may have pondered the question: What is it exactly that makes you, you? We’ll explore next time.
The Science Chronicle 