AUG 01, 2021

Actually, You DO Know You Are a Brain in a Vat: Exoskeleton Pros and Cons

WRITTEN BY: Mia Wood

“You do not know that you are not a brain, suspended in a vat full of liquid in a laboratory, and wired to a computer which is feeding you your current experiences under the control of some ingenious technician.” So begins a section of philosopher Jonathan Dancy’s chapter on scepticism.

Who wouldn’t quake at the thought, even if it has a long history? Long before his famous dream argument, in which Descartes considers the criteria by which he distinguishes dream from waking states, Plato’s Socrates discusses a perceptual deficit common to dreams, illusions, and hallucinatory diseases. In the same period, Chinese Daoist philosopher, Zhuang Zhou, wakes up from a dream in which he is a butterfly, “now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly, dreaming I am a man.” These scenarios ‘pump our intuitions’ about knowledge and reality.

In the 20th century, Robert Nozick asked if we would ‘plug into’ an “experience machine” that would provide us with ‘any experience desired.’ Even if we knew it wasn’t “real,” the question remains: Would we plug in? The issue ostensibly at the heart of Nozick’s thought experiment is about the quality of life. Nozick thinks “we want to do certain things…[and] we want to be a certain way.” Clearly, Nozick would not adopt Cypher’s view in The Matrix. At a “dinner” with Agent Smith, Cypher says, “You know, I know this steak doesn't exist. I know that when I put it in my mouth, the Matrix is telling my brain that it is juicy and delicious. After nine years, you know what I realize? Ignorance is bliss.”

Such thought experiments are no longer in the realm of the armchair or worries in the dark recesses of the imagination. While the prospect of uploading yourself to a computer is still the stuff of speculation, neuroscientists have been working on mind-controlled exoskeletons. It’s something closer to human bionics than disembodied minds. The robotic device, powered by motors and hydraulics, has been used in various ways, from the rehabilitation of amputees and quadriplegics and the restoration of movement to paralyzed patients, to enhancing weight-lifting capacities.

A new study from researchers at The Ohio State University and Texas A&M University, however, shows the exoskeleton taxes the brain in ways that undermine the device’s usefulness. Wearers asked to repeatedly lift a medicine ball during a 30-minute session received some benefit from the device, which was “designed to help control posture and motion during lifting to protect the lower back and reduce the possibility of injury.” When asked to perform a series of basic math calculations while repeating the exercise, however, the device became a hindrance. Its resources divided between attending to the math problem and coordinating with the exoskeleton to lift the ball, the brain’s resources were depleted.

 “All exoskeletons aren’t bad,” William Marras says. But, given the increasing popularity of the expensive device for industrial use, the senior author of the study points out, “You’ve got to use exoskeletons with some intelligence and some understanding of what the job entails.” Major companies, like Ford and Boeing, have outfitted workers with exoskeletons since at least 2018, but they didn’t just have their employees throw on an upper body exoskeleton as they would a backpack. Ergonomics engineers had to consider the type and diversity of work involved, such as repetitive lifting, throwing, or reaching above one’s head. Other considerations included a worker’s build and age.

A 2018 study Marras led found that there were trade-offs — decreased weight on the arms, which is good, but increased weight on the back, which is not. Exoskeleton companies continued to refine their industrial exoskeletons for optimal safety and efficacy, it’s clear there is confidence in the future of the exoskeleton market — the number of companies has increased 350% since 2015. Nevertheless, as Marras’s 2021 paper shows, the considerable improvements to comfort and flexibility have not resolved all issues associated with exoskeleton interactions.

The variety of exoskeleton uses — medical, military, industrial, sport, and recreational — means there are specific challenges to overcome. A medical exoskeleton, for example, has to substitute for natural limb movement or enhance speed, while a sport exoskeleton may have to fit on a set of fingers to enhance the grabbing movements involved in rock climbing. No longer considered the stuff of science fiction — think Sigourney Weaver in “Aliens” — in a few short years, exoskeletons will be increasingly task oriented. As such, the relation between the user and the exo is arguably more intimate; generating the same seamless connection between thought and movement as typically experienced without an additional skeleton, may be the last frontier for scientists.

Sources: American Council on Science and Health, BBC News, New Scientist, Science Daily, Applied Ergonomics , International Journal of Advanced Robotic Systems, National Center for Biotechnology Information, Applied Ergonomics 2, Ohio State News 1, Ohio State News 2, Ohio State University Spine Research Institute, Bloomberg News, EHS Today, Forbes, Stanford University, IMDB