Author: Vaishnavi Moturi

The human brain has always been a mystery, seemingly impossible to breach the barriers of research aimed at unraveling the inner workings of this miniature marvel. Thus, any condition of the brain has for millennia been viewed as an irreversible fate, one which can never definitively be cured but at best temporarily placated.

The “connections” we form in our brains form the cruxes of our existence, giving us the ability to ponder about everything from our primitive survival instincts to black holes billions of miles away from our humble dwellings. Yet for all its extraordinary capabilities, there is a sort of betrayal when our brains betray us causing us to lose our intrinsic identities or some fundamental human function.

Composed of 100 billion neurons, interconnected via a network of “connections” formed by the transfer of chemical signals between axons and dendrites — the “transmitters” and “receivers”, our brains are so remarkably complex that we understand awfully little about this 3-pound organ — despite the fact that we humans have been pondering about our brains for centuries. Building on the shoulders of giants like Aristotle, in 335 BC, who first suggested the brain was merely a radiator preventing our hearts from burning to 16 century Vesalius who created the first intricate map of the nervous system, humans have come a long way — but our journey ahead is anything but direct.

Our mobility depends on signals from our brains, which are sent via motor neurons in our spinal cord. These motor neurons then fire upon receiving the awaited signal from the brain, and an impulse is transmitted across the neuron’s axon to the muscle, where a chemical is released causing our muscle fibers to slide past each other, thereby resulting in motion. Thus motion is determined by the translation of our intent, formed in our brains, to the successful translation of this intent into our desired motion. Disruptions to this finely tuned pathway result in a host of mobility disorders categorized into a broad-ranging heading of “neuromuscular disorders” consisting of everything from quadriplegia to partial paralysis, to ALS (amyotrophic lateral sclerosis), and Multiple Sclerosis.

Over 5.6 million people in the USA suffer from devastating paralysis, often caused by spinal cord injury or ALS, leading to a drastic decrease in their quality of life preventing them from getting their ideas and thoughts across. As shown in startups like Neuralink and Synchron, BCIs promise to change this, offering a level of independence that was previously unheard of.

Beginning in the 1970s when Jacques Vidal, working at the Brain Research Institute at UCLA, introduced the concept of a brain-computer interface, the idea of this technology took hold, both in the public imagination and in research circles across the globe from Hans Berger, a German psychiatrist credited as the creator of the EEG, which can read brainwaves, to Apostolos Georgopoulos, at Johns Hopkins in the 1980s, who published a highly cited paper describing how the activity of motor cortex cells correlated to the specific movement of a rhesus macaque mouse’s limbs.

At its essence, a brain-machine/computer interface (BCI) can understand the brain’s signals from the cerebral cortex in the form of either invasive electrodes implanted directly onto the brain tissue or through noninvasive sensors attached through head caps on the user’s scalp. Invasive sensors, although achieve higher information transfer rates, run the risk of the formation of scar tissue or infection which can impede neurons’ ability to reform. Thus, patients must consider whether the potential benefits outweigh the risks of implantation. With either method, these electrodes pick up the voltage or electricity, differences between neurons which are then digitized in 0s and 1s and analyzed via computers.

These signals detected from the brain, however, need to be understood in terms of the intent of the user — or what the user desires to translate in terms of function (a certain movement of the forearm for instance). This is the goal of feature extraction, which aims to find distinct patterns, or spikes in neuronal activity, within the apparent nonsense of the signals. Feature extraction has of late been primarily achieved through artificial intelligence, in which complex patterns within the EEG signal data, invisible to the human eye, are uncovered through self-learning computer algorithms. Feature translation is finally accomplished once the intent is translated into a final task, usually, some output displayed on a computer screen representing the user’s thoughts or command — thereby achieving the ultimate goal of relaying a paralyzed user’s thoughts onto a visual medium.

BCIs have thus far accomplished and have remarkably even surpassed several milestones including in May 2021, when a quadriplegic was able to relay sentences through a computer under a Stanford University team, and in the same year when startup Synchron showed two people using their partially invasive BCI communicating via email and text with solely their thoughts. More recently, in the fall of 2022, Neuralink hosted a live demonstration of a reuses monkey typing without the use of its limbs — or in other words, with only its brain.

Although BCIs are primarily being investigated for people with neuromuscular disorders, applications are far-ranging such as the research of BCIs to restore the eyesight of individuals with acquired blindness. After Dr. William Harvey Dobelle implanted an electrode array into a patient’s visual cortex restoring the sensation of seeing light in 1978, multiple retinal prostheses emerged by either stimulating the visual cortex like Dobelle or by stimulating the optic nerve and thus further pushing the field of BCIs forward.

Overcoming the ethical hurdles of widespread acceptance of BCIs depends on people’s perception and collective mindset of a technology that can read our brain signals, which we have for eternity deemed private. This ethical dilemma persists because people do not wish to feel as though their brains are being trespassed, fearing a world in which their grasp on their individuality weakens. For people to reap the benefits of BCIs, the acceptance of this technology in our society lies in our trust in the institutions responsible for implementing these BCIs. The challenge lies in the transformation of people viewing BCIs as an intrusive necessity in their minds to an empowering device that can allow them to communicate and regain critical functions.

Brain-Computer Interfaces push the frontiers of scientific research as a whole and have the potential to upend the way we look at the inevitable merging of technology and biology. A field of research charged with an air of infinite prospects and capabilities, BCI technology has the potential to enhance the lives of millions, given that the research progresses cautiously, maintaining the user’s privacy at the forefront, before being implanted universally in human beings. Each step forward, both incremental and abrupt, will prove to be pivotal in how we perceive this technology and should be treated as thus if humanity is to create a society where individuals can reclaim fundamental parts of their identity.