By Dion Cheung
Imagine each neuron as a musician, and their electrical impulses as the musical notes they produce. When neurons communicate with one another, they do so through electrical signals, also known as action potentials. These signals travel along intricate neural pathways, forming the basis of all brain function.
Brain waves are rhythmic patterns of electrical activity generated by synchronised neural firing that occur at different frequencies, each associated with various mental states and activities. There are many different ways to observe and interact with this cerebral symphony. Some methods position us outside the doors of the concert hall, while others place us in the audience, or even allow us to play instruments within the orchestra itself.
Non-Invasive Techniques (Outside the Doors):
Think of non-invasive methods, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) as listening to the music from outside the concert hall. With EEG, we can observe the brain's electrical activity through electrodes placed on the scalp, much like enjoying a musical performance from outside the concert hall. Meanwhile, fMRI can provide detailed snapshots of brain activity by measuring changes in blood flow, offering an insight into the brain from the outside. In this analogy, the non-invasive brain-computer interfaces (BCIs) are listeners from outside, appreciating the performance of neurons without direct involvement.
[1] Task fMRI reveals biomarkers for mental health and cognitive resilience
Semi-Invasive Techniques (In the Audience):
Semi-invasive approaches, like transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), bring us closer to the neurons in the brain, almost like being part of the audience influencing the show. These techniques involve stimulating the brain with magnetic fields or mild electrical currents, giving us a more interactive role in the orchestra.
[2] This diagram shows how TMS works
[3] This diagram shows how tDCS work
Invasive Techniques (Within the Symphony):
Invasive techniques like deep brain stimulation (DBS) and intracranial electrodes allow us to become part of the orchestra, playing instruments within the symphony itself. In DBS, electrodes are surgically implanted deep inside the brain, creating a direct connection to the neurons. Like a musician actively playing for the orchestra, invasive neurotechnologies provide a way to precisely modulate neural activity, making them performers deeply immersed in the concert.
[4] Coloured X-rays of sections through the 1 head of a patient showing the electrodes (light lines) of a deep brain stimulator (DBS) implanted in the brain. Photo by Zephyr/Science Photo Library
[5] Schematic drawing of type implantation
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One important figure in the development of neurotechnology was Luigi Galvani [6], whose experiments in the late 18th century cast light on the connection between electricity and the nervous system. His groundbreaking work involved the use of electricity to stimulate the muscles of frogs legs, which, when exposed to electrical currents, twitched and moved. This discovery hinted at the relationship between electrical signals and the body's movements.
More recently, in the early 20th century, we saw the birth of the EEG. Invented by German psychiatrist Hans Berger [7], the EEG became a pivotal tool for capturing the brain's electrical activity, allowing researchers to gain a better insight into the brain’s functions.
However, in recent years neurotechnology has experienced a remarkable renaissance, thanks to advancements in computing, artificial intelligence, and insights from neuroscience. Innovations like AI-powered brain implants and ventures like Elon Musk's Neuralink [8] showcase the modern era of neurotechnology, promising a myriad of possibilities in fields like communication, healthcare, and human augmentation.
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AI-Powered Mind-Reading
AI-powered mind-reading, where thoughts are translated into written text, is an example of a fusion between neuroscience and artificial intelligence. This technology holds the potential to break barriers in communication, particularly for individuals who face challenges in speaking or writing due to disabilities.
At its core, this technology mainly takes advantage of neuroimaging techniques like FMRI and EEG as well as machine learning. fMRI, for instance, measures changes in blood flow in regions of the brain, indicating neural activity associated with specific thoughts or intentions. EEG also records electrical activity on the scalp, detecting patterns of brain waves linked to different cognitive processes.
The process begins when a user engages with an often wearable device equipped with sensors that can monitor neural activity. As the user thinks or focuses on a specific task, the sensors capture these neural patterns. Machine learning algorithms, trained on vast datasets of brain activity and corresponding text or commands, then come into play. These algorithms are used to decipher the complex relationship between trillions of neural patterns and ways of communication. They learn to recognize specific patterns associated with words, phrases, or actions and over time, the system becomes more and more accurate in translating these patterns into text. The “mindreading” process involves a bidirectional exchange, where a person thinks or intends to convey a message, the sensors capture their brain activity, and the AI then translates it into written text. To ensure individuals communicate their thoughts effectively, this process is refined so that it occurs rapidly and seamlessly.
In another remarkable achievement, scientists have reconstructed Pink Floyd's iconic song "Another Brick in the Wall" [9] by decoding people's brainwaves, marking the first time a recognizable song has been reproduced from recordings of electrical brain activity. Not only does this demonstrate the potential of neurotechnology, but also opens doors to helping patients with conditions such as stroke or amyotrophic lateral sclerosis (ALS) with expressing themselves. Unlike decoding speech from brain recordings, which often sounds robotic, this time scientists focused more on the emotional and prosodic elements of music.
Looking ahead, the widespread adoption of this kind of mind-reading technology holds immense promise. It has the potential to revolutionise the way we communicate, so that we can go beyond the traditional limitations of spoken and written language. Imagine a world where thoughts can be effortlessly conveyed, making education more accessible, business interactions more efficient, and relationships more profound. The applications that this kind of technology can offer are boundless, making a brighter future possible for those whose voices have long been unheard.
Mind-Controlled Gameplay
In "The Matrix" film series, Keanu Reeves famously plugged his brain directly into a virtual realm designed by sentient machines. While this plot may seem like dystopian fantasy, researchers at the University of Washington have taken a step towards demonstrating how humans can interact with virtual realities through direct brain stimulation.
In the early days of these game-changing experiments, participants were told to navigate through 21 different mazes, with their choices dictated solely by thinking about them. To move forward or down, they relied on their perception of visual stimulation artefacts known as phosphenes — perceived as blobs or bars of light that only we can see. The researchers ingeniously generated these phosphenes using TMS, which consists of a magnetic coil being placed near the skull to stimulate specific areas of the brain directly and non-invasively.
[10] The testers successfully navigated an average of 92 percent of the moves when they received input via direct brain stimulation to guide them through the experimental mazes (blue) versus only 15 percent of the steps in the control mazes when they received no such input (red mazes).University of Washington
Since then, mind-controlled gaming has advanced in unimaginable ways. What was once a niche experiment has transformed into a reality, with gamers now immersing themselves in popular games like Minecraft, Valorant and Elden Ring, only using their thoughts and EEGs. Not only does this showcase the potential of neurotechnology but also hints at the countless possibilities that await the gaming industry.
A popular Twitch streamer, Perrikaryal [11], captivates her audience by playing Elden Ring using EEGs. Perri explains that the technology records the unique patterns of her brainwaves and binds them to the corresponding in-game actions after adding in some code for the program to work, essentially turning her thoughts into commands. It's an immersive experience that not only showcases the potential of neurotechnology but also hints at countless possibilities in the gaming industry.
NEUROTECH AND PARKINSON’S
Neurotechnology isn't just about gaming and communication; it's making significant strides in the medical field. For those battling Parkinson's disease, a neurodegenerative disorder that has long presented a challenge for both patients and healthcare providers, deep brain stimulation (DBS) offers hope.
As mentioned when introducing invasive techniques, DBS is a surgical procedure that involves implanting electrodes into specific regions of the brain responsible for motor control, particularly the subthalamic nucleus. These electrodes are connected to a device similar to a pacemaker in the heart, known as a neurostimulator, placed beneath the skin in the chest area. Once activated, the neurostimulator emits electrical pulses that modulate abnormal neural activity, effectively dampening the tremors, rigidity, and bradykinesia caused by Parkinson's [12].
The science behind DBS revolves around disrupting the abnormal neural patterns that induce Parkinson's symptoms. The electrical pulses delivered by the neurostimulator effectively normalise the communication between neurons in the basal ganglia, a critical brain region involved in motor control. As a result, this correction of neural signalling can lead to significant improvements in a patient's motor functions, enabling them to go about their daily lives a lot more easily.
NEUROTECH AND ALZHEIMER’S
Alzheimer's disease, characterised by cognitive decline and memory impairment, poses a big obstacle for both individuals and their families and friends. Similar to Parkinson’s disease, there is no cure, but despite this, neurotechnology offers a chance for early diagnosis, treatment, and improved patient care.
One approach involves the use of neuroimaging techniques such as positron emission tomography (PET) and fMRI to detect early signs of Alzheimer's. These imaging methods can reveal changes in brain structure and function, including the accumulation of amyloid plaques and tau tangles, which are the hallmark indicators of the disease.
Additionally, cognitive training programs and brain-computer interfaces (BCIs) are being developed to aid individuals in the early stages of Alzheimer's. These programs aim to enhance cognitive function as well as memory retention by stimulating specific brain regions of patients when doing targeted tasks and exercises [13].
Scientists created these programs by taking advantage of neural plasticity — the brain's ability to adapt and rewire itself. Researchers have explored various methods including cognitive stimulation, cognitive training, and comprehensive cognitive rehabilitation, to stimulate patients’ neural pathways, potentially slowing down cognitive decline and improving memory cognitive abilities in AD patients.
In essence, neurotechnology is emerging as a potential avenue for enhancing rehabilitation efforts, not just for Parkinson’s and Alzheimers, but for many others as well. These new methods are offering symptom relief, but also contributing to the broader goal of unravelling the mysteries of these complex diseases. As research continues to advance, there is hope that one day, we may unlock even more effective treatments and, ultimately, a cure for these diseases through neural technology.
BIBLIOGRAPHY
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[6] Bern Dibner (2018). Luigi Galvani | Italian physician and physicist. In: Encyclopædia Britannica. [online] Available at: https://www.britannica.com/biography/Luigi-Galvani.
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[8] Neuralink (2021). Neuralink. [online] neuralink.com. Available at: https://neuralink.com/.
[9] published, C.S. (2023). Listen to Pink Floyd’s ‘Another Brick in the Wall,’ as decoded from human brain waves. [online] livescience.com. Available at: https://www.livescience.com/health/neuroscience/listen-to-pink-floyds-another-brick-in-the-wall-as-decoded-from-human-brain-waves [Accessed 26 Oct. 2023].
[10] Langston, J. (2016). No peeking: Humans play computer game using only direct brain stimulation. [online] UW News. Available at: https://www.washington.edu/news/2016/12/05/no-peeking-humans-play-computer-game-using-only-direct-brain-stimulation/ [Accessed 26 Oct. 2023].
[11] Bardhan, A. (2023). Twitch Streamer Plays Elden Ring Using Only Her Brain. [online] Kotaku. Available at: https://kotaku.com/twitch-streamer-elden-ring-play-brain-eeg-perrikaryal-1850024234 [Accessed 26 Oct. 2023].
[12] Vetlink, J. (2021). Artificial neuroprostheses as a solution for Parkinson’s disease [online] Available at: https://studenttheses.uu.nl/bitstream/handle/20.500.12932/41146/Bachelorscriptie%20Jet%20Veltink%20definitief%20(6188788).pdf?sequence=1 [Accessed 26 Oct. 2023].
[13] Beaini. F. Exploring Two Alternative BCIs for Improving Alzheimer’s Disease Rehabilitation [online] Available at:
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