Understanding Brain Functionality

The human brain consists of roughly 86 billion neurons, which are just one category of the various cell types present in our brains.

Neurons primarily function to transmit and receive information. They generally share three common components: dendrites that accept signals, a cell body (soma) that processes these signals, and an axon that propagates the signal to other neurons or specialized cells.

The signals communicated within neurons are electrical in nature. Every thought, emotion, and action we experience is derived from these electrical impulses in the brain.

Neurons connect via synapses, where an axon from one neuron meets a dendrite from another. When an electrical signal travels down an axon, it prompts the release of neurotransmitters—chemicals that convert electrical energy into chemical signals. These neurotransmitters cross the synapse and trigger ion channels in the dendrite, reinstating the electrical signal. While the specifics can be intricate, this process is essential for transmitting signals between neurons.

When a neuron receives a sufficiently strong signal, it generates an action potential, passing the signal onward. This action potential operates on an "all-or-nothing" principle: if the signal isn’t strong enough, it won’t trigger an action potential, halting the transmission. If the threshold is surpassed, however, the signal continues.

This simplified understanding of neuronal activity underpins our capabilities to see, think, move, and feel—essentially, everything we do is rooted in these electrical signals.

Given their electrical nature, placing electrodes near these axons allows us to detect action potentials, which is the foundation of Neuralink's technology.

While developing a comprehensive brain-machine interface remains a distant goal, Neuralink is concentrating on specific brain regions.

Certain brain areas correspond to distinct functions; for instance, the occipital lobe is linked to visual processing, while the frontal cortex governs higher cognitive processes such as memory, emotions, and impulse control.

A historical case illustrates this discovery: Phineas Gage, a railroad foreman in Vermont, experienced a life-altering accident in 1848. A tamping iron pierced his skull, leading to significant damage to his frontal cortex. Remarkably, he survived, but his personality changed drastically, demonstrating that this brain region is crucial for higher cognitive functions.

Although some may argue that Gage’s behavioral changes could be attributed to trauma, subsequent research has supported the connection between the frontal cortex and cognitive functions.

Neuralink's focus is on the primary motor cortex, which is vital for controlling bodily movements.

The company is developing an implant designed to detect electrical signals in the brain, allowing users to control devices solely through their thoughts.

The implant, referred to as "The Link," consists of two components: a small, sealed device that transmits the detected signals, and ultra-fine threads embedded with numerous electrodes.

These threads are inserted into the primary motor cortex, where they detect neuronal electrical impulses and relay this information back to the Link transmitter.

The entire device is implanted within the skull, with no external components, charging wirelessly from outside the body, similar to modern smartphones.

Due to the precision required for placing these threads, Neuralink is developing a robotic system, inspired by a prototype from the University of California, that will ensure accurate insertion of the microfibers.

Neuralink's Unique Approach

It's crucial to recognize that Neuralink is not the first to create a brain-machine interface; their technology builds upon decades of academic research, including several ongoing human trials.

Currently, only a limited number of devices approved for brain recording or stimulation exist, such as those used for deep brain stimulation (DBS) to treat neurological disorders like Parkinson's disease.

These devices typically modulate activity across broad brain regions, relying on fewer than ten electrodes and being substantially larger than Neuralink's threads.

Other devices in clinical trials for BMI movement control or sensory restoration have also been developed, but they generally feature only a few hundred electrodes and are either surface-mounted or rigidly positioned. In contrast, Neuralink's design includes an order of magnitude more electrodes and flexible threads that are precisely placed to optimize coverage while avoiding blood vessels.

The primary objective of Neuralink's device is to significantly advance the field by providing unprecedented accuracy and functionality.

Current Development Status

Although the implant hasn't been tested on humans yet, it has been successfully implanted in a pig. Gertrude, one such pig, was presented at a Neuralink event hosted by Elon Musk.

In the demonstration, Gertrude had the device implanted, with electrodes positioned in a brain region responsible for processing sensory input from her snout, which is highly sensitive.

The white spots in the video indicate spikes from individual electrodes, while the blue areas represent significant signals detected by the device.

This showcases that Neuralink has developed an implant capable of transmitting real-time brain recordings to a computer while the subject interacts with its environment, marking a significant advancement in brain-computer interface research.

While other wireless brain implants exist, they often require extensive surgical procedures and tend to be bulky or limited in placement options.

Although considerable research has been conducted on decoding brain data, efficient data collection remains elusive. If Neuralink can successfully transition this technology to human subjects, it could create exciting opportunities for researchers.

The Future of Neuralink's Innovations

Looking ahead, Neuralink's technology has the potential to transform the treatment of various debilitating neurological conditions. However, many are curious about the prospect of downloading knowledge directly into our brains, Matrix-style.

Unfortunately, that vision is still a long way off.

Elon Musk has expressed grand ambitions about merging human intelligence with artificial intelligence (AI), a goal that is anything but simple, and we are currently far from achieving it.

Presently, most brain-machine interfaces utilize a "biomimetic" decoding strategy. This involves recording brain activity while a user imagines specific movements, allowing researchers to decode subsequent movements by tallying action potentials.

While this method works for basic movements, its application to more complex thoughts remains uncertain. Even if Neuralink could sample a vast number of neurons in an individual’s brain, questions arise regarding the calibration needed for an effective mind-reading device and the variability in brain activity associated with repeated thoughts.

The evidence suggests that individual brain activity is unique, influenced by various factors over time, complicating the prospect of a standardized brain interface.

Some researchers believe that AI could help decipher these signals, akin to how it has improved speech recognition. Given enough data, AI might learn to interpret signals from any brain. However, unlike language, which has shared grammatical rules, individual brain activities are not standardized.

Recent investigations into brain function are exploring the activity patterns of large neuron groups. In the future, this could lead to the discovery of universal principles governing thought processes, simplifying mind-reading efforts.

Alternatively, we may need to consider brain-machine interfaces as skills that require mastery, similar to riding a bike. Users can learn to manipulate their brain signals through neurofeedback, suggesting that proficiency in this technology might vary among individuals.

The challenges escalate when considering influencing the brain instead of merely reading its signals. Electrical stimulation can activate many neurons simultaneously, but given the diverse roles of brain cells, creating meaningful experiences remains difficult. For instance, while stimulating visual areas can enable blind individuals to perceive flashes of light, replicating even basic visual scenes is still beyond our reach.

Nonetheless, Elon Musk's track record suggests that underestimating his ambitions is unwise. Neuralink's work holds tremendous promise, providing insights previously unattainable with existing BMI technologies.

While the brain's complexities present formidable obstacles, a truly bidirectional brain-machine interface is likely decades away. Nevertheless, Neuralink is making significant strides toward this ambitious goal.

Thank you for reading. Don’t forget to explore my other work and subscribe to my YouTube channel (The Dev Doctor) for audio versions of my articles.