Brain Implants: From Science Fiction to Reality

November 14, 2023
Science Magazine

Can you imagine being able to control devices through mere thoughts or communicate with others telepathically? In just a few short years, brain implants could leap from the pages of science fiction novels and grant us this extraordinary power. While this new technology faces several challenges, its implementation may represent the next frontier in medicine and neuroscience. 

What are brain implants?

These tiny devices are surgically implanted or injected into the brain, where they establish direct communication with the neurons. Neurons are the cells responsible for transmitting electrochemical messages throughout our body, enabling sensory processing and motor activity. Brain implants typically consist of a collection of electrodes attached to specific regions of the brain, along with a central control unit responsible for processing the signals received from these electrodes.

The electrodes in brain implants can be used to either stimulate or record neural activity. Stimulation electrodes deliver electrical impulses to the brain, offering a treatment approach for various neurological conditions, such as Parkinson’s disease. On the other hand, recording electrodes detect and capture neural activity for research purposes or to control prosthetic devices.

Above: An illustration depicting the attachment of brain implants to the body. Image courtesy of NBC News.


While brain implants might enable disease treatment and improve our understanding of the brain, their use presents several challenges surrounding safety and efficacy. 

Biocompatibility: One major concern regarding brain implants is their compatibility with the human body. Poor biocompatibility impedes long-term usage. Brain implants are generally made from conductive materials, including metals. These materials have completely different physical and chemical properties compared to neural tissue. This incompatibility can activate the immune system and trigger inflammation.

Cost: Brain implants can be costly and are often not covered by insurance. This reality limits access to this technology for individuals who would benefit but cannot afford the implant and associated medical care. 

Technical limitations: Developing and maintaining brain implants requires advanced technical expertise. Researchers still need to overcome many technical challenges to make these devices practical and effective. For example, developing algorithms that can accurately interpret the signals produced by the brain requires significant computational resources.

Ethical considerations: The use of brain implants raises many ethical considerations, particularly regarding informed consent and privacy. As technology advances, brain implants might extend the limits of human capabilities, leaving society to grapple with psychological effects, questions of identity, and the meaning of personhood. 

Despite these significant challenges, ongoing research in this field aims to overcome many of these obstacles. As these devices become more reliable, accessible, and affordable, they have the potential to significantly improve the lives of individuals suffering from an array of neurological disorders.

How are brain implants used?

Brain implants are used in a variety of ways, with one of the most established being deep brain stimulation (DBS). Deep brain stimulation is a surgical procedure that treats symptoms of several medication-resistant neurological disorders, including Parkinson's disease, epilepsy, and dystonia. The treatment involves implanting electrodes that deliver an electrical current directly to certain areas of the brain, alleviating associated symptoms for many patients. The global count of patients who have undergone DBS implantation has surpassed 160,000, and this number continues to rise each year.

Above: Deep brain stimulation involves the electric stimulation of specific regions of the brain. Image courtesy of Mediglobus.

Researchers have also focused their efforts on targeting the brain through the vagus nerve. The vagus nerve is the longest cranial nerve in the body and oversees a variety of functions. In vagus nerve stimulation (VNS), mild pulses of electrical energy are sent to the brain at a constant rate via the vagus nerve using a device that is similar to a pacemaker. The Food and Drug Administration (FDA) approved the implantable vagus nerve stimulator for the treatment of conditions such as epilepsy and depression and, more recently, for select individuals with a history of stroke.

One development that has captivated significant public attention is mind-controlled prostheses. This revolutionary technology involves the implantation of electrodes into both the brain and muscles, enabling amputees to move their prosthetic by simply thinking about it. Additionally, scientists have recently begun to use brain implants to address spinal cord injuries. In May 2023, researchers managed to restore the communication between the brain and the spinal cord through a digital bridge in a patient with chronic tetraplegia. This technology allowed the patient to stand and walk naturally. These remarkable results offer hope for a wide array of applications for brain implants in the treatment of central nervous system injuries.

Finally, some innovations appear straight out of science fiction, such as the ambitious vision of Neuralink, the startup founded by Elon Musk. Neuralink's goal is to create implantable chips capable of translating thoughts into actions. According to its  website, the company’s primary objective is to assist individuals immobilized by paralysis in regaining lost communication abilities. 

Above: Neuralink’s brain implant. Image courtesy of Neuralink

Specifically, Neuralink aims to help those who cannot speak or write to communicate with others via a virtual mouse, keyboard, or messages sent through thought. Recently, Neuralink received approval to initiate human trials and is actively recruiting participants. 

From the transformative potential of deep brain stimulation in treating neurological disorders to Neuralink’s innovative work bringing new communication capabilities to people with paralysis, brain implants are revolutionizing the way we think about health and technology. This progress is bringing once-fictional ideas from our TV screens to reality, demonstrating the extraordinary possibilities that await us in the future.

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