Krista and Tatiana Hogan are craniopagus conjoined twins, which means that they are physically connected at the skull. In this rare case, not only are their skulls conjoined, but so are their brains. The thalamus functions as the central information relay hub in the brain. You can think of it as the brain’s post office: processing and routing most motor and sensory information to different regions of the brain. The connection of each of the twins’ thalamus creates what is called a Thalamic Bridge. MRI imaging showed bidirectional neural transmission through this bridge.
When they undertook hospital tests, flashing a light in one twin's eyes produced a response in the other's visual cortex, even when her own eyes were covered. Further reports say that Krista and Tatiana share taste, share touch, can see out of each other's eyes, and the twins say that they can have conversations with each other inside their own heads. This demonstration of neural integration raises questions about the potential of neurotechnology and makes you wonder how your mind and consciousness could be shared with another person or even technology (1,2).
The human brain is considered the most complex object known to science. Neurotechnology has become one of the best ways to observe and understand the rapidly changing, complex patterns and signals of the brain. The field is accelerating faster than it ever has and is entering a period of explosive growth. At its core, neurotechnology is any technology designed to record, analyse, or modulate neural activity. This includes devices/equipment from cochlear implants, to brain-computer interfaces. A brain-computer interface (BCI) is a direct communication link between the brain's electrical activity and an external device, like a computer or robotic hand.
You can simplify the majority of BCIs into three components:
The probe: The part that directly connects to, retrieves signals from, or stimulates the brain.
The signal processing and decoding layer: Turns neural activity into an interpretable signal.
The software and application layer: This is where the decoded signals get applied, analysed, or used for feedback (visual, haptic or direct stimulation).
A BCI company called Science Corp, founded by former co-founder and president of Neuralink, Max Hodak, is working on a very interesting new type of probe called a Biohybrid Probe. Most traditional BCIs plug into the brain with electrodes, which can cause initial and continuing damage to the surrounding neurons. This means that the signals the probes are initially trying to read become degraded, and degrade even more over time. Science Corp believes the solution may be a biohybrid probe. The idea is that the probe uses engineered lab-grown neurons which are embedded in electronics and then engrafted onto the brain. The goal is that these neurons naturally grow into the brain, creating a biological bridge that can then transmit and receive signals to and from an external device. Although it is still in its early phases, there have been promising results shown across a variety of studies. They have tested the idea on mice and saw the transplanted neurons sending out fibres down into the brain of the mice. Some of these neurons also showed electrical activity, similar to the normal brain cells in the mice, suggesting they were behaving like functioning neurons and integrating with the mice's brain (3).
The founder of Science Corp likened the concept to having a “13th cranial nerve”; an additional neural pathway extending the brain's ability to connect with the external world. He also compared the idea to the movie Avatar, where the native people named the Na’vi have a ‘neural braid’ that allows them to form a direct biological connection with other living beings and with ‘Eywa’, the interconnected consciousness of their world (4).
As well as the early stages of their Biohybrid Probe, the company also has an established and clinically validated product called PRIMA. PRIMA is a retinal BCI implant that, in an almost biblical manner, is giving sight to the blind. It is specifically designed for people with age-related macular degeneration (AMD), which affects over 200 million people worldwide. Put simply, the user would wear special glasses with a small camera that captures images. The processed images are projected onto the implant using pulsed near-infrared light. The implant then electrically stimulates certain remaining retinal cells. Those signals travel through the optic nerve to the brain, which can then interpret the signals as visual information, helping someone see shapes, objects, and letters.
Although it only partially restores eyesight to a patient, PRIMA is a major display of the potential of BCIs. In a major international clinical trial of patients with an advanced, late-stage form of AMD, more than 80% of participants regained meaningful central vision. In July 2026, PRIMA was approved for commercial use in 30 European countries. It has now become the first commercially approved BCI for vision restoration (5, 6).
The capabilities of BCIs in general are becoming more established, with trials, studies and companies seeing immense progress. Some of the established capabilities of BCIs are:
Thought to speech - A patient can think of a sentence such as “Hello World”, and a BCI can decode it into text or computer-generated speech (7).
Controlling a computer with thought - A user can browse the internet, type, play video games, send emails, and much more (8).
Controlling a robotic arm or device - A user could think “I want my hand to move left”, and a computer can then convert the brain signals from that thought into a command for a robotic arm. A paralysed woman has started painting with a robotic arm thanks to Neuralink’s brain implant (9, 10).
All these capabilities aren't just mere one-time results or vague claims from researchers and companies. They are established, repeated capabilities that are becoming industry norms. For example, a 2026 study with a participant with Amyotrophic lateral sclerosis (a rare, fatal neurodegenerative disease that destroys the nerve cells responsible for controlling voluntary muscle movement) and severe paralysis demonstrated an implanted BCI being used for thought-to-speech for two years. The participant used it for more than 3,800 hours, producing more than 1.9 million words, with an average communication rate of 56 words per minute. In formal testing, attempted speech was decoded at more than 99% word accuracy (11).
The potential benefits of this field are extraordinary, such as treatments for conditions that affect billions of people, from mental health conditions to epilepsy, Alzheimer's and the majority of brain-related conditions where treatment is hindered due to our lack of knowledge and control of the brain. We are already seeing the field of neurotechnology achieve feats like restoring sight to the blind, providing treatments for Parkinson's (12), as well as relieving some of the most intense suffering that results from conditions such as full-body paralysis. A majority of suffering is an experience mediated by the brain. Through advanced neurotechnology, we could radically reduce or even abolish the experience of suffering. Many argue neurotech may even be essential to fight the problem with ‘AI alignment’ by enabling us to augment human intelligence to keep up with or compete with AI. Either way, the field is in its early stages, with the brain being observed and decoded in more detail than ever before.
References
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3. Brown J, Zappitelli KM, Dawson PM, et al. Optogenetic stimulation of a cortical biohybrid implant guides goal directed behavior [preprint]. bioRxiv. 2024. doi:10.1101/2024.11.22.624907.
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8. Card NS, Singer-Clark T, Peracha H, et al. Long-term independent use of an intracortical brain-computer interface for speech and cursor control. Nat Med. 2026. doi:10.1038/s41591-026-04414-6. Available from: https://www.nature.com/articles/s41591-026-04414-6
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10. Neuralink. Creating art with the mind [Internet]. LinkedIn; 2026. Available from: https://www.linkedin.com/posts/neuralink_creating-art-with-the-mind-activity-7461117355343982592-ZptQ
11. Card NS, Singer-Clark T, Peracha H, et al. Long-term independent use of an intracortical brain-computer interface for speech and cursor control. Nat Med. 2026. Available from: https://www.nature.com/articles/s41591-026-04414-6
12. National Institute for Health and Care Excellence. Deep brain stimulation for Parkinson's disease [Internet]. London: NICE. Available from: https://www.nice.org.uk/
13. Fulton JT. 9.1-2 An MRI image of the brains of the conjoined BC twin sisters [Internet]. ResearchGate; 2023. Available from: https://www.researchgate.net/figure/2-An-MRI-image-of-the-brains-of-the-conjoined-BC-twin-sisters-The-thalamic-bridge-is_fig10_372721878
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15. IEEE Spectrum. Biohybrid BCI adds more neurons to the brain [Internet]. Available from: https://spectrum.ieee.org/brain-computer-interface-2671151260
16. Lightstorm Entertainment. Avatar [film]. 20th Century Studios; 2009.
17. Science Corporation. PRIMA retinal implant [photograph]. In: CBS News. Tiny eye implant, special glasses help some legally blind patients read again [Internet]. 2025 Oct 20. Available from: https://www.cbsnews.com/news/eye-implant-special-glasses-help-some-legally-blind-patients-read-again/
18. Neuralink. Speaking with the mind [Video on the Internet]. YouTube; 2026 Sep 18. Available from: https://www.youtube.com/@neuralink
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