Brain implant

Brain implants, often referred to as neural implants, are technological devices that connect directly to a biological subject's brain – usually placed on the surface of the brain, or attached to the brain's cortex. A common purpose of modern brain implants and the focus of much current research is establishing a biomedical prosthesis circumventing areas in the brain that have become dysfunctional after a stroke or other head injuries. This includes sensory substitution, e.g., in vision. Other brain implants are used in animal experiments simply to record brain activity for scientific reasons. Some brain implants involve creating interfaces between neural systems and computer chips. This work is part of a wider research field called brain-computer interfaces. (Brain-computer interface research also includes technology such as EEG arrays that allow interface between mind and machine but do not require direct implantation of a device.)

Neural implants such as deep brain stimulation and Vagus nerve stimulation are increasingly becoming routine for patients with Parkinson's disease and clinical depression respectively, proving themselves a boon for people with diseases which were previously regarded as incurable.


Brain implants electrically stimulate, block[1] or record (or both record and stimulate simultaneously[2]) signals from single neurons or groups of neurons (biological neural networks) in the brain. The blocking technique is called intra-abdominal vagal blocking.[1] This can only be done where the functional associations of these neurons are approximately known. Because of the complexity of neural processing and the lack of access to action potential related signals using neuroimaging techniques, the application of brain implants has been seriously limited until recent advances in neurophysiology and computer processing power.


Research in sensory substitution has made significant progress since 1970. Especially in vision, due to the knowledge of the working of the visual system, eye implants (often involving some brain implants or monitoring) have been applied with demonstrated success. For hearing, cochlear implants are used to stimulate the auditory nerve directly. The vestibulocochlear nerve is part of the peripheral nervous system, but the interface is similar to that of true brain implants.

Multiple projects have demonstrated success at recording from the brains of animals for long periods of time. As early as 1976, researchers at the NIH led by Edward Schmidt made action potential recordings of signals from rhesus monkey motor cortexes using immovable "hatpin" electrodes,[3] including recording from single neurons for over 30 days, and consistent recordings for greater than three years from the best electrodes.

The "hatpin" electrodes were made of pure iridium and insulated with Parylene-c, materials that are currently used in the Cyberkinetics implementation of the Utah array.[4] These same electrodes, or derivations thereof using the same biocompatible electrode materials, are currently used in visual prosthetics laboratories,[5] laboratories studying the neural basis of learning,[6] and motor prosthetics approaches other than the Cyberkinetics probes.[7]

Schematic of the "Utah" Electrode Array

Other laboratory groups produce their own implants to provide unique capabilities not available from the commercial products.[8][9][10][11]

Breakthroughs include studies of the process of functional brain re-wiring throughout the learning of a sensory discrimination,[12] control of physical devices by rat brains,[13] monkeys over robotic arms,[14] remote control of mechanical devices by monkeys and humans,[15] remote control over the movements of roaches,[16] electronic-based neuron transistors for leeches,[17] the first reported use of the Utah Array in a human for bidirectional signalling.[18] Currently a number of groups are conducting preliminary motor prosthetic implants in humans. These studies are presently limited to several months by the longevity of the implants.

Much research is also being done on the surface chemistry of neural implants in effort to design products which minimize all negative effects that an active implant can have on the brain, and that the body can have on the function of the implant.

Another type of neural implant that is being experimented on is Prosthetic Neuronal Memory Silicon Chips, which imitate the signal processing done by functioning neurons that allows peoples' brains to create long-term memories.

In 2016, scientists at the University of Illinois at Urbana-Champaign announced development of tiny brain sensors for use postoperative monitoring, which melt away when they are no longer needed.[19]


Neurostimulators have been in use since 1997 to ease the symptoms of such diseases as epilepsy, Parkinson's Disease, dystonia and recently depression.

Current brain implants are made from a variety of materials such as tungsten, silicon, platinum-iridium, or even stainless steel. Future brain implants may make use of more exotic materials such as nanoscale carbon fibers (nanotubes), and polycarbonate urethane.

Historical research

In 1870, Eduard Hitzig and Gustav Fritsch demonstrated that electrical stimulation of the brains of dogs could produce movements. Robert Bartholow showed the same to be true for humans in 1874. By the start of the 20th century, Fedor Krause began to systematically map human brain areas, using patients that had undergone brain surgery.

Prominent research was conducted in the 1950s. Robert G. Heath experimented with aggressive mental patients, aiming to influence his subjects' moods through electrical stimulation.[20]

Yale University physiologist Jose Delgado demonstrated limited control of animal and human subjects' behaviours using electronic stimulation. He invented the stimoceiver or transdermal stimulator, a device implanted in the brain to transmit electrical impulses that modify basic behaviours such as aggression or sensations of pleasure.

Delgado was later to write a popular book on mind control, called Physical Control of the Mind, where he stated: "the feasibility of remote control of activities in several species of animals has been demonstrated [...] The ultimate objective of this research is to provide an understanding of the mechanisms involved in the directional control of animals and to provide practical systems suitable for human application."

In the 1950s, the CIA also funded research into mind control techniques, through programs such as MKULTRA. Perhaps because he received funding for some research through the US Office of Naval Research, it has been suggested (but not proven) that Delgado also received backing through the CIA. He denied this claim in a 2005 article in Scientific American describing it only as a speculation by conspiracy-theorists. He stated that his research was only progressively scientifically motivated to understand how the brain works.

Ethical considerations

Who are good candidates to receive neural implants? What are the good uses of neural implants and what are the bad uses? Whilst deep brain stimulation is increasingly becoming routine for patients with Parkinson's disease, there may be some behavioural side effects. Reports in the literature describe the possibility of apathy, hallucinations, compulsive gambling, hypersexuality, cognitive dysfunction, and depression. However, these may be temporary and related to correct placement and calibration of the stimulator and so are potentially reversible.[21]

Some transhumanists, such as Raymond Kurzweil and Kevin Warwick, see brain implants as part of a next step for humans in progress and evolution, whereas others, especially bioconservatives, view them as unnatural, with humankind losing essential human qualities. It raises controversy similar to other forms of human enhancement. For instance, it is argued that implants would technically change people into cybernetic organisms (cyborgs). It's also expected that all research will comply to the Declaration of Helsinki. Yet further, the usual legal duties apply such as information to the person wearing implants and that the implants are voluntary, with (very) few exceptions.

In fiction and philosophy

Brain implants are now part of modern culture but there were early philosophical references of relevance as far back as René Descartes.

In his 1638 Discourse on the Method, a study on proving self existence, Descartes wrote that a person would not know if an evil demon had trapped his mind in a black box and was controlling all inputs and outputs. Philosopher Hilary Putnam provided a modern parallel of Descartes argument in his 1989 discussion of a brain in a vat, where he argues that brains which were directly fed with an input from a computer would not know the deception from reality.

Popular science fiction discussing brain implants and mind control became widespread in the 20th century, often with a dystopian outlook. Literature in the 1970s delved into the topic, including The Terminal Man by Michael Crichton, where a man suffering from brain damage receives an experimental surgical brain implant designed to prevent seizures, which he abuses by triggering for pleasure. Another example is Larry Niven's science fiction writing of wire-heads in his "Known Space" stories.

Fear that the technology will be misused by the government and military is an early theme. In the 1981 BBC serial The Nightmare Man the pilot of a high-tech mini submarine is linked to his craft via a brain implant but becomes a savage killer after ripping out the implant.

Perhaps the most influential novel exploring the world of brain implants was William Gibson's 1984 novel Neuromancer. This was the first novel in a genre that came to be known as "cyberpunk". It follows a computer hacker through a world where mercenaries are augmented with brain implants to enhance strength, vision, memory, etc. Gibson coins the term "matrix" and introduces the concept of "jacking in" with head electrodes or direct implants. He also explores possible entertainment applications of brain implants such as the "simstim" (simulated stimulation) which is a device used to record and playback experiences.

Another example is "The Alliance ", in which a society is controlled by implants. Gibson's work led to an explosion in popular culture references to brain implants. Its influences are felt, for example, in the 1989 roleplaying game Shadowrun, which borrowed his term "datajack" to describe a brain-computer interface. The implants in Gibson's novels and short stories formed the template for the 1995 film Johnny Mnemonic and later, The Matrix Trilogy.

Pulp fiction with implants or brain implants include the novel series Typers, film Spider-Man 2, the TV series Earth: Final Conflict, and numerous computer/video games.



Video games

The game raises the question of the downsides of this kind of augmentation as those who cannot afford the enhancements (or object to getting them) rapidly find themselves at a serious disadvantage against people with artificial enhancement of their abilities. The spectre of being forced to have mechanical or electronic enhancements just to get a job is explored as well. The storyline addresses the effect of implant rejection by use of the fictional drug 'Neuropozyne' which breaks down glial tissue and is also fiercely addictive, leaving people who have augmentations little choice but to continue buying the drug from biotech corporations who control the price of it. Without the drug, augmented people experience rejection of implants, crippling pain and possible death.

See also


  1. 1 2 "Implantable Device that Blocks Brain Signals Shows Promise in Obesity". Medscape. Retrieved 2013-08-25.
  2. Patrick Mahoney (June 21, 2007). "Wireless is getting under our skin". Machine Design. Archived from the original on 2008-06-04. Retrieved 2011-08-14.
  3. Schmidt, E.M.; Bak, M.J.; McIntosh, J.S. (1976). "Long-term chronic recording from cortical neurons". Experimental Neurology. 52 (3): 496–506. doi:10.1016/0014-4886(76)90220-X. PMID 821770.
  4. Archived March 24, 2006, at the Wayback Machine. Cyberkinetics array
  5. Troyk, Philip; Bak, Martin; Berg, Joshua; Bradley, David; Cogan, Stuart; Erickson, Robert; Kufta, Conrad; McCreery, Douglas; Schmidt, Edward (2003). "A Model for Intracortical Visual Prosthesis Research". Artificial Organs. 27 (11): 1005–15. doi:10.1046/j.1525-1594.2003.07308.x. PMID 14616519.
  6. Blake, David T.; Heiser, Marc A.; Caywood, Matthew; Merzenich, Michael M. (2006). "Experience-Dependent Adult Cortical Plasticity Requires Cognitive Association between Sensation and Reward". Neuron. 52 (2): 371–81. doi:10.1016/j.neuron.2006.08.009. PMC 2826987Freely accessible. PMID 17046698.
  7. "Neuroscientists Demonstrate New Way to Control Prosthetic Device with Brain Signals" (Press release). Caltech. July 8, 2004. Archived from the original on July 19, 2011. Retrieved February 26, 2011.
  8. "Laboratory for Integrative Neural Systems | RIKEN". Retrieved 2011-08-14.
  9. "Blake Laboratory: Neural basis of behavior". 2007-08-16. Archived from the original on 2010-05-28. Retrieved 2011-08-14.
  10. "Robert H. Wurtz, Ph.D. [NEI Laboratories]". Retrieved 2011-08-14.
  11. "Brain Research Institute". Retrieved 2011-08-14.
  12. "Making the connection between a sound and a reward changes brain and behavior". 2006-10-19. Retrieved 2008-04-25.
  13. Chapin, John K. "Robot arm controlled using command signals recorded directly from brain neurons". SUNY Downstate Medical Center. Retrieved 2008-04-25.
  14. Graham-Rowe, Duncan (2003-10-13). "Monkey's brain signals control 'third arm'". New Scientist. Retrieved 2008-04-25.
  15. Mishra, Raja (2004-10-09). "Implant could free power of thought for paralyzed". Boston Globe. Retrieved 2008-04-25.
  16. Talmadoe, Eric (July 2001). "Japan's latest innovation: a remote-control roach". Associated Press. Retrieved 2008-04-25.
  17. Gross, Michael (September 2004). "Plugging brains into computers". Chemistry World. Royal Society of Chemistry. Retrieved 2008-04-25.
  18. Warwick, K.; Gasson, M; Hutt, B; Goodhew, I; Kyberd, P; Andrews, B; Teddy, P; Shad, A (2003). "The Application of Implant Technology for Cybernetic Systems". Archives of Neurology. 60 (10): 1369–73. doi:10.1001/archneur.60.10.1369. PMID 14568806.
  19. "Tiny electronic implants monitor brain injury, then melt away". University of Illinois at Urbana-Champaign. January 18, 2016.
  20. "Septal stimulation for the initiation of heterosexual behavior in a homosexual male". Science Direct.
  21. Burn, D. J.; Tröster, AI (2004). "Neuropsychiatric Complications of Medical and Surgical Therapies for Parkinson's Disease". Journal of Geriatric Psychiatry and Neurology. 17 (3): 172–80. doi:10.1177/0891988704267466. PMID 15312281.
  22. Pringle, David. Science Fiction: The 100 Best Novels. ISBN 0-947761-11-X. Retrieved 16 February 2016.

Further reading

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