Brain implant
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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, which became dysfunctional after a stroke or other head injuries. This includes sensory substitution, e.g. in vision. Brain implants involve creating interfaces between neural systems and computer chips, which are 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.)
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[edit] Research
Brain implants electrically stimulate or record from single neurons or groups of neurons (biological neural networks) in the brain. 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 also made steep progress in recent years.
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 have also proved useful in restoring patients hearing functions (however it is not clear whether these can be classified as "brain implants"). Multiple projects have demonstrated success at recording from the brain's of animals for long periods of time. Ed Schmidt's group at NIH recorded from Rhesus monkey motor cortex for over three years with immovable 'hatpin' electrodes<ref>xp Neurol. 1976 Sep;52(3):496-506</ref>, including recording from single neurons for over 30 days. 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<ref>Cyberkinetics array</ref>. These same electrodes, or derivations thereof using the same biocompatible electrode materials, are currently used in visual prosthetics laboratories<ref>[1]</ref>, laboratories studying the neural basis of learning<ref>[2]</ref>, and motor prosthetics approaches other than the Cyberkinetics probes<ref>[3]</ref>
Breakthroughs include the control of physical device by rat's brains ([4]), monkeys over robotic arms ([5]), remote control of mechanical devices by monkeys and humans ([6]), remote control over the movements of roaches ([7]), electronic-based neuron transistors for leeches ([8]), control of the movements of rats, etc. Currently both Cyberkinetics and the Nicolelis lab group at Duke University are conducting preliminary motor prosthetic implants in humans.
Since official statistics are not available, there is no way of knowing how many devices have been implanted in human brains. However The Times in 1994 estimated that there had been 15,000 cases in the previous decade, a number that includes cochlear implants as brain implants.
[edit] Rehabilitation
Brain pacemakers 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.
Research on neural implants is gaining impetus. One important effort is led by Theodore Berger, a professor of neural engineering at the University of Southern California. For 30 years, Berger has been developing a neural-silicon hybrid microchip that will mimic neurons to send signals from one brain cell to another, forming a bridge across damaged or dead brain cells that would originally block the message. The chip and the software have both been developed, but the hurdle is finding a compatible material for the microchip that would allow a stable connection between the chip and the constantly changing neural tissue. Possibilities include building the microchips out of materials that are compatible with the brain tissue, or coating the silicon microchips with molecules that will adhere to the brain tissue. This microchip could possibly help Alzheimer’s patients in forming memories once again. As time proceeds, it is feasible that these chips could be used in aiding the general public in memory recollection. Berger’s work may be an inspiration for a new biological computing era.
(see also nanotechnology, cognotechnology, and neurotechnology)
[edit] Historical research on brain implants
(see also: History of brain imaging)
In 1870, Eduard Hitzig and Gustav Fritsch demonstrated that electrical stimulation of certain areas 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.
Prominant research was conducted in the 1950s. Robert G. Heath experimented with aggressive mental patients, aiming to influence his subjects' moods through electrical stimulation.
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.
[edit] Ethical considerations
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. <ref>Burn D, Troster A (2004). "Neuropsychiatric Complications of Medical and Surgical Therapies for Parkinson's Disease.". Journal of Geriatric Psychiatry and Neurology 17 (3): 172-180. PMID 15312281.</ref>
Some futurists, such as Raymond Kurzweil, 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 is argued that implants would technically change people into cybernetic organisms (cyborgs). Some people fear implants may be used for mind control, e.g. to change human perception of reality.
[edit] Brain implants in fiction and philosophy
Rene Descartes, as part of arguing for how a being can be sure it exists, wrote in 1638 in his "Discourse on Method" of the possibility that an evil demon had trapped his mind in a black box, controlling all inputs and outputs. In Hilary Putnam's argument of the brain in a vat, he argues that brains, being directly fed with an input from a computer (instead of reality), would have no chance of detecting the deception. The popular 1999 film The Matrix, and its sequels, The Matrix Reloaded and The Matrix Revolutions, both in 2003, have expanded upon this argument, positing a world where machines have conquered humanity and placed the bodies in arrays to use for power, and are keeping them alive by immersing their minds in a computer-based constructed reality.
In the popular film series Star Wars, Anakin Skywalker (who becomes Darth Vader later) and Luke Skywalker both get their right hands cut off and they are replaced with robotic hands. Anakin also gets a breathing system attached to his chest when he becomes Darth Vader that helps him use and control his lungs.
In Bungie Studio's popular game Halo: Combat Evolved, the character Captain Keyes has neural implants which could be wirelessly updated at any given time.
In the 1983 film Brainstorm, a scientist develops the technology to record thoughts, feelings, and sensations, and to transfer them to another mind. It also hints at ethical problems when the military is trying to possess the technology.
In the video game Psychonauts, the mad doctor Caligosto Loboto implants a mutated lungfish with a brain implant. This implant causes the lungfish to kidnap psychic children to remove their brains. Within the psyche of the fish, the implant controls all of "Lungfishopolis" a fantasy city of anthropomorphized lungfish under siege by "Kochamora."
In the book The Terminal Man by Michael Crichton, a man suffering from brain damage caused by an accident undergoes experimental surgery to place implants in his brain. These implants are designed to calm him whenever it detects the start of a seizure. However, he soon abuses the chip, triggering it for pleasure; things deteriorate from there.
In the BBC serial "The Nightmare Man" the pilot of a high-tech mini submarine is linked to his craft via a brain implant. When the submarine is involved in an accident and is washed up on a beach the pilot releases himself by ripping out the implant and loses his mind completely, thus becoming a savage killer.
In another BBC series, 'Blake's Seven', a character called Gan has a brain implant known as a Limiter in the back of his skull. Convicted of killing an officer from the oppressive Federation, the Limiter is supposed to cut in when his stress levels might lead him to kill.
The anime and manga franchise Ghost in the Shell focuses on cyberbrain neural augmentation technology. It involves the implantation of powerful computers directly in the brain, giving a person a vastly increased memory capacity, total recall, as well as the ability to view his or her own memories on an external viewing device. Users can also initiate a "telepathic" conversation with another cyberbrain user, just by thinking it. However this opens up the possibility of cyberbrain hacking, malicious memory alteration, and the deliberate distortion of subjective reality and experience.
While popular treatises of brain implants are rare, discussion of mind control is more widespread. Especially popular visions of the control a totalitarian state can have over individuals' minds are Nineteen Eighty-Four, by George Orwell, and Brave New World, by Aldous Huxley. Stanisław Lem's The Futurological Congress, deals with control by drugs.
The novel series "Typers" focuses on military pilots flying ships with a sophisticated computer to which they are 'linked'; however instead of a direct brain implant the pilots are fitted with retractable metal spikes along their thoracic vertebra ('link prongs'). These appear to channel data to and from their brains via their spinal cords.
The game Shadowrun, published by FASA, popularized the use of the term "datajack" to describe such a port. A datajack was the most common way to operate a "deck" computer to interface with the game's "matrix" network. While access to the matrix though a helmet or web of external sensors placed around the head was possible, this method was more inefficient then a direct datajack connection. Datajacks could also be used for improved control over vehicles for "riggers" and for simple data transfer between external devices and memory inside the body, real or artificial.
The interface that humans used to connect their real bodies to the virtual computer world in the Matrix series of movies, a metallic port connected directly to a computer network, was very similar in opeation to the datajack concept in Shadowrun.
In the military science fiction series Exosquad, E-frame pilots control their machines (particularly, aiming and shooting functions) via "cyber jacks" connected to "cyber sockets" at the back of their necks, while the movement is steered manually.
In agent cody banks two, the villan uses a brain implant to control a dog, cody, and his bumbling partner.
[edit] See also
- Sensory substitution
- Mind control
- Biomedical engineering
- Cognotechnology
- Brain-computer interface
- Artificial brain
- Neuroprosthetics
- Cochlear implant
[edit] References
This article is based on the comprehensive illustrated essay "Brain Implants" by SkewsMe.com.
Additional References:
- Discover Magazine article on brain implants
- Neurotech Reports article on neural-silicon hybrid chips
[edit] External links
[edit] Further reading
- Theodore W. Berger's book Toward Replacement Parts for the Brain ISBN 0-262-02577-9.
- Jose Delgado's book Physical Control of the Mind
- Jim Keith, Mass Control: Engineering Human Consciousness. Adventures Unlimited Press. 2003. ISBN 1-931882-21-5.
