there is such surgery as brain implants
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.)
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[1], 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[2]. These same electrodes, or derivations thereof using the same biocompatible electrode materials, are currently used in visual prosthetics laboratories[3], laboratories studying the neural basis of learning[4], and motor prosthetics approaches other than the Cyberkinetics probes[5]
Schematic of the "Utah" Electrode ArrayBreakthroughs 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.
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.
2007-01-04 11:12:15
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answer #1
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answered by jamaica 5
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