Published on Mar 12, 2016
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 , popularly called brain-machine interfaces .
Some futurologists , 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
Brain implants in fiction and philosophy
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.
The neurotrophic electrode is implanted into the motor cortex of the brain using a tiny glass encasing. Neurotrophic growth factors are implanted into the glass, and the cortical cells grow into the electrode and form contacts. It takes several weeks for the cortical tissue to grow into the electrode. The neurons in the brain transmit an electronic signal when they "fire." Recording wires are placed inside the glass cone to pick up the neural signals from the ingrown brain tissue and transmit them through the skin to a receiver and amplifier outside of the scalp.
Brain Implants That Allow "Willful Thinking"
Neuroscientists have implanted a device in the motor neocortex of two people that has allowed them to operate a computer display by "thinking" about it. It has been known for many years that direct electrical stimulation of particular brain regions can elicit sensory experiences, memory recall, or motor responses. However, unlike scenes from many (oftentimes bad) science fiction movies, it has always been unclear whether or not brain cell activity could be used to control external machines.
Dr. Phillip R. Kennedy, a researcher who has worked with researchers at Georgia Institute of Technology and Emory University, developed an implant that can be used to detect that activity of neurons, and convey these signals to computers for further processing and control operations. The small recording sensor is enclosed in a glass envelope and coated with nerve growth factors that allow neurons in the region of the implant to establish functional connections with the sensor. Normally, when recording electrodes are implanted in brain tissue the region surrounding the electrode is enveloped by glial cells (Module 1; Principles of Psychobiology) that attempt to encapsulate the "foreign" material.
This electrically isolates the recording electrodes from small amplitude potentials that are conveyed by individual axons, dendrites or gap junctions (Modules 1-5; Principles of Psychobiology). The key development is the application of nerve growth factors that apparently encourages the growth of functional connections to the recording electrode -- This formation of intact connections could be followed after implantation by a change in the pattern of electrical activity detected by the electrode.
Surgeries on two patients were performed by Dr. Roy Bakay from Emory, who presented the findings at the Congress of Neurological Surgeons annual meeting in Seattle. The electrodes were implanted in the motor cortex, near the arm/facial region (Module 7c; Principles of Psychobiology), and signals were routed to a computer that moved a cursor across a screen to an icon region. Both patients were paralyzed and unable to move their limbs or speak. The first patient, who had the implant for 2.5 months before dying from amyotrophic lateral sclerosis, learned to control the signals in an "on-off manner" for seven days. The second patient (J.R.), who suffered brain stem stroke after a heart attack, has had the implant for 6 months. Initially, this patient had a problem stopping his brain's electrical activity, but researchers programmed a pause into the system so that whenever the cursor landed on an icon, it stopped. Eventually, the patient was able to stop the cursor at an icon and click it to say a word or a phrase.
The device, called the BrainGate system, uses a tiny silicone chip and electrodes implanted in the brain designed to allow people who can't move to operate a computer with their thoughts. Previous studies of the device in monkeys showed that it allowed the animals to use their brains to control cursor movements on a computer screen.
Experts say this is just the first of many such brain implants that will be moving from the drawing board and animal testing to clinical trials in humans in the not-so-distant future.
The hope is that these devices may eventually help people with movement problems caused by spinal cord injury, stroke, Lou Gehrig's disease, and other disorders, communicate better and gain greater independence.
Researchers say the advances made in treating disabled and impaired people with brain implants may also have much broader implications in treating a wide range of ailments -- from depression to cerebral palsy.
"There's something for the benefit of everybody with a better understanding of how the brain works," says Eric Braverman, MD, director of the Place for Achieving Total Health (PATH) in New York City.
But experts say the more immediate challenge will be translating the information gained in this first-ever trial of thought-controlled devices in humans into technologies that may restore movement in paralyzed people.
"It's a big step from controlling a computer cursor to ultimately controlling a robot arm or an artificial limb," says neurologist John W. Krakauer, MD, assistant professor of medicine at Columbia University in New York City. "It's not just a little bit more difficult, but it's a categorically more difficult problem."
More Seminar Topics:
Dual Energy X-ray Absorptiometry,
Disease Detection Using Bio-robotics,
Biometrics Based Authentication Systems,
Bacterio Rhodopsin Memory,
Carbon Nanotube Flow Sensors,