A
brain–computer interface (
BCI), sometimes called a
direct neural interface or a
brain–machine interface, is a direct communication pathway between a
brainThe brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all...
and an external device. BCIs are often aimed at assisting, augmenting or repairing human cognitive or sensory-motor functions.
Research on BCIs began in the 1970s at the University of California Los Angeles (UCLA) under a grant from the
National Science FoundationThe National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
, followed by a contract from DARPA. The papers published after this research also mark the first appearance of the expression
brain–computer interface in scientific literature.
The field of BCI has since blossomed spectacularly, mostly toward neuroprosthetics applications that aim at restoring damaged hearing, sight and movement. Thanks to the remarkable cortical plasticity of the brain, signals from implanted prostheses can, after adaptation, be handled by the brain like natural sensor or effector channels.
Following years of animal experimentation, the first neuroprosthetic devices implanted in humans appeared in the mid-nineties.
BCI versus neuroprosthetics
Neuroprosthetics is an area of
neuroscienceNeuroscience is the scientific study of the nervous system. Such studies span the structure, function, evolutionary history, development, genetics, biochemistry, physiology, pharmacology, informatics, computational neuroscience and pathology of the nervous system.The International Brain Research...
concerned with neural prostheses—using artificial devices to replace the function of impaired nervous systems or sensory organs. The most widely used neuroprosthetic device is the
cochlear implantA cochlear implant is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. The cochlear implant is often referred to as a bionic ear...
, which, as of 2006, has been implanted in approximately 100,000 people worldwide.
There are also several neuroprosthetic devices that aim to restore vision, including
retinal implantA retinal implant is a biomedical implant technology currently being developed by a number of private companies and research institutions worldwide. The implant is meant to partially restore useful vision to people who have lost theirs due to degenerative eye conditions such as retinitis...
s.
The differences between BCIs and neuroprosthetics are mostly in the ways the terms are used: neuroprosthetics typically connect the nervous system to a device, whereas BCIs usually connect the brain (or nervous system) with a computer system. Practical neuroprosthetics can be linked to any part of the nervous system—for example, peripheral nerves—while the term "BCI" usually designates a narrower class of systems which interface with the central nervous system.
The terms are sometimes used interchangeably, and for good reason. Neuroprosthetics and BCIs seek to achieve the same aims, such as restoring sight, hearing, movement, ability to communicate, and even cognitive function. Both use similar experimental methods and surgical techniques.
Animal BCI research
Several laboratories have managed to record signals from monkey and rat
cerebral corticesThe cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It constitutes the outermost layer of the cerebrum. In preserved brains, it has a grey color, hence the name "grey matter"...
in order to operate BCIs to carry out movement. Monkeys have navigated computer cursors on screen and commanded robotic arms to perform simple tasks simply by thinking about the task and without any motor output. In May 2008 photographs that showed a monkey operating a robotic arm with its mind at the Pittsburgh University Medical Center were published in a number of well known science journals and magazines. Other research on cats has decoded visual signals.
Early work
The
operant conditioningOperant conditioning is the use of consequences to modify the occurrence and form of behavior. Operant conditioning is distinguished from classical conditioning in that operant conditioning deals with the modification of "voluntary behavior" or operant behavior...
studies of Fetz and colleagues first demonstrated that monkeys could learn to control the deflection of a
biofeedbackBiofeedback is a non-medical process that involves measuring a subject's specific and quantifiable bodily functions such as blood pressure, heart rate, skin temperature, sweat gland activity, and muscle tension, conveying the information to the patient in real-time...
meter arm with neural activity . Such work in the 1970s established that monkeys could quickly learn to voluntarily control the firing rates of individual and multiple neurons in the primary
motor cortexMotor cortex is a term that describes regions of the cerebral cortex involved in the planning, control, and execution of voluntary motor functions.-Anatomy of the motor cortex :The motor cortex can be divided into six main parts:...
if they were rewarded for generating appropriate patterns of neural activity.
Studies that developed algorithms to reconstruct movements from
motor cortexMotor cortex is a term that describes regions of the cerebral cortex involved in the planning, control, and execution of voluntary motor functions.-Anatomy of the motor cortex :The motor cortex can be divided into six main parts:...
neurons, which control movement, date back to the 1970s. In the 1980s, Apostolos Georgopoulos at Johns Hopkins University found a mathematical relationship between the electrical responses of single motor-cortex neurons in
rhesus macaque monkeysThe Rhesus Macaque , often called the Rhesus Monkey, is one of the best known species of Old World monkeys.Adult males measure approximately 53 centimeters on average and weigh an average of 7.7 kilograms. Females are smaller, averaging 47 centimeters in length and 5.3 kilograms in weight...
and the direction that monkeys moved their arms (based on a cosine function). He also found that dispersed groups of neurons in different areas of the brain collectively controlled motor commands but was only able to record the firings of neurons in one area at a time because of technical limitations imposed by his equipment.
There has been rapid development in BCIs since the mid-1990s. Several groups have been able to capture complex brain motor centre signals using recordings from
neural ensembleA neural ensemble is a population of nervous system cells involved in a particular neural computation.- Background :The concept of neural ensemble dates back to the work of Charles Sherrington who described the functioning of the CNS as the system of reflex arcs, each composed of interconnected...
s (groups of neurons) and use these to control external devices, including research groups led by Richard Andersen,
John DonoghueCyberkinetics is an American company. It was cofounded by John Donoghue, Mijail Serruya, and Gerhard Friehs of Brown University and Nicho Hatsopoulos of the University of Chicago. Their work helped develop early-stage bionics in the form of implantable electronic devices and now spinoff...
, Phillip Kennedy,
Miguel NicolelisMiguel Angelo Laporta Nicolelis, MD, PhD, is a Brazilian physician and scientist, best known for his pioneering work in "reading monkey thought". He and his colleagues implanted electrode arrays into a monkey's brain that were able to detect the monkey's motor intent and thus able to control...
, and Andrew Schwartz.
Prominent research successes
Phillip Kennedy and colleagues built the first intracortical brain–computer interface by implanting neurotrophic-cone electrodes into monkeys.
In 1999, researchers led by Yang Dan at University of California, Berkeley decoded neuronal firings to reproduce images seen by cats. The team used an array of electrodes embedded in the
thalamusThe thalamus is a midline paired symmetrical structure within the brain of vertebrate animals, including humans. It is between the cerebral cortex and the midbrain, both in terms of its location and its neurological connections...
(which integrates all of the brain’s sensory input) of sharp-eyed cats. Researchers targeted 177 brain cells in the thalamus
lateral geniculate nucleusThe lateral geniculate nucleus is the primary processing center for visual information received from the retina of the eye. The LGN is found inside the thalamus of the brain, and is thus part of the central nervous system....
area, which decodes signals from the retina. The cats were shown eight short movies, and their neuron firings were recorded. Using mathematical filters, the researchers decoded the signals to generate movies of what the cats saw and were able to reconstruct recognizable scenes and moving objects. Similar results in humans have been since then achieved by researchers in Japan (see below).
Miguel NicolelisMiguel Angelo Laporta Nicolelis, MD, PhD, is a Brazilian physician and scientist, best known for his pioneering work in "reading monkey thought". He and his colleagues implanted electrode arrays into a monkey's brain that were able to detect the monkey's motor intent and thus able to control...
has been a prominent proponent of using multiple electrodes spread over a greater area of the brain to obtain neuronal signals to drive a BCI. Such
neural ensembleA neural ensemble is a population of nervous system cells involved in a particular neural computation.- Background :The concept of neural ensemble dates back to the work of Charles Sherrington who described the functioning of the CNS as the system of reflex arcs, each composed of interconnected...
s are said to reduce the variability in output produced by single electrodes, which could make it difficult to operate a BCI.
After conducting initial studies in rats during the 1990s, Nicolelis and his colleagues developed BCIs that decoded brain activity in
owl monkeysThe Night monkeys, also known as the Owl monkeys or Douroucoulis, are the members of the genus Aotus of New World monkeys . They are widely distributed in the forests of Central and South America, from Panama south to Paraguay and northern Argentina...
and used the devices to reproduce monkey movements in robotic arms. Monkeys have advanced reaching and grasping abilities and good hand manipulation skills, making them ideal test subjects for this kind of work.
By 2000, the group succeeded in building a BCI that reproduced owl monkey movements while the monkey operated a joystick or reached for food. The BCI operated in real time and could also control a separate robot remotely over Internet protocol. But the monkeys could not see the arm moving and did not receive any feedback, a so-called
open-loopOpen-loop may refer to:*Open-loop controller of a dynamical system*Open-loop model in game theory...
BCI.
Later experiments by Nicolelis using rhesus monkeys, succeeded in closing the feedback loop and reproduced monkey reaching and grasping movements in a robot arm. With their deeply cleft and furrowed brains, rhesus monkeys are considered to be better models for human
neurophysiologyNeurophysiology is a part of physiology. Neurophysiology is the study of nervous system function...
than owl monkeys. The monkeys were trained to reach and grasp objects on a computer screen by manipulating a joystick while corresponding movements by a robot arm were hidden. The monkeys were later shown the robot directly and learned to control it by viewing its movements. The BCI used velocity predictions to control reaching movements and simultaneously predicted hand gripping force.
Other labs that develop BCIs and algorithms that decode neuron signals include John Donoghue from Brown University, Andrew Schwartz from the
University of PittsburghThe University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...
and Richard Andersen from Caltech. These researchers were able to produce working BCIs even though they recorded signals from far fewer neurons than Nicolelis (15–30 neurons versus 50–200 neurons).
Donoghue's group reported training rhesus monkeys to use a BCI to track visual targets on a computer screen with or without assistance of a joystick (closed-loop BCI). Schwartz's group created a BCI for three-dimensional tracking in virtual reality and also reproduced BCI control in a robotic arm. The group created headlines when they demonstrated that a monkey could feed itself pieces of
zucchiniZucchini or courgette is a small summer squash. Along with some other squashes, it belongs to the species Cucurbita pepo...
using a robotic arm controlled by the animal's own brain signals.
Andersen's group used recordings of
premovement activityPremovement neuronal activity in neurophysiological literature refers to neuronal modulations that occur in neuronal firing rates before a subject produces movements. In a typical monkey experiment, an animal is required to withhold the movement until it receives a trigger stimulus. While the...
from the posterior parietal cortex in their BCI, including signals created when experimental animals anticipated receiving a reward.
In addition to predicting kinematic and
kineticKinetic may refer to:*Kinetic *Kinetic art*Kinetic, Seiko's trademark for its automatic quartz technology.*Kinetic theory*Kinetic energy*A projectile, which is a type of kinetic weapon....
parameters of limb movements, BCIs that predict
electromyographicElectromyography is a technique for evaluating and recording the activation signal of muscles. EMG is performed using an instrument called an electromyograph, to produce a record called an electromyogram. An electromyograph detects the electrical potential generated by muscle cells when these...
or electrical activity of muscles are being developed. Such BCIs could be used to restore mobility in paralyzed limbs by electrically stimulating muscles.
Miguel Nicolelis worked with John Chapin, Johan Wessberg, Mark Laubach, Jose Carmena, Mikhail Lebedev, Antonio Pereira, Jr., Sidarta Ribeiro and other colleagues showed that activity of large neural ensembles can predict arm position. This work made possible creation of brain–machine interfaces — electronic devices that read arm movement intentions and translate them into movements of artificial actuators. Carmena et al. (2003) programmed the neural coding in a brain–machine interface allowed a monkey to control reaching and grasping movements by a robotic arm, and Lebedev et al. (2005) argued that brain networks reorganize to create a new representation of the robotic appendage in addition to the representation of the animal's own limbs.
The biggest impediment of BCI technology at present is the lack of a sensor modality that provides safe, accurate, and robust access to brain signals. It is conceivable or even likely that such a sensor will be developed within the next twenty years. The use of such a sensor should greatly expand the range of communication functions that can be provided using a BCI.
Development and implementation of a Brain–Computer Interface (BCI) system is complex and time consuming. In response to this problem, Dr. Gerwin Schalk has been developing a general-purpose system for BCI research, called BCI2000. BCI2000 has been in development since 2000 in a project led by the Brain–Computer Interface R&D Program at the Wadsworth Center of the New York State Department of Health in Albany, New York, USA.
A new 'wireless' approach uses light-gated ion channels such as
ChannelrhodopsinChannelrhodopsins are a subfamily of opsin proteins that function as light-gated ion channels. They serve as sensory photoreceptors in unicellular green algae, controlling phototaxis, i.e. movement in response to light. Expressed in cells of other organisms, they enable the use of light to control...
to control the activity of genetically defined subsets of neurons in vivo. In the context of a simple learning task, illumination of transfected cells in the somatosensory cortex influenced the decision making process of freely moving mice.
Invasive BCIs
Invasive BCI research has targeted repairing damaged sight and providing new functionality to persons with paralysis. Invasive BCIs are implanted directly into the grey matter of the brain during neurosurgery. As they rest in the grey matter, invasive devices produce the highest quality signals of BCI devices but are prone to
scar-tissueScars are areas of fibrous tissue that replace normal skin after injury. A scar results from the biologic process of wound repair in the skin and other tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound Scars (also...
build-up, causing the signal to become weaker or even lost as the body reacts to a foreign object in the brain.
In
vision scienceVision science is the science dedicated to the interdisciplinary study of visual perception and the visual system. Vision scientists study various aspects of vision from the perspectives of cognitive psychology, neuroscience, computer science, psychophysics, and ophthalmology.- External links :* -...
, direct
brain implantBrain 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...
s have been used to treat non-congenital (acquired) blindness. One of the first scientists to come up with a working brain interface to restore sight was private researcher
William DobelleWilliam H. Dobelle was a biomedical researcher who developed experimental technologies that restored limited sight to blind patients. He is also credited as Dr. William Dobelle, Dr. William H. Dobelle, William Harvey Dobelle, Bill Dobelle and Dr. Bill Dobelle.-Childhood and Family:Dr...
.
Dobelle's first prototype was implanted into "Jerry", a man blinded in adulthood, in 1978. A single-array BCI containing 68 electrodes was implanted onto Jerry’s
visual cortexThe term visual cortex refers to the primary visual cortex and extrastriate visual cortical areas such as V2, V3, V4, and V5. The primary visual cortex is anatomically equivalent to Brodmann area 17, or BA17...
and succeeded in producing phosphenes, the sensation of seeing light. The system included cameras mounted on glasses to send signals to the implant. Initially, the implant allowed Jerry to see shades of grey in a limited field of vision at a low frame-rate. This also required him to be hooked up to a two-ton mainframe, but shrinking electronics and faster computers made his artificial eye more portable and now enable him to perform simple tasks unassisted.
In 2002, Jens Naumann, also blinded in adulthood, became the first in a series of 16 paying patients to receive Dobelle’s second generation implant, marking one of the earliest commercial uses of BCIs. The second generation device used a more sophisticated implant enabling better mapping of phosphenes into coherent vision. Phosphenes are spread out across the visual field in what researchers call the starry-night effect. Immediately after his implant, Jens was able to use his imperfectly restored vision to drive slowly around the parking area of the research institute.
BCIs focusing on
motor neuroprosthetics aim to either restore movement in individuals with paralysis or provide devices to assist them, such as interfaces with computers or robot arms.
Researchers at Emory University in Atlanta led by Philip Kennedy and Roy Bakay were first to install a brain implant in a human that produced signals of high enough quality to simulate movement. Their patient, Johnny Ray (1944-2002), suffered from ‘
locked-in syndromeLocked-in syndrome is a condition in which a patient is aware and awake, but cannot move or communicate due to complete paralysis of nearly all voluntary muscles in the body except for the eyes. Total locked-in syndrome is a version of locked-in syndrome where the eyes are paralyzed as well. It is...
’ after suffering a brain-stem
strokeA stroke is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by thrombosis or embolism or due to a hemorrhage...
in 1997. Ray’s implant was installed in 1998 and he lived long enough to start working with the implant, eventually learning to control a computer cursor; he died in 2002 of a brain aneurysm.
Tetraplegic,
Matt NagleMatthew Nagle was the first person to use a brain-computer interface to restore functionality lost due to paralysis. He was a C3 tetraplegic, paralyzed from the neck down after being stabbed.-Biography:...
became the first person to control an artificial hand using a BCI in 2005 as part of the first nine-month human trial of Cyberkinetics Neurotechnology’s
BrainGateBrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. The device was designed to help those who have lost control of their limbs, or other bodily functions, such as patients with...
chip-implant. Implanted in Nagle’s right precentral gyrus (area of the motor cortex for arm movement), the 96-electrode
BrainGateBrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. The device was designed to help those who have lost control of their limbs, or other bodily functions, such as patients with...
implant allowed Nagle to control a robotic arm by thinking about moving his hand as well as a computer cursor, lights and TV.
Partially-invasive BCIs
Partially invasive BCI devices are implanted inside the skull but rest outside the brain rather than within the grey matter. They produce better resolution signals than non-invasive BCIs where the bone tissue of the cranium deflects and deforms signals and have a lower risk of forming scar-tissue in the brain than fully-invasive BCIs.
ElectrocorticographyElectrocorticography is the practice of using electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. ECoG may be performed either in the operating room during surgery or outside of surgery...
(ECoG) measures the electrical activity of the brain taken from beneath the skull in a similar way to non-invasive electroencephalography (see below), but the electrodes are embedded in a thin plastic pad that is placed above the cortex, beneath the
dura materThe dura mater , or dura, is the outermost of the three layers of the meninges surrounding the brain and spinal cord. The other two meningeal layers are the pia mater and the arachnoid mater. The dura surrounds the brain and the spinal cord and is responsible for keeping in the cerebrospinal fluid...
. ECoG technologies were first trialed in humans in 2004 by Eric Leuthardt and Daniel Moran from Washington University in St Louis. In a later trial, the researchers enabled a teenage boy to play
Space Invadersis an arcade video game designed by Tomohiro Nishikado, and released in 1978. It was originally manufactured and sold by Taito in Japan, and was later licensed for production in the United States by the Midway division of Bally. Space Invaders is one of the earliest shooting games and features...
using his ECoG implant. This research indicates that control is rapid, requires minimal training, and may be an ideal tradeoff with regards to signal fidelity and level of invasiveness.
(Note: These electrodes were not implanted in the patients for BCI experiments. Implanting foreign objects into people's brains solely for experimental purposes would be
unethicalBioethics is the philosophical study of the ethical controversies brought about by advances in biology and medicine. Bioethicists are concerned with the ethical questions that arise in the relationships among life sciences, biotechnology, medicine, politics, law, philosophy, and theology.- History...
. The patients were suffering from severe
epilepsyEpilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures...
and had the electrodes temporarily implanted to help their physicians localize seizure foci; the researchers simply took advantage of this.)
Light Reactive Imaging BCI devices are still in the realm of theory. These would involve implanting a
laserA laser is a device that emits light through a process called stimulated emission. Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses...
inside the skull. The laser would be trained on a single neuron and the neuron's reflectance measured by a separate sensor. When the neuron fires, the laser light pattern and wavelengths it reflects would change slightly. This would allow researchers to monitor single neurons but require less contact with tissue and reduce the risk of scar-tissue build-up.
This signal can be either subdural or epidural, but is not taken from within the brain parenchyma itself. It has not been studied extensively until recently due to the limited access of subjects. Currently, the only manner to acquire the signal for study is through the use of patients requiring invasive monitoring for localization and resection of an epileptogenic focus.
ECoG is a very promising intermediate BCI modality because it has higher spatial resolution, better signal-to-noise ratio, wider frequency range, and lesser training requirements than scalp-recorded EEG, and at the same time has lower technical difficulty, lower clinical risk, and probably superior long-term stability than intracortical single-neuron recording. This feature profile and recent evidence of the high level of control with minimal training requirements shows potential for real world application for people with motor disabilities.
Non-invasive BCIs
As well as invasive experiments, there have also been experiments in humans using non-invasive
neuroimagingNeuroimaging includes the use of various techniques to either directly or indirectly image the structure, function/pharmacology of the brain...
technologies as interfaces. Signals recorded in this way have been used to power muscle implants and restore partial movement in an experimental volunteer. Although they are easy to wear, non-invasive implants produce poor signal resolution because the skull dampens signals, dispersing and blurring the electromagnetic waves created by the neurons. Although the waves can still be detected it is more difficult to determine the area of the brain that created them or the actions of individual neurons.
EEG
ElectroencephalographyElectroencephalography is the recording of electrical activity along the scalp produced by the firing of neurons within the brain . In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from...
(EEG) is the most studied potential non-invasive interface, mainly due to its fine
temporal resolutionTemporal resolution refers to the precision of a measurement with respect to time. Often there is a tradeoff between temporal resolution of a measurement and its spatial resolution. This tradeoff can be attributed to the finite speed of light and the fact that it thus takes a certain time for the...
, ease of use, portability and low set-up cost. But as well as the technology's susceptibility to
noiseIn common use, the word noise means unwanted sound or noise pollution. In both analog and digital electronics, noise or signal noise is an unwanted random addition to a wanted signal; it is called noise as a generalisation of the audible noise heard when listening to a weak radio transmission...
, another substantial barrier to using EEG as a brain–computer interface is the extensive training required before users can work the technology. For example, in experiments beginning in the mid-1990s, Niels Birbaumer of the University of Tübingen in Germany trained severely paralysed people to self-regulate the
slow cortical potentials in their EEG to such an extent that these signals could be used as a binary signal to control a computer cursor. (Birbaumer had earlier trained
epilepticsEpilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures...
to prevent impending fits by controlling this low voltage wave.) The experiment saw ten patients trained to move a computer cursor by controlling their brainwaves. The process was slow, requiring more than an hour for patients to write 100 characters with the cursor, while training often took many months.
Another research parameter is the type of waves measured. Birbaumer's later research with Jonathan Wolpaw at New York State University has focused on developing technology that would allow users to choose the brain signals they found easiest to operate a BCI, including
muMu waves, also known as the comb or wicket rhythm, are electromagnetic oscillations in the frequency range of 8–13 Hz and appear in bursts of at 9 – 11 Hz. Mu wave patterns arise from synchronous and coherent electrical activity of large groups of neurons in the human brain...
and
betaBeta wave, or beta rhythm, is the term used to designate the frequency range of brain activity between 12 and 30 Hz . Beta states are the states associated with normal waking consciousness. Low amplitude beta waves with multiple and varying frequencies are often associated with active, busy, or...
rhythms.
A further parameter is the method of feedback used and this is shown in studies of
P300The P300 wave is an event related potential which can be recorded via electroencephalography as a positive deflection in voltage at a latency of roughly 300 ms in the EEG. The signal is typically measured most strongly by the electrodes covering the parietal lobe...
signals. Patterns of P300 waves are generated involuntarily (
stimulus-feedbackAn event-related potential is any measured brain response that is directly the result of a thought or perception. More formally, it is any stereotyped electrophysiological response to an internal or external stimulus....
) when people see something they recognize and may allow BCIs to decode categories of thoughts without training patients first. By contrast, the biofeedback methods described above require learning to control brainwaves so the resulting brain activity can be detected.
Lawrence FarwellDr Lawrence Farwell is the inventor of brain fingerprinting which uses a technology that he developed, MERMER. He was formerly a research associate at Harvard University and is currently the chairman and Chief Scientist of Brain Fingerprinting Laboratories, Inc.TIME Magazine named Dr...
and Emanuel Donchin developed an EEG-based brain–computer interface in the 1980s. Their "mental prosthesis" used the P300 brainwave response to allow subjects, including one paralyzed
Locked-In syndromeLocked-in syndrome is a condition in which a patient is aware and awake, but cannot move or communicate due to complete paralysis of nearly all voluntary muscles in the body except for the eyes. Total locked-in syndrome is a version of locked-in syndrome where the eyes are paralyzed as well. It is...
patient, to communicate words, letters, and simple commands to a computer and thereby to speak through a speech synthesizer driven by the computer. A number of similar devices have been developed since then. In 2000, for example, research by Jessica Bayliss at the University of Rochester showed that volunteers wearing virtual reality helmets could control elements in a virtual world using their P300 EEG readings, including turning lights on and off and bringing a mock-up car to a stop.
In 1999, researchers at Case Western Reserve University led by Hunter Peckham, used 64-electrode EEG skullcap to return limited hand movements to quadriplegic Jim Jatich. As Jatich concentrated on simple but opposite concepts like up and down, his beta-rhythm EEG output was analysed using software to identify patterns in the noise. A basic pattern was identified and used to control a switch: Above average activity was set to on, below average off. As well as enabling Jatich to control a computer cursor the signals were also used to drive the nerve controllers embedded in his hands, restoring some movement.
Electronic
neural networksNeural Networks is the official journal of the three oldest societies dedicated to research in neural networks: International Neural Network Society, European Neural Network Society and Japanese Neural Network Society, published by Elsevier. A subsription to the journal is part of the membership...
have been deployed which shift the learning phase from the user to the computer. Experiments by scientists at the
Fraunhofer SocietyThe Fraunhofer Society is a German research organization with 59 institutes spread throughout Germany, each focusing on different fields of applied science . It employs over 12,500, mainly scientists and engineers, with an annual research budget of about €1.2 billion...
in 2004 using neural networks led to noticeable improvements within 30 minutes of training.
Experiments by
Eduardo MirandaEduardo Reck Miranda, Ph.D, , is a Brazilian composer of chamber and electroacoustic pieces but is most notable in the United Kingdom for his scientific research into computer music, particularly in the field of human-machine interfaces where brain waves will replace keyboards and voice commands to...
aim to use EEG recordings of mental activity associated with music to allow the disabled to express themselves musically through an
encephalophoneAn electroencephalophone or encephalophone is a musical instrument or diagnostic tool which uses brain waves to generate or modulate sounds....
.
The Emotiv company plans to produce a commercial video game controller (known as the Epoc) in 2009, which uses electromagnetic sensors.
MEG and MRI
MagnetoencephalographyMagnetoencephalography is an imaging technique used to measure the magnetic fields produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices . These measurements are commonly used in both research and clinical settings...
(MEG) and
functional magnetic resonance imagingFunctional MRI or functional Magnetic Resonance Imaging is a type of specialized MRI scan. It measures the haemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
(fMRI) have both been used successfully as non-invasive BCIs. In a widely reported experiment, fMRI allowed two users being scanned to play
PongPong is one of the earliest arcade video games, and is a tennis sports game featuring simple two-dimensional graphics. The aim is to defeat an opponent—either computer-controlled or a second player—by earning a higher score. The game was originally manufactured by Atari Incorporated , who released...
in real-time by altering their
haemodynamic responseHaemodynamics is a medical term for the dynamic regulation of the blood flow in the brain. It is the principle on which functional magnetic resonance imaging is based....
or brain blood flow through
biofeedbackBiofeedback is a non-medical process that involves measuring a subject's specific and quantifiable bodily functions such as blood pressure, heart rate, skin temperature, sweat gland activity, and muscle tension, conveying the information to the patient in real-time...
techniques.
fMRI measurements of haemodynamic responses in real time have also been used to control robot arms with a seven second delay between thought and movement.
More recently, research developed in the Advanced Telecommunications Research (ATR)
Computational NeuroscienceComputational neuroscience is the study of brain function in terms of the information processing properties of the structures that make up the nervous system...
Laboratories in
Kyotois a city in the central part of the island of Honshū, Japan. It has a population close to 1.5 million. Formerly the imperial capital of Japan, it is now the capital of Kyoto Prefecture, as well as a major part of the Osaka-Kobe-Kyoto metropolitan area....
, Japan allowed the scientists to reconstruct images directly from the brain and display them on a computer. The article announcing these achievements was the
cover storyCover story may refer to:* a story in a magazine whose subject matter appears on its front cover* a cover-up, or fictitious account that is intended to hide one's real motive* Cover Story , a 2002 film starring Elizabeth Berkley...
of the journal
NeuronNeuron is a neuroscience academic journal published by Cell Press. It has been in continuous publication since 1988....
of 10 December 2008.
While the early results are limited to black and white images of 10x10 squares (
pixelIn digital imaging, a pixel is the smallest item of information in an image. Pixels are normally arranged in a 2-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image, where more samples typically provide more-accurate representations of the...
s), according to the researchers further development of the technology may make it possible to achieve color images, and even view or record dreams.
Commercialization and companies
John Donoghue and fellow researchers founded
CyberkineticsCyberkinetics is an American company. It was cofounded by John Donoghue, Mijail Serruya, and Gerhard Friehs of Brown University and Nicho Hatsopoulos of the University of Chicago. Their work helped develop early-stage bionics in the form of implantable electronic devices and now spinoff...
. Now listed on a US stock exchange and known as Cyberkinetic Neurotechnology Inc, the company markets its electrode arrays under the
BrainGateBrainGate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. The device was designed to help those who have lost control of their limbs, or other bodily functions, such as patients with...
product name and has set the development of practical BCIs for humans as its major goal. The BrainGate is based on the Utah Array developed by Dick Normann.
Philip Kennedy founded
Neural Signals in 1987 to develop BCIs that would allow paralysed patients to communicate with the outside world and control external devices. As well as an invasive BCI, the company also sells an implant to restore speech. Neural Signals' Brain Communicator BCI device uses glass cones containing microelectrodes coated with proteins to encourage the electrodes to bind to neurons.
Although 16 paying patients were treated using
William Dobelle'sWilliam H. Dobelle was a biomedical researcher who developed experimental technologies that restored limited sight to blind patients. He is also credited as Dr. William Dobelle, Dr. William H. Dobelle, William Harvey Dobelle, Bill Dobelle and Dr. Bill Dobelle.-Childhood and Family:Dr...
vision BCI, new implants ceased within a year of Dobelle's death in 2004. A company controlled by Dobelle,
Avery Biomedical Devices, and Stony Brook University are continuing development of the implant, which has not yet received Food and Drug Administration approval in the United States for human implantation.
Ambient, at a TI developers conference in early 2008, demoed a product they have in development call The Audeo. The Audeo is being developed to create a human–computer interface for communication without the need of physical motor control or speech production. Using signal processing, unpronounced speech representing the thought of the mind can be translated from intercepted neurological signals.
MindballMindball is a two person game controlled by players’ brain waves in which players compete to control a ball's movement across a table by becoming more relaxed and focused. Mindball is produced by the Swedish Company Interactive Productline...
is a product developed and commercialized by Interactive Productline in which players compete to control a ball's movement across a table by becoming more relaxed and focused. Interactive Productline is a Swedish company whose objective is to develop and sell easy understandable EEG products that train the ability to relax and focus.
An Austrian company, Guger Technologies,
g.tec, has been offering Brain Computer Interface systems since 1999. The company provides base BCI models as development platforms for the research community to build upon, including the P300 Speller, Motor Imagery, and mu-rhythm. They commercialized a Steady State Visual Evoked Potiential BCI solution in 2008 with 4 degrees of machine control.
There are three main consumer-devices commercial-competitors in this area (expected launch date mentioned in brackets) which are going to launch such devices primarily for gaming- and PC-users:
- Neural Impulse Actuator
The Neural Impulse Actuator is a Brain-computer interface device developed by the OCZ Technology. BCI devices attempt to move away from the classic input devices like keyboard and mouse and instead read electrical activity from the head, preferably the EEG...
(April - 2008)
- Emotiv Systems
Emotiv Systems is an Australian-origin electronics company developing brain-computer interfaces based on electroencephalography technology. Emotiv Systems was founded in 2003 by four scientists and executives: neuroscientist Professor Allan Snyder, chip-designer Neil Weste, and technology...
(Summer - 2009)
- NeuroSky
NeuroSky, chaired by Stanley Yang, is a company based in San Jose, California, United States. Their technology is an example of a "brain-computer interface"....
(MindSet - June 2009, Uncle Milton Force Trainer - Fall 2009, Mattel MindFlex - Summer 2009)
Military applications
The United States military has been exploring applications for BCIs, to enhance troop performance as well as develop systems to interfere with the communications of perceived adversaries. As one report concluded,
The most successful implementation of invasive interfaces has occurred in medical applications in which nerve signals are used as the mechanism for information transfer.
The DARPA budget for the fiscal year 2009 to 2010 includes $4 million for a program named
Silent Talk, which aims to "allow user-to-user communication on the battlefield without the use of vocalized speech through analysis of neural signals."
A further $4 million was allocated by the Army to the
University of CaliforniaThe University of California is a public university system in the state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University system...
to investigate computer-mediated "synthetic telepathy". The research aims to detect and analyze the word-specific neural signals, using
EEGEEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...
, which occur before speech is vocalized, and to see if the patterns are generalizable. The research is part of a wider $70 million project that began in 2000 which aims to develop hardware capable of adapting to the behavior of its user.
Cell-culture BCIs
Researchers have built devices to interface with neural cells and entire neural networks in cultures outside animals. As well as furthering research on animal implantable devices, experiments on cultured neural tissue have focused on building problem-solving networks, constructing basic computers and manipulating robotic devices. Research into techniques for stimulating and recording from individual neurons grown on semiconductor chips is sometimes referred to as neuroelectronics or
neurochipA neurochip is a chip that is designed for the interaction with neuronal cells.- Formation :It is made of silicon that is doped in such a way, that it contains EOSFETs that can sense the electrical activity of the neurons in the above-standing physiological electrolyte solution...
s.
Development of the first working neurochip was claimed by a Caltech team led by Jerome Pine and Michael Maher in 1997. The Caltech chip had room for 16 neurons.
In 2003, a team led by Theodore Berger at the University of Southern California started work on a neurochip designed to function as an artificial or prosthetic
hippocampusThe hippocampus is a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long-term memory and spatial navigation. Like the cerebral cortex, with which it is closely associated, it is a paired structure, with mirror-image halves in...
. The neurochip was designed to function in rat brains and is intended as a prototype for the eventual development of higher-brain prosthesis. The hippocampus was chosen because it is thought to be the most ordered and structured part of the brain and is the most studied area. Its function is to encode experiences for storage as long-term memories elsewhere in the brain.
Thomas DeMarse at the University of Florida used a culture of 25,000 neurons taken from a rat's brain to fly a F-22 fighter jet aircraft simulator. After collection, the cortical neurons were cultured in a
petri dishA petri dish is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells. It was named after German bacteriologist Julius Richard Petri, who invented it when working as an assistant to Robert Koch...
and rapidly began to reconnect themselves to form a living neural network. The cells were arranged over a grid of 60 electrodes and used to control the pitch and yaw functions of the simulator. The study's focus was on understanding how the human brain performs and learns computational tasks at a cellular level.
Ethical considerations
Discussion about the
ethical implicationsMedical ethics is primarily a field of applied ethics, the study of moral values and judgments as they apply to medicine. As a scholarly discipline, medical ethics encompasses its practical application in clinical settings as well as work on its history, philosophy, theology, and sociology.Medical...
of BCIs has been relatively muted. This may be because the research holds great promise in the fight against disability and BCI researchers have yet to attract the attention of
animal rightsAnimal rights, also referred to as animal liberation, is the idea that the most basic interests of animals should be afforded the same consideration as the similar interests of humans...
groups. It may also be because BCIs are being used to acquire signals to control devices rather than the other way around, although vision research is the exception to this.
This ethical debate is likely to intensify as BCIs become more technologically advanced and it becomes apparent that they may not just be used therapeutically but for
human enhancementHuman enhancement refers to any attempt to temporarily or permanently overcome the current limitations of the human body through natural or artificial means. The term is sometimes applied to the use of technological means to select or alter human characteristics and capacities, whether or not the...
. Today's
brain pacemaker"Brain pacemakers" are used to treat people who suffer from epilepsy, Parkinson's disease, major depression and other diseases. The pacemaker is a medical device that is implanted into the brain to send electrical signals into the tissue. Depending on the area of the brain that is targeted, the...
s, which are already used to treat neurological conditions such as
depressionIn psychology and psychiatry, depression is a state of low mood and aversion to activity. While most often described as a disease or dysfunction, there are also strong arguments for seeing depression as an adaptive defense mechanism....
could become a type of BCI and be used to modify other behaviours. Neurochips could also develop further, for example the artificial hippocampus, raising issues about what it actually means to be human.
Some of the ethical considerations that BCIs would raise under these circumstances are already being debated in relation to
brain implantBrain 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...
s and the broader area of
mind controlMind control refers to a broad range of psychological tactics thought to subvert an individual's control of his or her own thinking, behavior, emotions, or decision making...
.
Theme in fiction
The prospect of BCIs and brain implants of all kinds have been important themes in
science fictionScience fiction is a genre of fiction. It differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically-established or scientifically-postulated laws of nature...
. See brain implants in fiction and philosophy for a review of this literature.
Organizations
(for a list of universities see Neural Engineering - Neural Engineering Labs)
Researchers listed in above text
- Theodore Berger at the University of Southern California
- Niels Birbaumer at the University of Tuebingen
- Thomas DeMarse at the University of Florida
- John Donoghue's lab at Brown University
- Eberhart E. Fetz at the Washington National Primate Research Center
- Apostolos Georgopoulos at the University of Minnesota
- Eduardo Reck Miranda
Eduardo Reck Miranda, Ph.D, , is a Brazilian composer of chamber and electroacoustic pieces but is most notable in the United Kingdom for his scientific research into computer music, particularly in the field of human-machine interfaces where brain waves will replace keyboards and voice commands to...
at the University of PlymouthThe University of Plymouth is the largest university in the southwest of England, with over 30,000 students and is the fifth largest UK university based on student population....
, England
- Miguel Nicolelis’ lab at Duke University
- Hunter Peckham at Case Western Reserve University
- Jerome Pine's lab at Caltech
- Andrew Schwartz at the University of Pittsburgh
- Yang Dan at University of California, Berkeley
- Jonathan Wolpaw at the New York State Department of Health
- Nitish Thakor at the Johns Hopkins University, department of Biomedical Engineering
Portals and articles
- BCI-info.org, BCI news and research portal
- Monkey Neural Interfacing, Monkeys Consciously Control A Robot Arm Using Only Brain Signals
- The open-source Electroencephalography project and Programmable chip version, Sourceforge open source EEG projects
- BCI Competition, run by Fraunhofer Institute, third and most recent competition closed mid-2005
- EEG database, Team Phypa's public hub for BCI data exchange
- The Next Brainiacs Wired Magazine, August 2001, article on Jim Jatich’s implant
- Controlling robots with the mind, Scientific American, 16 September 2002, article on Miguel Nicolelis
- Vision quest, Wired Magazine, September 2002, article on artificial vision
- Lymnaea stagnalis and the development of neuroelectronic technologies, Journal of Neuroscience Research, 2004, academic paper on a cell-culture BCI
- 'Brain' in a dish flies flight simulator, CNN, 4 November 2004, article on cell-culture BCI
- How to talk when you can't speak, Slate, 10 February 2005, article on using EEG to communicate with minimally conscious patients
- Mind Control, Wired Magazine, March 2005, article on Matt Nagle
- ...a step towards neuron-based functional chips, Biosens Bioelectron, January 2006, academic paper on a cell-culture BCI
- Functional alignment of feedback effects from visual cortex to thalamus Nature Neuroscience 9, 1330-1336 (2006), 17 September 2006, recent advances in decoding LGN visual signals
- The Memory Hacker, PopSci.com, April 2007, article on Theodore Berger, retrieved 10 April 2007
- The Outer Limits, Mind Reacher
- Brain Machine implant website
- Electronic system prearranged to replace in the electronic games the existing manual controls with equivalent controls directly commanded by the brain.
Lectures and videos