Brain Machine Interface 1 100913220844 Phpapp01

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BRAIN MACHINE INTERFACE



The bioport

load new skills into their colleagues'

brains



Remember the movie The Matrix, thoserebels putting on the computer cords atthe back of the neck.

The bioport (thats what the technologywas called in movie) was a way of giving theMatrix computers full access to the

information channels of the brain. The rebels use the bioport to load new skills

into their colleagues' brainswritingdirectly into permanent memory.



Imagine all this turning to reality.

All your exam time problems vanishing.

You being able to memorize your coursebooks with just a tap of button.

Futurists and science-fiction writers also

speculate about a time when brain activitywill merge with computers.





Moving to reality, many researches are actually goingon to explore the possibility of the man and machine

merger

Trials for the implanted chip technology have beenvery successful for monkeys, who have learned to

control a computer game with their brains.

Scientists are finding different ways of receivingsenses for people who have lost a sense, such as sightor touch, they are made wear an artificial sensor.

Scientists at the Max Planck Institute have developed

"neuron transistors" that can detect the firing of anearby neuron, or alternatively, can cause a nearbyneuron to fire, or suppress it from firing



The First Implant

Researchers at the University of California,Berkeley, have demonstrated how rhesusmonkeys with electrodes implanted in theirbrains used their thoughts to control a computercursor.

Once the animals had mastered the task, theycould repeat it proficiently day after day.

It reflects a major finding by the scientists: Amonkeys brain is able to develop a motormemory for controlling a virtual device in amanner similar to the way it creates such amemory for the animals body



The Berkeley researchers implanted arrays of

microelectrodes on the primary motor cortex,

about 2 to 3 millimeters deep into the brain,tapping 75 to 100 neurons. The procedure was similar to that of other groups.The difference

was that here the scientists carefully monitored the activity of theseneurons using software that analyzed the waveform and timing of

the signals.



Monitoring the neurons, the scientists placed the monkeys rightarm inside a robotic exoskeleton that kept track of its movement.

On a screen, the monkey saw a cursor whose position corresponded

to the location of its hand.T

he task consisted of moving the cursorto the center of the screen, waiting for a signal, and then draggingthe cursor onto one of eight targets in the periphery. Correctmaneuvers were rewarded with sips of fruit juice.

While the animal played, the researchers

recorded two data setsthe brain signals andcorresponding cursor positions.



During manual control [left], the monkey maneuvers thecomputer cursor while the researchers record theneuronal activity, used to create a decoder.

Under brain control [right], the researchers feed theneuronal signals into the decoder, which then controlsthe cursor.

This determined whether the animal could perform the same task using only its brain.

a decoder, to translates brain activity into cursor movement.

decoder is a set of equations , multiply the firing rates of the neurons by certain numbers, orweights. When the weights have the right values, you can plug the neuronal data into theequations and theyll spill out the cursor position. To determine the right weights, theresearchers had only to correlate the two data sets theyd recorded.

Next the scientists immobilized the monkeys arm and fed the neuronal signals measured in realtime into the decoder. Initially, the cursor moved spastically. But over a week of practice, themonkeys performance climbed to nearly 100 percent and remained there for the next two weeks.For those later sessions, the monkey didnt have to undergo any retrainingit promptly recalledhow to skillfully maneuver the cursor.



Medical Field

Scientists who are finding different ways of

receiving senses. People who have lost a

sense, such as sight or touch wear an artificialsensor.

This might be a video camera, or a touch

sensitive glove.Then, electrical pulses which

encode the sense are sent to brain via a stripon their tongue



REMOTECONTROL BrainGate technology is designed to read

brain signals associated with controlling movement, which acomputer could translate into instructions for moving a

computer cursor or controlling a variety of assistive devices.

Plugging a sensor into the human brain's motor cortex could

turn the thoughts of paralysis victims into action.Team of BrownUniversity scientists have expanded its efforts to developingtechnology that reconnects the brain to lifeless limbs.



BrainGate Neural Interface includes a baby aspirinsize brain sensorcontaining 100 electrodes

Sensor connects to the surface of the motor cortex (the part of the brainthat enables voluntary movement), registers electrical signals from nearbyneurons, and transmits them through gold wires to a set of computers,

processors and monitors.

BrainGate can assist those suffering from spinal cord injuries, muscular

dystrophy, brain stem stroke, amyotrophic lateral sclerosis (ALS), and othermotor neuron diseases



One researcher Peter Fromherz a director atthe Max Planck institute for biochemistry in

Germany has been studying possibleconnections between silicon electronics andbiological cells.

Fromherz, first grew neurons from the

medicinal leech on silicon chips and persuadethe two parties to talk to each other. Field effect transistor records the signal from

neuron The electronic stimulation of the neuron arises

from a voltage pulse applied to a capacitor



Fromherz and his coworkers established that an ordinary silicon

chip, with the outermost 20 nm oxidized, is an ideal substrate tocultivate neurons on.

The silicon oxide layer insulates the two sides and stops anyelectrochemical charge transfer, which might damage the chip orthe cell.

Instead, there is only a capacitative connection, established by aso-called planar core-coat conductor. Proteins sticking out of thelipid membrane ensure that there is a thin (50-100 nm)conducting layer between lipid and silicon oxide, whichconstitutes the core of the conductor.



In the neuron-to-chip experiment, the current generated by the neuronhas to flow through the thin electrolyte layer between cell and chip.

This layer's resistance creates a voltage, which a transistor inside thechip can pick up as a gate voltage that will modify the transistor current.In the reverse signal transfer, a capacitative current pulse is transmitted

from the semiconductor through to the cell membrane, where it decaysquickly, but activates voltage-gated ion channels that create an actionpotential.

The next challenge was to move upwards from oneneuron communicating with one stimulator or sensor tomore complex neuro-electronic architectures, with the

distant goal of getting entire neuronal networks pluggedinto electronics in a way that would allow their functionto be studied in detail or use them for computationaldevices.



For this first hybrid circuit, they usedneurons from snails.

As a substrate to grow the cells on, theresearchers designed a specific chip with 14two-way junctions ( ie areas that can both

send signals to neurons and receive signalsback) arranged in a circle of about 200μm diameter

Specifically, then the researchers turnedtheir attention to the rat hippocampus, abrain region associated with long-termmemory.

It is known that in this part of the rat brain,

a region known as CA3 stimulates the CA1to which it is connected by extensivewiring.

Brain slices can be prepared such that thecut runs alongside the CA3 to CA1connection and makes this entirecommunications channel accessible toexperiments.

Using such slices, Hutzler and Fromherzdemonstrated that their chip can (via itscapacitor) stimulate the CA3 region suchthat these brain cells pass on the signal toCA1, where it can be recorded with thechip's transistors.



With a relatively simple chip device, thespatial resolution remained low, but inprinciple, it can be improved to the size of

features on commercial microchips, currentlystanding somewhere near 100 nm. A CMOS (complementary metal-oxide-

semiconductor) chip with an array of 128× 128 sensors for neural recording

packed into one square millimeter. The chip can practically generate a movie of

neurons in action: it delivers 16 kilo pixels at2000 frames per second



Applications on the horizon

Sensors like the 16 kilopixel CMOS chip willenable researchers to fill the gap betweenstudies involving only a few cells and those

operating at larger scales like magneticresonance imaging. Processes like associativememory, could be studied in detail usingsimilar non-invasive devices.

Prosthetic devices to restore vision, hearing or

limb control might be the next step. Further in the future, the real dreams would

be the realization of the brain-in-computerand chip-in-brain arrangement



Gamers will soon be able to interact withthe virtual world using their thoughts and

emotions alone.

A neuro-headset which interprets theinteraction of neurons in the brain will go

on sale later this year.

It picks up electrical activity from the brainand sends wireless signals to a computer.

It allows the user to manipulate a game or

virtual environment naturally andintuitively.

The brain is made up of about 100 billionnerve cells, or neurons, which emit an

electrical impulse when interacting. Theheadset implements a technology known asnon-invasive electroencephalography (EEG)

to read the neural activity.

It·s a brain computer interface that readselectrical impulses in the brain and

translates them into commands that avideo game can accept and control the

game dynamically.



The headset could detects more than 30

different expressions, emotions and actions.

Gamers are able to move objects in the world just by thinking of the action



The Challenges and Future

Implications Thus the major challenge lies in fact that wiring of the spinal

cord is basically unknown. At best, on cats, researchers havebeen able to hook into their optic nerves, to see what a cat cansee. And in blind people, we can stimulate a handful of pixelsin their brain, but that's about it. The brain is still a black box.

A successful BrainGate2 trial could open up a number of newpossibilities, Although the technology is similar to what wasused in the original testing, the researchers are looking toenlist up to 15 patients this time and gather more informationthat will help them better understand brain signals as well as"the method by which they decode them.

Including the use of a second sensor to stimulate both sides of the motor cortex. Researchers thus far have implanted thesensor in the side of the brain that controls a patient'sdominant sidethe left cortex for righties and the right cortexfor lefties.



BrainGate2 is part of a larger mission to help paralysis victimsregain control of their bodies. They want to reconnect thebrain back to the muscles and eventually back to the entirelimb. They are attempting to recreate parts of the nervoussystem that have been disconnected from the brain.

Nanobot-based virtual reality is not yet feasible in size andcost(the one using neuron transistors), but researchers havemade a good start in understanding the encoding of sensorysignals.

For example, LloydWatts and his colleagues have developed a

detailed model of the sensory coding and transformationsthat take place in the auditory processing regions of thehuman brain.We are at an even earlier stage in understandingthe complex feedback loops and neural pathways in the visualsystem



The brain computer interfacing will become a profoundlytransforming technology by 2030. By then, nanobots (robotsthe size of human blood cells or smaller, built with keyfeatures at the multi-nanometerbillionth of a meterscalemade using neuron transistors) will provide fully immersive,totally convincing virtual reality in the following way. Thenanobots will take up positions in close physical proximity toevery interneuron connection coming from all of our senses(e.g., eyes, ears, skin).When we want to experience realreality, the nanobots would just stay in position (in thecapillaries) and do nothing. If we want to enter virtual reality,

they would suppress all of the inputs coming from the realsenses, and replace them with the signals that would beappropriate for the virtual environment.

Ultimately, we will merge our own biological intelligence withour own creations as a way of continuing the exponentialexpansion of human knowledge and creative potential.

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Brain Machine Interface 1 100913220844 Phpapp01