Conclusion There are perhaps few decisions made on behalf of students with visual impairments that are more crucial, yet subject to more confusion and controversy, than the decision regarding an appropriate reading medium.
History[ edit ] The history of brain—computer interfaces BCIs starts with Hans Berger 's discovery of the electrical activity of the human brain and the development of electroencephalography EEG. In Berger was the first to record human brain activity by means of EEG.
Berger's first recording device was very rudimentary. He inserted silver wires under the scalps of his patients. These were later replaced by silver foils attached to the patient's head by rubber bandages.
Berger connected these sensors to a Lippmann capillary electrometerwith disappointing results. However, more sophisticated measuring devices, such as the Siemens double-coil recording galvanometerwhich displayed electric voltages as small as one ten thousandth of a volt, led to success.
Berger analyzed the interrelation of alternations in his EEG wave diagrams with brain diseases.
EEGs permitted completely new possibilities for the research of human brain activities. Although the term had not yet been coined, one of the earliest examples of a working brain-machine interface was the piece Music for Solo Performer by the American composer Alvin Lucier.
The piece makes use of EEG and analog signal processing hardware filters, amplifiers, and a mixing board to stimulate acoustic percussion instruments. To perform the piece one must produce alpha waves and thereby "play" the various percussion instruments via loudspeakers which are placed near or directly on the instruments themselves.
His paper stated the "BCI challenge": Control of objects using EEG signals. The demonstration was movement in a maze. In report was given on noninvasive EEG control of a physical object, a robot. The experiment described was EEG control of multiple start-stop-restart of the robot movement, along an arbitrary trajectory defined by a line drawn on a floor.
The line-following behavior was the default robot behavior, utilizing autonomous intelligence and autonomous source of energy. The obtained cognitive wave representing the expectation learning in the brain is named Electroexpectogram EXG. Inthe BCI Society] was officially launched.
The board is elected by the members of the Society, which has several hundred members. Among other responsibilities, the BCI Society organizes international meetings. Neuroprosthetics Neuroprosthetics is an area of neuroscience concerned with neural prostheses, that is, using artificial devices to replace the function of impaired nervous systems and brain related problems, or of sensory organs.
The most widely used neuroprosthetic device is the cochlear implant which, as of Decemberhad been implanted in approximatelypeople worldwide. The difference between BCIs and neuroprosthetics is mostly in how the terms are used: 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, however, used interchangeably. Neuroprosthetics and BCIs seek to achieve the same aims, such as restoring sight, hearing, movement, ability to communicate, and even cognitive function.
Animal BCI research[ edit ] Several laboratories have managed to record signals from monkey and rat cerebral cortices to operate BCIs to produce movement. Monkeys have navigated computer cursors on screen and commanded robotic arms to perform simple tasks simply by thinking about the task and seeing the visual feedback, but without any motor output.
In the s, Apostolos Georgopoulos at Johns Hopkins University found a mathematical relationship between the electrical responses of single motor cortex neurons in rhesus macaque monkeys and the direction in which they moved their arms based on a cosine function.
He also found that dispersed groups of neurons, in different areas of the monkey's brains, collectively controlled motor commands, but was able to record the firings of neurons in only one area at a time, because of the technical limitations imposed by his equipment.
Prominent research successes[ edit ] Kennedy and Yang Dan[ edit ] Phillip Kennedy who later founded Neural Signals in and colleagues built the first intracortical brain—computer interface by implanting neurotrophic-cone electrodes into monkeys. Researchers targeted brain cells in the thalamus lateral geniculate nucleus 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.
Nicolelis[ edit ] Miguel Nicolelisa professor at Duke Universityin Durham, North Carolinahas been a prominent proponent of using multiple electrodes spread over a greater area of the brain to obtain neuronal signals to drive a BCI.
After conducting initial studies in rats during the s, Nicolelis and his colleagues developed BCIs that decoded brain activity in owl monkeys 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 the group succeeded in building a BCI that reproduced owl monkey movements while the monkey operated a joystick or reached for food. But the monkeys could not see the arm moving and did not receive any feedback, a so-called open-loop BCI.6 Grade Science Practice Test Quiz ; Science Quiz - Year 6 ; 6th Grade Science Quiz ; Featured Quizzes.
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