A Brief Introduction to Brain Computer Interfaces

Computers have been around in some form for over eighty years. The ways that computers have been controlled has changed over the past eighty years, moving from punch cards to much more sophisticated controls. The keyboard and mouse is probably the most common way for a user to directly interact with a computer and while perhaps the most common control interfaces, there are many other ways that computers are controlled. One type of alternate control that has many exciting medical applications is a BCI or Bran-Computer Interface.

A Brain Computer Interface creates a direct link between the brain and a computer. It allows the computer to be controlled by the brain and in some cases can also send signals to the brain. The first successful Human controlled BCI was not developed until the nineties, but scientists have been experimenting with BCI technology for almost forty years.

While it took until the mid-nineties for a successful human BCI, animals had been used to research BCI’s for some time. In 1970’s, scientists experimented on monkeys, determining that it was in fact possible to control the firing of neurons in the brain.

During the eighties, a scientist named Apostolos Georgopoulos discovered a way to mathematically describe the path of neurons and how the paths corresponded with movements of the arms. Again experimenting on monkeys, Georgopoulos also located a specific part of the brain that is responsible for many of the bodies motor commands.

Since the first successful human BCI, the research and development of BCI’s has rapidly increased. A good portion of this research has been aimed at decoding neuron paths to help decrypt the brain. To this end, scientists in 1999 embedded electrodes into the thalamus of cats.

The thalamus is the part of the brain that is responsible for feeling and seeing. The researchers, led by Yang Dan, showed the cats a series of eight different movies, while recording the way neurons were firing in the thalamus. They were then able to mathematically decode the neurons to partially reconstruct images and moving scenes.

The type of BCI used in the cats and in most animal research, is referred to as an Invasive BCI. An invasive BCI is one that is physically implanted into the brain. The BCI, which is attached during a surgical operation, offers the best signal, but does pose several health risks. Invasive BCIs are also commonly used to help those who are mobility challenged.

The medical applications of a BCI have yet to be fully realized, but they have already been successfully used to improve vision, hearing, and to move prosthetics.

The first commercial BCI was implanted into 16 blind patients. Developed by Jens Naurmann, the BCI was able to restore a great deal vision for the recipients. In 2005, a patient was able to successfully control an artificial arm, in addition to moving a cursor on a computer, and controlling the television.

The other type of BCI, called a non-invasive BCI, does not require any surgery. A person will wear a head covering or skullcap that contains many sensors to detect brain waves. There have been several successful experiments using non-invasive BCI’s, but the signal is much weaker than when using an invasive BCI.

For those who are mobility challenged, the prospect of a BCI is perhaps the most exciting, but there are many other practical applications of these types of computer interfaces. Hopefully one day, non-invasive BCIs will be available to allow full interaction between a person and their computer.

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