Brain-computer interfaces (BCI) allow living things to interact with technology in the simplest sense. Think about it: when you move your eyes to read or your fingers to type, you first transmit information from your mind to the parts of the body that you desire to move. Why can’t that same idea apply to our input with computer-based machines?
This idea of our brainpower moving the neurological responses throughout our body initially sparked interest in BCI. Through the development of algorithms to reconstruct movements from motor cortex neurons in the 1970s, scientists were able to establish that monkeys could quickly achieve voluntary control over the firing rate of individual neurons. Researchers adapted this concept more to gain a clear understanding of the functioning of brainwaves in these and other complex animals.
BCI technology advanced greatly in the 1990s, when different people and organizations worked on software that could decode neural transmissions. During this time, Miguel Nicolelis took advantage of robotics industry technology to design BCI devices that gave monkeys the ability to control robotic arms. In 1998, the FDA gave its approval to commence human trials. Neurologist Philip R. Kennedy’s organization, Neural Signals, Inc., implanted a device in a patient who had been completely paralyzed by a brain stem stroke. That implant allowed control of a computer cursor through the use of focused thinking.
Kennedy’s original implant would be considered partially invasive, since it was located inside the skull but not embedded in the gray matter of the brain. Putting it in this location avoids the brainwave distortion that comes from the skull, letting sensory electrodes disperse on the surface of the brain itself. This method is able to harness a moderate level of brainwaves. For example, with the use of electrocorticography (use of subdural electrodes planted inside the cranium), an implant enabled a teenage boy in 2004 to play Space Invaders. Partially invasive BCI implants generally leave a hole in the skull, but they do not lead to scarring on the brain.
Invasive BCI technology, on the other hand, is placed in the gray matter of the brain, where it directly transmits brainwaves from their source. These kinds of devices are most widely used to provide functionality for handicapped people. For example, these have successfully restored vision by connecting the brain with external cameras and restored the use of limbs with robotic arms and legs. These are the most effective method of capturing waves from the brain, due to their close proximity to it, but are highly susceptible to scar tissue build-up, causing the brainwave signal to become weaker over time as the body rejects the foreign material.
Noninvasive devices are likely the most useful form of BCI technology, since they are of little danger to the user, only being placed on the outside of a person’s cranium. This avoids the potential damage to the brain and skull that is present with invasive and partially invasive devices, but attains the weakest brainwave signal from the skull’s interference. Electrocorticography, the partially invasive technology, involves a layout of electrodes that are spread throughout the top of the brain. This concept is actually derived from electroencephalography (EEG), a noninvasive BCI method that measures the electrical activity of the brain through the connection of electrodes that are dispersed on the top of the head.
Because of its ease of use and lack of invasive surgery, EEG technology has been used as the basis for several different products that harness the energy of brainwaves. The Aurora Headband, which is worn as a person sleeps, uses EEG to track sleep cycles and lights and sounds to control lucid dreaming for users. Aside from products like this, EEG has also found its way into recreational technology. For example, the product Mindball detects Alpha and Theta brainwaves associated with relaxation and uses them between two competing players who attempt to drive a ball through their opponent’s goal simply by putting their minds at ease.
BCI technology opens a completely new frontier of treatment for people who ordinarily would have very few options. BCI has the potential to provide input that does not require muscular movement. While this technology is at a relatively early stage, it has the potential to provide advances for communication and computer interaction, possibly generating language simply from sensing brainwaves. Beyond this, there is much speculation on what BCI can accomplish, including direct telepathic communication between people and even direct brain communication with animals.