A brain-computer interface (BCI) is a direct pathway that communicates between the brain and an external device. BCIs are usually directed at assisting, enhancing or repairing human cognitive functions. These interfaces are used in many applications and are designed largely for training and demonstration purposes.
Using this technology on humans, University of Washington researchers have evinced that brain behaves much like it does when completing simple tasks like typing or waving a hand. Small electrodes placed on or inside the brain allow patients to interact with the computers or control robotic limbs just by thoughts about how to run those actions.
Learning to control artificial machines through thoughts could become second nature for people who are paralyzed or has lost the ability to speak. Thus, this technology improves their comfort in communication and daily life.
The results of the research were published online in the Proceedings of the National Academy of Sciences. Though, initially there will lot of engagement of the brain’s cognitive resources, but later on, those resources are not needed and the brain is set free.
As a part of study, seven people with severe epilepsy were hospitalized to carry out a process that tries to identify where the brain seizures start. Physicians placed a thin sheet of electrodes directly on top of the brain by cutting through the scalp and drilling into the skull. While physicians were watching for seizure signals, researchers conducted the study.
The patients were asked to navigate mouse cursor on computer screen by using their thoughts to control its movement. Electrodes on their brains directed the cursor to move by picking up the signals and sending them to an amplifier. The computer analyzed the intentions transmitted through the signal and updated the movement of the cursor on the screen in just 40 milliseconds.
During the study, the researchers found that a lot of brain activity was centered initially in the prefrontal cortex, an area related with learning a new skill. But as the task became familiar, frontal brain activity reduced moving the brain signals to those patterns seen during more automatic actions.
Earlier researchers have successfully demonstrated the usage of brain-computer interfaces in monkeys and humans, but this study pioneered in mapping neurological signals throughout the brain. It helped researchers to have a clear understanding of what exactly happens in a brain while learning a task.
There are many brain-computer interfaces like a invasive device placed on a person’s head that can detect electrical signatures of brain activity. This technology is not very reliable because of the interference of signals from eye blinking and other muscle movements.
The current study provides a more aggressive alternative by placing electrodes inside the brain tissue itself which enables to record the activity of individual neurons. This has been proved by the researchers at Brown University and the University of Pittsburgh by conducting experiments on human patients, who successfully learnt to control robotic arms using the signal directly from their brain.
The UW team tested electrodes by placing them underneath the skull that empowered them to record brain signals at higher frequencies with less or no interference from the scalp. In future, we can expect a wireless device that can remain inside a person’s head for a longer time which will help to control computer cursors or robotic limbs at home.
Funded by the the National Institutes of Health, the NSF, the Army Research Office and the Keck Foundation, the research study motivated the UW team to to continue developing these technologies in association with the National Science Foundation’s Engineering Research Center for Sensorimotor Neural Engineering.