A brain-computer interface (BCI), also known as brain-machine interface or mind-machine interface, is a direct link between the human brain and an external computer. The technology harnesses electrical signals produced by the brain. A device amplifies these signals and sends them to a piece of software that figures out how they should control the computer.
It sounds effortless, doesn’t it? But, naturally, there’s much more to it than that.
How does the Brain Produce Electrical Signals?
The human brain is made up of nonconducting tissue, so how is it able to generate electrical signals? It does this through complex chemical reactions that take place when thoughts are produced. Ions float in and around the neurons of the brain in a state of delicate equilibrium. When thoughts and impulses are created, the balance changes, and the movement of ions to restore it manifests as electrical signals.
How does the Brain Control an External Computer?
To control a computer, you need to detect the electrical signals from the brain, amplify them, and then interpret these into corresponding computer actions. Electroencephalogram (EEG) is a reasonably common technology used by neurologists to monitor the electrical activity of a brain. EEG is the easiest and least invasive way to record a brain’s electrical output.
The signals are then passed on to the BCI software, which makes use of machine learning (ML) algorithms that have been trained to recognize EEG readings associated with specific emotions and actions. The algorithms tag the EEG data with the corresponding commands to control the computer, and the BCI carries out these commands.
Using this system, you can move the computer’s cursor to the left or right by merely thinking about moving left or moving right.
Why is a Brain-Computer Interface Useful?
Using a BCI is a relatively new and unexplored field. As people get to understand better how it works, they are discovering more useful ways to employ the technology. One of the most attractive prospects is using it to control devices remotely. To date, there have been successful attempts at using BCI to control robots in hostile environments.
It is also helping us understand the detailed workings of the brain, mainly how biological neural networks function in real-time. BCI development can have many implications in artificial intelligence (AI) and artificial neural network research and development.
Researchers are also excited about the prospects of using BCI technology to improve the lives of people who have lost the use of their limbs. The late celebrated physicist Stephen Hawking was able to communicate his brilliant ideas by using a device that detected the movement of his cheeks and synthesized his speech. A BCI would have tapped directly into his brain and given him not just the ability to speak, but also to control prosthetic devices and computers.
Perhaps one of the most awaited developments is using brain-computer interfaces to control videogames. BCI technology promises to take virtual reality (VR) video gameplay to a whole new level for EEG-wired players.
What are the Barriers to the Development of Brain-Computer Interfaces?
The prospects of using BCI technology are enormous, and we may not even understand the extent of its full potential. But some issues are blocking progress in this field. Check out this short video to learn about some of the possibilities and the challenges facing BCIs:
While EEG is noninvasive, some advanced applications may require implanted sensors that directly interface with neurons. The technology to do this, however, is not yet fully developed, and many technical issues need to be resolved to advance to this level.
Some people are also objecting to BCI use based on ethical grounds. They fear that if the human brain can be connected to a machine, then it may not take long until others can hack into and take control of someone else’s mind.
What are the Real-World Applications of BCI Technology?
While BCI use is still bereft of several issues, it has useful applications that are already making a significant impact on end-users. Its beneficiaries would fall under three groups, namely:
- Individuals who no longer have neuromuscular control or paralyzed
- People who have little neuromuscular control and so suffer from muscle twitches or have limited eye movement
- Individuals who still have considerable neuromuscular control but need muscle-based assistive technology to do specific tasks
It remains unclear whether paralyzed people can still benefit from BCI. Also, BCI applications still need to be carefully assessed to determine if they can remedy issues related to attention, alertness, and higher cortical functions.
Despite the hurdles, however, we continue to see BCI’s adoption specifically for the following functions:
Researchers are currently using BCI to develop assistive technology for patients with physical impairment. These include those who have amyotrophic lateral sclerosis (AML) or little neuromuscular control. Patients who have late-stage AML can lose motor control, including the ability to speak. They can use BCI-powered EEG headsets that record brain signals and spell out their messages for others to read.
Other patients who can benefit from using BCI-powered EEG headsets include those with cerebral palsy, spinal cord injuries, chronic peripheral neuropathies, and brainstem stroke.
Some researchers are currently developing BCI-driven wheelchairs to provide some form of mobility for paralyzed patients. This technology employs intelligent algorithms to ensure that the user gets assistance when they give commands to the wheelchairs.
Another useful BCI application is restoring motor control in paralyzed patients. Experts have used BCI technology to develop exoskeleton prosthesis that allows patients to carry out motor functions that they lost along with their limbs. A study also revealed that tetraplegic patients could control an electrically driven hand orthosis using EEG signals from their brains. As such, the patient was able to control the paralyzed extremity.
Control of one’s environment
Most patients who lose muscle control are often home-bound. As such, one pilot study aimed to use BCI technology to allow them to control systems in their environment, such as lights, stereo sets, television sets, telephones, and front doors.
BCIs are also proving useful in assisting patients whose neuromuscular functions have been impaired by a central nervous system (CNS) disease or trauma. The technology helps them relearn how to perform motor functions with artificial limbs, leading to functional recovery.