Brain-Computer Interfaces

Diana Glendinning

An Interview with Diana Glendinning, Ph.D.

(Spring 2013)more conversations

Recently, there have been a number of news stories about mind-control or a brain-computer interface? What are these? Are they the same thing?

Brain-computer Interfaces (BCI) are devices that can record electrical signals from the brain and translate these signals into outputs to control an external device. The external device might be a small machine, such as a robot, or small computer program. Unlike other technologies that use brain electrodes, BCIs do not involve brain stimulation. They have been developed to record natural brain activity. Mind-control is a term used in the popular press to refer to these BCI technologies.

What are some medical applications of BCI?

There is a lot of potential for BCIs to help people with disabilities, although the work is experimental at this point. One of the most exciting possible applications for BCIs is to improve function in people who have been paralyzed or have diseases affecting the motor system. Steven Hawking, the famous astrophysicist who has ALS, is already participating in an industry-run trial to try out BCI. In ALS or in other conditions that disrupt brain-muscle connections, BCIs can record brain signals as someone attempts to move, and use those signals to stimulate muscles or move a robotic limb. BCI devices could also potentially produce speech for patients who have language losses. Speech or motor devices could be used by therapists to augment rehabilitation, or for patients to “take home” to improve their daily function. BCI technologies have other clinical applications such as remote monitoring of brain electrical activity (EEG) which might be useful for patients with seizures or sleep apnea.

Are all the applications medical?

No, BCI devices are also being explored for military applications and for some high-tech games. Many of the games being sold as mind-reading devices, however, may be using muscle signals rather than brain signals. One example of a military application of BCI is to use a device to pick up small “alarm” brain waves produced when any of us views something that feels wrong. The BCI device can amplify these signals and alert the user faster than their brain would. In other words, there is potential to make healthy brains even better.

Which branches of science are taking the biggest interest in this?

There are many neuroscientists studying BCI. BCI grew out of neuroscience discoveries related to cortical control of movement, sensation and speech. A particularly important discovery is that the motor and sensory cortices are “plastic”, meaning that they can relearn function following significant changes in the limbs. These changes include loss of limb function or use of tools and machines. Engineers play an important role in developing BCI. Sensitive electrodes are needed to record brain activity, but these also need to be practical and durable. Computer programs are needed to recognize features of the signals and translate them into outputs. Engineers are also developing output devices, such as robotic limbs, that will move the body. All of these devices pose a number of engineering challenges.

What parts of the brain are involved in a brain-computer interface? How are researchers studying this?

Most BCI systems pick up signals from the cortex with electrodes that are either placed into the brain, over the surface of the brain, or on the scalp. Those on the scalp are the crudest, but also the most practical, since they can be worn on a cap, rather than inserted invasively. The scalp electrodes can be placed on different parts of the head, to sample different regions of the cortex that control specific functions. Animal studies have been done using hundreds of electrodes positioned inside of the brain, and these are capable of controlling more complex devices.

What patient populations might benefit from BCI systems?

There are a number of clinical conditions affecting the central nervous system for which BCI technology and training might improve function and quality of life. Some examples are spinal cord injury, stroke, locked-in syndrome, or traumatic brain injury. In all these conditions, people have lost speech or motor function. If a device can translate their intent to move, or to say something, into actual movement or speech, this would improve their function immensely.

How close are we to helping people with neurological disorders?

There is a lot of promise for BCIs to help people with disabilities. Implanting small devices into the brain is already being done routinely. For example, cochlear implants are used in some hearing loss, and deep-brain stimulation is used for movement and behavior disorders. For motor disability, scientists have been able to use brain signals in healthy primates to control robots. A couple experiments have already been performed with humans who have quadraplegia. They are able to use cortically-recorded signals to crudely control a robotic arm, switches, or computer cursors. A number of issues will need to be worked out before BCI devices are used in medical practice. These include electrode durability, and the practical limitations of accessing and using the physical device outside of the clinic or lab. Practically, will the device be comfortable or produce any negative wear-and-tear on the body? Finally, it remains to be seen whether the devices will be better than existing prosthetics and methods to improve function with disabilities.

Are there ethical considerations?

The most important ethical issue with respect to patient treatment with BCI is the risk:benefit ratio. It needs to be demonstrated that the BCI works better than standard treatments, and will benefit the patient to a greater extent than less-invasive or less-expensive methods.

Are there any books or articles you would recommend for readers to learn about this topic?

Here are two books written for all audiences, scientists and non-scientists, on neuroplasticity, BCI and brain-machine interfaces. There is also a review article for the medical or scientific audiences.

The Brain That Changes Itself by Norman Doidge (New York: Penguin)

Beyond Boundaries: The New Neuroscience of Connecting Brains with Machines—And How It Will Change Our Lives by Miquel Nicolelis (New York: Henry Holt)

Shih JJ et al. Brain-computer interfaces in medicine. Mayo Clin Proc 2012: 87(3) 268-79.

Diana Glendinning, Ph.D. is an Associate Professor in the Department of Neuroscience and Cell Biology at Robert Wood Johnson Medical School. She is the Course Director for Neuron, Brain, and Behavior, a second year medical school course. Her research is in the area of movement disorders.



A Little Device That’s Trying to Read Your Thoughts (New York Times)

The Army's Totally Serious Mind-Control Project (TIME Magazine)

Brains-on with Muse, Interaxon's mind control headset (CNET)

Mind-Controlled Videogames Become Reality (Wall Street Journal)

A headset that reads your brainwaves (TED Conference Video)

Brain-computer interface reconnects disabled patient’s brain to his muscles (

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