Using a brain-computer interface, a patient with locked-in syndrome was able to play music just by thinking about it, according to UK researchers who wrote a paper published online recently in the journal Music and Medicine.
The Brain-Computer Music Interfacing (BCMI) System was developed by Eduardo Miranda, a composer and computer-music specialist based at the University of Plymouth, who describes himself as a “working at the crossroads of music and science”, with the help of computer scientists at the University of Essex.
Miranda and colleagues carried out a proof-of-concept study to test the BCMI with a female patient with Locked-in Syndrome at the Royal Hospital for Neuro-disability, in London.
The patient, who was paralysed after a stroke, can only make eye, facial and slight head movements.
The BCMI picks up tiny electrical impulses made by the patient’s neurons or brain cells.
The system uses a method called Steady State Visual Evoked Potential (SSVEP), which shows the patient targets that look like flashing buttons on a computer screen. Each target corresponds to a different action, so to choose which action she wanted to perform, the patient gazed at the corresponding target.
The patient was able to grasp the concept quickly, and “rapidly demonstrated her skill at controlling the system with minimal practice”, wrote the authors.
For example, she learned how to vary the intensity of her gaze (which changed the amplitude of her EEG brain pattern) to control various musical parameters available with that target.
EEG is short for electroencephalography, a cost-effective, well established brain scanning technology that uses electrodes placed on the patient’s skull to pick up faint signals generated by neurons in the brain.
The EEG signal can be processed quickly, giving a “real time” feel to the interface.
The BCMI changes the size of the target in response to the intensity of the user’s gaze; thus once trained, the user can produce a variety of musical notes by focusing on the targets and varying gaze intensity.
According to Nature News, the patient learned how to use the BCMI in just two hours, and was eventually playing a melody with a backing track. She reported that “it was great to be in control again”.
Miranda and colleagues noted in their paper that:
“We have proved the concept that such a BCMI system is cost-effective to build, viable, and useful.”
Now there is a need to improve the ergonomics and design to make it more practical for clinical use, they wrote.
For example, the current prototype design is time-consuming to set up because it needs a therapist to “place individual electrodes and calibrate a user’s response to each stimulus”.
A new version will only need a headset to be positioned, and will have advanced algorithms that obviate the need for calibration.
The researchers hope that the system can be developed so people with severe physical disability, such as that caused by brain or spinal-cord injury, will be able to make music for pleasure or as part of treatment.
Currently, such patients can only take pleasure in music by passive listening.
“Brain-Computer Music Interfacing (BCMI): From Basic Research to the Real World of Special Needs Music and Medicine .”
Eduardo R. Miranda, Wendy L. Magee, John J. Wilson, Joel Eaton, and Ramaswamy Palaniappan.
Music and Medicine, first published on March 7, 2011 as doi:10.1177/1943862111399290
Additional source: Nature News (18 Mar 2011).
Written by: Catharine Paddock, PhD