An international group of researchers has created a hands-free, thought-controlled musical instrument, the encephalophone.
The encephalophone is a musical instrument that can be played by the mind alone. Image credit: University of Washington.
The encephalophone is based on brain-computer interfaces using an old method, called electroencephalography, which measures electrical signals in the brain.
The instrument collects brain signals through a cap that transforms specific signals into musical notes.
The invention is coupled with a synthesizer, allowing the user to create music using a wide variety of instrumental sounds.
“The encephalophone may have potential applications both as a novel musical instrument without requiring movement, as well as a potential therapeutic biofeedback device for patients suffering from motor deficits (e.g., amyotrophic lateral sclerosis, brainstem stroke, traumatic amputation),” the scientists said.
“The encephalophone is a musical instrument that you control with your thoughts, without movement,” said Dr. Thomas Deuel, a neurologist at Swedish Medical Center and a neuroscientist at the University of Washington.
“I’m a musician and neurologist, and I’ve seen many patients who played music prior to their stroke or other motor impairment, who can no longer play an instrument or sing.”
“I thought it would be great to use a brain-computer instrument to enable patients to play music again without requiring movement.”
Experimental setup: electroencephalogram (EEG) signal from subject wearing electrode cap is sent from Mitsar 201 EEG amplifier to computer #1 where 8–12 Hz posterior dominant rhythm (PDR) or Mu power is converted to a value from 1 to 8; this value from 1 to 8 is sent via OSC to computer #2 where it is converted to a musical piano tone in the key of C (seven tones of C major scale and octave, from C4 to C5); subjects generating tones attempt to match them with a presented target tone. Image credit: Deuel et al, doi: 10.3389/fnhum.2017.00213.
In a paper published recently in the journal Frontiers in Human Neuroscience, Dr. Deuel and his colleagues from the University of Washington describe their development of the encephalophone, as well as their initial studies showing evidence of how easily the instrument might be used.
The preliminary study showed that a trial group of 15 healthy adults were able to use the instrument to correctly recreate musical tones, with no prior training.
“We first sought to prove that novices — subjects who had no training on the encephalophone whatsoever — could control the device with an accuracy that was better than random,” Dr. Deuel said.
“These first subjects did quite well, way above chance probability on their very first try.”
The encephalophone can be controlled via two independent types of brain signals: either those associated with the visual cortex (i.e. closing one’s eyes), or those associated with thinking about movement.
“Control by thinking about movement may be the most useful for disabled patients, and we plan to continue researching this application,” Dr. Deuel said.
“But for now, the current study shows that, at least for this small group of novice users, control by eye closing is more accurate than control by imagining movement.”
Dr. Deuel and co-authors are working with more people to see how much users can improve with training.
They also plan to begin clinical trials of the encephalophone later this year to see whether it may be useful or enjoyable for disabled patients.
“There is great potential for the encephalophone to hopefully improve rehabilitation of stroke patients and those with motor disabilities,” Dr. Deuel said.
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Thomas A. Deuel et al. The Encephalophone: A Novel Musical Biofeedback Device using Conscious Control of Electroencephalogram (EEG). Front. Hum. Neurosci, published online April 26, 2017; doi: 10.3389/fnhum.2017.00213
