Neural interfaces represent an increasingly hot topic in the field of scientific research: we often hear of brain-computer interfaces as a new frontier for medical applications and for human enhancement, which is particularly important in the field of assistive technologies for people with disabilities. A brain-computer interface (BCI), in fact, is a tool that allows a user to interact and communicate with the surrounding environment without the need for any voluntary muscle control. Precisely for this reason, the BCIs are often used as assistance devices for people who suffer from severe disabilities, who cannot communicate through the channels normally available because of brain damage, spinal cord injury or neuromotor degeneration.
For decades, researchers have experimented with human-machine interfaces to give people with severe disabilities the power to communicate using only the mind. In particular, in recent years the BCI technology has undergone considerable development, allowing people with disabilities to write messages, send e-mails, surf the Internet, control smart home and even drive a motorized wheelchair.
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But scientists’ goals are increasingly high: starting from simple communication as the transmission of information aimed at carrying out normal daily activities, scientists are increasingly aiming to create algorithms through which these subjects can express their creativity.
We consider a subject suffering from a neurodegenerative disease such as ALS (amyotrophic lateral sclerosis): the patient will be imprisoned in a condition in which he will still be able to think, dream, perceive emotions, but he will not be able to express them. Already in 2010, a research group in Germany used the BCI to test the first brain painting of people with ALS, unlocking the creativity of people with paralysis. In the last year, an important innovation has arrived, able to expand the artistic potential of BCI technology: a team of neural engineers in Austria has, in fact, designed a special interface that allows paralyzed subjects suffering from ALS to compose music using only the power of thought. It is the first musical composition program controlled exclusively by the brain.
The study, published in the journal Plos One, was conducted by a team of scientists led by Gernot Müeller-Putz, head of the Neural Engineering Institute of the University of Graz in Austria. The scientists designed the Brain Composing system, consisting of an EEG acquisition system, and software for composing music, using a method that uses the P300 produced by the brain based on visual stimuli. The team adapted the P300 signal model, well known in this field and already used for various brain-computer interface applications (such as environmental controllers, web browsers or mind-painting algorithms), to music composition.
Thanks to the gel-free biosignal acquisition system, the team recorded the signal that was then processed thanks to a universal P300-based control system, connected to a powerful open-source music composition software, MuseScore 1.3.
Researchers have studied efficiency, effectiveness and subjective criteria in terms of satisfaction, fun, frustration, and attractiveness, evaluating the results obtained by a group of seventeen participants all capable of playing an instrument and a professional composer. The participants received instruction for the correct use of the application in order to carry out copying of writing, copying of composition and free composition with the system, “thinking” the melodies on a musical score.
The results obtained show a high precision average: 88.24% (copying of writing), 88.58% (copying of composition) and 76.51% (free composition). The professional composer has overcome them: 100% (copy of writing), 93.62% (copy of composition) and 98.20% (free composition). The subjective evaluation of the criteria revealed that users were highly satisfied with the application.
This study is the first step towards a system of composition as a means of entertainment and, above all, of expression for people with severe disabilities.
The long-term goal, as Müeller-Putz claims, is to move from a laptop-based interface to a smaller one so that it can be supported by a smartphone: the best way to bring into musicians’ homes a special system that allows them to share their musical creations with the world.