Scientists demonstrate that it is possible to dissociate brain waves from actions, possibly identifying a new way to operate prosthetics.
Roald Dahl’s Matilda was a favorite book of mine as a child, and this, long before the movie was released in 1996. Like many children, I wished I could move objects using only my mind, just like the little girl in that book. Although that specific skill probably won’t be possible in our lifetime, scientists recently revealed that we are now one step closer to harnessing the mind’s power to move objects and, more importantly, we are now also one step close to significantly improving the lives of people affected by spinal cord injuries.
In an article published in Nature, Dr. Jose M. Carmena and his team of researchers reveal that they have been able to isolate specific brain waves independently from the physical movement that they normally trigger. Thus, this innovative study opens up the possibility of prosthetics that could be completely controlled by the mind, allowing people who are completely paralyzed to use them.
To demonstrate this, the researchers set up an experiment in which rats had to complete an abstract task in order to get a food reward. The catch? The rats could only complete the task if they didn’t use physical movement.
The scientists outfitted each rat with a brain-machine interface (BMI). This machine converts brain waves into auditory tones. The only way to obtain the food reward was for the rats to modulate their thought patterns within a specific brain circuit. This modulation in turn raised the pitch of the signal, allowing them access to sugar water, or lowered the pitch of the signal, allowing them to access food pellets. If, however, the rats used the targeted group of neurons to twitch their whiskers, their usual function, then the BMI would fail to change the pitch of the auditory tone, and they would not gain access to any food.
It took only two weeks for the rats to learn how to get the food. Through this training process, the rats learned to associate certain thought patterns with the appropriate pitch and were able to control when and how often they were rewarded. In essence, the researchers managed to separate the role of the targeted motor neuron that triggers whisker twitching from the action.
Dr. Carmena, UC Berkeley associate professor of electrical engineering, cognitive science and neuroscience, believes that this study demonstrates the very real possibility that a patient could one day control a prosthetic without having to use any physical movement.
“This is something that is not natural for the rats,” said Dr. Rui Costa, co-principal investigator of the study, “This tells us that it’s possible to craft a prosthesis in ways that do not have to mimic the anatomy of the natural motor system in order to work.”
The researchers hope that this study will lead to the development of new and more innovative prosthetics. So, although we won’t be using “The Force” for telekinesis any time soon, it is possible that we might see those who have lost motor control regain some agency and control over their lives in the next few years, which is just as extraordinary if you ask me.
Koralek, A., Jin, X., Long II, J., Costa, R., & Carmena, J. (2012). Corticostriatal plasticity is necessary for learning intentional neuroprosthetic skills Nature DOI: 10.1038/nature10845