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An experiment in which 36 people were fitted with a robotic third thumb has demonstrated the brain’s uncanny ability to adapt and leverage an entirely new body part, and in ways the researchers are still trying to understand.
The Third Thumb started as an award-winning graduate project at the Royal College of Art in London, England, and it was done to reframe the traditional view of prosthetics. “The project began as a way to better understand what it was like to control something extra attached to my body,” Dani Clode, designer of the Third Thumb, explained in an email. “As a prosthetic arm designer, I wanted to understand the unique relationship between a person and a prosthesis. It’s a relationship unlike any other product, and I wanted to explore that.”
Indeed, the Third Thumb represents an augmentation of the human body, as opposed to the replacement or restoration of “normal” human functionality. It’s a very transhumanist concept, but scientists don’t actually know if the human brain can meaningfully support an added body part or the long-term consequences of the extra cognitive load.
“These questions are complex and require the collaboration of experts from different fields,” Tamar Makin, professor of cognitive neuroscience at University College London and head of the Plasticity Lab, said in an email. “In our study, we used Dani’s cleverly designed Third Thumb to explore how the human brain can support an extra body part, and how the augmentative technology might impact our brain.”
The answers are important, as an additional thumb could lead to a host of benefits. It could help with repetitive, difficult, and physically demanding tasks, while also being of assistance to people who have either permanently or temporarily lost the use of one hand. It could also result in entirely new capabilities and activities, whether it be a new way of playing a musical instrument (or enabling the invention of a new type of musical instrument!) or the advent of an entirely new sporting activity.