Sunday, July 11th, 2021 -- Most prosthetics are made to replace a part of the body that was lost, such as an arm, hand, or leg. However, designer and researcher Dani Clode designed a prosthetic that extends the human body instead of replacing parts of it. She created a 3D-printed, moveable prosthetic thumb called the “Third Thumb”. Clode and neuroscientists at the University College London are conducting a research project about human augmentation’s effects on the brain using the Third Thumb.
Dani Clode created the Third Thumb as her master’s degree project. The prosthetic is very flexible and is controlled by pressure sensors under the user’s toes. It is powered by motors in a watch strap and connects the pressure sensors’ signals to the Thumb with Bluetooth controllers. The Thumb can be used when sitting or standing, but not while walking.
The purpose of the research project was to see if the human brain’s neuroplasticity allows the body to adapt to an extra body part, as well as how the usage of an extra body part impacts the brain.
Participants used the Thumb for 2 to 6 hours per day for 5 days, both in the lab and at home, allowing them to utilize the Thumb in structured practice and daily use. Some of the tasks they performed include stacking building blocks, stirring a drink while holding the cup, touching the tip of the Thumb to each of their fingers, and playing the guitar. Most participants said that the Thumb had become “part of their bodies” and even changed their regular hand movements to adapt to it.
Comparing the brain scans from before and after usage of the Thumb, researchers observed that the brain’s representation of the hand changed. Only a week after they stopped using the Thumb, participants’ brain structures reverted back to representing their normal hand structures, showing that the effects of human augmentation on the brain may not last long. Also, participants were able to control the Thumb when distracted (i.e. doing a math problem) or not looking at it (i.e. when blindfolded); this shows that participants’ proprioception of the hand also changed when using the Thumb.
This research project has proven that the brain can easily adapt to an extra body part because of its neuroplasticity. Further research about human augmentation and the Thumb include confirming that the changes of human augmentation on the brain are truly short-lasting. For society, the Thumb can be an important and useful tool; it can improve a surgeon’s ability to perform a surgery, increase an assembly line’s efficiency, allow people with 1 functioning hand to perform tasks that would require 2 hands, etc.
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(2021) What is Proprioception, and Why Is It So Important? In: Healthline. https://www.healthline.com/health/body/proprioception. Accessed 2 July 2021.
Prosthetic: an artificial body part
Human augmentation: the use of prosthetics to improve a part of the human body’s performance.
Neuroplasticity: the brain’s ability to adapt or change, based on experiences
Proprioception: a person’s awareness of their body movement and position without directly paying attention to it