Thumbs up for the Extra Thumb
Researchers have developed a robotic spare thumb that could help us to grasp objects and also allows us to lift more objects at once. Convenient, right? Still, how long would it take us to get used to an extra digit like this?
Sometimes two hands and ten fingers just don’t seem to be enough. Try opening a door while carrying bags full of groceries, or opening a bottle while scrolling on your mobile. These are the times when an extra digit could come in handy, or at least so the researchers at the University of Cambridge thought. They set out to create a "third thumb”.
Six fingers on one hand
The scientists wanted to find out how quickly people would learn to handle an extra thumb. So they temporarily gave about 600 subjects a hand with six fingers. The participants, who were all aged between 3 and 96 years old, were given a mechanical thumb strapped underneath their little finger. This robotic thumb could be moved using pressure sensors under their feet. Then they were given one of the following tasks: they had to pick up pins and put them in a basket or move objects of different shapes and sizes.
Brain adaptation
The results were astonishing. Almost all the participants (98%) were able to operate the thumb and move objects successfully within one minute - whether they were male or female, skilled or clumsy.
It was also found that their brains adapted to the new body part surprisingly fast. This was demonstrated on brain scans of subjects who completed additional thumb dexterity tests for another five days. The brain signals associated with moving their own five fingers can usually be easily distinguished from each other. After the experiments with the robotic thumb, these became more similar.
A handy addition
This may seem like a comical experiment, but it does have some serious aims. For example, it could help with the development of prostheses for people who have lost a hand, arm or leg, or produce exoskeletons and robotic body parts to improve our motor skills. In any case, the extra mechanical thumb proved very handy: the people wearing it were able to hold more objects at once. Some tasks that usually require two hands could be done with just one hand. Who knows, perhaps we will all have six fingers on one hand soon?