Dealing with an extra thumb

In 2022, the team had the opportunity to test Third Thumb at the Royal Society’s annual Summer Science Exhibition, where people of all ages could use the device for a variety of tasks.

The results were published today IN Science Robotics.

Over five days, the team tested 596 participants ranging in age from three to 96 and from a variety of demographic groups. Of these, only four were unable to use their third thumb because it either did not fit well in their hands or they were unable to control it with their feet (the pressure sensors developed especially for the exhibition were not suitable for very light children).

Participants were given up to one minute to familiarize themselves with the device while the team explained how to perform one of two tasks.

The first task involved picking up pegs from the pegboard, one at a time, using the third thumb and placing them in a basket. Participants were asked to move as many pegs as possible in 60 seconds. This task was completed by 333 participants.

The second task involved using the third thumb in conjunction with the user’s biological hand to manipulate and move five or six different foam objects. The objects had different shapes that required various manipulations, increasing the dexterity of the task. Again, participants were asked to move as many items as possible to the basket in a maximum of 60 seconds. This task was completed by 246 participants.

Almost anyone could use the device immediately. 98% of participants were able to successfully manipulate objects with their third thumb within the first minute of use, and only 13 participants were unable to perform this task.

Participants’ skill levels varied, but there was no difference in performance between genders, and handedness did not influence performance – even though the Thumb was always worn on the right hand. There was no definitive evidence that people who could be considered “good with their hands” – for example, had learned to play a musical instrument or had a job that required manual dexterity – were better at performing tasks.

Older and younger adults showed similar levels of skill in using new technology, although further research within the age range of older adults showed a decline in performance with age. The researchers say this effect may be due to a general degradation of sensorimotor and cognitive abilities that are associated with aging and may also reflect a generational relationship with technology.

For younger children, outcomes were generally worse. Six of the 13 participants who could not complete the task were under the age of 10, and among those who did successfully complete the task, the youngest children tended to perform worse compared to older children. However, even older children (aged 12–16) had greater difficulties than young adults.

Dani Clode he said: “Enhancement is about designing a new relationship with technology – creating something that goes beyond being just a tool and becomes an extension of the body itself.

“Given the diversity of bodies, it is critical that the design phase of wearable technology is as inclusive as possible. It is equally important that these devices are accessible and functional for a wide range of users. Furthermore, they should be easy to learn and use quickly.”

Co-author Lucy Dowdallalso from the MRC Cognition and Brain Science Unit, added: “If motor enhancement – ​​and even broader human-machine interactions – are to be successful, they must integrate seamlessly with the user’s motor and cognitive abilities.

“We will need to take into account people’s different ages, genders, weights, lifestyles, disabilities, as well as their cultural and financial backgrounds, and even their likes and dislikes for technology. To achieve this, physical tests on large and diverse groups of people are necessary. goal.”