to complete tasks such as building Jenga towers, picking up wine glasses, and scooping marbles out of cups. Before and after the training, the volunteers had their brains scanned using fMRi (functional magnetic resonance imaging).

The researchers’ focus was on a particular region of the brain called the ‘primary sensorimotor cortex’, which is activated when we move our fingers. They wanted to find out whether training with the thumb could affect this region.

And their preliminary results suggest that it can - after training, a volunteer typically showed fewer differences between the brain activity patterns for individual fingers. In other words, the finger activity patterns were less defined, which suggests that training with the thumb weakened the hand’s representation in the brain. 

This is an example of the brain’s plasticity - its ability to rewire itself when faced with new experiences or situations. More research is needed to understand why these brain changes take place, and what their effect might be.

The findings will be of great interest to those developing the next generation of brain-controlled prosthetic devices. This technology “critically relies on our brain’s ability to learn, adapt and interface with these devices,” write the researchers.

“Importantly, though, such successful human-robot integration may have consequences on some aspects of body representation and motor control which need to be considered and explored further.”

ScienceFocus