Foot painters’ toes mapped like fingers

The brain has a dramatic ability to forge new connections.

A study of two British foot painters born without arms because their pregnant mothers were given Thalidomide has shown that a part of their brains usually devoted to finger activity has been repurposed to help out the toes.

The finding adds to the growing literature on neuroplasticity – the brain’s dramatic ability to forge new connections well into the lifespan – and will be leveraged in future research to see if robotic limb prostheses become represented in the brain in a similar way.

The stars of the study were Tom Yendell and Peter Longstaff, who also use their feet to manipulate cutlery, write and type on the computer.

A team led by Daan Wesselink from the Institute of Cognitive Neuroscience at University College London (UCL) in the UK, used ultra-high-resolution MRI scans to examine the pair’s brain responses to having their toes tapped.

In most people, each finger is represented by its own little section of the brain, but there’s no distinction between brain areas for each of our toes, says Wesselink. This is in contrast to nonhuman primates species that regularly use their toes for dextrous tasks such as climbing. Their toes and fingers are specifically represented in their brains.

When the toes of Yendell and

Longstaff’s painting foot were tapped, the scans showed clearly separate brain areas for four of the five digits. The sensory map for their feet had also invaded the brain region that would usually represent the hand.

The study appears in the journal Cell Reports.