Drastic surgery to remove a tumour reveals the brain to be remarkably adaptable. 

We used to think that brain circuits, controlling everything from walking and talking to seeing, hearing and feeling pain, formed during childhood and were, from then on, pretty much set for life.

Neuroplasticity, made famous in Norman Doidge’s bestseller The Brain that Changes Itself, tells us that is not so. After a stroke, for example, restraining the good arm in a sling forces the paralysed side to move, and recruits new brain pathways that can breathe life back into the frozen limb.

The degree to which plasticity can overcome damage to the visual part of the brain has been less certain. A new study, however, led by neuroscientist Marlene Behrmann at Carnegie Mellon University in Pittsburgh, US, has uncovered the brain’s remarkable ability to compensate for even a devastating loss of tissue involved in visual perception.