Mirror Magic

During a stroke, reduced blood supply to part of the brain often results in paralysis on one side of the body. If the mind ‘learns’ that a limb cannot move, paralysis then becomes a habit, even when connections from brain to limb are restored. Stroke recovery is improved with mirror box therapy, where an illusion of the paralysed limb moving is produced from the mirror-image of movement in the matching, healthy limb. How this works is not clear but scientists have started to unravel the regions of the brain involved using functional Magnetic Resonance Imaging (fMRI), which employs magnetic fields to observe changes in brain activity. Two regions, labelled A and B in the image, are activated. Both are important for self-awareness and memory, but not for muscle movement. Could mirror box therapy be helping the brain to ‘unlearn’ paralysis by making it conscious that a limb can move?

Written by Julie Webb

Julie Webb

Writer

Julie began her career as a researcher in genetics. In 2000 she won a Wellcome Trust award for her work on a collaborative science drama, staged at the Edinburgh Festival. She now works as a freelance science writer and communicator.

• Courtesy of Ruud Selles
• Published in Journal of Neurology, Neurosurgery & Psychiatry