For the first time, one of the tics that bedevil people with Tourette’s has been induced in volunteers who don’t themselves have the disorder, an experiment that might help us to understand and even treat the condition. Jennifer Finis of Heinrich Heine University in Düsseldorf, Germany, and her colleagues suspected that a type of Tourette’s tic called echophenomena, which involves mimicking other’s movements, may be caused by over-excitation of the supplementary motor area (SMA) – a brain region involved in the initiation of movement.
