Doctors have found what is potentially a new way to determine if a patient who appears to be in a permanent vegetative state is actually conscious:

The research team, led by Damian Cruse and Adrian M. Owen of the University of Western Ontario, gave simple instructions to 16 people said to be “vegetative”: each time you hear a beep, imagine squeezing your right hand into a fist. The subjects were given this task and another — hear a beep, wiggle your toes — and ran through up to 200 repetitions.

In healthy people who executed these instructions, the EEG picked up a clear pattern in the premotor cortex, the area of the brain that plans and prepares movements; the electrical flare associated with the hand was distinct from that associated with the toes.

The brains of three of the supposedly vegetative people showed precisely that; the subjects were a 29-year-old, a 35-year-old and a 45-year-old, all men who had been pronounced vegetative three months to two years previously.