The most profound loss of communication occurs in people who remain conscious, but are unable to speak or move. In march a team including neuro scientist ugwald chowdre and others at the university of tubing in germany reported re starting communication with a man who has ameotrophic lateral scuerosis - motor neurone disease. They used electrodes placed on the cortical surface that detect the averaged activity of neuronal populations. The signals are not as fine grained as those from electrodes implanted into the cortex, but the approach is less invasive. Last year they reported that this device enabled a person left unable to talk by a brain stem stroke to communicate using a pre selected vocabulary of 50 words