An audit of the state of neurological science is to be carried out by Britain's pre-eminent scientific academy to establish rules for conducting research and treating and altering people's brains.
Scientists believe they are on the verge of making giant strides into understanding how the brain works and how to treat diseases that afflict it. They are also close to understanding how drugs and surgery can manipulate areas like intelligence and personality.
Now a major project is being launched by the Royal Society to assess the likely advances that will be made and what moral and ethical guidelines should be laid down.
There is particular concern about advances in neuropharmacology, which have prompted renewed interest in creating chemical and biological weapons capable of incapacitating or killing people.
There are also civil liberties issues, which involve the possibility of predicting and therefore preventing criminal behaviour or the likely deterioration of an individual's mental health.
The brain is the most complex of the human organs and, with its huge range of functions, has proved the hardest to understand, but with the advent of technology such as neuro-imaging, including computed tomography (CT) and magnetic resonance imaging (MRI) scans, researchers have been offered unprecedented views of how the brain works. Advances in genetic research have provided similarly rapid discoveries.