It is the study of the nervous system and, most notably, the brain. There are several areas of interest: neurobiology looks at the chemistry of cells and their interactions; cognitive neuroscience looks at how the brain supports psychological processes; and computational neuroscience aims to create computer models of the brain to test theories. Questions could include anything from why certain proteins appear in neurons to how the brain supports consciousness.
It seems to be a boom area in science at the moment, why?
The discovery of the first effective psychiatric drugs in the 1950s and 60s made neuroscience both useful and profitable and drug companies have poured billions into the area ever since. In the 70s, neuropsychologists studying brain-injured patients discovered that the mind seemed to be divided unevenly across the brain, suggesting the exciting possibility of an innate structure to the self. The birth of functional brain imaging in the 90s allowed us to see, at least vaguely, the brain in action and the images fuelled a massive popular interest.
A lot of neuroscience appears focused on brain processes we would never notice. How much brain activity is involved in powering the unconscious?
Probably a great deal, although the concept of the unconscious is a slippery one. What we experience consciously depends both on the context and what else the brain is doing. A brain function may go completely unnoticed in one situation but will lead to a distinct and noticeable experience in another. Recent studies on people waking from anaesthesia
have put paid to the idea that "almost all" brain activity is unconscious. Massive amounts of neural activity are needed to keep us aware of the world. Probably, like an orchestra, not every component can be individually picked out, but almost all are needed to produce the final experience.