1 Cognitive neuroscience: introduction and historical perspective

The brain is life’s most magnificent enigma. Nestling snugly inside the skull sits the most complex object anyone will ever know. The seat of all intelligence, creativity, hope, faith, desire, rage, genius, joy and despair, this grey lump of tissue hides its secrets in deep, shadowy crevices and shiny protrusions. Roughly the weight of a bag of sugar, partially hollow and composed of three-quarters water, one hundred billion cells cling together in its wet darkness, clasping hands and whispering messages to their neighbours. And in this constant chatter of neurons, the electric hum of signals sent in milliseconds, that fathomless universe behind the eyes can generate more thoughts than there are atoms in all of creation. It is a greedy organ; it demands 20 per cent of the body’s blood and oxygen sup-ply to carry out its myriad functions. It can repair itself to a remarkable extent when damaged, as cells grow new connections to bridge the gaps in broken process-ing chains. It contains many paradoxes, being simultaneously ugly in form and yet strangely elegant. It is malleable – rewiring its physical structure with every new experience – but also stubborn: connections made in childhood can last until old age