Donna Addis (Neuroscientist, University of Auckland), Tali Sharot (University College-London), Micah Edelson (Weizmann Institute of Science), Yuki Kamitani (Computational Neuroscientist), Alain Brunet (Psychologist, McGill University), Lois Bouchet (Patient), Steve Furber (Computer Engineer, University of Manchester)
Freeman: We all spend our lives on a search for something so close, yet always just out of reach. Some call it the ego, others, the soul. Now, modern science is prying into our thoughts, our memories and our dreams - and asking the profoundly puzzling question : what makes us who we are?
Freeman: Our memories are not just a record of the events that took place in our lives, they are malleable and fallible. Our identities are created with constant input from our society. No man is an island. But could we go a step further and deliberately reengineer someone's identity? To do that, you'd have to be able to peer into a person's innermost thoughts - and, believe it or not, that technology is already here.
Fenton: If you experience something, there's been an electrical activation somewhere in the brain, that spreads through the brain, and that is your experience. As in a city, there are roads that connect one district to another district, and those roads can be very big boulevards and send a lot of traffic, or they can be small alleys that send very specific information, but nonetheless, not very rapidly or very easily.
Freeman: For years, scientists thought the pathways in our brains were set in stone after we matured from babies to adults - alleys could not become wider, highways could not become narrower. But now, it has become clear that the roads in our adult brains are under constant construction. Every time we store a new memory, electrical activity propagates through millions of neurons. Just as Andre is forced to find a new route if his pathway is blocked, our neural pathways adjust themselves to process and record new experiences.
Fenton: And so, what neuroscientists understand is that there's a sufficient amount of this plasticity throughout life, and that it is effected and modulated and controlled by experience.
Freeman: The journey to forming an identity begins when a body, guided by networks of neurons, struggles to try to navigate its way through the world. It learns, adapts, remembers and, eventually, becomes self-aware. What makes us who we are? Our identities are built bit by bit from our memories, our dreams and our imaginations. No-one's sense of self is fixed. Life is a journey that makes us all unique - and discovering who we are is our greatest, and longest, adventure.