PRESENTER: The brain is the most complex and least understood organ in the human body. Years of research have revealed a certain amount about how the brain functions, but many of the explanations are still hypothetical, especially where memory is concerned. Various theories have been postulated, but the fact is that no one knows what memories are. At one time, scientists believed that memories were stored in so-called "grandmother neurons" — one neuron holding grandma's face, one for her smell, and so on. But researchers now think that grandmother is in none of these places. She exists in the charged connections between different sets of neurons. It seems that memory, emotions, the soul itself, may all be manifestations of the physical activities of the brain. Someone who knows a great deal about the mysteries of memory at first hand is Amanda Hammond. Amanda, tell us something about your experience. AMANDA: Oh, yes ... I was driving my children to school when another car — it was apparently driving at high speed ... you know, exceeding the speed limit... anyway, it ran a red light and rammed into ours. Something must have been wrong with my seatbelt, because it came loose and I hit my head on the windscreen. That's what they tell me happened, anyway. You see, when I woke up in hospital I couldn't remember anything. PRESENTER: You had amnesia? AMANDA: Yes. That's what they call retrograde amnesia -everything in my memory up to that moment was totally wiped out. Since then, my memory has functioned normally, but my entire past is gone. When I woke up I did not know who I was or where I was — I had forgotten the language. My memory was a complete blank. Apparently I was a corporate workaholic before, but that person is dead. I'm a different person now. PRESENTER: How did you manage to get from there to here? AMANDA: I learned to speak through tapes and friends. It really was learning from square one. Once a friend told me it was raining cats and dogs and I panicked, I ran to the window expecting to see flying animals! But relearning love was the hardest thing. When I saw my children, I felt nothing ... they could have been any children off the street. How do you explain love to someone who has no memory of love? It's been an uphill battle. PRESENTER: Are you still having to learn new things? AMANDA: Oh, definitely. There's all of history to relearn. I mean, history has no meaning to someone whose own history has been erased. And even in a practical sense I was totally lost. I'd see something on TV about past events and think, "Did that really happen?" For example, I saw a programme about the Holocaust, and I was flabbergasted. Could people really have done such things? It just seemed unbelievable. PRESENTER: Do pieces of the old Amanda ever appear in dreams? AMANDA: No ... and I don't worry about her. I'm happy with the person I am now. PRESENTER: And who is that? AMANDA: I work with people who've had brain injuries. Since I've experienced this thing myself, I know what it can be like, trying to cope when part of yourself is missing. It takes courage, a determination not to throw in the towel, and I'm amazed every day by the amount of courage I see. These are people who are trying to rebuild their lives ... maybe not from scratch, as I had to, but often with a lot of pieces missing ... and they are managing, many of them. They are learning to support themselves, to function outside of institutions, And the important thing is that they care about each other. When you've had this kind of experience, you realise the fragility of human life ... you learn that life should never be taken for granted. I suppose you learn what being human really means. PRESENTER: Amanda, thanks for coming in.