Series in which Dr David Eagleman takes viewers on an extraordinary journey that explores how the brain, locked in silence and darkness without direct access to the world, conjures up the rich and beautiful world we all take for granted.

This episode explores the question of how the brain gives rise to our thoughts, emotions, memories and personality. We see how the process of becoming 'you' starts at birth. The brain of a newborn baby is not yet fully developed, instead it grows and shapes itself around life experience.

Wiring up begins immediately, and rapidly, as the child's brain starts to adapt to whatever situation - culture, habitat, language - it's born into. This allows humans to flourish in any stimulating environment, but as the story of three Romanian orphans reveals, a lack of social contact and stimulation can result in permanent brain damage as the brain fails to make vital connections in those critical early years.

Tracing the development of the brain - the 'making of you' - through a lifetime, Dr Eagleman tests the social stress levels of teenagers as their brains go through profound changes, meets London cabbies whose intense training to memorise street maps physically alters the shape of their hippocampus, and joins a group of elderly nuns who are defying the symptoms of Alzheimer's by keeping their brains active and building up 'cognitive reserve'.

As we make new memories, learn new skills and have life experiences, the brain is constantly and dynamically rewiring itself. It never stops. Nor do we - the human brain is always changing, and therefore so are we. From cradle to grave, we are works in progress. Show less