David explores explores how almost every action we take, every decision we make, every belief that we hold is driven by parts of the brain we have no access to.

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 great deception that greets us each morning when we wake up - it feels as though we are in conscious control of our lives, but in fact almost every action we take, every decision we make, every belief that we hold is driven by parts of the brain that we have no access to.

Dr Eagleman reveals the electrical storm of unconscious neural activity that accompanies even the simplest of actions. We meet a patient who has lost the ability to walk without consciously controlling every movement. If he's distracted for even a moment he will fall.

To demonstrate the proficiency of the unconscious brain, Dr Eagleman competes with a ten-year-old world champion in the sport of cup stacking. Wearing EEG caps to record their brain activity reveals that although the champion is performing at much greater speed and precision, his brain is almost at rest. When a skill sinks below the level of conscious, controlling this allows for much greater speed and efficiency.

Dr Eagleman reveals that everything from who we find attractive to how we describe the relationship we have with our mother can be influenced by factors that we have no conscious control over. But the unconscious has a dark side, as the story of Ken Parks - who killed his mother-in-law in his sleep - demonstrates. Our consciousness is needed to arbitrate between competing systems in the brain that, left to their own devices, are liable to run amok.

Dr Eagleman ends with a brief journey through free will, and the deep question of whether we have any conscious control over our lives. Although there is tantalising evidence that we can feel as though we are consciously in control when we are not, the experimental jury is still out on whether or not free will is an illusion. However, free will or no free will, the human brain's extraordinary complexity guarantees that life will never feel predictable.