PBS: UK PREMIERE Wednesday 2 and Thursday 3 August at 7.10pm

The extent to which the human brain shapes – and even generates – what we subjectively perceive as ‘reality’ has been a question addressed by philosophers, scientists and speculative writers down the centuries.

What, ultimately, drives our decisions? Is what might appear to be our own conscious control, our free will, actually no more than an illusion? How deeply can science delve into the subconscious and its secrets? Where does the brain end and the mind begin?

In this two-part NOVA documentary, neuroscientist Heather Berlin applies the latest scientific research and insights to an age-old topic, shedding new light on some of the perceptual tricks and shortcuts employed by this most complex and enigmatic of organs, and revealing some surprising discoveries.