The Human SensesNearly everyone has experienced a moment when a faint fragrance brings a memory of a long-lost moment in time crashing back to the forefront of their minds.Often we will have forgotten about the event completely, yet it transpires our unfathomable minds have filed it neatly in some unreachable corner of the brain, primed for instant retrieval.

Nigel Marven goes in search of the most disgusting and the most attractive smells, sets out to discover why we are excellent at seeing some things, but sometimes miss what’s right in front of our eyes, the biological reasons why humans eat such a diverse range of foods, from rotten raw ducks eggs to a sweaty blue cheese, demonstrates that when it comes to our sense of touch humans are similar to elephants, tracks down the sounds which have the most powerful emotional effects on us and joins stunt co-ordinator Marc Cass for a dramatic drive and experiences how the balance organs let us know how we’re being yanked around and even turned upside down.

Humans’ real specialty is checking each other out. We’re so good at it, we do it without even being aware of it. With the help of the latest eye-tracking technology and scientists from Sussex University, we show some unsuspecting volunteers what their eyes really get up to. We are also very skilled at gauging depth and distance. Nigel discovers how top baseball players manage to track a ball coming towards them at high speed. This skill is an extreme example of the basic hand/eye co-ordination that we all acquire as we grow up.

Watch the full documentary now (playlist - 3 hours, 28 minutes)