Derek tastes of earwax.

Documentary looking at people who have synesthesia, a condition in which their senses get mixed up. They describe how their condition feels. Adding colours to numbers and words is the most common form of synesthesia but some people also 'taste' the things they see and hear. Professor Ramachandran ran tests to prove that synesthesia really exists and further experts interpret MRI scans to further prove that the synesthesic brain functions differently. However, recent research has shown that almost 1 in 100 of us has synesthesia in varying degrees. There also seem to be, according to Ramachandran, strong links between synesthesia and creativity, leading back even to the formation of language.