David Eagleman: The afterlife, synesthesia and other tales of the senses

Neuroscientist by day, novelist by night - David Eagleman has just written an extraordinary little novel about the afterlife. He's also a leading researcher in synesthesia, studying people who taste sounds, hear colours, and live in a remarkable world of sensory cross-talk. He joins Natasha Mitchell in conversation about life, death and the in-between.