The smell of freshly ground coffee or the taste of an orange are things that most of us enjoy and take for granted. But for some people the world is a tasteless, smell-less place, and for others it is a nightmare of grossly distorted tastes and odours.
Geoff Watts talks to Dr Robert Henkin and some of his patients at the Center for Molecular Nutrition and Sensory t)isorders In Washington. about the nature of these problems and their possible treatment.
Producer ALISON RICHARDS