Colours of week and tasty riffs on menu at Trinity

Some people can taste the letters of the alphabet while others can taste the sound of a guitar, or see colours when faced with music – a sensory "crossover" known to doctors as synaesthesia.

Also known as “sensory cross-activation” it happens when the brain makes unusual connections between sensory centres that it would not normally be able to make. Those with synaesthesia get a more complex response, for example hearing colours, tasting words or feeling flavours.

Synaesthesia will be up for discussion from today when Trinity College Dublin hosts an international three-day conference on the subject in conjunction with the UK Synaesthesia Association.

Between 1 and 4 per cent of peope have the trait, TCD associate professor of genetics Kevin Mitchell said. Although it is clear the condition involves extra brain wiring, it is not clear why it happens, he said.

Prof Mitchell studies the condition because it may tell something about how people learn. “We don’t really know how that works and synaesthesia may give us a window into it.”

Sensory response

The condition mixes sensory response. One person with the condition thinks the letter R is grey and tastes of cooked carrots. For another August is like wallpaper and tastes of cream cheese.

Dr Richard Roche of Maynooth University studies the condition but also has it.

“I have coloured days of the week. My numbers have personalities as well,” he said. For him seven and three get on very well but six is a nasty number and is evil to four.

There is a public lecture on the subject today at 6pm in the Science Gallery, TCD. It is free but must be booked at sciencegallery.com