Synaesthesia research

A unique opportunity to explore perception

This fascinating phenomenon can link any of the senses, most commonly seen in vision and audition, providing an unusual perspective on perception.

You may have synaesthesia if you:

• see colours when you think of letters
• remember music by the visual patterns you see
• smell sounds
• feel tastes
• hear colours.

In synaesthesia, a stimulus in one sensory modality results in an unusual additional experience. For example, when hearing a sentence, a synaesthete may also see vivid colours accompanying each word. In other cases, the taste of certain foods might evoke specific tactile sensations.

Estimates of prevalence within the adult population vary from one in 500 for the more common types of synaesthesia (letter-colour), to one in 25,000 for rarer forms (such as sound-odour synaesthesia).

As synaesthesia rarely interferes with daily life (it is not a disorder), many people do not realise they are unusual. The extra experiences typically occur from a young age and remain consistent over time.

Our research

We have been studying synaesthesia since 1999: initially at Monash University (with Professors John Bradshaw and Jason Mattingley), then in further studies at the University of Melbourne (with Professor Jason Mattingley).

Since 2007 we have been studying synaesthesia at Macquarie University, where Professor Anina Rich heads the Synaesthesia Research Group in the School of Psychological Sciences.

Synaesthesia provides a unique opportunity to explore how we perceive the world. By looking at the way the synaesthetes' unusual experiences arise, we can:

• find out more about how the brain processes incoming information from the senses and puts together our conscious experience of the world
• provide insights into the role of learning and experience in our perception.

We use questionnaires, computer-based tasks and non-invasive brain imaging to explore the experiences of synaesthetes. These techniques allow us to examine the:

• characteristics of synaesthetes
• regions of the brain involved in their experiences
• role that attention and consciousness play in this fascinating phenomenon.