Composer and synesthete Harley Gittleman visited our institute today to discuss his perception. Synesthesia is when you experience more than one sensory perception in response to stimulation of  a single sensory modality. Often, people see numbers as having colors (even when they are uncolored physically, they see specific replicable colors matched to numbers. Estimates are as much as 5% of the population have some degree of synesthesia.

Harley perceives specific colors and shapes when he hears certain tones. That’s especially interesting in his case because he is a professional composer and musician. Harley played some of his wonderful music for us = and pointed to colors as he experienced synesthesia in relationship to the tones, in real time. His daily life is awash in color, motion and shape. He listens only to talk shows when he drives and he’s been known to walk into a wall or two when he absent-mindedly attends to the floating colors and shapes in front of him instead of to the real world.

Current theories suggest that synesthesia is due to wiring between neighboring brain areas that usually are not connected together. This idea is bolstered by brain imaging studies showing increased connectivity and mutual functional activation between neighboring brain areas in synesthetes  as compared to non-synesthetes.

Synesthesia might be due to mutations in genes controlling neural plasticity and pruning of neurons. In that case, it may have an adaptive value from an evolutionary standpoint, as it brings new insight and relationships between neural experiences in a way that is interesting and fairly harmless.

Do you experience synesthesia? If so, is it useful to your everyday life?

Stephen Macknik