But, so far, no known synesthetes have died and left their brains to science. It tells us something about the nature of perception and what makes things perceptually similar to one another. Synesthesia may help us to understand how the concept of similarity is embedded within the nervous system. In addition, Dixon suggests, the fact that synesthetic perception interferes with the perception of physical stimuli highlights an important aspect of cognition. But there are many instances where meaning goes back down and influences our lower-order perception of the world.
Synesthesia is just one very rare and exceptional example of that.
It would be a gene that, in either of its forms, results in a healthy human but has a profound effect on the organization of the nervous system. At a practical level, many researchers observe, research on synesthesia will help raise the condition's visibility, reducing the risk that clinicians might mistake it as a sign of mental illness. If so, synesthesia may be an ideal laboratory for studying those mechanisms. Unlike patients who experience hallucinations, synesthetes are not medicated, so you don't have that confounding factor. We're able to talk about our experiences.