What We Know and Don't Know
How many of us know what synesthesia is? What do we eat it with? How is it used or what is it used with. Well let me just tell you that synesthesia is a condition in which people have difficulty distinguishing between various sensory inputs.
Synesthesia comes from two Greek words, syn, which means together, and aesthesis, which means perception. Therefore synesthesia literally means, "Joined perception." "Synesthesia is an involuntary joining in which the real information of one sense is accompanied by a perception in another sense."(web.mit.edu) In addition to being involuntary, this additional perception is regarded by the synesthete as real, often outside the body, instead of imagined in the mind's eye. It also has some other interesting features that clearly separate it from artistic fancy or purple prose. It's reality and vividness are what make synesthesia so interesting in its violation of conventional perception. Synesthesia is also fascinating because logically it should not be a product of the human brain, where the evolutionary trend has been for increasing separation of function anatomically.
Synesthesia can also involve any of the senses. The most common form, colored letters and numbers, occurs when someone always sees a certain color in response to a certain letter of the alphabet or number. I will now give you and example: a synesthete might the word "count" and think of shoes or the number "9" and think of the color bright green. There are also synesthetes that who hear sounds in correspondence to their smell, who smell is in response to touch, or who feel something in response to sight. Oh by the way, any type of combination of the senses is possible; so don't think that there is a specific type that everyone has. There are even some synesthetes that can combine up to three of their senses, but this would be extremely rare.
Although there is no officially established method of diagnosing...