To Bob, a symphony concert doesn't just sound like a blissful masterpiece, it also tastes like a cup of hot apple cider. For Elaine, whenever her family sits down to a nice steak dinner, she doesn't just taste the feast set before her, she sees a gorgeous palette of colors sweeping across her mind's eye. In the case of Sam, a gifted mathematician, the numbers he sees on the page not only represent a numerical value and quantity, but they also possess a personality trait that a human may possess such as generosity or arrogance. If while reading any of these scenarios and they didn't make much sense to you, then there is a pretty good chance that you do not have a puzzling and fascinating neurological condition known as synesthesia. If you are reading this and these scenarios sound like your average Tuesday, then you should probably read this paper carefully because it is likely you are a synesthete, or a person affected by synesthesia. .
By definition from the website, Mixed Signals, which was created by synesthetes for synesthetes, synesthesia " refers to the fact that in some animals, a stimulus in one sense modality involuntarily elicits a sensation or experience in another sense modality." (Emerson, 2002) This means that a synesthete can experience one stimulus with two different senses simultaneously. An example of this phenomena would be the sound of Beyonce's voice appearing as shimmering silver waves or the taste of sour grapes evoking the color pink. "The elicited synesthetic experience does not replace the normal experience but instead always adds to it." (Emerson, 2002) Synesthesia has also been referred to as an "everyday Fantasia," referring to the 1940 Disney Movie where orchestral music is accompanied by whimsical and surreal scenes of animated animals and patterns. .
It is understood that synesthesia, although a little perplexing to the non-synesthete, is a real and scientifically proven phenomena, but how does it come to be? There are a few different hypotheses.