Synesthesia :: Biology Medical Medicine Research

In the mornings, my cat often takes up a post on my chest. His presence is heralded by a chirpy meow and four quarter-sized points of pressure where his feet make contact; as he relaxes, he settles into a loud, rhythmic purr, and the pressure of his 16 pounds is more evenly distributed across my ventral torso. If I'm slow to open my eyes, he reaches out a paw and gently pricks my face with his claws †¹ enough to make an impression but not do real damage. When I do open my eyes, I see the triangles of his ears, the dense, velvety blackness of his fur and the sheen of his nose; his yellow irises are thin rings around his dilated pupils in the dim, early light. Suppose I experienced all of those sensations up to the point of opening my eyes †¹ the pressure of my cat's weight and the pricks of his claws, his meowing and his purr †¹ and then I opened my eyes to the absence of any visual evidence of a cat. I'd be confused and disoriented, and if the tactile and auditory stimuli continued, probably panicky. A fundamental reworking of how I understand the world would be necessary to account for an invisible cat. Now suppose that the next time I heard guitar music, I failed to perceive a soft brushing sensation around my ankles. It would not bother me a bit. But for Carol Crane, a guitar that didn't affect her ankles might provoke the same sort of confusion and anxiety an invisible cat would induce in me. To Crane, the ankle-brushing sensation has always been an integral part of guitar music, just as violins always act upon her face and trumpets on the back of her neck. Crane has a rare condition called synesthesia, in which a stimulus usually perceived in one sensory modality produces a sensation in one or more other sensory modalities. (1). Synesthesia has many forms †¹ synesthetes may taste shapes or feel odors, for instance, or perceive alphanumeric characters in particular colors. Synesthetic perceptions are involuntary and are reliably triggered by the phenomena that induce them. They are also consistent over time for a given synesthete; that is, a true synesthete for whom the musical note E produces a percept of red triangles on a field of yellow will invariably experience that sound that way.