Synesthesia has been instrumental in allowing us to ask questions about the nature of perception, but it also raises questions about the nature of our experience.
When I ask myself what experience is, despite all my efforts to not atomize the word "experience" into its constituent sensations, I invariably come to the conclusion that experience is the sum of our psychophysical perceptions.
I then ask myself what perception is. It's easy to be caught up in the nuances of that question, but, in essence, I believe the answer to be that perception is the conveyance of spatial disturbances. For example, when I drag my finger across a block of wood, the interaction of the electromagnetic waves in my finger and those in the block of wood result in force applied to my skin, the firing of neurons, etc. When I attempt to balance, I am utilizing the somatosensory data in the form of pressure, vestibular data, etc.
If experience is composed of these sensations, then why does experience seem so basic? Why do we not tell stories as a recount of all our physical sensations? I'm tempted to say that we perform some sort of analysis on the sensations, picking up a narrative from our interpretation of our perception; but then I run into synesthesia.
If our experience was our interpretation of data, how can our brain be tricked into thinking that a musical note is a color? Wouldn't the brain recognize that sounds shouldn't be colors and give the resulting experience of a sound sans vision?
Which brings me to my question: is our experience not an interpretation of data, but a superpositioning of our sensations?