I know that these ideas have been floating around out in many minds for some time, but I am always surprised when I start thinking about them. Even though they are completely logical and obvious once pointed out, the fact that our sensory perception is entirely subjective is quite weird.
I was thinking about this today while sitting in the neuro class that I am TAing. We were discussing the auditory system and how it works, when it suddenly hit me again that sound is nothing but vibration (usually of the air). We perceive tones in our brains, but this is just a way for our ears to tell us, “hey, I’m getting a loud frequency of 262 Hz from the left ear.”
Which makes that question- that I always thought of as stupid- much more interesting: “If a tree falls in the forest, and no one is there to hear it, does it make a sound?” If “no one” includes any creature that can obtain information from vibrations, then it actually doesn’t make a sound. I usually think of sound as something defined by vibration, but in terms of biology it is defined a bit differently, as an interpretation of that vibration.
The same idea applies to touch, vision, smell, taste, and the rest. When you bite into that delicious juicy steak that makes your brain happy, really all that is happening is that proteins in your taste buds interact with specific chemicals from the meat and then pass this info along to the brain, saying “hey, I found some acetate!” and the like. Your brain then sums these different chemical inputs into a taste perception.
A little weird to think about, huh?