As you probably know, there are more than five senses. And I’m not at all certain why anyone ever claimed that there were only five senses. When I discuss this with people, I always start with the sense of acceleration. You don’t need to have one of the “five senses” to experience a roller coaster ride. Certainly there are elements of the Big Five from the feeling of the wind through your hair to the taste of acid reflux. But it is the acceleration that most defines the experience.
The easiest trans-five sense to demonstrate is balance, or “equilibrioception” for those who like seven syllable words. I suspect that the reason that people do not want to call this a sense is that it isn’t due to any single thing. Balance depends most upon the visual system and vestibular system, in the ear. But the truth is that none of Big Five are quite so distinct either. The simplest example is the way that taste and smell work together. But the truth is that even our vision is very messy; it is so much more than simply the recording the light rays focused on our retinas.
When people asked him later on in life why he pushed Gregg Toland to create deep focus in Citizen Kane, Orson Welles would reply that he just wanted the film to look the way the real world looked to the human eye. But that isn’t really the way the vision system works. The human eye is just as constrained as a camera lens. At any given time, most things are out of focus. It is our brain that “fixes” all of that. What I mean is that our brain lies to us about what we are actually seeing. It also acts as a kind of steadicam.
Thus it isn’t surprising that when people hear a car crash, they often mistakenly believe that they saw it — even though they simply moved their focus to it as a result of the sound. They aren’t lying when they claim they saw the accident; their brain was just lying to them about what they saw. The entire human body is a system for creating meaning out of far too little knowledge.
There are other trans-five senses such as the sense of pain and the sense of heat. But the sense that I find most fascinating is proprioception. It is the sense of knowing where your body is. The most gruesome aspect of this is phantom limb syndrome, where people continue to feel the existence of a limb that is physically gone. But more generally, we all sense how our bodies are oriented. As I write this, my left knee is bent upward because my foot is resting on top of one of my computers while my right leg is sprawled out in front of me and my torso leans far back in my chair. I don’t need to look at my body to know this. I just know it because of proprioceptors in the skeletal muscles. But don’t ask what they are because you get into a kind of tautology. Of course the same thing is true of seeing and hearing, but we’ve all gotten way past caring about that.
Of course, there are lots of senses that other animals have that we lack like echolocation. And there are a whole lot of things we can’t see like anything in the ultraviolet. We also can’t see infrared, but we can feel it. It’s curious. Biology is a most amazing thing. In the end, should humans ever crack the riddle of consciousness, I feel certain we will learn that it is all a trick: a bunch of cells so complex they delude themself into thinking they are a single thing. But you still have to marvel at all living things in the same way you do a Caravaggio painting or a black hole.
My left leg is now bent behind me.