Proprioception

Science fiction used to have great fun hypothesizing further senses that an alien might have, beyond or instead of our traditional five. But even here on earth there are abilities we recognise as senses once they are presented to us as possibilities.  Animals that can detect magnetic fields or that use echolocation would qualify.  A sense of balance is based on internal awareness rather than external stimuli, as is spatial awareness.  Would we call hunger and thirst senses?  Sure, once we think of it.

It was years ago that someone described proprioception, our sense of body position, as The Sixth Sense, so that one has always stuck in my mind as the best example. It is both conscious and unconscious, as the five we are used to. If we stand in one place and close our eyes, we can tell without looking if our knees are bent or our arms raised. We can describe it instantly.  But it also goes on all day without our attending to it, so that we don't bump our head or hand against something as we walk. Even in the dark we can remember where objects are and have some idea whether we are in line to run into them.

I remember marveling at such a thing when first told about it. I remember closing my eyes in class in sixth grade and checking where all my pieces were. When I checked by sight, they were exactly where my internal sense told me they would be. Mrs. McKeon, long-suffering, asked me what I was doing, but in a less exasperated tone than my previous teachers. Perhaps she was proud of me, perhaps she had just given up.  Either way,  she told me to focus on my work.  I had learned under previous teachers not to counter that I had finished my work.

I have thought only occasionally - less than once year or even decade - about it since, but each time it pleases me. But I have noticed it lately, because it is less accurate than I remember.  My hand might be turned an inch more outward than I estimated, or be a bit higher or lower.  As I have always been clumsy, so maybe this is just noticing what has always been there.  The sense does deteriorate with age, and leads to worse balance and more falls. Yet if anything, I am falling less than I used to.  I don't know if anything is really up or not.

Nor do I much care.  One thing I learned from working in mental health is that if something is not a problem, it's not a problem.  If it gets worse, it might become a problem, and then I will worry about it.  As Tevye says "Good news will keep and bad news will refuse to go away."