Dogs and Trust

It's remarkable, sometimes, the things our dogs (and cats) prompt us to consider.

I was up quite late last night, so this afternoon I lay down for a bit. Faith decided to snuggle up, and I started stroking her head and back. And Faith closed her eyes. She did so with no hesitation, and with no greater delay than any other dog might. And it suddenly occurred to me that this was quite remarkable.

Humans go insane (literally) if deprived of sensory input for too long. A person at rest has two main streams of time-varying sensation: sight and hearing. When at rest, the sensations of taste, touch, smell, and proprioception are quickly filtered out by our brains, because the inputs from those senses (when at rest) do not change very much. In consequence, if we are deprived of both sound and sight, we get very close to a state of sensory deprivation. Part of the challenge in transitioning to a sleep state is getting past this transition.

Because we have two time-varying senses, a blind or deaf person is not totally isolated from a sensory point of view. One sense does not function, but the other provides time-varying input. The thing is: a blind person cannot close their ears, but a deaf person can close their eyes. And when a deaf person closes their eyes, they give up both of the major time-varying sensory inputs.

If you hear and see, and you sit calmly in a chair in a dim room and close your eyes, you will quickly find that you hear all manner of distracting things, and that (for lack of anything better to do) your brain invests great effort to place each of those sounds in the space around you, trying to build a map of what is going on. Take a moment and try it.

Given enough time, you would learn how to do some degree of echo-location; this is approximately how a blind person navigates by tapping with a cane. An advanced martial artist, blindfolded, can quite literally hear a strike coming (no, that's not just in the movies). Now contemplate, just for a moment, how you might perceive that room if you did not hear.

I'll never know, but I suspect that the effect of hearing loss is stronger for cats and dogs than it is for humans. Snickers (our cat), while blind, tracks things with amazing accurately. His hearing, of course, is better than ours, but beyond that, he has a remarkable ability to place the origin of sounds in a three-dimensional space. I've done enough surround-sound audio mixing to appreciate how hard that is. Surround sound is about "fooling" the ears into hearing a desired placement of sound. The physics and the psycho-acoustics of sound placement is pretty well understood, and it doesn't involve any really fancy math. I can work the equations, and I actually understand them. I can explain the limits of localization accuracy in humans and why they occur. I can't explain how accurately Snickers can localize sounds from certain directions. If I didn't love the little booger, he'd make me nuts!

Watch a resting dog closely when an interesting sound occurs, and you'll see that the ears move to localize the sound with surprising precision. That reaction happens first; the turn of the head to bring sight to bear is slower. In some cases, you can watch the ears perk up, and then see them drop; the dog has decided that the sound wasn't interesting and isn't worth further attention. In many cases, the eyes never open.

And so as Faith closed her eyes, it occured to me that closing your eyes when you are deaf involves a very profound act of trust and vulnerability. Sure enough, if my hand is in contact with her and it moves, or if I am stroking her and the next stroke does not come when expected, her eyes open immediately.

It's not just that the dogs make me learn about them. It's that they make me learn about me.

If you are blind or deaf, and I have managed to get this wrong, please feel free to offer your insights and corrections. That's important! As you do so, please recognize that I am trying to convey matters as best I can, and that I am working to be respectful as I do so. If I have gotten it wrong, let's work together to set it right.