change thresholds

Do you remember the last time you hiccuped? Perhaps you do, perhaps not. Nothing remarkable either way. But do you remember ever realizing your hiccups have stopped the same instant that happened? Let's give it an allowance of a few seconds, if you want. Even then, I bet not. We eventually realize we are hiccuping no more, but only after a while.

But I just had the once-in-a-life-time experience of knowing exactly when i had my last hiccup!

Not only that, it was easily the biggest hiccup I have ever had (at least in memory). I am sure i freaked my cube-neighbors out with that monster hiccup! Perhaps, I was so shocked at its magnitude, that my hiccups stopped right there!!!

I find this phenomenon of not detecting the end of such things interesting. Other examples include coughs, temporary pains, etc. One possible explanation could be that our brains are for the most part designed to detect change (in stimuli) a lot better than constancy. This might sound contradictory - when something stops happening, it's a big change. True. But, if the stopping happens gradually, the rate of change or frequency becomes so low at some point, that it falls below our brain's threshold. So we never notice the transition (from presence to absence).

This is pure lazy speculation on my part. But, while at it, let me have some fun.

As with most things, there should also be an upper threshold for rate of change that our brains can detect/cope with. An example I can think of is looking out a moving train. As long it is moving slowly (or the horizon is far away), we find it an interesting spectacle. But once the speed at which the scenery changes becomes too much, we tune out.

On the other hand, suppose that the train is passing through a desert. Now, again, we'd tune out quickly, but this time because the change is too little - the other extreme. I find this fascinating.

If you can think of more examples (or counter-examples) for the presence of the higher-threshold, or some real science related to this, do let me know.