Habituation and thought

From Wikipedia:

In psychology, habituation is an example of non-associative learning in which there is a progressive diminution of behavior response probability with repetition of a stimulus. It is another form of integration. An animal first responds to a sensory stimulus, but if it is neither rewarding nor harmful the animal learns to suppress its response through repeated encounters. One example of this can be seen in small song birds - if a stuffed owl (or similar predator) is introduced into the cage, the birds react to it as though it were a real predator, but soon realise that it is not and so become habituated to it. If another stuffed owl is introduced (or the same one removed and re-introduced), the birds react to it as though it were a predator, showing that it is only a very specific stimulus that is being ignored (namely, one particular unmoving owl in one place). This learned suppression of response is habituation.

However, not all habituation is conscious like this - for example, a short amount of time after dressing, the stimulus the weight of clothes creates is 'ignored' by the nervous system and we become unaware of it. In this way, habituation is used to ignore any continual stimulus, as changes in stimulus level are normally far more important than absolute levels of stimulation. Negative feedback from the brain to peripheral sensory organs inhibits the transmission of the stimulus at the source of the stimulus.

This 'learning' is a fundamental or basic process of biological systems and does not require conscious motivation or awareness to occur. Indeed, without habituation we would be unable to distinguish meaningful information from the background, unchanging information.

Habituation is obviously an important and necessary part of nervous system functioning. But it also causes problems. We become habituated to the things we love that are constantly present. We become habituated to the vastness of the sky. We become habituated to watching birds play. We become habituated to amazing advances in technology. Hardest of all, we become habituated to the people we love the most. It takes effort to see past this effect, to learn to appreciate things and be fully conscious of their real value to us.

I think that may be part of how people get depressed in this age of wonders. How can people see the world as ugly while surrounded by birds, trees, flowers, butterflies, fish jumping in the river? Intellectually it's easy to focus on negative things, and somehow our thoughts seem more real than our actual surroundings.

After more than a year of daily, or almost daily, meditation, I'm finding it's a lot harder than I thought to look deeply at my actual surroundings and see past whatever random thoughts come up in response to them, or more often, in response to other thoughts about other other thoughts. But as I learn to create a little more space between those thoughts, and work a little harder to see past habituation, now and then a little love letter from the universe* itself gets past all that interference.

*Thanks to Jack Duffy for sharing the metaphor about love letters from the Universe.