There's a book called The Spell of the Sensuous by David Abram, and a sequel called Becoming Animal, that I think are relevant. They aren't based on neuroscienc

There's a book called The Spell of the Sensuous by David Abram, and a sequel called Becoming Animal, that I think are relevant. They aren't based on neuroscience but philosophy (mostly Merleau-Ponty phenomenology, a little bit of McLuhan, plus an interesting critique of alphabetic writing) and some field anthropology. Basically he is defending the importance of embodied cognition within non-man-made environments. From the first book: > Today we participate almost exclusively with other humans and with our own human-made technologies. It is a precarious situation, given our age-old reciprocity with the many-voiced landscape. We still need that which is other than ourselves and our own creations. The simple premise of this book is that we are human only in contact, and conviviality, with what is not human. I bet there's also a bunch of articles written from a Heideggerian perspective about being-in-the-world as a hiker. I'd expect the "three day effect" to work very well when you are hiking from place to place, engaged in that kind of simple and "primordial" activity. There's a NASA report that I can't find that was about psychological requirements for long-term living on space stations and one thing they recommended was an explorable space with height differences creating a shifting horizon, so you get that nice free feeling of walking in a landscape. Which reminds me that The Spell of the Sensuous has an interesting discussion of Heidegger's use of the concept of a horizon, and how it relates to the experience of time... Oh yeah and I've heard lots of people say, and I concur, that meditation retreats usually shift in character after around the third day, like it takes about three days for the mind to really get into the new situation, fully adjust to the rhythm. After that there's a different flow and meditation feels deeper. BTW, I love hiking and meditation, but I'm a little wary of romanticism and religion. There's interesting critique of the concept "nature," for example Timothy Morton's Ecology Without Nature. Yet there's obviously lots of fascinating effects on mental health. Then I'm also a little wary of "scientizing" or "psychiatrizing" both nature and meditation. It has to do with what Heidegger thought of as the technological mindset of treating the world as a big resource to use for various purposes. I think there is some kind of truth in the way many hikers and meditators want to keep those things "sacred" in some way, regardless of what religious or romantic theoretical framework they use to justify that. If you try to use nature, or meditation, to alleviate the stress from your life, in an instrumental way full of expectations, I can easily see it gradually losing its efficacy, if it becomes yet another maintenance strategy and you lose the sense of noninstrumentality, free exploration, suspension of ordinary pursuits, etc.