In his book In An Unspoken Voice (p. 135), Peter Levine tells us:

...consciousness actually unfolds through the development of body awareness, of learning to understand the nuances and the meaning of our internal physical sensations, and of our emotional feelings as well.

I completely agree. We are sensory driven organisms.  In other words, our brains develop because of the sensory input that goes to it.  The neurons that are used are strengthened.  The ones that are not degenerate.