[robinhoode]

This much we know:

* Brain cells die. * Brain cells hold ideas. * We need to regenerate brain cells to continue to support the brain past 80-90 years. * Each new brain cell will probably adopt the ideas of the surrounding culture.

So I would suspect that over time, an aging but renewed brain will adapt to the conditions of the culture it lives in. Some brain cells are more stubborn than others, but a serious and dedicated effort to not adapt will be met with obvious survival constraints.