To put it most fundamentally: it appears that the twin hemispheres of the brain are differentially specialized (1) for operation in unexplored territory, where the nature and valence of things remains indeterminate, and (2) for operation in explored territory, where things have been rendered either irrelevant or positive, as a consequence of previous exploration. Our brains contain two emotional systems, so to speak. One functions when we do not know what to do, and initiates the (exploratory) process that creates secure territory.
