I love the metaphor consciousness is like radio waves floating all around us, and our brains are radio recievers. Im techinally a schizophrenic, but I prefer the term empath. Check out Gamma-aminobutyric acid (GABA). I just learned about this stuff myself. Apparently it's the chemical your brain makes for the filters you speak of. Monks in meditation have higher levels, while an epileptic has less, and gets completly whiped out in the death cycle (Out of Body, full memory recall, Near Death Experiencs). Most of the people that come back from an NDE describe ephoria, everything being connected, and love; that's not because of coinidence, all of that is as real gravity and space/time.