Attention is something mysterious. I think that if we would know what attention actually is, we would probably understand a major part of how counsciousness works. Attention and counsciousness are weird things: we all know what the words refer to, in the sense that we understand the meaning of a phrase like 'pay attention', or 'it's an altered state of counsciousness'. But we don't realy know what counsciousness or attention are.