Could it be a case of 'less is more', type of thing? Because I personally find my cognitive powers to be greatly enhanced under strong yet manageable doses of psilocybin. I find that proper use of this molecule causes incredible thoughts, ideas, and their articulations to stream with absolute effortless ease. Maybe much of our ordinary brain activity is incessant and unnecessary, and psilocybin clears up some of the clutter if you will, so that our minds may be freed to more essential levels of realization that we have lost touch with over time. So maybe what enlightenment is then, is a rekindling with this most basic and obvious form of understanding, which we have grown distracted from by an over-active set of thought processes (ie- mental chatter). In other words, perhaps it's a dissolution of the same old habits of mind chugging along which allows us to access what seems to be a broader, more open and expansive sense of reality.
This does seem to fit with my experiences in a way, because the molecule definitely breaks down previously established patterns of thought, allowing me to transcend the psychological routines I've habituated myself to and step beyond old paradigms. I've broken out of many a mental rut with the help of these transformative agents. It's almost as if they were enzymes for the mind, digesting wastes that have been left behind. The fact that the study also mentions psilocybin as promoting long term nerve growth, connectivity, and neuro-plasticity would seem to fit right in with the idea that it helps us re-establish and evolve our mental framework.
Anyway, that's just me trying to relate this new information with my experiences.
Hey, I wonder how the brain activity of monks, mystics, yogis and the like might contrast/compare with all of this..