As a pre-1st path who seems to have made it into equanimity, I can't say I've experienced fruitions personally. However, my experiences with jhana and with my more intensive insight experiences make me think "some kind of temporal lobe weirdness involved here." Could fruitions be a very specialized form of temporal lobe seizure?
http://www.epilepsy.com/epilepsy/epilepsy_temporallobe
They quote a "suspected temporal lobe seizure" in Dostoevsky that has some resonance:
He remembered that during his epileptic fits, or rather immediately preceding them, he had always experienced a moment or two when his whole heart, and mind, and body seemed to wake up with vigor and light; when he became filled with joy and hope, and all his anxieties seemed to be swept away for ever; these moments were but presentiments, as it were, of the one final second…in which the fit came upon him. That second, of course, was inexpressible.
Next moment something appeared to burst open before him: a wonderful inner light illuminated his soul. This lasted perhaps half a second, yet he distinctly remembered hearing the beginning of a wail, the strange, dreadful wail, which burst from his lips of its own accord, and which no effort of will on his part could suppress. Next moment he was absolutely unconscious; black darkness blotted out everything. He had fallen in an epileptic fit.
What's interesting is that the way you folks discuss it, you don't have to deal with the second piece of it--just the first. That actually sounds like a rather fantastic trick, to get some very specialized form of temporal lobe seizure (very often associated with spiritual experiences) that gives you the upside (and possibly
more upside) but not the really unfortunate downside.
Or, this could be just me spinning my wheels. Just thought I'd pass it on.