Richard, I believe MMY believed soma actually exist as a chemical in the stomach of advanced meditators. This chemical is the source of bliss that meditators experience as part of the meditation practice. As such, the meditators are favored by the demigods since they too are seeking for this soma or amrita, the food of the gods.
He invited researchers to work on this to discover the chemical involved. But I don't know if this research was actually undertaken. David Frawley wrote about this aspect of soma in relation with meditation in a book he published a few years ago.
