In a pre-literate society these kinds of works (including much of Shakespeare) would've been composed in verse form to aid with memorization. So if you intend to recite from memory for six hours straight, like in the article, you probably want that rather than Britannica or the phone book.

I do find it plausible that certain (combinations of) language and verse metre might have mantra-like qualities, conducive to achieving trance states that could affect the brain. India has been on the case for a looong time, so it wouldn't surprise if Sanskrit + Vedic poetry present a particularly sophisticated example.