Earlier quoted context omitted.
Herbert and similar are the release of information, the main "psi phenomenon" explored over the XX century being precisely the remotely induced belief in "psi phenomena". That rabbit hole goes deep, though I have my doubts as to whether it leads out .
No, psi predates modern sci fi and experiences of it are not generated by that. Belief is easy to find in preceding centuries too
IME, what you refer to by a Greek letter is either "just there" as part of one's perceptual and cognitive functioning, or "just isn't" - the latter obviously being the predominant case, being more adaptive for survival in a newly Enclosed world. One even has some degree of control as to enabling or disabling it. Without guidance as to avoiding its many pitfalls, though, it's still very easy to end up in a psychotic state, or some other uncomfortable frame and shape. Subsequently, the manifestation of cosmic love commonly called "natural selection" does what it's known to do...
(My pet theory is that Abrahamic faiths, the promotion of Christianity to state-religion, and the consequent Dark Ages, were all parts of a sort of mass political reaction to people overdoing that sort of thing. Took a bunch more centuries than expected to even force it underground, though. And, as these things go, it reemerged nearly simultaneously in the form of the indigenous knowledges of colonized folk, who were subjected to more of the same violence, and then some.)
What was being tested last century is whether the so-called "they" can switch it on or off for you, remotely; authors of fantastic literature, even if not directly informed from "on high", happen to be in a good position to sense these workings and conduct discourses on them. Makes for good business, too, since it is only natural for humans to want some enchantment in their lives. However, the background psychological pressures of living in perpetual encirclement naturally (well, mimetically) drive people to compartmentalization, such as the confining of these experiential coagulates into the sphere of "fictions" (if not outright "delusions", the distinction being, for the most part, simply of medium of conveyance.)
Thankfully, as we all know, fiction is something that doesn't exist, and it doesn't take much to realize how this statement cuts both ways.