From wiki.

One criticism of panpsychism is that it cannot be empirically tested.A corollary of this criticism is that panpsychism has no predictive power. Tononi and Koch write: "Besides claiming that matter and mind are one thing, [panpsychism] has little constructive to say and offers no positive laws explaining how the mind is organized and works."

John Searle has alleged that panpsychism's unfalsifiability goes deeper than run-of-the-mill untestability: it is unfalsifiable because "It does not get up to the level of being false. It is strictly speaking meaningless because no clear notion has been given to the claim."

Which is what I think too.