If I remember right, it was Terrance McKenna's theory... Coming from a mushroom trip itself.

I love Terrance for doing a lot of wonderful work but he certainly went off the deep end repeatedly. EG look into a story of him eating a fresh psilocybin containing mushroom the size of his head...in the Amazon... His brother had to carry him around and it took him a long time to really come back to reality.

His philosophy and musings on human consciousness and spirit are beautiful. He's not who I would go to for scientific fact however. His brother, Dennis McKenna, is the scientist and stayed much more reasonable up to present time. But he doesn't study consciousness and doesn't say scientific sounding things about it, always bold disclaimers "these are ideas I have and ponder. These aren't facts and I have little to no evidence to support it objectively" sort of fella