This idea of reality being &quot;passed through&quot; multiple filters, and these filters being reduced or disabled on psychedelics, is developed (somewhat unscientifically) by Huxley in &quot;The Doors of Perception&quot;- it&#x27;s a fairly good read.<p>If I remember correctly, the main criticism against this is that if it were the case brain activity should be reduced, at least in some regions, when on psychedelics. However, observing people on psychedelics with fMRIs does not match with that.