MAPS Canada School of Psychedelics

Talk abstract

The psychedelic state has often been described as a "higher state of consciousness." But what could this mean, experientially -- for instance, are there tests where a psychedelic user can perform better than a sober individual? Our visual system constructs whole objects and scenes from basic features in our environment such as shape, texture, and motion; much of what we see, however, is also influenced by our prior expectations -- this is called 'top-down' processing. Researchers have found that psilocybin (a classic psychedelic) alters perception by disrupting top-down processes, thereby reducing the influence of our prior expectations on perception. We can test this claim by observing how psilocybin affects well-understood cases of top-down vision. Many visual illusions, for example, are driven by our prior expectations, leading us to misperceive certain images: we might see two equal lines as differing in length, or observe a hollow mask as convex. If psilocybin disrupts top-down processing, however, then perhaps one wouldn't make these same errors -- one might instead be able to make more accurate judgements on certain visual illusions. A psilocybin user might see both lines as equal, when in fact, they are. By testing the perception of visual illusions in experienced psilocybin users, we can determine to what extent psilocybin affects top-down vision. If individuals tend to make more accurate judgements under the influence of psilocybin, we may very well identify a unique situation where the psychedelic state can be appropriately described as a "higher state of consciousness."