MAPS Canada School of Psychedelics

Talk abstract

The psychedelic state is sometimes described as a "higher state of consciousness." But what could this mean, experientially -- are there tests where a psychedelic user could perform better than a sober individual? Our visual system constructs the objects and scenes in our environment from basic features 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 brain's expectations on perception. We can test this by observing how psilocybin affects well-understood cases of top-down vision. Many visual illusions, for example, are driven by our prior knowledge leading us to misperceive certain images: we might see two equal lines as differing in length, or observe a hollow mask as being convex. However, if psilocybin disrupts top-down processes, then perhaps a psilocybin user wouldn't make these same errors -- they might instead be able to make more accurate judgements on certain visual illusions. They might see two lines as being equal, when in fact, they are. By investigating how psilocybin users experience different visual illusions, we can determine to what extent psilocybin affects top-down vision. If individuals tend to make more accurate judgements under the influence of psilocybin, then this may be a unique situation where the psychedelic state is truly a "higher state of consciousness."