Visual recursion

Visual recursion is the perception of visual forms folding back upon themselves to produce nested, self-similar structures in which each element appears to contain smaller versions of itself.

As a drug effect it is acute and strongly dose-dependent, appearing only at high doses and easing as the substance wears off. It ranges from a mild sense of layering within patterns to fully immersive loops in which the visual field iterates infinitely inward or outward.

Visual recursion is uncommon even among regular users of the substances that produce it. It is most commonly induced at high doses under psychedelics such as LSD, psilocybin mushrooms, and DMT, and at high doses under cannabinoids such as AB-FUBINACA; it also appears under deliriants such as Amanita muscaria.

Visual recursion is felt as a collapse of visual scale: surfaces, objects, or geometric patterns fold inward or expand outward in repeating tiers, each containing a miniaturized echo of the whole. It often carries a quality of spatial impossibility — the eye cannot resolve where the recursion ends.

Attending to a recursive element tends to deepen it, drawing attention further into the loop. At higher doses, particularly under psychedelics, the recursion can engulf the entire visual field, rendering ordinary surfaces as endlessly replicating structures.

Visual recursion arises through different pathways depending on the drug class:

• Psychedelics — act on 5-HT2A receptors in visual cortex, disrupting the hierarchical processing of spatial form and allowing feedback loops within the visual system to manifest as perceived self-similarity.
• Cannabinoids — act on CB1 receptors; at high doses, disruption of temporal and spatial binding in visual processing can produce recursive patterning, though this pathway is less characterized.
• Deliriants — alter cholinergic signaling in ways that destabilize scene construction, occasionally producing recursive or nested visual structures.

How much each pathway contributes in a given case is not fully understood.

Who experiences it, and how strongly, varies widely. It is tightly dose-dependent — below high doses it rarely appears at all. Unfamiliar or visually complex environments amplify it, especially under psychedelics and high-potency cannabinoids, as does a prior history of strong visual effects on psychoactive substances.

Expecting or attending to visual phenomena can bring it on sooner and deepen it once present. A calm, featureless setting and moderate doses tend to keep it at bay.