The visual phenomena that can arise after consuming certain species of mushrooms are a subject of scientific interest. These experiences, called “mushroom visuals,” involve complex alterations to sensory perception, particularly sight. They represent a departure from ordinary consciousness where the processing of visual information is temporarily changed. The brain’s ability to generate such varied perceptual shifts is a window into the relationship between neurochemistry and our experience of reality.
The Neurochemical Basis of Mushroom Visuals
The primary compound responsible for the visual effects is psilocybin, which the body converts into its active form, psilocin. Psilocin has a molecular structure similar to that of serotonin, a neurotransmitter that regulates mood and perception. This resemblance allows psilocin to bind to and activate 5-HT2A serotonin receptors, which are found in high concentrations in the brain’s visual cortex.
The activation of 5-HT2A receptors by psilocin leads to overstimulation in the visual cortex. This disrupts the organized flow of information, causing disorganized neuronal firing. Instead of processing external stimuli in an orderly fashion, the visual system begins to generate its own internal signals, leading to perceptions not based on outside reality.
This neurochemical cascade also affects large-scale brain networks. Psilocin decreases activity in the Default Mode Network (DMN), a collection of brain regions active when the mind is at rest. The DMN is involved in self-referential thought and maintaining our sense of a stable self. By reducing the DMN’s influence, psilocin may allow for new patterns of communication between brain parts that do not normally interact, contributing to the visual experience.
Types of Visual Experiences
The visual alterations that occur can be categorized into two types: those that happen with the eyes open and those that occur with the eyes closed. Open-Eye Visuals (OEVs) involve the distortion of the existing environment. Colors may appear intensified, surfaces can seem to ripple or “breathe,” and moving objects might leave behind visible trails or tracers. Geometric patterns can overlay onto walls, floors, and other surfaces.
These phenomena result from the brain’s altered processing of incoming light and spatial information. The normal boundaries of objects can appear to dissolve or become fluid, leading to a perception of melting or morphing. Faces and objects in the environment may appear to shift and change, reflecting the brain’s struggle to impose order on the disorganized signals it is receiving.
Closed-Eye Visuals (CEVs) occur in the absence of external light, such as when one’s eyes are shut or in a dark room. These are entirely internally generated and can be vivid and complex. Common CEVs include rapidly moving geometric patterns, fractals, and kaleidoscopic structures of immense detail and vibrant color. Individuals often report traveling through tunnels of light or witnessing abstract, flowing seas of color.
In some instances, CEVs can evolve into more structured and narrative scenes. These can be dream-like, featuring landscapes, entities, or entire scenarios that are fully immersive. These complex visions are thought to arise from the brain’s enhanced top-down processing, where higher-order cognitive regions, such as those involved in memory and imagination, exert a greater influence on the visual cortex.
Factors Influencing Visual Intensity and Character
The intensity of the visuals is directly influenced by dosage. Low doses may produce only mild enhancements of color or subtle movements in the peripheral vision. Higher doses can lead to fully immersive hallucinatory states where the distinction between the internal and external world becomes blurred.
Beyond dosage, the individual’s psychological state and the surrounding environment play a large part in shaping the character of the visuals. This interaction is described by the concept of “set and setting.” “Set” refers to a person’s mindset, including their expectations, mood, and intentions. A calm and open mindset may contribute to more positive visuals.
“Setting” refers to the physical and social environment where the experience takes place. A safe, comfortable, and supportive setting can influence the emotional tone of the experience and the nature of the visuals. Conversely, a chaotic or unfamiliar environment can increase the likelihood of anxiety, which may manifest as more unsettling imagery.