Why does the world look different under psilocybin? The role of the visual cortex

Psilocybin is the active ingredient in magic mushrooms and magic truffles and is known for the way perception can temporarily change. For example, users describe more intense colors, moving patterns, distorted shapes or the feeling that objects are “breathing.” These visual changes may seem like random hallucinations, but are closely related to how the brain processes visual information ¹.

Psilocybin can temporarily alter the filtering of visual stimuli, causing colors, patterns and details to be perceived more strongly than normal.

Neuroscience research shows that psilocybin affects several brain regions, including the visual cortex in the occipital lobe. In this article, we explain why the world can look different under psilocybin and what role brain networks play in it.

Various visual changes can occur under the influence of psilocybin. Common experiences include more intense colors and contrasts, geometric patterns, moving surfaces and enhanced details in textures or objects. These effects occur because the way the brain filters, organizes and interprets visual information temporarily changes.

The visual system normally works efficiently and selectively, with the brain ignoring many stimuli to create a stable image of reality. Psilocybin seems to partially loosen this filtering system, allowing more details to be seen ².

An important brain network, the default mode network (DMN), normally helps organize and interpret information. Under the influence of psilocybin, activity in this network is temporarily reduced. This gives the visual cortex more freedom to process signals as strong top-down control decreases.

Research with brain scans additionally suggests that psychedelics increase communication between different brain regions. Information from the visual cortex can therefore be more strongly transmitted to networks involved in emotion, memory and meaning-making. This may explain why visual experiences sometimes feel emotionally intense or symbolic.

Activation of serotonin receptors

Psilocybin is converted in the body to psilocin, which binds to 5-HT2A serotonin receptors. These receptors are located in the visual cortex, among others.

• Increased neural activity
• Amplification of sensory signals
• Change in balance between inhibitory and stimulatory brain cells

As a result, visual information is often perceived more intensely and less filtered.

Altered brain networks

Imaging research with fMRI shows that psychedelics alter connectivity between brain regions. Networks that normally work separately temporarily communicate more strongly with each other ³.

For visual perception, this means that signals are less tightly filtered and internal images or memories can mix more easily with perception. This allows patterns, colors and movements to emerge that do not come directly from external stimuli.

• Dose: Visual effects usually increase at higher doses of psilocybin.
• Environment: patterns often become more apparent in nature, textures or in dim light.
• Mental state: emotions and expectations can influence how visual changes are perceived.
• Individual differences: the intensity of visual effects varies from person to person.

Want to learn more about the effects of psilocybin, truffles and perception? Check out these related articles:

• How do magic truffles work in the brain?
• What are the effects of magic truffles?
• Buying magic truffles: types and strengths

1. Journal of Neuroscience – Broadband cortical desynchronization underlies the human psychedelic state (2013)
2. Pharmacological Reviews – Psychedelics (2016)
3. Psychopharmacology – Psilocybin-induced experiences and neuronal oscillations (2015)

This article is intended for educational and informational purposes only. The use of psilocybin-containing substances may be subject to legislation and carries potential risks. The information in this article does not constitute medical advice. Always consult a qualified professional with health questions.