How does psilocybin affect perception?

Psilocybin affects perception primarily through what is known as "perceptual blending" or synesthesia, alongside significant activation of the brain's serotonin 2A receptors. Here’s a breakdown:

1. Perceptual Blending: Individuals using psilocybin often report experiencing synesthesia, where senses blend together. For instance, music might influence visual hallucinations, causing individuals to see geometric patterns influenced by the sound. This blending extends to other senses, such as linking the rhythm of breathing to auditory and visual perceptions 1.

2. Visual Cortex Activation: Psilocybin strongly binds to serotonin 2A receptors, which are abundant in the visual cortex. This results in intense visual hallucinations, even with closed eyes. The visual effects can include geometric shapes and changes in the perception of external objects, like faces morphing or environments melting 2.

3. Broadened Sensory Information: Psilocybin alters the flow of sensory information within the brain. Typically, sensory information is processed in a hierarchical and modular manner. However, psilocybin induces a more broad and interconnected processing of sensory inputs, leading to experiences where sounds, emotions, and visual phenomena intermingle in unusual ways 3.

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     1

     Psychedelics and Perception

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     2

     Psilocybin Experience Insights

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     3

     Psilocybin and Brain Activation

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These changes in perception can result in profound shifts in how individuals experience the world, potentially offering unique therapeutic benefits but also requiring careful contextual management to ensure safety and effectiveness.