_edited.png){kind=small}
Entangled Senses: Synesthesia and the Psychedelic Brain 🌈
- sofiamanne
- Jul 16
- 2 min read
Synesthesia, the involuntary cross-activation of sensory modalities, has long intrigued neuroscientists, artists, and psychonauts. Whether congenital or drug-induced, synesthetic
experiences reveal a more fluid model of perception than the traditional five-sense framework suggests. In the context of psychedelic states, this blending of senses is frequently reported, prompting ongoing debates about whether these substances induce synesthesia or reveal latent multisensory capacities already present in the brain.
How synesthesia works in the brain: Classic psychedelics such as LSD, psilocybin, and mescaline act primarily as agonists at the 5-HT2A receptor. These receptors are densely expressed in cortical regions involved in sensory integration, including the posterior cingulate, precuneus, and associative areas of the visual and auditory cortices. Psychedelics are thought to increase neural entropy, disrupting typical top-down predictive processing and enabling novel bottom-up associations. As a result, sensory modalities that are normally segregated begin to interact in unexpected ways—sound may acquire form, color may carry emotion, and music can seem almost tactile 🎶.
Among psychedelic users, the most commonly reported form of synesthesia involves auditory-visual pairing. Sounds, particularly music or speech, are perceived visually through dynamic patterns, light fields, or geometric structures. Distinguishing synesthesia from hallucination is critical in this context. These effects are not hallucinations in the strict sense, since they depend on actual auditory stimuli. Instead, they represent a reconfiguration of perceptual mapping—an altered translation of sensory input that still retains an external anchor. With synesthesia a tone may evoke a visual shape, or a word may trigger a specific hue. It does not create new sensory content from nothing but instead remaps existing input across neural circuits not typically engaged in tandem.
One well-documented case highlights this difference clearly. During a controlled LSD session, a participant reported that human speech was consistently accompanied by colored auras that seemed to emanate from each speaker. Each voice produced a distinct chromatic field that remained stable throughout the experience and across repeated exposures. These perceptual pairings were not described as bizarre or disruptive, but rather as coherent and emotionally resonant—evidence of a stable, synesthetic coupling rather than random visual intrusion.
Although the precise mechanisms remain unclear, several hypotheses attempt to explain these effects. Disinhibited feedback between sensory regions, increased thalamocortical communication, and reduced precision of predictive coding all offer partial accounts. What is clear, however, is that psychedelics have the capacity to temporarily reorganize the brain’s perceptual architecture 🧠. These synesthetic experiences point toward a broader neuroplastic potential and invite a reevaluation of how separate our senses truly are.
The beauty of it all: Synesthesia offers a glimpse into the hidden artistry of our minds—a reminder that perception is not a static system but a living, breathing interplay of senses. When sound becomes color and touch evokes taste, we’re invited to appreciate the sheer beauty of being human: complex, creative, and endlessly capable of experiencing the world in ways we’ve barely begun to understand.
OpenAI was used to help write and generate this article.
Comments