What Actually Happens in a Psychedelic Journey — Part 1: The Senses
A four-part series on the effects of psilocybin. We start where most people start: the body.
Floating mountains with lush green forests and dramatic waterfalls cascading through clouds — evoking the awe-inspiring visual landscapes reported during a psychedelic journey
This is the first in a four-part series on what actually happens during a psychedelic journey. Part 2 covers emotional effects. Part 3 covers the mind — insights, shifts in thinking, changes in self-perception. Part 4 goes into mystical and spiritual experience. Each post stands alone, but they build on each other.
Research consistently finds that a vast majority of people who go through a psychedelic experience rate it among the top five most personally meaningful and spiritually significant events of their lives — ranking it alongside milestones like the birth of a first child. For a few hours on a mat, with music playing and eyes closed, something happens that people carry with them for decades.
But what, exactly?
That is what this series is about. Not the philosophy or the promise, but the texture of the experience itself — what it feels like, why it happens, and what it means beyond the ceremony room.
We will move through four layers of experience across four posts. Sensory effects first. Then emotional. Then the mind — insights, shifts in thinking, changes in how you see yourself and your life. And finally, what researchers call mystical or transcendent experience: the dissolution of the ordinary self, the sense of unity, the encounters that defy easy description.
This first post is about what the body and the senses experience. It is usually where the journey begins.
Why the senses change — the neuroscience in plain language
Before we get to what it feels like, it helps to understand why it happens at all.
Psilocybin works primarily through serotonin receptors — and those receptors are distributed widely across the brain and body, not just in the regions associated with mood or emotion.
One of the effects most consistently documented in neuroimaging research is a dramatic increase in connectivity between brain regions that do not normally communicate directly with each other.
You can think about it like this: under ordinary conditions, the brain runs on relatively fixed circuits. The visual system does its thing. The auditory system does its thing. The regions that process meaning, memory, and emotion each operate within their usual networks, largely in parallel.
This is efficient. It lets you function without being overwhelmed.
Psilocybin temporarily disrupts this separation. Brain regions that are usually functionally isolated begin to exchange information. The visual cortex starts talking to regions that process sound. The senses begin to inform each other in ways they normally do not.
This is the neurological basis for most of what follows.
The first sign something is happening
In my first psychedelic journey, I knew something was changing when the music started to have a colour.
My mind registered the strangeness immediately: this should not be like this. That quiet recognition — that the ordinary rules of perception have shifted — is usually the first signal.
It tends to arrive gently. A softening of edges. A quality to the light that was not there before. A sense that sound has texture, or that texture has sound. The technical term for this is synesthesia — the cross-activation of sensory pathways — and it is one of the most commonly reported early effects of psilocybin.
For most people, it is not frightening. It is, if anything, quietly astonishing.
Visuals
Psilocybin journeys are probably most known for their visual effects, and that reputation is earned.
Patterns and geometries are common — intricate, often symmetrical, frequently moving. Colours intensify. The surfaces of things seem to breathe or shift. At higher doses, or with eyes closed, the visual field can become populated with images, landscapes, and presences that bear no relationship to anything in the room.
In my own journeys, the range has been enormous.
There have been journeys in which I was flying through the universe — floating among galaxies, moving through coloured gas clouds that were breathtakingly lit, passing comets in a silence that felt enormous.
There have been others where I was in deep, ancient forests, the moss impossibly green, the light coming through the canopy in a way that felt more real than real.
And there have been sessions where there is nothing. Just black — and the effects are felt in other ways entirely.
Animals are common for many people. For me, there are often snakes. Others report insects, birds, wolves, big cats — sometimes benign, sometimes unsettling, sometimes acting as guides.
Alongside animals, unusual architectures and landscapes appear: constructions that have no equivalent in waking life, environments of a strangeness and scale that is hard to convey.
I was once in a world that recalled the scenery from the film Avatar — enormous floating mountains, waterfalls pouring out of the sky, a scale so vast that ordinary perception had no reference for it.
These spaces can hold a beauty that is genuinely difficult to put into words.
Majestic is not quite right. Awe-inducing comes closer.
But even that falls short of what it actually feels like to be in one.
For those who want a felt sense of what altered visual perception looks like before ever sitting with a medicine, this virtual simulation of an ayahuasca experience offers a glimpse — with the caveat that it captures the visual dimension only, and the real thing is felt in the whole body.
The practice of returning, again and again, to what the body is actually experiencing — without the stories the mind adds to it — is not just a coping strategy. It is a reorganisation of the relationship between sensation and meaning.
What the body experiences
The body is not a passive observer.
Temperature shifts are common. I get very cold — cold enough that I always bring extra blankets now. But warmth is equally possible, and for some people the temperature swings within a single session.
Energy moving through the body is a frequent report. For me this manifests as twitching — jolts, like a current passing through — which was disorienting the first time it happened and is now simply a familiar part of how the experience moves through me. For others it is a sense of vibration, or pulsing, or waves.
Pain is possible. Pleasure too. The body can become a site of very intense sensation — not always comfortable, not always pleasant, but always meaningful when it is met with curiosity rather than resistance.
Sound and the intensity of hearing
Music is central to how we work at Hearts Door Retreats, and there is a reason for that beyond aesthetics.
Under psilocybin, sound is experienced with an intensity that is difficult to prepare for. Music that was chosen carefully — building, releasing, holding space — lands differently than it does in ordinary listening. The emotional content of a piece of music becomes almost physically present. Melodies can feel as though they are moving through the body rather than entering through the ears.
At the same time, sensitivity to unexpected or jarring sound increases sharply. A bottle dropped on the floor can feel genuinely painful.
This asymmetry — high volume of chosen music tolerated easily, a small accidental sound almost unbearable — is something that experienced ceremony facilitators hold carefully. Different instruments, introduced at different moments, create specific effects in the space.
The less comfortable parts
Nausea is possible with psilocybin truffles, as it is with most psychedelics.
In the spiritual traditions that have worked with plant medicine for centuries, nausea and purging carry specific meaning. The Amazonian traditions that work with ayahuasca call it la purga — the purge — and it is understood not as a side effect to be managed but as a release. Something that does not belong in the body is being eliminated.
And people who have gone through it report that what follows the discomfort is a profound sense of relief and lightness.
My own experience with nausea in ceremony has taught me something about the practice of equanimity — of being with what is happening without resistance.
The nausea does not always resolve quickly. But when I have been able to meet it without fighting it, without telling myself a story about how bad this is or what it means, it moves differently. The resistance is often what makes it unbearable.
Which brings me to what I think is the most important thing to understand about the sensory dimension of a psychedelic journey.
What all of this is actually training
If you have read our earlier posts on interoception — the body's capacity to sense its own internal state — what I am about to say will land differently.
Here is my theory about why the psychedelic experience, at its best, is one of the most powerful things a person can do for their relationship with their own body.
The sensory intensity of a journey is not incidental. It is not a side effect. It is, in a real sense, the work.
When the body is producing strong sensations — cold, heat, twitching, nausea, waves of pleasure or discomfort — the only way through is not to manage them or suppress them. It is to be with them.
In psychology, this is called non-judgmental acceptance. In the contemplative traditions that have worked with these medicines for centuries, it is called equanimity. In both frameworks, the practice is the same: feel what is happening, as precisely as you can, without adding a story about what it means.
There is a practice in psychology called Focusing — developed by philosopher and psychotherapist Eugene Gendlin — that does exactly this.
You turn attention toward the body. You locate the sensation. You ask: where is it? What texture does it have? What shape? Is it light or heavy? Does it change as you attend to it?
These questions are not abstract. They are the practice of bringing precise, non-reactive awareness to what the body is already telling you.
And what happens, consistently, when you do this — when you give the sensation your full attention without the overlay of interpretation — is that the sensation shifts.
Sometimes it releases.
Sometimes it transforms.
Sometimes it simply becomes bearable when it was not before.
I had a story in my head for a long time that brain fog meant the burnout was coming back. That if I felt that particular heaviness and confusion, something was wrong and would stay wrong.
When I could simply feel the brain fog — locate it, attend to it, stay with it without the story — my response to it changed entirely. It stopped being a signal of catastrophe and became just a sensation.
One that passed.
Now imagine doing that practice when the brain is in a state of remarkable plasticity and flexibility. When the walls between experience and response are temporarily more permeable. When the usual neural shortcuts — the automatic meanings the mind assigns to what the body reports — are less fixed than they ordinarily are.
Psilocybin creates precisely those conditions.
The research on neuroplasticity and psychedelics shows that the period during and after a ceremony is a window of unusual malleability — the kind of flexibility in neural pathways that is more commonly associated with early childhood than with adult life.
During that window, the practice of returning, again and again, to what the body is actually experiencing — without the stories the mind adds to it — is not just a coping strategy. It is a reorganisation of the relationship between sensation and meaning.
What this looks like in practice, inside a psychedelic journey is simply asking:
What do I feel in my body right now?
Where is it located?
What texture does it have?
What colour, if any?
Is it light or heavy?
Is it moving or still?
Does it change as I bring my attention to it?
Over and over. Without judgment. Without needing the sensation to be different from what it is.
This is what meditation trains, over years of practice. This is what Focusing teaches. This is the foundation of what researchers mean when they talk about building interoceptive awareness — and weakening the automatic, often fear-based stories the mind constructs around what the body reports.
In a ceremony, this process is dramatically accelerated. Not because the medicine does it for you — but because the conditions it creates make the training extraordinarily potent.
How we hold this at Hearts Door Retreats
This is not accidental in how we work.
The days before a ceremony at Hearts Door Retreats are not downtime. They are preparation at the level where the work actually lives.
Every morning begins with breathwork — not as relaxation, but as a way of meeting the nervous system where it is and beginning to move it toward something more open.
The body-oriented practices that follow are designed to build exactly the capacity described above: the ability to notice what is happening, physically and emotionally, without immediately reacting to it.
By the time the ceremony begins, participants have been practising this for days.
Not through dry instruction, but through direct experience — through simple practices drawn from contemplative traditions that have always known, in their own languages, what the neuroscience is now beginning to confirm.
The ceremony then becomes a place to take that practice somewhere far deeper than daily life usually allows.
"I am so glad that I found this retreat. I expected a lot and it was so much more than I could imagine it would be. All the exercises were so insightful and helpful, even this alone would be a precious and deep and meaningful retreat experience. The truffel ceremony was my first experience with phychedelics and you gave me a safe & loving & caring & respecting to be and feel. I now know why it is called a journey and I am very thankful for your guidance."— Participant Foundation retreat, Nov. 2025
The next post in this series covers the emotional dimension of a psychedelic journey — what surfaces, why it surfaces, and what it means that the medicine seems to go, consistently and unerringly, to exactly what most needs attention.
Our Foundation Retreat — 9 to 12 July in the Netherlands — is built around exactly this: careful preparation, a ceremony held with full attention, and integration support that helps what arose in the journey take root in daily life. If you are curious whether this is the right moment for you, we would love to talk.
Post by co-founder Ioana.
Ioana is a researcher, psychedelic facilitator, and coach whose work sits at the intersection of science, embodiment, and lived experience. She spent years inside academia studying psychedelics, health and wellbeing — and eventually decided the most useful thing she could do with that knowledge was bring it into the room with people, not just onto the page. These posts are her attempt to make psychedelic science accessible and honest — without flattening it into wellness copy or drowning it in jargon.
