Science and Philosphy

The Science and Philosophy of Dreamachine

A rad wolf

What did you see? What did you feel?

Every Dreamachine experience is completely personal and unique.

Understanding the effect that flickering light and sound has on the mind and body has fascinated, baffled and challenged scientists and philosophers for centuries.

Here’s a brief introduction to what we know about what you may have experienced and what is going on while you were in the Dreamachine Immersive Experience.

What you saw

Many people have striking and memorable visual experiences in the Dreamachine. In fact, for decades we’ve known that if we’re exposed to flickering light with our eyes closed it can trigger vivid patterns and colours, a phenomenon that remains an active area of research in psychology and neuroscience today.

Why does it happen?

Part of the answer is that flickering light influences our brain rhythms, in particular the ‘alpha’ rhythm of slow brain waves that’s normally present when we’re relaxed but awake, and is also prominent in visual parts of the brain.

Another idea is that the patterns relate to the way the visual cortex is wired and its underlying circuits are organised. Either way, the Dreamachine reveals the extraordinary power of our brains and minds to create our conscious world.

What you heard

We have many ways of perceiving the outside world, as well as what’s happening inside our bodies, and psychologists and neuroscientists have long been interested in how different ways of sensing interact with each other. The Dreamachine’s flickering light is accompanied by a specially composed soundtrack. What you saw would have been affected by what you heard – and maybe the other way around too.

These interactions between the senses happen in our everyday lives too – for example, the flavour of food and drink depends on their smell as well as their taste. And for people with synaesthesia the mixing of the senses can become unusually profound and vivid – some experience colours when they see printed, black letters, and sounds can create sensations in parts of the body for others. But even though our brains are interpreting many different sensory signals in any given moment, we have a single, ‘joined up’ conscious experience. Understanding how this happens remains a scientific and philosophical challenge.

What you thought

We’re not just aware of things in the world around us: we’re also aware of time passing, of being in a body that’s in a particular place, and of being a ‘self’. These experiences – of time, location and self – can also change in the Dreamachine,

But how exactly does brain activity create these experiences? Neuroscience is finding out more about the relation between the brain and the mind. For instance, ‘out of body’ experiences can be created by stimulating a specific part of the brain, and experiences of time passing seem to depend on how much ‘change’ the brain has to deal with. Despite these discoveries, deep philosophical questions remain, such as the relationship between what we experience and what’s really there and what it is to experience things that don’t ‘exist’.

What you felt

Our emotions play a huge role in the quality and meaning of our existence. You might have experienced surprise, joy or anxiety – or something else entirely – in the Dreamachine. If you did feel emotions, the music probably contributed. Psychologists and neuroscientists are still figuring out exactly how music generates such powerful reactions and why our emotional responses can vary so much.

But what exactly are emotions?

There’s a surprising lack of agreement on this. We do know that a lot of different things occur when we feel emotion. If we feel fear when we see a snake, there’s evaluation (danger!), physiological response (increased heart rate and blood pressure), experience (an unpleasant feeling), motivation (run away!) and mental activity (focus on the snake). It could be that emotions are our awareness of changes in our body’s internal state. In other words, perhaps we don’t feel scared because we see a snake, we feel scared because we perceive our body preparing to fight – or run away.

Transformative experiences

What is it like to bungee-jump or taste vegemite? Many philosophers believe that you can only know these things by experiencing them. No descriptions, however detailed, can impart the same knowledge. There are also experiences that change your beliefs, desires and life preferences. Examples include becoming a parent, having a religious or spiritual encounter, and having an experience of the sublime – perhaps in the presence of great art or the awesome force of nature. When experiences both reveal something otherwise unknowable, and change us in some fundamental way, philosophers call them transformative experiences.

Some transformative experiences give us powerful new perspectives on our place in the world and within nature. As the philosopher Emily Brady writes, these experiences can be humbling and can make us feel small and insignificant, yet at the same time exalting us, and making us feel special. Such experiences can change what we believe about the nature of the universe, and hence what we find important and valuable in life. Perhaps your experience in the Dreamachine has something of this character, perhaps not.

Transformative experiences can have an impact on how we live our lives. If what you find valuable and important changes, then the choices and decisions you make may change too. And since there’s no way of knowing in advance what the effect of transformative experience will be, there can be no principled way to decide whether or not to have one.

Perception and reality

How does our conscious experience relate to what’s really out there? It is easy to assume the world just pours itself into our minds through the transparent windows of our eyes, ears, and other senses. But how things seem is not always a good guide to how they are. In the 19th Century, the German scientist Hermann von Helmholtz proposed that perception – figuring out what’s out there in the world – involves the brain combining ambiguous sensory signals with its best “informed guesswork” about the world. This has led some to the view that our perceptual experience comes as much from the inside-out as from the outside-in. On this view, the sensory signals coming into our eyes, our ears, and our other senses are used mainly to update the brain’s “best guesses” about what is going on.

Others maintain that what the brain is really up to is using its best guesses to allow us to be open directly to the world. Deciding between these views is a hot topic in both science and philosophy.

What’s clear is that the brain can generate experiences that do not directly reflect the way the world is. This power is at the heart of the Dreamachine experience. We seem to be aware of colours and shapes that don’t exist out there in the world, and that certainly don’t exist inside our brain. Where are those things and what is their nature? The active role of the brain can lead it to seemingly create an alternative reality experienced within our conscious minds – a kind of “waking dream”.


For each of us, consciousness is all there is – without it there’s no world and no self. The human brain is extraordinarily complex, an adult brain containing about 86 billion neurons and a thousand times more connections. But how can electrical and chemical signals in our brain cells produce feelings of love and hate, sensations of colour and movement and sound and smell, and the singular experience of being you?

One philosophical idea, known as dualism, is that the conscious mind is something over and above physical processes. Another – materialism – is that everything that exists is made of physical stuff, like atoms or quarks. If that’s right, then consciousness must also be made of physical things or brought about by a physical process. But there’s no consensus on whether that’s true – or how it happens.

As we learn more about the brain, the possibility that we might finally understand the nature of consciousness is one of the most exciting frontiers in all of science and philosophy.

Individual differences

Because our brains play an active role in interpreting sensory data,our perceptual worlds will be unique for each one of us. Your experience in the Dreamachine was unique to you, even if there will have been similarities with the experiences of others. What may be surprising is that this applies during everyday experience too. We’re all now familiar that people differ in many ways that are visible from the outside, in terms of height, and skin colour, and so on. But this external diversity is accompanied by an equally significant inner, perceptual diversity – a diverisity which, because our perceptual experiences are subjective and private to each one of us, has remained largely hidden.

Sometimes it is easy to recognise that other people experience things differently, but this is often only when the differences are rather large. For example, people with a condition called synaesthesia may experience colours when others do not, and people with autism may experience their perceptual world as being more intense than others. And sometimes, perceptual diversity can be revealed by specific images – a few years ago there was a photo of a dress that half the world saw as blue and black, while the other half saw it as white and gold.

A key goal of the Dreamachine project is to deepen our knowledge of perceptual diversity, both by looking at how peoples’ experiences within Dreamachine itself vary, and through an ambitious citizen science project called the Perception Census, which will allow scientists to understand much more about what we each experience of the world in the way that we do. By taking part in the Perception Census, you will not only help advance science, but you’ll discover much more about how unique you really are.

Written by Anil Seth and Fiona Macpherson

Discover more:

Learn more about perception, consciousness and the science and philosophy behind Dreamachine:

– Take part in our ground-breaking Perception Census, a new citizen-science project of unprecedented scale. We’re charting – for the first time – how each of us experiences the world differently. By taking part you’ll be helping to advance research and you’ll learn how your way of experiencing the world is unique to you.
– Read the book Being You – A New Science of Consciousness (Faber, 2021), by Dreamachine lead scientist Anil Seth.
– Visit the Illusions Index
– Listen to a Philosophy Bites Podcast about Hallucination featuring Dreamachine philosopher Fiona Macpherson.
– Watch Anil Seth’s popular TED talk on consciousness, perception and self.
This site is registered on as a development site.