Conscious Reality Could Be A Controlled Hallucination Argues Neuroscientist


Dr. Alfredo Carpineti


Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

Alfredo (he/him) has a PhD in Astrophysics on galaxy evolution and a Master's in Quantum Fields and Fundamental Forces.

Senior Staff Writer & Space Correspondent

Image Credit: Benjavisa Ruangvaree Art/

If everything is a hallucination, don't I deserve another slice of pizza? Image Credit: Benjavisa Ruangvaree Art/

Understanding consciousness is a holy grail of science and philosophy and it underpins not just your personal experience, but every single social enterprise. We are human and we are conscious. But what is consciousness and how does it arises?

Neuroscientist Dr Anil Seth has an interesting approach in trying to explain how what we call consciousness is like. In a delightful and informative video, he argues that our brain “hallucinates” everything we sense, and that’s where consciousness comes from.


This idea is a hotly debated topic and hits at the heart of the complex quagmire of our understanding of consciousness. The first concept we have to become familiar with is qualia. Qualia are the subjective properties of experiences. The taste of a delicious pizza, the pain after you stub your toe on that darn coffee table, how blue the sky is. Those are all examples of qualia.

Dr Kai Hamburger and Katharina Graben have previously written in the journal Perception about the similarities and differences between illusion, hallucination, and indeed consciousness. From Descartes Cogito Ergo Sum (I think therefore I am) to the Matrix movie by Lana and Lilly Wachowski, consciousness and the idea of the self is unquestionable. But maybe the rest of reality is just a hallucination. One that we just happen to share with others.

Dr Seth’s approach starts right there on the definition of illusion and hallucination as well as the limitation of our perception. All the qualia boil down to electrical impulses, from our sensory organs to our central nervous system. If we consider our brain the seat of our consciousness, our experiences are not direct but mediated through the biological processes of our body.

“So perception -- figuring out what's there -- has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations or beliefs about the way the world is to form its best guess of what caused those signals. The brain doesn't hear sound or see light. What we perceive is its best guess of what's out there in the world,” Dr Seth explains in the TED 2017 video.

They look different but the two squares marked with 'X' are actually the same color. A similar illusion is used by Dr Seth in his talk. Image Credit: Peter Hermes Furian/

The neuroscientist shows many sensorial illusions that truly make us question what is real. But it also provides us with some insight into how our brain operates. And that’s where his idea that the brain in a way hallucinates your conscious reality comes from.

“If hallucination is a kind of uncontrolled perception, then perception right here and right now is also a kind of hallucination, but a controlled hallucination in which the brain's predictions are being reined in by sensory information from the world,” Dr Seth explained in the talk. “In fact, we're all hallucinating all the time, including right now. It's just that when we agree about our hallucinations, we call that reality.”

His approach is heavily based on our biological mechanism and this has three important implications. It suggests that the I think therefore I am is not as foolproof as one might think. If the external reality is conditional to our bias brain so it is our internal world. Secondly, if biology is key then we can’t just download our brain into a computer. And thirdly, our consciousness could just be a small fraction of what consciousness is truly like and the forms that might exist.

You can watch the full video below:



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