Published by Open Neuroscience Β·Β 26th March 2026 Β· Interviewed by YegΓ³r Karimov
Right now, something remarkable is happening inside your skull. A dense tangle of roughly 86 billion neurons is firing electrical signals, processing light, regulating your heartbeat, and somehow β no one quite knows how β producing the feeling that you are here. That sense of being a self, looking out at the world. Not just processing it. Experiencing it.
We sat down with Dmitri Filimonov β neuroscientist, electrophysiologist, and one of the people actively hunting for answers inside the human brain β to find out what we actually know, what remains stubbornly mysterious, and why the question matters far more than we might realize.
Dmitri Filimonov is Doctoral Researcher at the University of Turku, where he studies the neural correlates of consciousness β the specific patterns of brain activity that seem to accompany subjective experience β and teaches electrophysiology. His peer-reviewed work has appeared in NeuroImage, Neuropsychologia, and Consciousness and Cognition, examining everything from the electrophysiological signatures of visual awareness to whether auditory consciousness is graded.
Outside the lab, Dmitri's life takes some unexpected turns. He is a ranked climber with winter expedition experience β and maintains a studio practice that has produced poetry, sculpture, and a musical device he calls the "Neuro-Organ." Before the lab and the papers, there were thousands of kilometers of Siberian road, hitchhiked. Philosophy and literature remain constant companions. At Quadrivium Academy, he leads the Open Neuroscience project β bringing neuroscience to non-specialists through public education and cross-disciplinary study.
Dmitri, when someone asks you at a party here in Tallinn what you do, what do you say?
π¬ I don't go to parties because I'm a scientist (laughing). But when I do, my answer varies wildly: anything from "construction worker" or "security guard" to "scientist," no doubt. Being a bit of a trickster is a good antidote to over-rationalising life and reminds not to take your own too seriously. I actually enjoy construction work, and I worked as a security guard back in school.
π¬ When it comes to science β and neuroscience, obviously β people often assume itβs something close to that flashy βneuroβ mumbo-jumbo that has taken over the Internet. In the end, many people simply donβt know what neuroscience is, what it does, and what for should we love it.
The next question is the canonically boring one β how does neuroscience actually define itself as a field?
π¬ I wouldnβt dare define the whole field, but in general, it is the science of the nervous system, including the brain. From there, it branches out into cognitive neuroscience β which studies how the brain is related to thinking, memory, and planning; affective neuroscience, which investigates how the brain is related to emotions; clinical neuroscience, which is more pathology-oriented; and so on. Neuroscience can also be molecular, focusing on the chemical processes; systems neuroscience, which asks about functionally-relevant subsystems within the neural architecture; or even computational, which focuses on how information is transformed. There is even neurophilosophy.
π¬ There is also the neuroscience of consciousness, which studies brain processes and brain areas in relation to subjective experience. And that is mostly what I do. Though, more accurately, it should be called the science of consciousness, because many different disciplines contribute to it. Physics or philosophy of mind can address the problem without neurobiology, but of course, nowadays, the "neuro" part is almost always present in consciousness science.
So, what neuroscience actually covers isn't just the biological brain?
π¬ Yes, not just the brain. Anything that has a neuron, or several.
Humans have been thinking about the mind since antiquity. Why did we suddenly need a laboratory for it?
π¬ Thank you for this one. My best guess is because you can have near to infinite philosophies, topologies, and possibly even logics; with the lab you can easily narrow it down to something that works β which in science means "predicts the future". Empirical facts together with our broader progress comfort us with hope that "the truth is out there" Β©, in the converging evidence.
π¬ Yet that would be oversimplified: if only it were that easy, we wouldn't have hundreds of neuroscientific theories of consciousness. Yet, such answer would be oversimplified: if only it were that easy, we wouldn't have hundreds of neuroscientific theories of consciousness. Still, better hundreds than thousands, and at least now we have tools to fight the number down.
Most people, including me, hear the word "consciousness" and assume they know what it means. But you spend your career studying it, which suggests it's not that simple. What does the word actually mean when you use it?
π¬ For me, and for some scientists, consciousness is what [makes, allows, emerges, contains] subjective experience. Easier to say than to truly understand. Philosophers talk about qualia, but perhaps the closest everyday term is "image". Not the image on a phone, but one in our minds.
π¬ When I look at, let's say, a tree, there is no tree in my brain β only a specific physiology unfolding within a specific anatomy. When it "clicks," I see a tree. Even without a tree present, when it "clicks," I hallucinate one.
π¬ So the tree I experience is an image, not the real thing out there, which β like the Kantian thing-in-itself β could in principle be anything, unknown to us. We're like a Mary in Lynch's red Black Lodge β cut off from the "true" world by a proxy of our sensory systems, and proxies of our consiousness and cognition.
π¬ But here is where it gets stranger. The image of a tree is not the same thing as the physiology and anatomy that make it happen. One is a physical process, the other is beyond that. Think about it for a while.
I find it paradoxical. Consciousness feels like the most immediate, obvious thing in the world. And yet it seems almost impossible to study. How do you take something that's completely private and internal β my experience of, say, the nice weather β and drag it into a laboratory?
π¬ There is a way. We assume, based on overwhelming evidence, that brain affects the mind and is linked to it. The same lesions lead to the same deficits, like colour blindness or inability to perceive motion. These are changes in conscious experience produced by physical changes in the brain.
π¬ From there, we temporarily set aside the philosophical question of how exactly the brain is linked to the mind, and focus instead on where and when. We manipulate the experimental environment so that either the state of consciousness (dreaming, wakefulness, anaesthesia, LSD, meditation) or its content (seen or not seen, heard or not heard, felt or not felt) varies. Then we look for the related brain activity.
π¬ The complicated part is isolating the related brain activity from everything else happening at the same time.
Before we go further β can you give us the "Hard Problem" in one breath? Because it seems like it keeps coming up as the thing neuroscience struggles with.
π¬ Yes β 1994, David Chalmers, Tucson conference, Arizona. The classical formulation is: how the material brain "generates" seemingly immaterial consciousness? And what for? Why do we need it?
π¬ It is a descendent of an old psychophysical problem of body and soul. Outer versus inner. Microcosmos and macrocosmos. The difference is that there is no religious connotation and, perhaps, a greater degree of precision.
π¬ Some scientists think consciousness is simply an illusion and there is no problem at all. But then β if it is an illusion, who is the one being fooled?
π¬ In 2023 in New York, Joseph LeDoux and his band, the Amygdaloids, performed their hit exactly about that:
"I got body
And I got mind
I got a problem
I don't know what to do
Ma body wants you so
But ma mind says no"
π¬ E la nave va.
What does a day of actually studying consciousness look like? Electrodes, stimuli, measurements β what is the actual experimental procedure?
π¬ Depends on the day! Sometimes, yes β preparing equipment, calibrating, running the experiment. But I usually don't do that anymore, teaching the masters students to run the electroencephalography instead. Sometimes it is the data analysis behind the computer with elaborated statistical toolboxes. Sometimes designing and programming experiments. Sometimes writing the scientific article for a journal- a proof of what youβve actually discovered to the world. Sometimes peer-reviewing articles from colleagues, sometimes teaching. And sometimes thinking and doing nothing, having a cake and eating it.
How do you choose which tools to use when studying something as elusive as consciousness β and what are the trade-offs in that choice?
π¬ Long story short, it depends on the particular neurophysiological processes we are trying to probe. The particular trade-offs lie within the methods' limitations: EEG, MRI, PET, fNIRS, TMS and other fancy abbreviations have their own weaknesses β for example, EEG is fast but not very precise in locating where the effect took place β spatially β while fMRI is vice versa.
You published a paper last year on whether auditory awareness is graded or dichotomous. Was it about whether consciousness is like a dimmer fading gradually in and out, or a simple on/off switch?
π¬ Since then we have published a couple of more. If youβre interested in LoP β the Levels of Processing β let me try to explain.
π¬ This is not about the whole consciousness per se, or consciousness as a state. It is about a particular sensory information entering consciousness. When someone tries to listen to a sound below the hearing threshold, they do not hear it. But when the volume slowly and softly increases, what happens next? Does our perceptual clarity β this "image" of the sound in consciousness β gradually become clearer, or is it either fully clear or absent, all or nothing?
π¬ We found that both are true: a gradual increase in perceptual clarity happens when we focus on the lower-level features of the stimulus, such as its colour, shape, or pitch, while the all-or-nothing dichotomy appears when we focus on semantic category β is it an animal or an object, for example.
Why does knowing whether consciousness is gradual actually matter β what changes if we get that answer?
π¬ This seems like a rather nuanced question. But if the levels of processing are proven to exist, this underlines at least two different streams of stimulus-related information transformation in the brain, which affects many other knowledge domains linked to perception and consciousness. It also makes the phenomenological picture of consciousness clearer and more detailed. And it will end up in a question of what makes these streams or levels feel differently from the subjective experience point of view.
You study something called the Neural Correlates of Consciousness β the NCC. Say someone's been in a car accident, they're in a vegetative state, and their family is in the waiting room. How might your work eventually matter to that moment?
π¬ The neuroscientist Adrian Owen and colleagues asked healty people to imagine playing tennis while in an fMRI scanner. Then they asked the same question to non-responsive patients. The assumption was that those who had consciousness would hear them and do so. And indeed, the same brain areas activated in some of those patients.
π¬ The science of consciousness definitely should answer, and does answer, whether a person has consciousness or does not. My own work hasn't touched this area as of yet, but for several years I had some ideas on combining eye-tracking and EEG to detect covert perceptual consciousness, which I haven't pursued partly due to a lack of resources β but recently, exactly this was done by a group at Yale University. They found a relation between consciousness and pupil dilation. Well, not just that: the question is a bit more nuanced and complex than I am making it sound, but that is the core idea.
There's also a direction that points toward AI β whether a machine could ever be conscious, whether we'd even be able to tell. Is that a question your field is equipped to tackle, or does it require something we don't have yet?
π¬ I would say we need to take philosophy seriously here β not in order to answer this question with 100% certainty, which we currently might not be able to do, but to understand what different answers would actually mean and at what cost. What concepts and axioms we would gain, and which we would have to abandon.
π¬ Yet I think AI doesn't have consciousness, and I am 99.9% sure of that right now.
On April 14th, you're opening a course β "Brain and Consciousness: From Neuroscience Theory to Experiment" β to non-specialists. No prior background required. What made you want to do that? You could just stay in the lab.
π¬ To be completely honest, I am yet to discover why I give public lectures in Estonia. My motivation is sometimes adrift. Fame or fortune is a joke for topics like brain and consciousness β especially considering trends among our population.
π¬ I think of it as a mixture of social responsibility and leisure, time well spent. On the side of social responsibility: science should explain to society what it does, and that is better done by its practitioners β scientists. As for the leisure part: I like talking about consciousness, I guess. It is fascinating even when it is your full-time job.
π¬ Yet I am never a populariser or science journalist β I don't do it regularly, nor do I advertise. Science is my work. I also teach at the University, but not a lot. With that said, this course is a link between science and society for me. It makes me curious how interested in "hard" science society might actually be.
The course runs eight sessions over two months and ends with participants designing their own consciousness experiment. That's an audacious thing to promise non-specialists. What does it mean in practice to "design a consciousness experiment"?
π¬ Nah, we're good (laughing). If university students who aren't yet specialists can do it, why can't we?
π¬ To design an experiment in this context means gaining a basic understanding of how experiments are designed and proposing one β with feedback. Some of the proposed experiments could already be implemented in practice, but that is not the point. The point is to understand how and why scientists do what they do. Someone could walk away with a real advantage if they ever pursue a neuroscience career.
Session 5 is called "Consciousness Battles" β a debate-style workshop where participants defend philosophical positions. Why force a science course through a philosophical argument before getting to the neuroscience?
π¬ The science of consciousness, unlike other disciplines, doesn't rest on a single uniform philosophical foundation. There are several alternatives β and if you don't understand philosophy, you end up living by someone else's.
Last question. Someone's reading this. They're curious about the mind, they've read a pop-science book or two, but they feel like "real neuroscience" is above their level. What would you tell them directly?
π¬ What I usually tell my university students: your tortures will be legendary, relax and enjoy. Sometimes I forget to tell them the second part. The same goes for any worthwhile pursuit in life. But we shall keep things easy here, given the miscellaneous backgrounds of those attending. My experience in public lecturing has taught me how to make the material understandable.
Eight sessions. Two months. One of science's deepest open questions.
Brain and Consciousness: From Neuroscience Theory to Experiment begins April 14th, 2026, with Dmitri Filimonov. The course requires no prior background β only curiosity. By the end, you'll understand the major theories, know how to read the research, and have designed your own experiment. Participants who complete the full course receive a Certificate of Completion from Quadrivium Academy.