Neuroscience Can Model Consciousness

By Georgeann Sack

Everything is physical, even the mind

Historically, consciousness has been called mind, or soul. Consciousness is the subjective experience of being alive. To this day, many believe that while the body is physical, consciousness is a force beyond scientific understanding. This is called Mind-Body Dualism.

Two people who have given this a lot of thought are philosopher Jussi Jylkkä and cognitive neuroscientist Henry Railo, both researchers at the University of Turku in Finland. In a recent paper, Jylkkä and Railo argue that subjective experiences are physical and can be understood through science (“Consciousness as a concrete physical phenomenon,” published in Consciousness and Cognition).

I spoke with Jylkkä and Railo individually to ask why they felt this paper needed to be written. Their answers were as interesting as the paper itself. I believe they have their finger on the gushing wound of what is so damn difficult about the modern day study of consciousness.

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When asked why he was compelled to write this paper, Railo said, “Dualistic thinking is very deep rooted in the science of consciousness. Most people seem to think consciousness and experiences are somehow fundamentally different from other physical phenomena. We wanted to clear some of the mysticality from consciousness studies.”

Jylkkä said that philosophers believe in dualism because they have read too much Plato and Descartes. Plato (427–347 BC) believed the soul was independent from the body and could transfer into a new body. René Descartes (1596–1650) believed the soul was thinking and immaterial, a gift from God that could exist without the body.

Cartesian dualism, named after Descartes, has had a long reach. The belief that the soul is somehow separate and privileged from the normal physical functioning of the body still resonates with some philosophers and within our larger culture today. How a separate soul and body might interact and further arguments for the truth of dualism continue to be discussed.

In contrast, physicalistic monism is the belief that our soul (i.e. our conscious, subjective experiences) are physical processes within the body, and thus depend entirely on the body to exist.

If we endorse the physicalistic premise that all concrete natural phenomena are physical, it follows that our experiences are physical phenomena.

Jylkkä and Railo (2019)

Jylkkä and Railo call their breed of monism Naturalistic Monism, to distinguish it from Russellian Monism, named after Bertrand Russell (1872–1970). Russellian Monism argues that experiences are concrete natural phenomena but then divides properties of experience into categories: extrinsic, observable aspects, and intrinsic, non-observable (and therefore science-transcendent) aspects.

This differentiation between physical, observable aspects of experiences and the non-observable aspects is why Jylkkä and Railo call Russellian Monism dualism in disguise. Railo said, “If we commit to that kind of distinction that there is ordinary physical stuff, and then there is the phenomenal consciousness non-ordinary physical stuff, we already commit to some form of dualism.”

Scientists are not immune to this deeply rooted dualistic thinking. In modern day neuroscience, consciousness has been described as an epiphenomenon and an emergent property. Both imply that there is a physical basis of consciousness, but that consciousness itself is something more than that.

Here we are, 400 years after Descartes, still looking for the seat of the soul. For example, much of the current research aims to identify the Neural Correlates of Consciousness.

We seek, in particular, the neuronal correlates of consciousness (NCC), defined as the minimal neuronal mechanisms jointly sufficient for any specific conscious experience.

Christof Koch (1956- ), “What is Consciousness?,” Nature.

“The term correlate has a strong meaning behind it,” Railo said. “It implies that you are not really measuring the phenomenon you are interested in, you are just measuring something that correlates with it.” Jylkkä and Railo propose that we use the term “Constitutive Mechanisms of Consciousness” instead.

Jylkkä and Railo are not calling for a methodological revolution in order to study consciousness. Railo described the current neuroscientific approach as “exactly right.” He is studying visual experience using a similar approach to others who are identifying the neural correlates of consciousness. Jylkkä said, “You don’t have to change your methodology or the paradigm of science. It’s possible to study consciousness by doing business as usual.”

What they do suggest is that we change the way we talk about consciousness. In particular, they wanted this paper to influence the way neuroscientists think and talk about consciousness.

When asked why he thinks some neuroscientists are reluctant to study consciousness, Jylkkä said, “I think they are afraid of the risk. If they say they are studying consciousness they make their approach somehow unscientific or pseudoscientific. I would say that much of neuroscience currently is actually studying consciousness or at least processes that are closely tied to consciousness.”

The philosopher and the empiricist

Henry and I have known each other for something like fifteen years. We play in the same band together. We have talked about these issues a lot. I have always been the philosopher in these discussions and he has always been the empiricist.

Jylkkä, in conversation
Jylkkä (left) and Henry Railo. Photo by Frans Rinne.

Philosophers believe knowledge can be gained through reasoning, and work toward truth using systematic thinking. Empiricists believe knowledge must be gained through sensory experience, and work toward truth using systematic observation and experimentation, i.e. the scientific method. Is there anything to gain from conversations between philosophers and empiricists? How about from comparisons of knowledge gained?

Jylkkä, a philosopher, and Railo, an empiricist, decided to write this paper together after years of casual discussion. I asked each of them whether or not they thought better communication between philosophers and scientists would be useful for the study of consciousness. They both said yes.

For philosophers, Jylkkä believes there are advantages to constraining their thinking within the bounds of what has been learned through empirical methods. “Coupling philosophy with empirical science grounds philosophy,” he said. “I think that is really important, facilitative communication.”

For scientists, Railo believes there are benefits to understanding the philosophical foundations of what they are studying, especially if they are studying consciousness. “Neuroscientists should be aware that their work relates to philosophical and theoretical issues,” Railo said. “Their experiments and findings are not independent of philosophical discussions. Any empirical claims build on philosophical groundwork, assumptions, and reasoning.”

Without adequate communication, it is easy for philosophers and scientists to step on, or over, each other’s work. Words are redefined and used without consideration of the historical meaning those words have had in the other discipline, making it difficult for philosophers to interpret empirical studies and vice versa. As Jylkkä pointed out, one scientific model of consciousness, Global Workspace Theory, has been largely ignored by philosophers because it doesn’t talk about qualia.

Qualia are the qualitative feelings associated with experiences. Jylkkä says he was motivated to write this article by anti-physicalistic arguments by the philosophers David Chalmers (1966- ), Frank Jackson (1943- ), and others who claim that qualia are beyond scientific understanding. Philosophers have defined qualia as immaterial, epiphenomenal or non-dispositional (qualia have no causal power), non-relational (qualia exist without dependence on other properties), and non-structural (qualia do not contribute to the structure of a system).

Jylkkä and Railo believe that subjective experiences do have causal effects. They ask that philosophers and scientists do away with the notion of qualia, and instead make the assumption that all aspects of experiences are physical.

If we assume that all the properties of experiences (including what they feel like) are physical and causally efficacious, then they can causally interact with measuring devices. Thus, it is possible to observe and model consciousness itself, not just its correlates.

Jylkkä and Railo (2019)

When explaining why this is important, Jylkkä said, “I think it is like [Daniel] Dennet [1942- ] says. You define consciousness as something that you cannot study scientifically, and then you wonder how could you study consciousness scientifically, so it’s like a circle.”

Jylkkä compared the neuroscientific efforts to observe and measure consciousness to astronomy. “When you study some distant planets, you can see how the planet is revolving its sun, and you see dips in the luminosity,” Jylkkä said. “In principle you could go closer and see the planet itself, not just the dips in the luminosity of the star. We see signs or effects of consciousness and could also see the experience itself. It would be difficult but not, in principle, impossible.”

There is always going to be a gap

There is an epistemic gap between any concrete phenomenon and its scientific model, due to the distinctness between the model and the phenomenon.

Jylkkä and Railo (2019)

It is true that measures and models of experiences are not the same as the experience itself. Those who study consciousness would be wise to remember that any scientific model is not going to be the same as the thing itself.

This understanding was Jylkkä’s big aha moment, many years ago, that ultimately led to this paper. “You cannot capture things in words,” he said. “Your word for this cell phone is not the cell phone itself. The cell phone itself is something that transcends our words and ways of describing it. Our consciousness and experiences can be described in words, but they are always something beyond words. I thought this was applicable to consciousness, to the hard problem, because in science you want to describe things with words, but the thing described is always, in a sense, transcendent with respect to science. And I thought ‘that’s the hard problem.’ It’s not particular or specific to consciousness. It’s about everything. It’s the human condition, basically.”

In the study of consciousness, the question of why we have subjective experiences is called the hard problem. This idea was formulated by Chalmers in his 1995 paper, “Facing up to the problem of consciousness.”

So why is the study of consciousness so damn hard? Personally, I think it is because our theoretical understanding of living systems has some catching up to do if we are to model living systems as successfully as non-living ones.

Human beings struggle to believe that something as deeply felt as our subjective experiences could be physical. I used to think this was due to our inflated self-importance. Now I wonder if it is because we cannot reconcile the sloppy, emotional experience of what it feels like to be alive with any kind of predictive laws.

I agree with Jylkkä and Railo that subjective experiences are physical. It follows, then, that our understanding of subjective experience is dependent on our understanding of physics. Physics has come a long way since the cause and effect days of Isaac Newton’s (1643–1727) laws of motion. I wouldn’t be able to fathom that consciousness arises from those laws either.

To understand consciousness, we need better theoretical and mathematical models of the physics of living systems. Scientific research has given us an appreciation of the probabilistic and dynamic nature of biology, especially within the last hundred years. Hell, especially within the last decade. Models of living systems based on this information are being generated and refined right now. This is an exciting time to be a physicalist.

Biology is moving very fast and so the same kind of people who became physicists in those days now tend to become biologists. Theoretical biology is now becoming much more of a real subject than it used to be, so a lot of people who are really computer scientists are doing biology. The line between mathematics and biology is not so sharp anymore. I would say that’s where the young people are. They’re having the same good times now that we had 50 years ago.

Freeman Dyson (1923- ), theoretical physicist, Q&A in Nautilus.

According to Jylkkä, reactions to their paper so far have been binary — people either think it is correct and trivial or wrong and absurd. Whether you think they are right or wrong, trying to explain why is incredibly challenging and worth your time to consider deeply.

In conversation, Jylkkä and Railo are curious, questioning, and humble, openly asking for reasoned out contrary opinions so that they can continue refining their ideas. So please, question them, and question yourself. Are subjective experiences physical? Do you think they can be measured? How?

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