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Thoughts on Thought

From Birds To Brains

Jonathan Moens considers whether emergence can explain minds from brains.

One September in Rome, as I waited for the 700 bus, I looked up and noticed a black tide of birds hanging over Il Vittoriano monument. Tens of thousands of starlings had gathered here to dance their graceful, synchronous dance. They raced and morphed, splintered off and coalesced: they formed an endless stream of imaginary shapes in the tangerine sky, I was mesmerized by the scene above me.

I had recently learnt about ‘emergentism’: the view that complex systems, including certain substances, cells, bodies, brains, and ecosystems, can exhibit behaviours that are greater than the sum of their parts. The wetness of water, for example, can’t be explained by individual water molecules alone, which are not themselves wet. The wetness emerges when we have trillions of water molecules acting together. Similarly, the destructive power of a tornado can’t be explained by the individual water droplets, dust particles, and debris that feeds it – none of which individually are themselves violent. Even consciousness – that inner, subjective realm comprised of the fleeting sensations, feelings, and thoughts that shape our everyday lives – can’t be found in the activities of individual brain cells. And now here I am, observing the starlings’ collective murmuration.

Starling murmuration
© Mostafameraji 2014 Creative Commons 4

There’s nothing particularly mystical about how individual starlings behave: they mate, migrate, search for food, and perch themselves comfortably on balconies. But the shapeshifting choreography of the starlings flying together involves the kind of spontaneous finely-tuned collective decision-making that scientists still can’t predict by looking at any one bird alone. The murmuration simply emerges as an incomprehensible seamless phenomenon. I was in awe. “Each bird is responding to local information,” explains Timothy O’Connor, a philosopher at Indiana University specializing in emergent phenomena: “But somehow, a kind of organized behaviour just spontaneously emerges through all these little local interactions” (Most of the quotations in this article are from audio interviews conducted by the author).

Emergence, explains O’Connor, is not a new idea. In writing it dates back to the ancient Greek philosopher Aristotle, who first articulated the idea in his Metaphysics (c.350 BCE) when describing how the ‘the whole is something besides the parts’ in entities composed of several parts. But while the concept has a long history, its usage in science and philosophy has been scarce. It’s only in the past few decades, with rapid developments in computer technology bolstering interest in complex systems, that the notion of emergence really took off. As O’Connor says, “Emergence is back in vogue.” Thus, since the 1980s, scientists have studied emergent properties in all kinds of dynamic systems, from flocking behaviours in starlings to shoaling in fish, all the way to traffic congestion and synchronous clapping in concert halls.

While these and other complex systems differ in many respects, they also share key similarities, including the spontaneous creation of order; quick, seamless adaptation to the environment; and behaving in novel ways, unpredictable from the behaviour of the individual parts. Identifying such patterns has enabled scientists to extend the concept of emergence across natural phenomena, including for hurricanes, tidal waves, and tornadoes.

Conscious Emergence Emerges

While emergent phenomena really do appear to emerge out of thin air, O’Connor thinks science will eventually be able to explain exactly how they work. Hence he describes this type of higher physical behaviour as a ‘weak’ form of emergence. “Ultimately, it’s an empirical question,” he says, “but I don't think there’s any reason to think that there’s some kind of irreducible group [behaviour].” Indeed, studies are already beginning to unpack the mystery of the starling dance by showing how individual bird movements can communicate information across entire flocks, enabling them to behave as if they have a ‘unified mind’. However, there may be a ‘strong’ kind of emergence that could defy scientific explanation altogether: consciousness from brain activity.

With on average around eighty-six billion neurons each, each neuron having on average about ten thousand synaptic connections to other neurons, the human brain is arguably the most complex system in the universe. Within this structure lies one of the greatest mysteries in the universe: our conscious experience. How and why do collections of neurons – these tiny, spider-like cells – give rise to externally invisible, immaterial, and fundamentally different experiential phenomena? As Philip Goff, a philosopher at Durham University, says, “The redness of a red experience, the taste of chocolate – you can’t capture these kinds of qualities in a purely quantitative vocabulary.”

It’s a difficult problem. In fact, the question of consciousness has so eluded scientists and philosophers that it’s been labelled ‘the hard problem’. To quote the nineteenth century English biologist T.H. Huxley, how brain processes lead to subjective experiences is “just as unaccountable as the appearance of Djinn when Aladdin rubbed his lamp.” Despite rapid advancements in brain science, researchers are still scratching their heads for answers. “Let’s just say that neuroscience on its own doesn’t seem to resolve that question,” says David Chalmers, the philosopher at New York University who first gave the hard problem its name.

For Chalmers, neuroscience can potentially tell us how the brain produces certain processes that result in outputs along nerves that assist us in our daily lives. Using neurosciences to understand memory, learning, strategising, reasoning, planning – these are all examples of what he calls the easy problems (although he’s quick to warn that the ‘easy problems’ really aren’t all that easy). However, these problems of how the brain physically reacts to sensory inputs don’t answer the more fundamental question of how or why we have subjective experiences as a result of these reactions. “There’s just always this further question”, Chalmers says: “Why doesn’t this [brain activity] happen in the dark, without any conscious experience?”

No-one knows. To begin with, researchers don’t even agree on what consciousness is. And although some philosophers treat consciousness as indubitably real, others say it’s an illusion. And while many say consciousness is a purely biochemical phenomenon, others say it’s a separate substance distinct from brain activity. And while some argue that consciousness extends to the instruments we use to think with (pencils, calculators, and smartphones…), others like Goff go even further, and say consciousness pervades the entire universe.

With so many wildly different and incompatible theories of consciousness, the field has become fragmented. Giulio Tononi, a neuroscientist at University of Maddison, says, “There’s no ‘we’ in consciousness research – forget it. We all have different opinions.” Could emergentism bring consensus?

Emergent Issues

To some, there’s something satisfying about thinking of consciousness as something distinct from the brain. It certainly feels that way in our lives: we talk about how minds inhabit our bodies; how powerful emotions possess or enslave us; how our thoughts, fleeting as they are, wander into daydream; and so on. Indeed, Paul Bloom, a psychologist at Yale University, says it’s precisely this compelling sense of separation between our minds and bodies that makes us ‘natural born dualists’ – naturally inclined to the theory that the universe is made up of two very distinct substances: mental and physical.

Emergentism, which doesn’t necessarily invoke different substances, is also attractive, though, in how it seems to capture how the world works. According to Tononi, “It would be absurd not to be able to talk about how societies emerge, families emerge, how companies emerge” – so perhaps the same is true of the brain and mind. The basic idea is that consciousness – thoughts, feelings, etc – somehow simply appears when the signalling activity between brain cells becomes complex enough in the right way.

Tononi himself recognizes the usefulness of thinking of the brain as a complex system in which consciousness, loosely speaking, emerges. Tononi’s own work measures the level of complexity in the brain by mathematically calculating the degree of integration of information in brain activities. The higher the degree of integration (a measure he denotes as ‘phi’), the richer the kinds of experiences that brain activity is able to create. Thinking in this way has already proven fruitful for clinicians to understand key differences between vegetative, minimally conscious, comatose, sleeping, dreaming, and wakeful states. “It’s still a crude measure,” Tononi says: “But this is actually working better than anything else right now, to be able to get an empirical assessment of consciousness even if the patient is unresponsive.” However, as soon as scientists consider whether emergent properties exist as totally new, unpredictable entities that can’t explained by their component parts, even in principle (such as with consciousness), Tononi thinks the idea gets a little spooky: “It sounds magical.” To him and many other scientists like him, ‘emergence’ has become an all-purpose buzzword used to describe phenomena that seem to defy scientific explanation. Sure, ‘emerge’ seems to be a good verb to describe how consciousness, tornadoes, and flocks of birds spontaneously arise. But would consciousness emergence be the same kind of emergence as other ‘physical from physical’ types of emergence? And are these emergent phenomena actually something more than the sum of their parts? And if they are, it begs the question: how is this creation of this extra something possible?

Answers to these questions can only be speculative, says O’Connor. To him, emergent properties may arise spontaneously, but their emergence is also predictable. “There needs to be the right kind of organization,” he says, “and when that happens, then – boom – these things join together and give rise to a kind of fundamental disposition to the whole.” In many ways, he says, it is science’s job to decipher what kinds of organizational patterns a system requires for new properties to emerge. Others, like George Ellis, professor of complex systems at the University of Cape Town, on the other hand, are more fatalistic: “I think it might remain unsolved forever.”

But perhaps there’s a simpler explanation for the mystery underlying emergent properties: perhaps the science just isn’t mature enough. Consider that centuries ago scientists thought life was driven by an elusive ‘vital force’ – the theory called ‘vitalism’. But scientific progress has now debunked this theory, replacing vital force with a mechanistic explanation of how DNA, metabolism, and other basic cellular processes work in concert to produce life. The scientific theory of life isn’t complete, but it is largely resolved. Couldn’t scientific progress do the same with all emergent phenomena? Is it just a question of time?

As I watched the starlings break in and out of their dance, whirling and tumbling as a lissome mass, I wondered not just about their murmuration, but also about tornadoes, waves, consciousness – are they really beyond the reach of science? Every fall, the starlings come back to fly over Il Vittoriano. And every fall, I’m left amazed, stupefied – and totally clueless.

Jonathan Moens is an investigative journalist based in Rome. jonathanmoens.com