I’m sitting on a bright green couch. Sitting across from me is associate professor of experimental psychology Sebastiaan Mathôt. He’s wearing a wool cardigan and grey trousers that have a patch on the knee. I want some coffee, so I pick up the cup in front of me and take a sip. The hot liquid warms my throat.

I know that I’m sitting here. I’m conscious of it. But what that means exactly and whether Mathôt is conscious of his own presence is something I’m not sure I know how to express.

‘Unravelling consciousness is the Holy Grail for psychology, the same way the Theory of Everything is to physics’, says Mathôt. For years, academics and philosophers tried to understand this concept, but they didn’t make much headway. Mathôt was so fascinated by it that he ended up writing a book about. It will be published in September. 

Livestock

Figuring out consciousness isn’t an easy process, but it could definitely have effect on our society. ‘In livestock farming, for instance’, says Mathôt.  ‘While people might be able to conceive of cows having a consciousness, they’d have a harder time thinking the same of shrimp.’

Mathôt thinks that some processes would become less acceptable once we figure out whether livestock animals have consciousness.

This Holy Grail could also impact the future of artificial intelligence. Once we know how consciousness works, does that mean AI could have a subjective experience? Or perhaps AI lacks something fundamental and it can never experience consciousness. 

AI does nothing to maintain itself

Mathôt thinks AI differs from living things because it’s emotionless. ‘AI does nothing to maintain itself’, he explains. ‘When people perceive danger, they can run away. If we’re injured, there are processes that take place in the body to heal that injury.’ One theory says that these processes are linked to consciousness.

But what about a robot vacuum that returns to its charging station? That could be considered an action to maintain itself. Does that mean the vacuum has consciousness? In the future, AI will be able to maintain itself independently. According to the theory, that would look like a form of consciousness. How do we relate to animals, plants, and robots?

Hard and easy

An oft-used theory describes two problems of consciousness: the hard problem and the easy problem. 

‘The hard problem asks how a lump of meat in our heads leads to people experiencing a subjective first-person perspective’, says Mathôt. 

That first-person perspective is exactly what I was unable to express: me, sitting on a couch across from Mathôt, drinking coffee. ‘It’s also called the “what it is like aspect” of consciousness’, he explains.

The hard problem has been very difficult to study. Mathôt: ‘We don’t know where to start. It’s based on quite a few assumptions and it’s difficult to tell something or someone “you are conscious”.’ 

The easy problem of consciousness is a little clearer. It focuses on what someone’s brain is doing when they are or aren’t conscious. This can be measured through experiments.

‘In a classic psychology experiment, people are looking at a picture that disappears at a specific time’, says Mathôt. ‘Equipement is used to measure the difference in brain activity, and that comes close to measuring consciousness.’

Pupil reflexes

In his research, Mathôt studies how people use their senses to perceive the world around them and how they selectively pay attention to various aspects. 

Mathôt specifically studies pupil reflexes. Pupils constrict when exposed to bright light, and expand in the dark. ‘Participants in the experiment have to look at the middle of the screen while focusing their attention on the right or left side of the screen without moving their eyes’, he says. 

It’s difficult to tell something or someone ‘you are conscious’ 

The researchers then made part of the screen light up and looked at the participants’ pupil response. Here’s what they saw: ‘When people were focusing on the left side and that was also the side that lit up, their pupils would display a more intense response than if they’d been focusing on the right’, Mathôt explains.

Ingenious

It’s an ingenious cognitive process, the researcher says. ‘Even just talking about light can elicit a response in someone’s pupil’, he says. This could be a preparatory response, which takes clues into account to prepare for any potential changes. 

The first time Mathôt saw this, it seemed almost too good to be true. ‘The extent to which the pupil responded was proportional to the attention people paid to it’, he says. Electrodes measuring the retina activity also saw a difference in activity when people were focusing on the light part instead of the dark one.

‘This particular study was replicated quite a lot, but it’s still fascinating to see how a little circuit in the eye manages all that.’

Consciousness

Mathôt’s research has more to do with perception than with consciousness. Perception is a description of behaviour, he explains. ‘We receive information and act accordingly.’

But that doesn’t necessarily correlate directly to consciousness: a self-driving car also perceives its environment and brakes for pedestrians, for instance. Does that mean the car is experiencing consciousness?

Is a self-driving car that brakes for pedestrians a conscious being?

The problems that Mathôt’s research focuses on are small, mechanistic issues related to the hard problem. But this could be a first step towards figuring out consciousness.

‘Solving the easy problem could contribute to solving the hard problem’, he says. ‘In his book Being You, Anil Seth writes that solving the easy problem would vaporise the hard problem. But I can’t say with certainty whether that’s true.’

Elusive

Whether researchers will every be able to dissect consciousness, Mathôt can’t really says. He doesn’t think the most essential discoveries happen along a nice, linear path.

‘When it comes to self-driving cars, you can easily make concrete predictions, but with matters like these there’s often a tipping point, someone making the tiniest discovery’, he says. ‘After that, it could all go very fast. It might happen tomorrow, or we might never find it.’

The lack of starting points makes it very difficult to study consciousness. Because it falls outside the limit of what we can measure, none of the current measuring equipment is useful. Mathôt: ‘It’s almost as if it was never meant to be measured.’

So how do researchers tackle this problem? One example Mathôt often gives is how we think about life. ‘Life used to be something just as elusive’, he says. These days, scientists know a lot more: they catalogued important life processes and discovered cells. 

‘To figure out the concept of “life”, researchers would look at the things we considered alive and the things we didn’t’, says Mathôt. ‘They then identified the common denominator. Perhaps we will do the same in our studies of consciousness. Or maybe it’s a qualitatively different problem altogether.’

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