Technology

Neuroscientists are increasingly convinced insects have subjective consciousness. The findings are meaningful for the evolution of artificial intelligence and raise serious ethical questions. By Amalyah Hart.

Insect studies evolve AI consciousness

Two fruit flies take part in a “courtship dance”.
Two fruit flies take part in a “courtship dance”.
Credit: VW Pics / Getty Images

Ten fruit flies, encased in individual test tubes, pace the lengths of their glassy quarters like the prisoners they are.

On a screen, a graph is plotting each fly’s horizontal position over time. For periods, the flies are still. The occasional nudge spurs a flurry of activity.

Bruno van Swinderen, a professorial research fellow at the University of Queensland’s Brain Institute, has dedicated the better part of two decades to investigating the brain of the common fruit fly, Drosophila melanogaster.

This experiment, which I’m watching online, involves a system van Swinderen and his colleagues created in 2015, the Drosophila Arousal Tracking (DART) system. Van Swinderen investigates attention, sleep and memory in these creatures, all of which he links to the slippery concept of consciousness.

“This is a hypothesis, but all animals seem to have quiet sleep, where they slow down, become quiescent and take care of stuff that is incompatible with the animal moving around,” he explains.

“What we’ve discovered is that some animals seem to have what we call active sleep. In humans we would call it REM sleep, when we have our vivid dreams. The brain doesn’t look any different to an awakened brain, but the animal is disconnected from the outside world.”

If a fly is inactive for a long time, DART might give it a nudge. The fly will respond differently to the nudge depending on its sleep phase, indicating that those phases cycle. That suggestion has been supported by imaging the fruit fly’s sleeping brain.

This is more than an exercise in curiosity. “I think an animal as simple as a fly can be used to understand the evolution of consciousness,” van Swinderen explains.

His theory is that creatures that move – and so must actively negotiate the world – may possess some form of consciousness. He thinks dreams may have a role in helping these creatures reduce real-world mistakes, by running scenarios while asleep.

There have been other exquisite studies into dreams in animals, such as a 2000 study by neuroscientists at the University of Chicago that found evidence to suggest zebra finches practise intricate melodies in their sleep.

Just because flies cycle through a stage of sleep that looks like REM, there’s no guarantee they’re having dreams. But if it is true, it could hint at the existence of a kind of subjective experience – what some researchers call “phenomenal consciousness”, and others refer to as “sentience”.

In 2012, a group of neuroscientists at a conference in Cambridge co-wrote a document titled the Cambridge Declaration on Consciousness. That document, which van Swinderen helped edit, posited that mammals and birds – and potentially other creatures – had independently evolved consciousness. Consciousness, it argued, was not the lonely realm of the human.

The declaration was a boon to animal rights groups, but consciousness has now become a debate of scale, with scientists trying to pinpoint where in the evolutionary tree it begins. Insects are the final frontier.

Lars Chittka, author of the book The Mind of a Bee and a zoologist at Queen Mary University of London, suspects bees – and possibly other insects – are conscious and experience emotions.

“It’s formally impossible to ascertain whether anything other than us humans is conscious, because animals can’t verbally communicate about their inner experience,” he says. But Chittka’s many experiments with bees have indicated, among other things, a capacity for optimism and pessimism, modulated by the release of dopamine; evidence of pain; and even play-like behaviour.

“All of that taken together I think nudge probability in the direction that indeed you have a sentient being in front of you.”

Neuropsychologist Nicholas Humphrey – who has recently published a book, Sentience, on the topic – is unconvinced.

“My current view about consciousness is that we really have to divide off cognitive consciousness, a computational way of dealing with information … and what we call phenomenal consciousness,” he says.

“And while the majority of philosophers and scientists think [phenomenal consciousness is] where consciousness began, and other forms of computational and intellectual consciousness arrived later, I think it’s the other way around.”

Humphrey believes phenomenal consciousness is “a very sophisticated brain operation”. “I don’t think we need this kind of qualitative experience until we become social creatures who need to think what it’s like to be me and what it’s like to be you,” he explains.

Humphrey is quick to point out van Swinderen’s and Chittka’s bodies of research are “amazing”: “I think what we’re discovering is how unbelievably complicated and complex a very small brain can be.”

These studies into insect consciousness have implications for the progress of artificial intelligence and raise heavy ethical questions.

Macquarie University neuroscientist Andrew Barron, director of the Macquarie Minds and Intelligences Initiative, works closely with honey bees. He has mapped decision-making processes in bee brains as they manoeuvre from flower to flower. The ease with which a bee negotiates uncertainty in the physical world has so far eluded AI.

“In terms of real-world applications, we can go ahead with this biologically inspired model for making smart, dynamic decisions,” he explains. “And we could end up with robotic systems that are naturally risk-averse and very accurate in how they process information.”

The race to develop software that possesses the flexibility of biological intelligence is on. In October last year, researchers in Melbourne showed that 800,000 neurons cultured on a computer chip could be taught to play the computer game Pong. None of the researchers involved in that study believes their system displays anything resembling consciousness, but the direction of travel means many AI developers will be looking to emulate the biological in some way.

If it’s possible, as van Swinderen and Chittka suspect, that insects might be conscious, what would scientists’ ethical responsibility be if they did develop a machine that possessed a bee-like intellect? And how could they be sure it wasn’t conscious when there’s no way to prove it?

Van Swinderen acknowledges it’s almost impossible to tell, but he’d be looking for signs of digital sleep as an early warning. “If it needs to be offline, in its own virtual reality for a bit to be able to maintain a level of flexibility, it’s a bit of a weak clue but I’d be looking for that, because it’s so prevalent in evolution,” he says.

In March, a group of AI researchers and others involved in the field penned an open letter warning AI posed an existential risk to humanity at least as severe as pandemics and nuclear war. Those concerns mostly involved the risks of humans weaponising AI, but some experts are afraid such a system might become uncontrollable. The moral panic over whether AI might one day “wake up” is embedded in culture.

In Sentience, Humphrey tackles this question, writing that while people often assume once robots reach a certain level of complexity they’ll simply become conscious – as if out of thin air – he thinks consciousness evolved through natural selection because of specific social pressures on human beings that made it more likely. Those pressures are unlikely to be present in machines.

Barron believes consciousness is altogether simpler.

“I think consciousness is a property of how our brain works, but you need a brain that is doing a specific type of computation,” he says. “We don’t need magic mysteries about it.” He doesn’t see why it shouldn’t be possible to build a consciousness, with the right blueprint.

Adding to the ethical quagmire is the question of how we as a society should respond if insects are found to have subjective experience.

At least a trillion insects are killed for food and animal feed each year, and the insect protein industry is tipped to grow in response to the twin pressures of climate change and population growth. An estimated 3.5 quadrillion insects are thought to be killed or harmed by pesticides in the United States alone annually, experiencing paralysis, asphyxiation or dissolved internal organs.

Governments are adjusting their animal welfare approaches to other creatures. Britain, for example, included lobsters, crabs, octopuses and related species under its Animal Welfare (Sentience) Act 2022.

Chittka hopes understanding our tiny invertebrate cousins in this way will help to protect them.

“If people recognise there is the potential that there are very alien but still conscious minds out there in these insects around us, and that these are likely to have a capacity to suffer, I think there is more hope.”

This article was first published in the print edition of The Saturday Paper on June 17, 2023 as "The possible dream".

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