This episode explores the scientific and ethical challenges of measuring consciousness, especially in individuals with severe brain injuries or vegetative states. Neuroscientist Adrian Owen’s work with a woman in a vegetative state revealed that brain activity during imagined actions—like playing tennis—mirrored that of healthy individuals, suggesting she was conscious despite being unable to move or speak. Similar results have since been observed in 20–25% of such patients, prompting interest in new methods like the imagination test and brain stimulation with magnetic fields. These techniques aim to detect neural coherence as a marker of consciousness. However, researchers emphasize that no single test is definitive, and multiple methods must be combined for meaningful results. The technology remains complex and costly, limiting immediate medical use. Ethical concerns are profound, especially regarding the moral status of fetuses, animals, and future AI systems if they are found to possess consciousness. Experts agree that while these tools offer valuable insights, they also raise critical questions about human rights, animal welfare, and the boundaries of artificial intelligence. Ultimately, consciousness remains a deeply personal and elusive concept—central to human experience and identity—driving both scientific inquiry and philosophical debate.
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You're listening to Shortwave from NPR.
Hey Shortwaveers, Regina Barber here with our next installment of Shortwave's summer series,
Tech Camp. Every Monday, check the speed for a new episode about the technological frontier,
tracking down the breakthroughs, experiments, and innovations that could change everything.
And today, producer Rachel Carlson is here to talk about consciousness. Hey Rachel.
Hi, Regina. So a lot of people have been thinking about this, especially in the context of AI.
Like, is that AI models sentient? Do they have their own experience of the world?
But it's a really tricky question to answer just for humans.
So that's where we're going to start. With a neuroscientist named Adrian Owen,
he's a professor at the University of Western Ontario, and he's also the Chief Scientific Officer
at Crayos, which sells a system to assess brain health. Back in the early 2000s,
Adrian met a woman who'd been hit by two cars and suffered severe brain injury as a result.
She was in what doctors call a vegetative state. And right now, the big test doctors use
if someone's in this kind of state to see if they're conscious or not involves asking them to
look at objects or respond to sounds or move their hands. But this woman couldn't do those things.
Her eyes were open, but she couldn't respond to doctors to tell them if she was aware of what
was happening or in pain. Wow. Okay. So was she conscious? No one was sure. But Adrian wasn't content
just not knowing. So he decided to see if he could find out if she was aware of anything going
on around her. To do that, he put her in a brain scanner and asked her to imagine playing a game
of tennis. So if you or I do this exercise, Gina, it probably sounds something similar to
what Adrian thinks about. I'm on my own at the, I'm saying Wimbledon.
I'm facing my opponent at the other end of the court and I'm waiting for a fast serve.
And here it comes. I'm swinging my arm, hanging it with my right arm. It's going back to my
opponent. It's coming back to me again. I'm going at it with my left on my back hat.
Adrian's an imaginary tennis pro. So he kind of has this whole action sequence going.
I don't actually play much tennis, but I do play it in my mind quite often.
When he does this with people like you and me, healthy conscious patients, he sees activity in
their brains related to movement as if they're actually playing tennis. So what happened in this woman's
brain? He saw the exact same thing. Her brain activity was indistinguishable from a completely
walking, talking, healthy person. Wait, so she was conscious? I mean, she couldn't move,
but she seemed to know what he was asking her to do. And her brain responded just like ours would.
I know it seems pretty wild, but later studies with a lot more patients in vegetative states showed
around 20 to 25% had similar responses. That's a large percentage. Yeah, and that's why techniques
like Adrian's imagination tests are getting a lot more attention and consciousness research.
As of right now, clinicians don't have one standard way of deciding who is or isn't aware,
unless that person can use their words or their bodies. Okay. But some neuroscientists are asking
what it would mean if there was a test that did exactly that. So today on the show, measuring
consciousness, you're listening to shortwave. The science podcast from NPR.
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at Wise.com. Teas and sees apply. So Rachel, we're talking about consciousness, but I'm not
totally sure I know exactly what that word describes. So you're not alone. There's not really one
answer, but when I asked researchers, I sort of got answers like this. What's consciousness?
It's the experience we're having right now. What it is like to eat a chocolate or to look at the
blue sky. Everything that fades when I fall into dreamlessly. I think the best way to define
consciousness is the way you might go about defining jazz. You don't try and give a musical
definition in terms of theory or rhythm or court progression or instrumentation. You play, you know,
you play some jazz. What it is like to be you, and what it all really boiled down to was this.
Without consciousness there really isn't anything at all. I mean, life matters to us because we are,
we're capable of having experiences. So consciousness is everything, like our experiences, our emotions.
Yeah. Okay. Pretty much. It's not just one thing. Like even in your daily cycle or my own,
we're going through different stages of consciousness, right? Like I'm dreaming or I'm starting
to wake up or I'm falling asleep, you know, it's a spectrum. And that's exactly what makes the idea
of deciding who is or isn't conscious so hard, even for you and me. And especially for people
in vegetative states, like the woman we heard about earlier, when they can't just tell us what
they're experiencing or other states like Komas. Yeah. So Anilseth, a neuroscientist at the
University of Sussex in the UK, says if we could understand this better or if we could have some
kind of measurement, it would completely change how we understand people in the position like
that woman, her quality of life. We humans, we moral agents in that we make decisions about how to
treat other systems. And one of the criteria for making those decisions is whether or not
that other system is conscious or capable of consciousness. But like you said earlier,
researchers are experimenting with new ways to get information about these different levels of
experience, right? Yeah. So we heard about one of those ways that's the imagination test. Yeah,
the tennis. Yes. That's like the tennis test we heard about from Adrian earlier asking people to
imagine doing something and then just seeing how their brain reacts. Okay. Another method combines
two things. One is a magnet that stimulates the brain. And then the other part is a measurement
of activity in the brain. I want to hear about this magnet. Yeah. That magnet is basically meant to
disturb a brain a little bit because neuroscientists know that if you disturb a healthy brain with
something like a magnet, it responds. I'm trying to imagine this. So it's like if you touch a block
of jello and it like jiggles. Yeah, there's like the cause and effect. So the idea was to try this
with people in vegetative states to see if their brains responded like healthy brains. So it's a
little bit like binding on the brain with an electrical hammer and you listen to the echo.
I talked about this with one of the people who've been at the forefront of this project. Marcello
Massimini, a neuroscientist and a doctor, and he says once you disrupt the brain a little,
you measure the echo it creates. You are kind of looking for an orchestra that is well trained and
you know super cohesive with different instruments and different partitions. So in theory, the more conscious
someone is, the more complex and cohesive that symphony would sound. So it's sort of like all the
different regions of their brain are working in harmony. But if they are disconnected, they don't
hear each other. They don't play along together. You're going to have something that is maybe just
local and not propagated to the orchestra. Marcello co-founded a company building a device
that does this. So what do other researchers think about this test? The ones I spoke to were
generally pretty excited and optimistic about it, which was actually quite surprising for me because
scientists who study consciousness usually disagree a lot. I find it to be a very impressive test
for consciousness, but it's one out of several. Also the other tests that we have kind of to our
disposal are also quite good. And I think that only by combining those tests and comparing between
in them will we be able to
to actually get closer to being able to detect consciousness.
That's Leade Moudric. She's a professor of neuroscience and psychology at Tel Aviv University
and she also co-directs the CFAR Brain Mind and Consciousness program with Anilset,
who we heard from before. Okay, so she's saying this is one option, but we should use it with other
things, things like that imagination exercise we heard about earlier. Exactly. Okay. Plus,
I will say most of these tests for consciousness are many years away from being used regularly.
Oh, okay. You know, they're complicated, they're expensive, and they're not the easiest to
immediately apply in medical settings. I know we talked about the medical reasons a
test for consciousness would be helpful, but I imagine this could go south like pretty quickly,
so are there any reasons we shouldn't have tests like these? I definitely had that question too.
I was thinking about like IQ test and some of the ways those have not always been used for good,
and Leade said it's true. There are some really big ethical questions here since we often associate
having consciousness with having moral worth. Every question we ask about consciousness is loaded
with ethical implications and definitely being able to detect consciousness has wide implications.
So think about being able to detect consciousness in fetuses at what point in pregnancy
does the fetus become conscious? That's a huge question that has a lot of implications.
It's really a question that once we have an answer for ourselves, for humans,
it immediately has really broad applications beyond people. Being able to differentiate between
animals who are conscious and animals who are not, then also in AI or one day in robots,
what happens when we start thinking about those robots as, you know,
entitled to some ethical considerations when they become conscious?
It's honestly overwhelming when you start unraveling it. Yeah. So I also talked to a philosopher
at Monash University. His name's Tim Bain. He co-directs the C far-brain mind and consciousness program
with Anil and Leard. And he agreed with Leard, but he also made this point.
When we treat certain animals in certain ways or certain machines in certain ways,
we're assuming that they are all around conscious. When a surgeon starts surgery
on someone who's had a general anesthetic, they're assuming that the person's not that they're
not experiencing pain. And so you're better off doing your best to provide those assumptions
with as a solid, as theoretical scientific basis as you can.
Okay. So we're always kind of making these assumptions anyway. So having a better way to measure
it means that we'll have more data to work with. Yeah. That's kind of a version of what everyone
I talked to said. And it does make sense to me. Like if you think back to the story, Adrian Owen
told us at the beginning of this episode, doctors were making assumptions about what that woman was
or wasn't experiencing like whether she was in pain or whether or not she was aware of
what they were doing or saying around her until Adrian did this tennis experiment with her.
He told me that some patients he's talked to who've regained their ability to speak or move
later remembered everything that was happening around them. What? And that's definitely not true
for everyone. But I do think it points to how important consciousness is when it comes to these
very real decisions about someone's quality of life. Plus Gina, everyone I spoke to was thinking
about future uses for things like this, you know, like the tech camp of it all. And I feel like
we're at this juncture in time where humans are really interested in exactly what it is that
makes us human. And if or how we're different from things like AI or robots and consciousness is
an emerging tension point in that discussion. So I kind of expect to see a lot more research in
this area in the coming years. Rachel Carlson, thank you so much for bringing us the story.
It's made me think about consciousness so much more. Thanks Gina. This episode was produced by
Rachel Carlson and Hannah Chin. It was edited by our showrunner Rebecca Ramirez and it was fact
checked by Tyler Jones. Robert Rodriguez was the audio engineer. I'm Regina Barber. Thank you
for listening to shortwave from NPR. Support for this program comes from Texas Mutual Insurance Company. A workers
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Podcast Summary
Key Points:
Neuroscientist Adrian Owen used a brain scanner to test a woman in a vegetative state by asking her to imagine playing tennis, revealing brain activity consistent with conscious awareness.
Similar brain responses were found in 20–25% of patients in vegetative states, suggesting that consciousness can be measured through neural activity, not just physical responses.
Techniques like the "imagination test" and brain stimulation with magnetic fields are being developed to assess consciousness in individuals who cannot communicate.
These methods rely on detecting brain coherence and connectivity, with more conscious individuals showing synchronized, integrated brain activity.
Researchers agree that no single test can definitively determine consciousness, and combining multiple approaches is essential for reliable results.
Ethical concerns arise regarding the application of consciousness tests in fetuses, animals, and artificial intelligence, raising questions about moral status and rights.
Current tests are complex, expensive, and not yet ready for routine medical use, though they offer promising scientific and clinical insights.
Consciousness is central to human identity, experience, and moral decision-making, making its study vital for understanding life, care, and technology.
Summary:
This episode explores the scientific and ethical challenges of measuring consciousness, especially in individuals with severe brain injuries or vegetative states. Neuroscientist Adrian Owen’s work with a woman in a vegetative state revealed that brain activity during imagined actions—like playing tennis—mirrored that of healthy individuals, suggesting she was conscious despite being unable to move or speak. Similar results have since been observed in 20–25% of such patients, prompting interest in new methods like the imagination test and brain stimulation with magnetic fields.
These techniques aim to detect neural coherence as a marker of consciousness. However, researchers emphasize that no single test is definitive, and multiple methods must be combined for meaningful results. The technology remains complex and costly, limiting immediate medical use.
Ethical concerns are profound, especially regarding the moral status of fetuses, animals, and future AI systems if they are found to possess consciousness. Experts agree that while these tools offer valuable insights, they also raise critical questions about human rights, animal welfare, and the boundaries of artificial intelligence. Ultimately, consciousness remains a deeply personal and elusive concept—central to human experience and identity—driving both scientific inquiry and philosophical debate.
FAQs
Consciousness is defined as the subjective experience of being aware—what it feels like to eat chocolate or look at the sky. It's not a single thing but a spectrum of awareness that includes emotions, thoughts, and sensory experiences.
Researchers use brain scanning techniques like imagining a tennis game or applying magnetic stimulation to check brain activity, which can reveal whether a person is conscious even if they can't respond physically.
When she imagined playing tennis, her brain activity matched that of healthy individuals, suggesting she was aware of her surroundings—even though she couldn't move or speak.
Yes, methods like brain stimulation with magnets and measuring the brain's response (called the 'echo' response) are being explored to assess consciousness by observing brain coherence and connectivity.
It helps determine a patient's quality of life and ability to experience pain or awareness, especially in vegetative or minimally conscious states, guiding care decisions and ethical treatment.
Tests could lead to debates about when a fetus or animal becomes conscious, or whether AI or robots might be considered conscious, raising questions about moral rights and treatment.
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