105 | Ann-Sophie Barwich on the Science and Philosophy of Smell

We gather empirical evidence about the nature of the world through our senses, and use that evidence to construct an image of the world in our minds. But not all senses are created equal; in practice, we tend to privilege vision, with hearing perhaps a close second. Ann-Sophie Barwich wants to argue that we should take smell more seriously, and that doing so will give us new insights into how the brain works. As a working philosopher and neuroscientist, she shares a wealth of fascinating information about how smell works, how it shapes the way we think, and what it all means for questions of free will and rationality.

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Ann-Sophie Barwich received her Ph.D. in Philosophy at the Centre for the Study of the Life Sciences, University of Exeter. She is currently Assistant Professor in the Department of History and Philosophy of Science and Cognitive Science Program at Indiana University Bloomington. She has previously been a Presidential Scholar in Society and Neuroscience at The Center for Science & Society, Columbia University, and held a Research Fellowship at the Konrad Lorenz Institute for Evolution and Cognition Research, Vienna. Her new book is Smellosophy: What the Nose Tells the Mind.

• Web site
• Indiana University web page
• Google Scholar publications
• Blog at Psychology Today
• Talk on the Philosophy and History of Olfaction
• Twitter

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0:00:00 Sean Carroll: Hello, everyone, welcome to the Mindscape podcast. I’m your host, Sean Carroll. To anyone who is listening to this, in the future, a hundred years from now, who knows, I don’t know, a thousand years from now, how long are people are going to be listening to the Mindscape podcast. No one can tell. But this has been recorded in the midst of what is still a quarantine for the COVID-19 pandemic chasing around the world. In some places in the world, things are looking up a little bit, not everywhere. Where I am in Southern California, not really looking up right now. But what I want to talk about today is actually not viruses or pandemics, but the metaphor I just sneaked in to that little intro there. I was talking about things looking up. Turns out that if you think about it, we use these visual metaphors all the time for things that have nothing to do with actual vision. When I say that things are looking up in certain parts of the world, I don’t mean that the people there are looking into the sky or at their ceilings or anything like that. But vision is something that gives us such clear and distinct information about the world around us that we tend to privilege it over the other senses.

0:01:07 SC: So today’s guest, Ann-Sophie Barwich, is against that. She thinks that we are privileging vision too much. In fact, she is a philosopher who has decided to specialize in the sense of smell. And therefore, almost inevitably, her first book, which is just about to come out and which I can highly recommend to you, is called Smellosophy. But it’s not just about we should think this and that way, about what we smell. It’s about the fact that by thinking of other senses other than vision, we get a new window onto how the brain works, how consciousness works, how we perceive the world and think about it. And I really admire what Ann has done, because not only is she a philosopher who is blazing new ground in this way of thinking about the world, but along the way to learning how to do this, she of course had to learn some neuroscience, she hung out with neuroscientists. And at some point someone said like, “Look, you’re doing and thinking so much about neuroscience, why don’t you just start your own lab?”, which she has done.

0:02:04 SC: She is now a working neuroscientist as well as a philosopher, taking data, buying lab equipment, that whole bit. That’s the kind of interdisciplinary move that I really admire, and that’s the kind of people I like to have here on the Mindscape podcast. And I think that you’ll really enjoy the conversation; not only will you learn some new things about how smell works and what it means, but it does help to remind you of some of the assumptions that are just there in the background when we think about how the brain works and how we think about the world.

0:02:33 SC: Let me just very briefly mention, for those of you who don’t ever drop by, we do have a website for the podcast, preposterousuniverse.com/podcast, where not only can you get show notes for the episodes and links, so for example, you can get a link to Ann-Sophie’s new book, but also there are full transcripts for every episode, which are paid for by income from the Patreon that we also have, and you can find the Patreon also on the website. So don’t just listen to the podcasts. If you have the chance, check out the website, there’s a bounty of information there. Look at it, smell it, whatever it is you want to do. So with that, let’s go.

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0:03:25 SC: Ann-Sophie Barwich, welcome to the Mindscape podcast.

0:03:28 Ann-Sophie Barwich: Well, thank you for having me.

0:03:30 SC: So you’re making a claim in your new book, and in your work more broadly, for the importance of smell, both scientifically and philosophically. So, let me start off just by letting you give the sales pitch for smell. You make the case that we tend to privilege vision and sight when we talk about how our minds comprehend the world, and you think that we should be paying more attention to smell.

0:03:53 AB: Indeed I do. So most of our understanding of mind and brain is based on the visual system, and for two reasons. One reason is that, well, we see things that’s immediate to our consciousness. So if we talk about objects of perception, perceptual objects, these kind of things, we think of visual things, but you can’t really apply the same notion so easily to smell. So if you think of something, well, what’s the boundary of a smell? Well, what’s the discreteness of a smell? And even if we think of something like orientation, it does make no sense to say, “Well, there’s an orientation of a smell.” And also the way we talk about mental stuff, it’s always about pictures, it’s always about images, of thought images, these kind of things. And I thought, “Well, hang on a second, do these ideas also apply to smell?” And it seemed to be, first of all, that this was a very neglected area for a long, long time. And then furthermore, that actually we have to rethink these central concepts and perhaps that tells us not only about other senses, but also some new things about vision.

0:04:58 SC: Okay, yeah, and so, maybe we can compare it to vision a little bit. I guess that the typical person would think of vision first as the thing that gives us the most accurate picture of the world. In fact, just using the word “picture” is sort of prejudicial there. Is your claim that you get an equally or more accurate view of the world through smell? Or just it’s a different view, and one that it should be given equal prominence?

0:05:25 AB: That’s a very good question, because I have a little bit of an unorthodox view. I think that the nose is actually harder to fool than your eyes. I think it’s much more accurate, actually. It’s very easy to fool your visual system through illusions, so this is… People who work on the visual system know that, actually. We just think smell is not so objective, or not so real, or gives us no sufficiently material or substantial account of the world because it seems so subjective. We all smell things differently. Not just you and I would smell the same odor potentially as different kind of qualities, but even you, yourself, the same smell varies over time. Whether you smell it now, or later, etcetera. And this actually is a good point about smell because it is not there to have just the stability of always the same quality for the same stimulus, but always in relation to your own physiology and to the environment. So it’s an incredibly accurate measure of context. And it often is harder to fool than visual illusions. A visual illusion, where actually you can quite often fool the retina by by having two images that are different, but that elicit the same mental image.

0:06:38 SC: Yeah, I mean, we think that one reason why there are visual illusions is because our brain does a lot of processing on what we see. It’s not this very simple picture that we’re just video cameras recording reality, but we get some visual stimulus and then we put it together in some complicated way. And what you’re saying is that it… I think what you’re saying, let me paraphrase, sometimes we can trick the brain by using its favorite ways of putting things together from the visual input, but it’s harder to trick it from its olfactory input.

0:07:10 AB: Absolutely, and what is cool to know is that in the 19th century, one of my favorite historical scientists, Hermann von Helmholtz, he actually made that claim already. He said, “Well, actually a lot of visual images have the same pattern on the retina and in the brain, and so we have differences. Therefore, we have to move to figure out the differences between images.” And with smell, for instance, it’s actually much harder to fool because not only are you in direct contact with the chemicals, but also the context is part of the reason why you smell a certain thing as a certain thing.

0:07:47 SC: Right. I can see why the science of how this works. The science of how you go from the sensory input to the reconstruction of reality in your brain is fascinating, but, you, at least, started life as a philosopher. You seem to be a rare person who is becoming more of a scientist over time and less of a philosopher, but… Maybe not less of a philosopher, but at least more fraction of your time is spent literally in a lab, but… So what is the particularly philosophical impact of this? Is this really changing how we perceive reality or something like that?

0:08:20 AB: Oh, absolutely, actually. So one of the things that I always found fascinating is, how can we actually think of objectivity, of reality, if we all perceive it in a different way? And this is often a cause for relativism that, well, we all have different perspectives, and we can’t have an objective truth or ground truth. And I thought, hang on a second, maybe the question is ill-phrased. Maybe the question is mis-framed. And smell is a beautiful sense to think about that, because it has been neglected for the whole time. It’s kind of a Cinderella of the senses, so to speak. It’s always been… Philosophers had just bad things to say about it. Well, it has nothing to do with cognition, it’s like this subjective sense. It’s a [0:09:03] ____ sensation. It’s unimportant. My favorite quote, actually, is by Immanuel Kant, who said, “Well, it’s the most dispensable and ungrateful sense, and it doesn’t give you much pleasure because there are many more stinky things than good ones.”

0:09:19 AB: And I thought, hang on a second. A, why is Kant a good authority on pleasure? This is the guy who possibly was the least funniest person on Earth. Smart, yeah, but not really funny in that sense.

0:09:31 SC: Yeah.

0:09:31 AB: And this prompted me, all these negative images about smell, it’s just something neglectable. So well, hang on a second, is that really true? And then to look at smell, a lot of philosophical questions opened up. When it comes to how many senses are there, even just how many senses of smell are there. And actually, there are two. And my favorite example of why smell is really interesting, also from a philosophical perspective, is when you would ask people, “How many sense of smell do you have?” They would look at you as if you’re a little bit crazy and say, “Well, one, of course. You’ve got one nose and you smell a smell.” So what they personally thought. But actually it’s two. So everything you call taste, when you taste something, or strawberry or mint or vanilla, etcetera, that is actually smell. And we know that because if you have a cold, you can’t smell it. You can’t smell and you can’t taste a thing.

0:10:25 SC: Yeah.

0:10:26 AB: Even Immanuel Kant must have had colds and he still didn’t get the causality right. So you have a sense you don’t know you have.

0:10:35 SC: Well, this is one of the things I wanted to get into, but there’s no reason we need to go in order. So help me out understanding the relationship between taste and smell. When I was in grade school and I learned about the five senses, I learned that taste and smell were different things. And then when I’ve grown up, people are increasingly telling me that, in fact, taste depends on smell. Is that completely accurate, or is it just a slight exaggeration or completely wrong?

0:11:03 AB: No, actually, this is the crucial bit. Well, we often say that taste depends on smell, but I would actually twist it around even more. So taste is really what you perceive through your taste buds. And if you look at your tongue, you’ve got salty, you’ve got bitter, you’ve got umami, sweet, sour, and apparently, now also fat, actually. So a couple of years ago, the fat taste receptors were discovered. But all the other things you actually perceive as taste such as, as I said, mint, strawberry, liquorice, all these kind of things, there is no mint receptor on your tongue, so how can that be your perception of a flavor? And this is the phenomenon. So flavor is what you perceive through the nose. And you might wonder, “Hey, how does that work?”

0:11:49 AB: So what happens is, when you chew, you’ve got the odor molecules released from your food. And they travel through the back of your nose, through the back of your mouth, your throat, to the open space into your nose. It’s being pushed up to the nose, to the epithelium with the air from your lungs. So they hit the epithelium and this is why, when you have a cold, you don’t smell anything. And sadly, this phenomenon has become a very, very, very accurate and modern topic through COVID, because one of the key symptoms is that people suddenly stop smelling.

0:12:21 SC: And tasting, right?

0:12:22 AB: And therefore tasting. Yep. Precisely.

0:12:23 SC: Yeah. Well, okay, I think… So this is an important moment in my life because I think that actually made perfect sense to me, and I’ve never understood it before. So the taste buds are a coarse thing that give you senses of just a few different textures in some sense. Textures is not the right word, but salty and umami and sweet and so forth. Whereas the details of the flavor are coming through smell, is that safe to say? Is that right?

0:12:52 AB: Absolutely, yeah, and it’s quite fascinating to think how that all interacts, because it shows wonderfully how integrated the senses interact. Because when we taste something, there’s also texture, and we are influenced by the crunchiness, also the sound, so to speak. And there have been some great studies looking at multisensory, cross-sensory phenomena, and of course, smell is one of the key aspects of that issue.

0:13:18 SC: Okay, okay. This is great. That’s very good. So maybe this is the right time to back up a little bit and talk about the neuroscience of smell. And maybe it would be useful to contrast it with the neuroscience of vision, which I’m sure many listeners are not completely up on. But I was always surprised to learn… I was surprised to learn it the first time that we really do have a little part in the brain, in the visual cortex, that basically maps onto our visual field in a one-to-one correspondence. It really is like the detector of a video camera. But nothing like that is true for smell, right?

0:13:53 AB: No, this is one of the things that I found most fascinating. So it’s of course a very simplified picture of vision as well, and I often get a bit of pushback by visual researchers who say, “Well, it’s a bit more complicated than that.” And I grant you that, but the point is that smell is even more complicated. And that’s the really cool thing, because it prompts us to rethink, are these specific organizations of the visual cortex, where really you’ve got certain activations in the retina, and you can trace where they project to in the visual, in the primary visual cortex. And there have been some really cool studies on monkey brains, where they had a monkey look at a certain kind of stimulus, an image, and then later they could actually, through some metabolic traces, they could dissect the brain and show precisely that image as the monkey saw it in the visual cortex, and it looked precisely like that.

0:14:50 AB: So as you say, precisely as you say, sudden you find this map of the world in the visual cortex. And this is of course a very, very strong image. It sounds fascinating. It gives us this idea of that there is some reality reflected in the brain. And if we just know how that image is there, we have this objectivity, we’ve got this grounding in reality. But smell doesn’t work like that. It’s this mosaic. It just fans out, it’s beautiful, but there is no order. And also, it’s different across different individuals. So you might wonder how does the brain then know what a smell is, what kind of smell it is, how similar it is to another? And that’s a question that’s been engaging many researchers, scientific… Olfactory scientists over the past couple of decades. And the short answer is, we still don’t quite know, but we’re getting there.

0:15:43 SC: It makes sense to me, coming at it as a physicist, as I usually do. There’s a kind of linearity in vision, there’s the location you’re looking at, the brightness of what you’re looking at, and the color. And you can vary all of those smoothly. Whereas with smell, it’s really more of a lock and key kind of thing. You have different compounds that interact in complicated non-linear ways with your nose and your brain.

0:16:10 AB: Oh, yeah, absolutely. I think this is what fascinated me the most is because, as you say, there seems to be this linear trajectory in the visual system. And of course within that trajectory, you can always add more complexity. But with smell, it already starts at the molecular level. So when you smell, you actually perceive airborne molecules, volatiles. And what is really cool is that, even just a single molecule, it’s not just simply one smell. So if you think of the comparison to vision, there you perceive electromagnetic wavelength, which is a low-dimensional stimulus. So you really have the receptors in your eyes chopping up the spectrum into specific bits. So you’ve got the blue, the green and the red receptors, and the further colors come out of a combination from these receptors.

0:17:02 AB: Now, with smell, it’s a bit more complicated, because one molecule doesn’t just have one smell. So it’s not just you see… In vision, you only see the red. You don’t see the blue at the same place where the red is. But some molecules, if you smell them, they have more than one quality. So there are some molecules, if I give you cis-3-Hexenal, which is one of my favorite molecules, it smells of fresh cut, green grass. But more than fresh cut green grass, it also has a leafy note, an earthy note, so there are different kind of notes and qualities to it. And that’s just a single molecule. But most of the things you smell are mixtures, hundreds of molecules. Coffee has about 800 molecules. So there is much more going on, and it’s not that you have one receptor just detecting one molecule, but you’ve got a combinatorial explosion.

0:17:49 AB: So what I find really cool is that you’ve got one molecule can be detected by a variety of different receptors and one receptor can detect different parts of different molecules. So this is why we can smell so many different things, and furthermore, we can smell things that haven’t existed in nature before because we can synthesize molecules that do not exist, that do not necessarily have a natural origin from a plant or something, and that might not have any quality previously known to mankind, and still, we will smell it immediately. We don’t have to grow or evolve new receptors, otherwise perfumery would be pretty in a bad shape, let’s put it that way.

0:18:32 SC: Yeah, and if you just do… The nonlinearity shows up in the sense that if you just change one atom in a molecule, it can smell completely differently, unlike if you change the wavelength of a photon by a little bit, it looks almost exactly the same.

0:18:43 AB: Yeah, absolutely. And really, not just even smelling slightly differently, but being a complete different quality. So with some molecule, if you change a small thing, it goes, for instance, from pear to banana, so a completely different quality in comparison. It’s quite striking, and some molecules also have directly two qualities. And there’s one example, which is one of my favorites, is enantiomer. So these are molecules that are identical in shape, but they are mirror imaged, so you can’t superimpose them. And there’s one case, some smell alike and some don’t. And there’s one, the S and the R carvones, and one smells of mint and the other of caraway. So completely different. It’s quite striking.

0:19:30 SC: When you say that something smells of mint, should I imagine that that compound actually appears in mint or in the scent of mint, or is there some family resemblance somehow?

0:19:40 AB: Oh, you’re asking one of my favorite questions, because the answer is yes and no. So there’s some molecules which have…

[chuckle]

0:19:47 AB: I know. This is the philosophical answer, yes and no. But there are some molecules which are very, very similar in structure and they have a similar smell, but you also have the opposite, that you’ve got molecules very, very similar in structure with completely different smells, and also molecules that have completely unrelated kinds of microstructures, but very, very similar smells, the same kind of category. My favorite example is musk. So musk is an ingredient that’s very popular in perfumery. And you have some musks that are, for instance, that have a cyclical compound, others have nitrogen in them. So, there’s no similarity between these molecules and yet they’re still part of the same quality group.

0:20:32 SC: Right, right. So, does that mean that the wine people or the whiskey people or the coffee people are not crazy when they taste these, “Here’s the scent of barnyard and pomegranates and pencil shavings.” There really is some science that would back these up, the plausibility of actually detecting those objectively?

0:20:52 AB: Absolutely. So you mentioned my very example, namely wine tasters. The first time… I’ll be honest with you, the first time I saw wine tasters, I thought, “They can’t possibly smell that.” They smell the wine, they shake it a little bit, they stir it a little bit, swirl it, and then they go with all these descriptors from, “Oh, this has kind of vanilla in it, and oak, and… ” In fact, there is no oak tree in this wine, so how can you smell that? And I just smell red wine, it’s wine. I was very unsophisticated back then, and I thought, “I want to know what’s going on here, I want to learn what these people can do.” And this is where I realized, “Oh, hang on a second, this is an incredibly cognitive process, this is highly analytic and really kind of a Sherlock Holmes deductive way of perceiving.”

0:21:39 AB: I mean, wine tasters, especially experts of many years, they do this really not just for years but decades to get to the point where they can, in a minute, tell you what wine it is, which vineyard, which year, and all these kind of things. And it’s not wizardry and it’s not some kind of con-artistry. They have a beautifully cognitive way of doing that. And there is a movie for the listeners actually who want to Google that called Somm. A couple of years ago, it’s on Netflix. And, there’s one scene you can find directly, by a sommelier called Ian Cauble, who in one minute, deduces the kind of wine. And, he talks faster than I do even. And you think, “How can he come up with it.” And, then you just have to look at what he does, because he doesn’t just smell and say, “Okay, this is the Riesling from so and so.”

0:22:34 AB: He first holds the glass at a 45 degree angle, and you wonder why is he doing that? It looks very posh, but that’s not the reason why they do that. He looks at the edges of the wine to see, “Well, how does it actually reflect the light? Is there any oil film on it?” That gives you already an idea of what kind of wine it is based on the color, based on how viscous it is. And then you see him swirling the glass, and the reason for that is that you basically increase the surface of the wine and you’ve got a broader bouquet coming out of it, especially more lighter notes and qualities. And, that’s how you start to develop some first hypothesis. And then he smells it again, and they just spout out these words which make no sense quite often to anyone who’s just listening. And in that scene, he even goes like, “Well, there’s lime candy and lime zest,” etcetera.

0:23:28 AB: And, he only mentions three, actually. He doesn’t give you that many different descriptors. He only gives you three because there’s also a biological cap at how many things we can instantaneously detect or identify in a mixture. And then he breaks it down even further, because then he focuses his mind on specific qualities, while his idea in his mind, it could be this wine or it could be that wine. They have a library of wines they learn to recognize over years, over decades. And at some point, he starts the tasting to see how much tannin, what’s the acidity. So, it’s really just a step-by-step. It’s not just sniffing and knowing what wine. It’s really, actually getting rid of all potential things it is not and honing in on what kind of wine it might be. Like, go through a mental library of potential wines.

0:24:19 SC: Karl Popper would be very, very happy at this technique. They falsified all the different bottles of wines that it could be. But I’ll also mention, Mindscape listeners know that we had an episode on wine tasting with a local sommelier, Matthew Luczy, and he talked about exactly the process that you do go through. The first thing you ask, “Is it a thin-skinned grape or a thick-skinned grape?” So, it’s not magic or BS, there really is some science there. But, you make a good point, which is that you train yourself, you can get better and that extends beyond sommeliers. The sense of smell, you make a point in your book, is one that we can learn to be better at.

0:24:58 AB: Absolutely. So people often think that sommeliers or perfumers, they must have these super noses or some freakish powers. No, not at all. They actually have normal noses. This is something everybody can start to get better at. And there have been also some interesting studies looking at people’s learning how to smell. Doing smell training every day for 20 minutes and after six weeks, which is very, very fast, they could already record changes in the thickness of the cortex, so it really changes your brain.

0:25:32 SC: Oh, wow, okay, so I thought you were going to say that they had really picked up some skills, but you could actually physiologically measure how they had changed.

0:25:39 AB: Oh, yeah, they also started to smell better, in terms of detecting smells, not just smelling better themselves. But yeah, you could actually really show that in the brain. And that is what I found so fascinating. It’s not just that it’s… It’s this integration of on the one hand, a cognitive skill, and on the other hand, you can trace it in the brain. This is something that has a profound physiological mechanism. You can study it.

0:26:04 SC: Yeah, I want to get into a little bit more the specific science of what happens when someone smells something. So, it starts in… Tell me where it starts, in the nose or in the olfactory bulb, is that in the brain? And there’s both the chemistry of how you physiologically detect the chemical and then there’s the neuroscience of how you interpret it.

0:26:24 AB: Precisely. So the olfactory pathway is beautiful because it looks pretty straightforward; however, it turns out a bit more complicated than that, but it’s three steps, basically. The first step is that you’ve got the molecules interacting with the epithelium in your nose where the receptors are situated in the sensory neurons, where they interact in this combinatorial fashion. And that signal is then sent further to the olfactory bulb, which is at the frontal lobe, right at the front of your brain. And it’s really really… It’s just one synapse into it, and what is really cool is that you must imagine that you’ve got millions of cells in your epithelium, detecting all these cells in a combinatorial fashion. So you’ve got one molecule hitting a couple of, let’s say, 10, 20 different receptors activating them. Now, imagine you’ve got 800 in coffee. Imagine what kind of mosaic explosion on your epithelium must happen. So how does the brain know where it’s coming, what and what’s it from etcetera?

0:27:30 AB: The real cool thing is that the second step, there’s a beautiful engineering trick of the olfactory brain. Namely, you’ve got every sensory neuron expresses only one receptor. So there is already some order. And then the next thing is that all these sensory neurons, which have one specific kind of receptor, humans have about 400 different types. These neurons with one receptor converge in one particular place called the glomerulus, which is a spherical, neural structure in the olfactory bulb. And so what the consequence out of that is that you actually have a spatial pattern in the bulbs. We’ve got an individual fingerprint for each molecule. That’s the second step. The third step, this is where it gets messy, is that the bulb then further projects its signal, so it sends its signal to the primary olfactory cortex, which has the beautiful name piriform cortex because it’s shaped like a piriform. And this is where the big difference between olfaction and the visual system emerges because if the olfactory system was like vision you would have this kind of map also in the olfactory cortex, you would have it maintained. But it’s not, actually it disperses, it goes in all kind of directions, it’s a mosaic, it’s mayhem, it’s chaos.

[chuckle]

0:28:47 AB: So these three steps is basically what olfaction is about. And you would think actually, “Hang on a second. If it’s so simple, what’s the difficulty?” And this was one of the things Ramón y Cajal already noted, in the beginning of the 20th century saying, “Well, olfaction might be the best model of the brain you can have because it only has two synapses straight into the cortex from the ear to the brain, the most direct pathway for a sensory perception.” So if we can crack that, we might understand how we perceive, how we think and… Well, just for comparison, two synapses don’t even get you out of the retina and vision. So this is why people will think about, “This is simple, we can do this, we march through the system and we know how it works.” And then a couple of decades later, “Well, maybe it’s not that simple, there’s lots of stuff going on here we haven’t figured out.”

0:29:41 SC: So but in some sense, can I analogize it to a big data problem? There’s an enormous amount of information coming into the nose and somehow, I don’t know, the brain does a principle component analysis and says, “Oh, yes, that smells like pencil shavings” or something like that.

0:29:57 AB: Yes and no, I like the comparison. On the one end you’re absolutely right, there is a big data problem because you’re hit with so many signals. But there’s something more towards just figuring out what the signal means. It’s also that the signal itself is ambiguous. Because what people often forget is that molecules don’t just have different qualities to them, but they also appear in different contexts. And with these contexts come different behavioral meanings. So my favorite example is an experiment that was done in 2001 by Rachel Hertz, actually, where she gave people two vials and they looked almost identical, and how that… I’ll come to in the moment how that links to our conversation, but she gave these people two vials, and one was called parmesan and the other was called vomit. And people were…

0:30:51 SC: Vomit, yes.

0:30:52 AB: Yeah, people were adamant, these are different smells, and they had a preference of course, for parmesan.

[chuckle]

0:31:00 AB: Mostly, I’m pretty sure there was always one person who went like, “Oh, no, I actually like vomit.” But people were adamant and she did that with different kind of pairs. Now, the interesting thing is it was the same mixture, it was a mixture of butyric acid. And people out of… They didn’t realize that it was the same mixture and it’s often used as, “Oh, I see, this is why smell is so unreliable and it’s just illusionary.” No, not at all, because both parmesan and vomit do contain butyric acid. You have certain molecules in different context, giving you completely different meanings, in this case, food and contaminants. So you must imagine that you have a promiscuous stimulus that just means different things in different parts, so different qualities are more prominent. So the sensory system of olfaction needs to figure out what is the context in which this signal means that, or it means that, or it means that.

0:31:52 AB: You have much more information than the brain is basically processing and bringing into conscious awareness. And then I found super interesting because it goes a little bit against the idea of a map when it comes not just the brain mapping reality, but also the mind picturing or mirroring reality in a more philosophical sense. But it’s much more about, “Okay, our brain measures basically what is there and in what kind of gradient, in what kind of concentration, in what kind of context. Is it more? Is it less?” And the mind is much more in terms of, “Okay, you basically have a contextual evaluation, you’ve got a behavioural measure that is tailored to your body, that is tailored to the environmental context, you’ve got a statistical evaluation of where you are and what you need,” so to speak, and that’s a pretty cool thing to have as a sense. And this is why smell is much more accurate actually than people think.

0:32:46 SC: I was a little bit worried that you’d bring up this example of parmesan cheese and vomit, because it’s an incredibly good example. It’s obviously the right one to use, but on the other hand, I worry that you have ruined parmesan cheese for me forever. I’m not sure how I’m going to deal with this going forward in my life.

0:33:03 AB: Yeah, I’m sorry, I ruined pasta. And the thing is, nobody has vomit ruined for them, ironically. This is something I find super fascinating. Nobody went like, “Oh, yeah, vomit, it smells just like parmesan.” Now, I can…

0:33:14 SC: Very tasty, yes.

0:33:15 AB: Yes.

0:33:18 SC: But should I think of this, I guess this is where we begin to get philosophical. So it’s the power of suggestion, in some very hand-wavy sense, but it’s also the power of context, as you said. We have a brain that perceives a certain chemical reaction, but then the words that we attach to it absolutely depend on what else we’re thinking about and so forth. And is the idea that maybe vision is the same way and it’s just as bad, we just don’t notice, or is it just, is it just, is there a lesson to be drawn about how we construct models of the world based on our sensory inputs?

0:33:54 AB: These are two good questions. The first, let’s start with the one in terms of, well, is vision just like that perhaps? Yes and no. On the one hand, I think we can learn about vision from that example, because we do have… Vision is not just simply from input to the perception. There’s a lot of stuff going on which we often call illusions, where context matters also how we interpret images. And then some visual images that actually are not well-understood because it is very contextual, such as faces, for instance. And I think there’s a good analogy between faces and smells often, ’cause they’re very individualized, we do have to learn how to discriminate them, think of, for instance, twins, where after a while, we actually figure out how they’re different, but there is something different as well. There are some similarities when it comes to context and certain visual effects, for instance, it’s much less straightforward than we often like to think, but there is something different about smell when it comes to precisely a certain form of contextuality and also the fact that it’s not just one physical thing in the world, having one kind of meaning and it’s being constructed by the brain in certain kind of perspective and variant ways. So objects are perspective and variant in vision.

0:35:15 AB: If I turned around my table here, it will still look like a table, but if I spritz an odor in different context to you, you will think it’s a different quality, a different mental object. And it’s not in terms of oh, because smells are so ephemeral and unreliable, but it just means in a different context. Your brain is focusing on different facets, on different notes of the odor and it elicits a different mental image. It’s just it’s doing something different. And that is philosophically interesting. Maybe the senses do have different functions, they’re integrated, they do work in tandem with each other, but we shouldn’t just model all the senses based on one sense, which has been vision, mainly.

0:35:56 SC: There’s a famous philosophical question, which I’ve always thought was a little bit misguided. Is the red that you’re experiencing the same as the red that I’m experiencing. Does thinking about smells instead shed any light on this?

0:36:09 AB: Oh, yes. So I have to be honest, I hate the whole Qualia debate so much. I possibly shouldn’t say this too loud, but then again, I’m not on the market anymore. But I always found this as one of the most ridiculous philosophical debates you can imagine. And the reason why smell is actually a good case to show… We’re missing the point of understanding how the senses work is through smell because quite often people say, “See, your smell is so subjective and variant between individuals, even within the same individual, so we can’t really know what you’re smelling, what I’m smelling,” but it’s actually traceable through fundamental physiological and genetic processes to explain why we have a variation. So there’s a difference between variation and subjectivity.

0:36:58 AB: Subjectivity means just like it’s in your head, there’s no relation, no grounding in objective reality, but variation just means, well, there’s a difference in perception, but we can bring that variation, we can link that variation to a certain cause or principles. And these can be studied objectively. So there really, really recently was a series of studies showing that a lot of the perceptual variation in smell links to the high, like the super extreme genetic diversity between humans with a sense of smell. So the olfactory system is one of the genetically most diverse systems. And there’s a good example. Do you like cilantro?

0:37:36 SC: I like cilantro. Yes, I know what you’re talking about.

0:37:38 AB: Good, but many people will not like it. So I often ask my students, for instance, in class, “Who of you doesn’t like cilantro?” Because there are some people who don’t perceive it as fresh, but as kind of pungent or soapy, it just doesn’t taste nice. These are mutants in the sense like in… Like, kind of X-Men mutants, they have a genetic mutation near one of the olfactory’s receptor genes. So you can actually link certain differences towards material causes, so it’s not subjective, and it shows a bit that the quest of “Is my blue the same as your blue?” that’s asking the wrong question, that’s just a pseudo problem of separating the mental image from the causal processes that actually create that image. And this is what we need to study in order to understand how it is that we perceive the world and how we also can perceive the same thing differently or sometimes perceive it the same.

0:38:35 SC: Yeah, raw tomatoes, actually, I happen to know because my wife, Jennifer, cannot stand the taste of raw tomatoes. And it turns out that there’s a mutation, that there’s a surprisingly large number of people who just can’t stand it and they get… It’s interesting because it also goes into social norms, if you don’t like raw tomatoes, unlike cilantro, which people can take or leave, but if you don’t like the taste of raw tomatoes, people judge you harshly. They think that you’re just not a good taster or a good human being or something like that. It’s weird how we go from this manifestly personal thing to moral judgements very, very quickly.

0:39:14 AB: You’re absolutely right. I hadn’t thought of that for a long time, but you’re right, we often speak of taste, of tastelessness, but I’m surprised, A, that people would judge you because you don’t like tomatoes is wow.

0:39:27 SC: Oh, yeah.

0:39:28 AB: Okay, that’s harsh.

0:39:29 SC: Well, they’re vegetables, they’re supposed to be healthy for you, right? Yeah, society… Society doesn’t like people who deviate from the norms in many ways. I just did a podcast a short while ago with Olga Khazan, who… Same thing, she did a whole thing about being weird and how society judges you very quickly, so the fact that people have different sensory responses to the world is something that gets… Becomes normative very, very quickly. [chuckle]

0:40:02 AB: Which is a shame, actually, because I think this is where smell is such a fascinating topic because you can extend your perception and your perspective on how others perceive it, and you can connect it much more by understanding where that variation comes from. Well, it’s just… It’s not just simply some whim, but you can explain it causally, and you can also extend your perception to sometimes perceive what the other person is perceiving, so if you… You can learn for instance to detect certain notes. If you have a wine taster tells you, “Oh, yeah, this Riesling wine has some petrol in it,” or, “There’s this wine which has cat pee in it.” I kid you not, these are real descriptors. And you think, “These people are weird, how can you smell cat pee in wine?”

0:40:45 AB: Well, and if you’re trained, if you… If you, for instance, what wine tasters do is they have benchmark reference odorants. They smell and they then identify in that mixture. So at some point, you will smell the pee in the wine, you will smell the petrol in the wine. It’s this distinctive smell, and you can extend your own perception, you can reach out also to how others perceive the world. And this is why… I actually like what you get… What you see is not what you get, in a certain way. To turn it around, it’s like, well, what you smell can be many different things, and you have to actually cognitively evaluate and train to figure out what different things you can perceive. You can augment your consciousness, you can augment your access to conscious perception. It’s a beautiful sense.

0:41:29 SC: Yeah, and the origin of these… I guess, I keep trying to… Want to calling them subjectivities, but individualities in how we perceive senses are very interesting. You make the point in the book that the olfactory bulb is sort of, I guess, how to just put it. The structure of your olfactory bulb, which is this intermediate step between your nose and your brain, is not purely determined by the genes that code for it, there’s a developmental aspect as well.

0:41:56 AB: Oh, yeah, and that’s one of the most fascinating things. And I noticed it’s something where people are like, “Yeah, what does it matter whether it’s developmentally-induced, kind of a spatial structure developmentally-induced, or genetically predetermined?” There is a huge difference. So you must imagine that when you have the bulb, you’ve got a spatial pattern that represents the chemical input. However, it’s different in genetically diverse organisms. So you actually have a different neural representation of a stimulus in different individuals because it’s not there to give you a map or some kind of chemical classification of the stimulus, it’s not in your brain that, like in the bulb that you would have your aldehydes next to the ketones, or you would have some odor qualities next to like rose, next to lavender, but further away from mint.

0:42:49 AB: That’s not what’s happening. You’ve got similar odor and sometimes in different areas, and different odors sometimes in more closely related areas. What’s happening here is something much more, I find subtle and cool, namely you’ve got a measure of what’s actually in your environment as kind of chemical features, how often do they occur. It’s a measure of contrast, like what’s more, what’s less? And you might wonder, “Okay, why?” Well, one of the reasons is that our chemical environment is so diverse, there’s you’re constantly surrounded by hundreds of molecules, and humans change habitats, so we often move a lot.

0:43:27 AB: We move a lot not just in terms of our daily circles and habits, but even just moving around. I mean, I’m originally from Germany, I moved to England, I moved then to Austria, I moved to New York, and then to Bloomington. Other people might move. For instance. To Singapore or to South Africa, etcetera. So there are so many different chemical environments, and the real cool thing is that after a while your nose actually changes the expression of receptor patterns to adapt to actually accommodate these different chemical environments. So you need a much more flexible system to be able to respond to something in an accurate and in a behavioral relevant manner.

0:44:05 SC: So in some sense, the sense of smell is more… We said it’s sort of context-dependent, but it’s also more context-adaptive than the sense of sight, like our vision is more or less the same no matter where we go, but the sensory input that we get from a smell does depend on the environment we’re in. Is that right?

0:44:26 AB: Absolutely. Absolutely. Spot on. And this is where I thought, “This is cool,” because this gives us a beautiful way to think about how we should model the mind as in interaction with our environment. It’s not just a mirror of things, it’s really actually how the organism is always in an interaction with the environment, and it shapes how we perceive and it shapes also the physiological basis that allow us to perceive these things. It’s quite cool.

0:44:53 SC: Yeah, and so good. So this gets into the philosophical weeds a little bit because I abstracted that part of what you’re saying is a response against or a push-back against the idea that the job of our senses is to make a map of the world, right? I mean, we have this metaphor that we are little video cameras or something like that, and there’s a three-dimensional space that we’re in and we map it out and we call that reality. And you’re saying that if we were more olfactory-centric, we would have a very different set of metaphors.

0:45:27 AB: I think so, I think so indeed. We would stop thinking about mirrors, for instance, and we would also… It wouldn’t be about that what is objective or what is real is measured by, we all perceive the same thing, we all have the same kind of image, but it’s much more about perception is not a mirror, it’s not a representation of something, but it’s an acquisition, it’s an augmentation of consciousness, and it’s a constant evaluation. So it’s not that what gets into the brain and gets mirrored, but more what’s the brain for? How do we respond to our environment? And also, how can we learn? Quite a lot of perception. And this is also the link to cognition, is we don’t just have things somehow being projected into our mind and suddenly there’s the image, we have to learn how to see things as well, which is forget that we have to do it because we were kids at some point and a lot of things where we’re kind of not conscious anymore, we don’t have it in our memory.

0:46:26 AB: But with smell, we constantly have to learn it and this is the big difference why I think it’s important to go beyond vision is because the kind of image metaphors. With vision, everything is in your consciousness right away and we track things because we can just see things moving. With smell, they pop in and out of consciousness and we have difficulties of finding out what the same thing is over different instances, so it tells us something about to what extent we have to learn to recognize things, we have to learn to even just to know what certain things are and what context they are, and I think it gives us a better understanding of to what extent what we think of our world is actually… It’s not relative in the sense that anything goes, but it is learned, it is acquired to a certain extent.

0:47:21 SC: And you make the point that there’s a sense in which the amount of sensory input we get from smell is enormously larger than what we’re consciously aware of. We filter out all the background very effectively, and that made me think of an interview I did recently with Robin Carhart-Harris about the use of psychedelics to treat patients and just for therapeutic reasons, because apparently, if you take LSD or something like that, a psychedelic that makes you see visions and so forth, the argument is that those visions are always there but our brain filters them out. What we’re doing is just sort of lowering the barriers to the ongoing noise that is in our brain in some sense. And I wonder if anyone has looked at psychedelics and smell. Do we smell more of the world or are we aware of more of what we’re smelling all the time if we lower our barriers, our filters in that way?

0:48:20 AB: Absolutely. So this is one of the things that quite often you don’t think smell is that important because you don’t pay attention to it, but as soon as you do, so as soon as you start focusing on smells and how your environment smells and you train your nose, for instance, to recognize certain wines or you go outside, you actually… It first looks at, oh yeah, because I told you that, that people might say, “Yeah, maybe,” but actually, it does lower the threshold of detection. So it’s smells you’re familiar with and you train yourself to recognize, you have a lower threshold just physiologically to detect them, so you literally learn how to perceive more of the world, how to detect more of the world, and then cognitively to get a much more subtle picture. And it’s actually not that far removed from vision, so if you, for instance, think of how many things we see just not consciously, change blindness, these kind of things. It’s kind of similar with smell, as soon as you train yourself to know what to pay attention to, you start to perceive more qualities, more things, and at least with smell the nice thing is you also lower your threshold for what you can detect, so molecules in lower concentrations.

0:49:35 SC: Yeah, it does remind me of the whole set of ideas concerning embodied cognition and the idea that it’s a mistake to think of the brain as this sort of isolated reasoning computer. Really, our brains, our minds are in our bodies and that really matters, and maybe the fact that we’re constantly smelling and for that matter, probably tasting, hearing, touching things in the world is an important part of this permeable membrane that connects us to the outside reality.

0:50:02 AB: So I’m one of those people who’s on the one hand, fond of embodied cognition, and on the other hand very critical of it. Which might sound strange given what I said about this interaction with the environment, but in a certain way I am actually quite neuro-centric. My issue with embodiment ideas is that they kind of take this brain almost also separate from the body, like well, you perceive outside your brain and the body. It’s like, well, your brain is part of the body, of course how your body interacts is going to have certain changes and effects in the brain, and in order to understand the brain, you of course have to understand the body, but I don’t think that means something in the sense of, “Oh, well, we perceive outside the brain,” in terms of that there’s any form of causal primacy of a process. There are some philosophers such as Alva Noë who wrote this book Out of Our Mind or Out of Our Heads, where he kind of makes the claim that we perceive outside the brain, we sense outside of the brain.

0:51:02 AB: I thought, well, I don’t know about that so much because I read too much Oliver Sacks and I saw what can go wrong. So I just think there are too many cases showing just because there is a very, very big importance to be placed on the body doesn’t mean that the brain is not the central organ. I’m much more along the lines of Patricia Churchland here who’s also, on the one hand, very neuro-centric and on the other hand, also takes into account evolutionary processes and embodied parts, but actually to understand the brain as the central processing organ.

0:51:39 SC: Okay, neuro-centric, I like that. That’s a perfectly, a good thing to be. I mean, there’s an ongoing… I’m sure that this is one of those questions where everyone is a little bit right, and we’re trying to figure out what the balance is. Obviously, the body matters, obviously the senses and the external world matter, obviously the neurons matter as well, so that’s a good thing to keep in mind. But does this have… Can we bring this back to questions? I know you gave your opinion on qualia, very good. The other thing that people are going to want to know about is free will. If we think that our brains are physical systems obeying laws of nature, they’re determined and so forth, is our sense of smell affecting how we reason and how we make choices? How much should our sense of smell and how we perceive the environment around us through olfaction changing decisions that we make?

0:52:34 AB: I see you’re coming with a kind of easy questions, I like that.

[laughter]

0:52:38 SC: Yeah, I know, we’re… No, look, we’re highly paid academics here. We’ve got to put forward the biggest questions, come on.

0:52:45 AB: That is a great question. So let’s put it that way, there is a lot of things when it comes to our decisions, that these decisions are definitely influenced by smell and quite often in a way that we might not consciously process. My favorite example is actually partner choice. So we often like to think, especially when we’re listening to songs and reading poetry that, you know, we’re looking for our soulmate and there’s some romantic connection about some… I like that person because she or he is funny and etcetera, etcetera, etcetera. Actually, it’s much more physical, and smell is a good part of that and it’s just not processed necessarily consciously. So there was a really cool study showing that women prefer men… They did a body odor test, so they gave women some t-shirts to smell which men had worn and they preferred the smell of men who had a complementary immune system, so there was a slight genetic difference.

0:53:46 AB: And now comes the real shocker, because women who are on the pill, who had a hormonal change, changed their preferences, they had a preference for men or the body odor of men with a more similar immune system to themselves. And I thought this might explain some divorce rates, because when do people get divorced? Quite shortly after marriage when they get rid of contraceptive routines, like oh, wow, so the love of your life might really lose some sex appeal after marriage if you change your contraceptive routine. I thought like, ouch, this is… People don’t like to hear that because we would like to think of humans as these kind of rational agents and it’s not that we’re irrational. But we are physical creatures and smell is an important part because it tells us a lot of things. It tells us about whether somebody is sick, for instance.

0:54:37 AB: It tells us also about the dietary habits of somebody, because the metabolic changes and the emanation from your skin, they tell you something about the health, the chemical emanations of another person. And that also has some good medical applications. So a colleague who I interviewed for instance for the book, Andreas Mershin, he got interested in looking at can we detect cancer through changes in body odor. So can we develop little electronic noses that record the body odor and if there’s a certain change, for instance, it would alert you to check with your dermatologist, to go to your doctor. And our nose is actually very susceptible to that, because you might know like, “Well, hang on a second, we can’t possibly perceive that.” We can, it’s just often unconscious and some people… There are a few people who actually gained some, you could say attention also in popular science, there’s the case of the British nurse Joy Milne, who became famous for sniffing out Parkinson. So she sniffs the t-shirts of patients and says, “This guy has Parkinson, this woman has Parkinson,” and she’s right.

0:55:50 SC: And so the implication of this is that when we say, “Oh, I broke up with this person because they were financially irresponsible,” it might just be because we didn’t like how they smelled or our brains, our subconscious didn’t like how they smelled.

0:56:03 AB: It could be, so you know, when you meet somebody new and let’s put it that way, that person can be the funniest, most attractive, wittiest, smartest person, if the smell is off, if it’s off, you can’t. It’s something that just closes the deal in terms of no, it just breaks the deal. It’s just something we cannot get simply over. We might adapt to somebody’s bad humor but not to somebody’s bad smell.

[laughter]

0:56:34 SC: So that would go along in the direction of saying that we’re a little bit less perfectly rational, reasonable creatures than we like to think we are. We justify our choices ex post facto but probably a large amount of our decision-making is just these factors we don’t even know about, we’re not even aware of.

0:56:58 AB: I think that’s a good point because it is not necessarily less rational, it’s just that they are factors we’re not necessarily consciously aware of, and I think there is a form of biological rationality and rationality in scare quotes to actually follow your nose in that sense, because it does tell you about the hidden things. The things that are not visible. So a lot of things, they might look nice but they might be rotten to the core. You smell your milk, you don’t look at if you take it out of the fridge. So there is… It’s not irrational to actually follow your nose. We just have a very, very kind of abstract view of decision-making when it comes to why we decide for certain things and this is where it is actually interesting to look at what are the factors that A, make it into conscious decisions and B, really influence our choices.

0:57:50 SC: Yeah, okay. I think that’s right, that’s a better way of putting it. It’s just the point being that it’s less our cognitive rational part of our mind that is doing the decision-making than we like to give it credit for, but it still might be our sensible, a rational, maximizing some kind of utility kind of decision.

0:58:09 AB: Absolutely, and to bring this back to the big question of free will, it does tell us something about how we make choices also in different contexts and how these choices have a biological basis. And how there’s always different levels to what we mean by choice, what we mean by will, certain choices might have been willed and some choices we think are willed for different reasons than potentially… That potentially actually informed the decision. I think it just shows how we shouldn’t frame any notion of free will based on what I think was the reason for my decision and should just expand the different levels of what informs our choices here.

0:58:54 SC: Okay, let me switch gears a little bit, because I can’t let you go without digging into this question of science and philosophy, right? Who better that I could talk to? I know plenty of people who got PhDs in science and then moved into philosophy, I don’t know that many who started out as philosophers and then started a lab. Maybe there are others, I don’t know, maybe you can mention some of the big names in the field, but how do you conceptualize both what the relationship of science and philosophy should be and also how it is in the real world of academia?

0:59:27 AB: Big question. I love that you’re asking that because the… You know how we often like to say interdisciplinarity, we all want to be interdisciplinary and I gotta be honest, I… Let’s be really honest. It’s very, very hard, for the reasons that you really have to learn an entire new field and you often hear people talking about putting their different hats on. Like, if I talk to a neuroscientist, I put my neuroscience hat on. If I talk to philosophers, I put my philosophy hat on. I don’t think this is the kind of interdisciplinarity that we should aim for, especially when we think of something of the integration of science and philosophy. But it’s much more to develop an integrated expertise that goes beyond just having two different hats, and more in terms of what kind of future questions can we derive through the integration. My favorite example for this, actually, Dobzhansky, who wrote Genetics and the Origin of Species at the beginning of the 20th century in the first half. And if you look at the book, there are no new data, there’s actually nothing new in that book. But the book became foundational for the new synthesis, for the integration of evolutionary theory, to have it in a united field and to integrate genetics and natural history, who really hated each other back then.

1:00:47 AB: And he did that by an integration that prompted new questions, a new perspective on how to look at the data. And this is the role of philosophy and science in integration. I actually also would like to see a little bit more in current developments. As you say correctly, there are more scientists who at some point develop an interest in the history and philosophy of science. And actually, the scientist I spend most of my time with in the lab of Stuart Feinstein, he was the kind of person, or is the kind of person. So he does a lot of science, but he became more and more interested in the history and philosophy of science, and that’s how we ended up being together in a lab. And ironically, while he’s writing more and more philosophy-oriented books, I’m starting a lab, because at some point I thought, I wanted more. We like to say that philosophy can inform science by providing rationalization of an analysis of models and conceptual foundations and clarification. I thought, “Well, that’s all very nice,” but I wanted something more productive, because there is a way in which philosophy used to be… In natural philosophy, there used to be a way of asking questions through the experimental investigation, through the material basis that are deeply philosophical in nature.

1:02:10 AB: So to bring natural philosophy back into the 21st century and have a much more integrated role of philosophy, not just as an analysis and observer, but really actually as a producer of good questions. And that’s why I’m so much of a fan of Pat Churchland because many people reduce her work of neurophilosophy to, “Oh, there’s this idea about the mind is the brain, and we have to explain mental concepts through the brain.” She did something much more radical, something I absolutely started to understand only when I was in the lab. Her big idea was really that neuroscience has advanced so vastly, so many new things came into our general knowledge that you could say that challenged traditional philosophical notions of what the mind is, what certain mental concepts such as memory are. So maybe we should ask new philosophical questions that are arising out of the contemporary developments of science, and that’s when I saw this kind of opportunity was smell. So there are lots of new questions coming out of that that are deeply philosophical. The current questions in olfactory science are philosophical questions. Starting with the seemingly simple question, what are odors? What do they represent? What kind of information is actually processed in the brain? These are deeply philosophical.

1:03:38 SC: I did, I had Pat Churchland as a guest on Mindscape, and it was interesting to me that, if I’m remembering it correctly, she said that her approach to neurophilosophy got much more positive feedback from scientists than from philosophers in general. I was surprised by that.

1:03:54 AB: Oh… I’m not, actually. I very much agree with her on that because I had the same experience. The philosophers didn’t really think that Pat Churchland was doing proper philosophy, whatever that means. And there was a lot of, you could say, disciplinary gate-keeping and it’s still happening. I had unfortunately, even now, much later than Patricia Churchland started this idea of neurophilosophy, but I still had the same challenges and problems. So often I heard, “Is that still philosophy or why is that philosophy or how is that philosophy?” And I thought, “Well, it is. It is a way of philosophy that it used to be.” There’s a very limited view of what philosophy can do and should do, and it was accepted much more positively by the scientists. When I talked to the variety of scientists for the book, they actually were incredibly welcoming.

1:04:53 AB: They liked this idea, and they really said, “Well, actually, we like these ideas, have you thought of going experimental?” There was a conversation I had with Gordon Shepherd, who’s one of the most prominent neuroscientists, but especially also olfactory neuroscience. And he sat me down for breakfast and I thought, “Oh, I’m interviewing him for my book. Wonderful.” I had an interview with him already, but there were some follow-up questions. Gordon had a bit of different ideas because he saw a talk I gave and he’s like, “Okay, have you thought of going experimental, because these are philosophical ideas, sure, but they are also applicable in an experimental setting, have you tried that? Have you thought of trying that?” And his confidence in the possibility of doing that and that I could do that was for me the kind of last push to say, “Okay, I want to learn an experimental technique.” This is how the whole shenanigan started, so to speak.

1:05:45 SC: And do you think, this might be too bold, but do you think that there is intrinsically any barrier at all between science and philosophy, or do you think it’s just a continuum and the structure of academia into departments and faculties is what breaks it up like that?

1:06:05 AB: I don’t think there’s an intrinsic barrier when it comes to philosophy as a practice and science as a practice. There are differences in the way we conceive of them, but I think it would be more integrated and so I would go with your second part and say it quite often, the way we institutionalize these different… These different disciplines and put them not just in different places, but different departments, and also how these different areas cultivated their own language, their own discourse and really started to delineating what it is that is philosophy, or what it is that is a certain science.

1:06:41 AB: And this is where I quite like cognitive science because it’s such a smorgasbord of different approaches, you have computer simulations, wet lab research, philosophers who do some form of cognitive science. This is much more where I would like to see also philosophers and neuroscientists interact a bit more. I’m afraid there is a lot of disciplinary gatekeeping and…

1:07:06 SC: Right.

1:07:07 AB: Yeah, I think it’s mainly the way we organize academia, we organize publications, it’s very hard to get anything that is truly interdisciplinary-funded and published. Not… It’s a buzzword, but it’s hardly really implemented.

1:07:23 SC: Yeah, no, it was a leading question. I’m completely on your side here, and it’s been very frustrating for me. The work that I do, the research that I do, has become more along the lines of things that are sympathetic to philosophers of physics and people say, “Are you moving into philosophy?” And my attitude is, “I’m not doing anything different. I’m trying to understand the world. I don’t care what you want to call it.” But then when in the real world, you have to apply for grants, you apply for jobs, you go to conferences, and whether it’s physics or philosophy or whatever, it matters a lot certainly ’cause we have a structure that cares deeply about this.

1:08:02 AB: I totally agree, yes, and I agree with you to say, I don’t care whether it’s philosophy or whether it is science. I’m interested in a question, I’m interested in a problem. And you just…

1:08:13 SC: Trying to understand the world.

[chuckle]

1:08:15 AB: Yes, so I would very, very much agree with you, and this is… I notice there are a number of people who are sharing that frustration, so it’s actually many more people than I thought there would be. And what is really cool to see is that there’s a new generation, especially in philosophy of science, many PhD students, many postdocs who are really trying to go out there, they’re talking to scientists, they’re also doing interviews, they’re trying to do observations of laboratory, some are also starting to find experimental approaches. That gives me hope. That gives me a lot of hope.

1:08:54 SC: Yeah.

1:08:54 AB: I just feel bad because they all, at some point, will be on the job market.

[laughter]

1:09:00 SC: It is a worry. But the kids are alright. They’ll figure some things out that us old bogies, it’s too late for us, but I do have to ask… It’s easy for me to write a paper that appears in a philosophy journal ’cause I’m a theoretical physicist, and the actual action that I’m doing sitting at my desk scribbling equations doesn’t change at all, but you had to set up a lab, which must be a bit of culture shock. What was the biggest thing that you learned or was surprising in the process of setting up a lab, which I personally would have no idea how to even begin doing.

1:09:33 AB: Welcome, yes, welcome to what went on in my mind. I have no idea. Yes, so I had to actually acknowledge the fact of how little I really know in a positive sense.

[laughter]

1:09:46 SC: Yeah.

1:09:47 AB: I think I actually had one advantage over the scientists doing that, which is I know how little I actually know, I know my limits, I might not always know what I don’t know, so to speak, but I do know that there’s shit tons, official metric, shit tons of things I really still have to learn, that also means I just ask people. So the last years, I’ve been talking to so many different scientists, I felt comfortable saying, “Sorry, I don’t know what that means. Or what do I do here?” And I realized, one wonderful thing, this is where I got more and more enamored with the way the scientific community works, it’s much less isolated than philosophy, that people were happy to help you. So I…

1:10:31 SC: Yeah, it’s true.

1:10:32 AB: In a way, happy that I thought, “Wow.” They really went out of their way to tell me, “Okay, you should really think about this. This is a bit more ambiguous, depends on what you want to do.” And they make you think. And one of my friends and colleagues, he actually went back when I told him, like, “Listen, I actually must be honest, I’m a little bit insecure here.” And he’s like, “Listen,” and he’s like, he’s approaching the 80s now, and he’s like, “Well, you know, when I started my lab I was 28 and the machine I wanted to use was just invented, so I’ll ask them every kind of question, I’m pretty sure I had no idea what I was talking about. And welcome to the club, kiddo.” So we all have to… We have to all go through that kind of fire and I learned a lot, and I learned that the only way to approach science, it’s not that there’s some kind of hidden barrier, some kind of secret club.

1:11:28 AB: It’s really just actually acknowledging that you might not know everything and actually you will not know everything, but you will learn how to make better decisions based on asking better questions. And you acquire new skills, and with these new skills, you will realize more and more of what you don’t know. And this is where philosophical training is actually of advantage, and I think this is why philosophy of science should be integral to scientific education, because you learn how to ask the questions in a way that I think the scientists would value, and philosophers would value I hope at some point a bit more also to get an idea of how these philosophical questions matter, both in conceptual analysis of science, but also actually setting up a lab, what are the things I don’t know? What issues might actually play into a certain measurement that I haven’t even thought about? So… Yeah, and I should say, I also have the advantage that I’m literally coming from the laboratory that brought you ignorance and failure…

[chuckle]

1:12:24 AB: I like to say that. I came from Stuart’s lab, and he talked a lot, he’s not your garden variety scientist, I mean, he wrote a book on ignorance, he wrote a book on failure, provocative titles but really to say, science is not the accumulation of facts, but the way to ask better questions. And the way we do that is really we’re accumulating more and more knowledge, but with that knowledge, it’s more like a sphere, you’ve got the circumference of ignorance, your knowledge grows…

1:12:48 SC: Yeah.

1:12:50 AB: Your ignorance grows, you just ask more and more sophisticated questions about the things you don’t know.

1:12:54 SC: Yeah, I think that it was a sad day when not only did natural philosophy split off from science, but they went into completely different schools in the university, right? It’s not just a different department, but one is humanities and one is sciences, that makes it very difficult to cross over sometimes, but okay… One last question. When are we going to get Smell-O-Vision?

[laughter]

1:13:19 SC: We already have things that give the sounds and vision over our TV sets, but when are we going to get the smells?

1:13:25 AB: So let’s put it that way. It depends on what you want, so you can have… You’ve got sometimes these kind of cinematic experiences where they spritz a couple of odors into the room while you watch a movie. I’ve got to be honest, I’ve found that super distracting. It’s just perhaps because I am so sensitive towards smells. It’s just like, well, I can’t concentrate on too many things, and it just brings me out of that immersive state. Yeah, I recently actually saw on Twitter, I was in a debate where the question was, “Well, can I record a smell? And then send it digitally to somebody else?” And it’s a nice idea, but it’s not going to work, and why? It’s actually that… Well, you would have to have… You would have to record a… Let’s say it’s just this coffee, with 800 molecules. Every coffee brand is different.

1:14:17 AB: You would have to release exactly the same molecules in that composition on the other hand, now imagine how many molecules are around, you would have to have an indefinite library of different odorants on the other hand, and on the other side, being released. So it’s impractical, it’s impossible, and the only thing you can have is that you might have some kind of device next to your computer with some cartridge of predefined scents, like a limited number, that’s… Just when you push a button it releases a certain scent, but that’s… Yeah, that’s kind of… Not really interesting, if I might be honest. And you can just probably…

[chuckle]

1:14:57 SC: I actually…

1:14:58 AB: Yeah, sorry?

1:15:00 SC: That makes perfect sense. When we go back to your point that it’s difficult to have olfactory illusions… In some sense, TV and movies are visual illusions, they make us think that we’re seeing this thing, which we’re really not, but doing that for scent is much harder.

1:15:15 AB: It is, it actually is, because, if you think of… I’m sorry to bring it up again, but the parmesan vomit thing, it’s not an illusion because both is correct. It is both parmesan and vomit, so you can’t really trick your nose, it’s not that you’re fooling your nose, you’re just putting the emphasis on a different part of the image. So yeah…

1:15:37 SC: Alright, well, there we go.

1:15:38 AB: Unfortunately, in a cinema it would be harder. Yup.

1:15:41 SC: Okay. I will not buy stock in any Smell-O-Vision companies, that’s good financial advice, but I will be continually amazed at the wonderful things that we can do with the interdisciplinary boundaries between philosophy and science, so Ann-Sophie Barwich, thanks so much for appearing on the Mindscape Podcast.

1:15:58 AB: Well, thank you so, so much for having me. This was a lot of fun.

1:16:01 SC: Yeah, I think so. Alright, thanks very much. And everyone should buy the book.

1:16:07 AB: Please do. [chuckle]

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