Scent Tracking, Dark Dining, & Other Sensations * Interview with Lawrence Rosenblum, Perceptual Psychologist

*See What I’m Saying: The Extraordinary Powers of Our Five Senses is one of my favorite nonfiction reads in recent years. In it Lawrence Rosenblum, a perceptual psychologist and professor at UC Riverside, explains how our brains are so often taking in more of the world than we are aware, that we are perceiving much more than we are conscious of. From echolocation to our multisensory appreciation of food, Rosenblum makes connections between the super senses of exceptional cases—like blind mountain bikers and professional tasters, and the rest of us.

We spoke during Rosenblum’s morning commute to his lab. Our conversation was free-wheeling and fun; it’s been edited for clarity and space constraints. He is an intensely curious person and so, despite my best efforts, we began our interview with a question for me: why I decided to start Aromatica Poetica!*

Lawrence Rosenblum: I looked over your website again it’s really interesting. I know this is an interview for me, but what made you decide to set up the website?

Leona Godin: Oh boy, well, the short answer is that I haven’t been blind my whole life, and I recently got into smell—maybe in the last five years or so and as soon as I started digging, I found it so interesting. There’s just so many things that I never thought about before, so as my vision went away, smell kinda opened up this whole other world. And then I’m a big fan of places where you can have a conversation with a lot of different disciplines.

Also I wanted to flex my editorial muscles. At first I was doing all the writing for it, but now we’re starting to get submissions and stuff, and eventually I would love to be able to really build the Aromatica Poetica media empire!

And then the other part of it is that I like the idea of having a place where it’s not about blindness–’cause I’ve been thinking about and writing about blindness for 20 years—but rather blind friendly.

LR: Well, is that your experience, other blind folks that you’ve talked to are more aware of the nuances of scent and the meanings of scents and things like that?

LG: No, no, not much. It’s kind of interesting, I feel like this has a lot to do with a bias against scent. I don’t know if it started in the Victorian era, but I know from another perceptual psychologist that you recommended Rachel Herz [The Scent of Desire]that there’s been a bias against scent research. And outside of the sciences our culture just sort of downplays how important it is. I think that that has greatly affected the blind community ’cause it feels like there’s such a huge possibility there in both smell and taste.

Although, I have managed to get some of the blind folks to reveal the fact that it is important to them, but I hadn’t read about it very much aside from Helen Keller, who is a big influence. She calls it “the fallen angel” because people discounted how important smell was to her.

LR: Well, it’s really interesting, I should tell you, historically in perceptual psychology, professors kind of throw it to their teaching assistants to cover the scent material in their classes.

LG: Really?

LR: Yeah, because the idea is, Well, the big questions about perception are in sight and maybe in hearing to some degree, but scent isn’t really all that important to humans and it’s really just a chemical interaction and it’s really considered like, I don’t know, the runt of the litter of the senses. And it’s unfortunate. And, I’ll be quite honest, it wasn’t until I wrote the book that I realized how amazing it is, and how much wonderful research there is in it Now.

LG: OK, your turn! We’ll just start at the very beginning. For those who know nothing, what’s a day in the life of a perceptual psychologist?

LR: What we do in my lab is we do research on audio-visual speech perception mostly, and also face perception and voice perception. We don’t do neuroscience we do behavioral science. So most of our experiments involve setting up stimuli for people to identify, and then having undergraduate subjects come in and respond to them and analyzing the data and coming up with ideas. My research is very theoretically motivated, and so we spend most of our time—most of our exciting time—designing experiments to test theoretical ideas.

The theoretical issues I deal with are to what degree do the senses work together, or can be considered really much more similar to each other than we used to think. and I think there’s been more and more research supporting that idea, that the brain isn’t really design to be working with individual senses, it’s designed to be working with the senses together, and there’s been neuroscience to show that, but there’s also behavioral science to show that, and that’s the end of the research spectrum that we work on.

LG: So what brought about the idea for See what I’m saying, which I adore, And what were some of the things that you wanted to do in that book?

LR: The reason I probably got into perceptual psychology was because both of my parents worked with sensory-impaired communities. My dad ran a Lighthouse for the Blind in Syracuse, New York. And my mom worked with deaf children and their families. They’re both old-school social workers. So in the old days, they provided services for folks, and I used to go to their offices and meet folks they were working with and learn about all the different devices they had designed and training they had designed to help these folks.

I think probably one of the aha moments was when I saw that schools for the blind had sports teams, you know, intramural sports teams, when they were playing baseball, and football and soccer and were able to do so through sound. And I thought, oh my gosh, it’s amazing that there’s this type of information in sound. And also, I’m a musician—it’s my serious hobby—and I’ve been playing since I was a little kid, and so I was interested in sound. Then I got interested in the senses overall and started taking the fun classes in college…

So with the book, I think the thing that has always attracted me to perceptual psychology and probably science in general, is the wow factor, they call it. The idea that you can discover something that nobody realized before.

So much of my research, for better or worse, is to uncover things that we didn’t know that the brain could do. and as I went through that research, as I designed that research in my lab, and I read other people’s research, there was more and more of that kind of thing appearing. And a theme emerged, where it seemed like our senses were doing things that we didn’t realize they could do—at least most of the public didn’t realize they could do. and I thought that would be a really fun idea to put in kind of a pop science book. And yeah man, there was so much great new research on neuroplasticity and multi-sensory perception and mirror neurons and that sort of thing. And I thought it really needed to be conveyed to the general public in a readable fashion. So it was kind of a nice convergence of all these things.

Smell Like a Dog

Two hound dogs tracking, one nose down, the other with nose in the air.

LG: So one of the moments that I really like, and I’m not sure if this is exactly about neuroplasticity Or not, but I love that moment of the peppermint experiment, and I just wanted you to talk a little bit about what that felt like to be on a scent trail.

LR: it’s really interesting. When you’re down doing that, you really feel like there’s almost this gradient of scent, where when you’re close to the scent rope, when you’re down there, you’re really thinking and concentrating on the smell, you can get a feel for how scent disperses. You feel like once you’re down their concentrating on it, you’re kind of riding this kind of trough of scent, where it’s strongest at the bottom where the rope is and becomes more diffuse as you lift your head and go from side to side. So you kind of feel like the scent is drawing you down into this groove, and then you just follow the groove. And you’re just kind of astonished—not how easy it is, because it’s challenging, you know, there’s a lot of distractions and stuff—but that it’s there. The smell’s almost a tangible thing that’s there in front of you. That is kind of drawing your path, and it’s really fun.

I teach a class based on the book and in our lab sections we do the demonstration and I think that’s probably one of the ones that’s most successful. I have the students go outside and put on headphones and blindfolds and track the peppermint rope and I think they really enjoy that. and are surprised they can actually do it.

LG: Yeah, and that leads me to wonder is that more about selective attention or is there kind of a rewiring? Like at what point does it turn from being attention to actually changing your brain?

LR: Okay, well, that’s a deep philosophical question because, in theory, anything you do with your brain subtly changes your brain. But I understand what you’re saying.

So the question might be, is it a long-term change or a short-term change or something like that? And certainly when you’re doing that, it’s not a long-term change.

I think you said that you taught yourself braille, right?

LG: Yeah, and I’m trying to get good enough to be able to read my book for the audio version.

LR: That’s beautiful! Love that. So you certainly have effected larger changes, where short-term changes become long-term changes.

It’s like learning any new skill, whether you’re learning a musical instrument or learning a sporting task or something like that. First, you need to do the basics of kind of getting yourself into the mode. It’s the idea of warming up, right? So when you’re first learning a musical instrument, you really have to warm up for a long time in order to get the sound you want out of the instrument, but then once you’ve gotten it, you don’t really need to warm up anymore. And I think that’s probably the most intuitive kind of phenomenology We have of short-term plasticity going into long-term plasticity.

I did a senior recital class in college—I play classical guitar—and what my guitar teacher told me is that you need to practice well enough, So when you come in from the upstate New York cold (where I went to college) and you sit down, pull out your guitar, the first time you play, it should sound great. Your skill has to get to that point. Even though your hands are still cold, you haven’t warmed up, haven’t really settled into your environment, that’s how good you have to be to do a recital.

LG: So there’s a sense then that if you were to do this tracking experiment on a daily basis and get more challenging tasks, that you really could become, for lack of a better term, more dog-like in your ability to track?

LR: Absolutely. So I’m trying to think, I know you’ve interviewed perfumers and folks like that, and certainly, they had long-term plasticity changes when it comes to scent. I’m wondering if there are people whose profession not only improved their sense of smell generally, but improve their sense of localizing or determining the locations of smells. I don’t know, maybe people who have to check gas lines or something like that, or something where the integrity of some sort of gas or scent has to be evaluated across space in some way.

I’d have to think about that… So who could probably get down and do the scent tracking task right away, without having to bring all their serious attention to it. I have to think about a profession. That’s really interesting for the second addition of the book…

LG: Perhaps blind people that are maybe in specific situations, I can imagine especially somebody who was born blind, who lives in the country, they might be more attuned to scent-tracking. If you have to walk a path that’s a mile or something. It seems to me that that spatial sense would be much more important.

LR: Yeah, maybe, yeah, so folks that find wild flowers or orchids or whatever, maybe they have to know the direction of a scent well enough that they really could ace that tracking task.

LG: well I look forward to the next iteration! Do you think from doing that tracking experiment that you and your students come closer to knowing what a dog experiences?

LR: I don’t know. I have a dog, and I just took him out, and it looks like he’s guided by smell all the time. I was struck by this back when I was living in the Northeast with a dog: when I would take him to the park, he looked like he was just randomly rummaging around the ground and didn’t follow smells. Then when it snowed (this is kind of gross), you could see the pee trails of the dogs in the snow. And I could still see my dog rummaging around in the same way, but now I could actually visibly see what he is rummaging around after—the exact same way that the pee trails were laid out on the snow. So obviously that’s something that they can do and they’re drawn by smells…

You know, I think a lot of what the research on smell is showing is that We’re doing a whole bunch of stuff unconsciously. And when it’s brought to our conscious attention—when we’re asked to recognize somebody by smell, by smelling their t-shirt or raiding attractiveness by smelling a t-shirt, or all of that sort of really cool stuff that’s in that second smell chapter,

You know, it could be that dogs have more on-line awareness of What the information is, they say. Oh, there’s my buddy, my buddy Fido down the street, he was just here this morning. Where we actually might have an unconscious sense of that through smell, but dogs have more of a conscious awareness of smell.

Pheromone Mind Control

Pheromones: bee, butterfly, beetles, oh my!

LG: right, right, well that leads me to this idea of pheromones. And I know this is a little far afield from your research, but I’m a complete layperson, and in the book there’s a bit about pheromones. Can you tell me what they are and why do you think that they’re so controversial ?

LR: Well, what’s controversial—and I would imagine you’re dealing with this thing, this process a lot with your website—is that sent is in some ways the most mysterious sense, right?

I mean it does seem they can go right for the emotions and facilitate these memories and all that sort of thing. And we seem surprised by the power of it. So when one hears that there’s ways of influencing each other, so that you seem more or less attractive, or can entice somebody to have a romantic liaison, it’s a scary thing.

So I think there’s a kind of a public idea of this being, “Wow, this is some sort of coercion that comes through our unconscious, that we have no willful control over. And so I think there’s the controversy on that side of the public perception of what pheromones might be able to do.

I don’t really feel that there should be that concern there. To the degree that they exist, I don’t think that they have more coercive power than (as I say in the book) as Marvin Gaye music.

LG: Ha!

LR: Right? That’s some sexy, sexy music. It puts you in the mood as does dark lighting and all that sort of stuff. And maybe we’re more conscious of it than of pheromones. But I don’t think that we’re always conscious of the way a hotel lobby’s visible decor or music influences us.

Scientifically, it is controversial, I think, largely because we have not found a very obvious receptor in humans for pheromones. And we do believe we have found that in other animals that do seem to be guided by pheromones—that there is a specific receptor.

And the other thing is, I think, kind of a philosophical problem as well. Animals that seem to be guided by pheromones have been thought to be reacting in a reflexive way. For example, the pigs that seem to like spontaneously go into a mating stance when they sense the male pheromone nearby, right? Well, as it turns out, it’s more complicated than that; they need to see the other pig, they need to Hear the other pig. It’s not a reflex necessarily.

We just assume it’s a reflex because of our intuition that animals behave in reflexive ways most of the time, which we really don’t know. And just because when we are subjected to what could be the pheromone of another person, we don’t go into our mating stance, doesn’t mean that it doesn’t have some small influence on us.

The influence could be much smaller and very less guided by pheromones than other animals, but that doesn’t mean it’s not a part of our repertoire when it comes to these things. There is that cool research showing that when you’re asked to judge the attractiveness from somebody’s t-shirt, their genetic makeup can determine that in terms of their smell signature, and how compatible their immune system is to ours.

And that’s something we know occurs in animals. Now, I’m not sure that we’re 100% clear that that’s also working in humans… and there’s that research that shows that people that have less compatible immune systems that are dating, have more affairs and fantasies. So we might not ultimately pick our spouses based just on pheromones, But it might play a little bit of a role, just like the color of the hair and then the sound of the voice and all that sort of stuff.

LG: Yeah, and I think that’s why your book is so important, is to realize that something can play a role without being the whole thing. Like there’s all these different things going on, and then we have a conscious mind to react in different ways. Just because we discover that smell might have an influence, doesn’t mean that that’s everything.

LR: Yeah, one of the most interesting things I found when I started talking to people—especially in the fields that were relevant to smell, like those scent designers for the hotel lobbies and that sort of thing. They kept coming up again and again with folks who either had dastardly reasons to want to use smell—to coerse people to gamble, or, on the other hand, people saying, “Oh don’t do this don’t do this! This is having such power over us. This should be illegal,” and all that sort of thing.

And they were just amazed that people thought smell had such a power over us. I’m sure you’re very aware of some of the novels like Perfume, that they turned into a movie.

LG: Sure!

LR: Where smell leads to murder and that sort of thing. I don’t know, there’s a certain romance to smell that isn’t obvious with the other senses.

LG: Right, and it seems like kind of a vicious cycle too. If we think only about the poetry of smell, and we don’t do the science research, it remains mysterious, like it’s This thing beyond our knowledge. and I sometimes wonder about how much of our ideas about the elusiveness of smell is simply because the science isn’t getting done. Because, as your book shows, so much of all of the sense data—even through our eyes and ears—comes to us without our being fully conscious of it.

But I’m wondering, do you think that there’s a fundamental difference between smell and sight for example—in the first case, the chemical molecule is in the nose, whereas with sight, the light waves affect your photo-receptors. Is there a difference there, or does it just not matter?

LR: Well, okay, so it’s gonna depend on the perceptual psychologist you talk to, but in principle, I don’t think there should be a difference. So let me ask you, what is your intuition of what the difference would be?

LG: Hmm. I guess it has to do with the fact that I think of the chemicals as being differentiated by olfactory receptors as opposed to light waves affecting the photo receptors in our eyes… I guess it’s a difference between entering and being identified by…

LR: Yeah, yeah, that makes a lot of sense, but I could come back and say, “Well we have different photo receptors in our eyes for different colors. so it’s the same type of thing, right?

Even beyond that, people might say well we don’t have a photoreceptor for a car, but just push it a little bit further in the nervous system, and there you go, we’ll have a little mechanism that can respond to things that look like cars. And just because it’s not at the receptor level–it’s very peripheral, it’s not clear to me what the philosophical basis of that difference should be.

That said, talk to Rachel Herz, and she might say something very different. I’d be very curious.

LG: And I like that. I was pushing on it, but I sort of prefer that. I think that so much of why we think that smell is so different from all the other senses has so much to do with our biases.

LR: right. Well, the way we’re wired has something to do with it. Smell seems to have a direct line into the amygdala, which is supposedly emotion-laden, that sort of thing.

Well, this is maybe my bias as a behavioral scientist rather than a neuro-scientist as such: I think the phenomenology is just really interesting on its own. And the perceptual experience, the tests that can be done just with reception can be as illuminating. So yes, it would be fun to look in the brain and say, “Oh that’s why our sense of smell is so different from the other senses!” But there could be behavioral differences too. And you’re right, there could be contextual, cultural differences. And don’t forget, in order to look for those differences in the brain, we have to have the different experiences of sent versus sight in order to ask those questions.

But ask other people. I’m not a scent researcher. Maybe they can tell you why scent is so different. They might say, “You can poke at the brain and it’s right there!”

Dining in the Dark

Elaborate dining table in severe black and white.

LG: Well yeah, I appreciate you thinking about this on the fly. I’m not one to harp on definitive answers. I definitely think the exploring is the exciting part. But speaking of personal experience, what did it feel like to dine in the dark, and what does it say about the science of smell and taste and its relationship to sight?

LR: Well, certainly the point of it was really interesting. I had not done the reading on the research when I went to this restaurant, and I didn’t know what to expect. There was this trendy new restaurant in Los Angeles, and I thought it would be an interesting place. As I said, the smell and taste are the chapters we give to our teaching assistance—very often it’s left out of perception courses, sadly. Although I’m hoping that’s changing a little bit, ’cause I was really impressed with the smell and taste research.

But I didn’t know about that research when I went to the dining in the dark restaurant, and so I didn’t know what to expect when it came to actually tasting the food. I really left their suspicious—just thinking that it was a crappy restaurant. In fact, I left the name of the restaurant out of the book—I originally had it in there. But I took it out because early readers said, “The way you’re talking about this food, no one’s gonna go to this restaurant!”

It’s really funny—so this is the state of undergraduate academics now: while I’m lecturing, people are looking up the reviews of the restaurant, and I always have a hand raised—“what You’re saying about the food being bland is exactly what all these Yelp reviews say.”

Now we know that it’s because of sight not being there. Site turns out to be an important part of our taste experience. When one loses their site slowly, compensatory factors come into play. So you probably don’t have the experience of food tasting more bland, and obviously smells are very vivid to you now. However, if you’re blindfolded, or in a dark restaurant, the immediate effect is to wipe out a lot of flavor.

So it wasn’t until I went home, and started reading the case literature that I knew what was going on. And Knowing it, I’d like to go back sometime and really concentrate—see if I can bring back the flavors.

I was there with friends and it was a social evening so I really didn’t have time to do the full-on nerdy introspection. I’d like to try it again, if it weren’t so damn expensive. Or just try it at home to see if slowly you could bring back the flavors.

I talk in the book about a few experiments on touch—blindfolding people So they can improve their sense of touch, and learning braille experiments. And anecdotally, one of the first things people say when they’re blindfolded is that food tastes very bland to them, but I know that over the course of the five days, it does start to come back. And I’m curious to know what happens? I assume that there’s some sort of shifting from the parts of our brains that are involved with taste then get co-opted by other sensations—like the texture of the food, and the smell of course… So it does seem that the compensation does seem to start kicking in fairly quickly, but it certainly didn’t that night for me.

LG: And it’s so counter-intuitive! I have a blind friend, Hoby Wedler, in Northern California who does wine-tasting blindfolded to get people to start to think about the nuances and stuff. It feels like just the most obvious thing that you’d taste more when you can’t see, and I’m sure that’s what motivated them doing the dining in the dark thing. They must not have checked out the taste research… I mean maybe they need to reformulate, and prepare people for this counter-intuitive experience.

LR: I think that might not be a terrible thing. I don’t know how the restaurant is doing. It’s still in business, which is rare for Los Angeles, and I guess it’s doing okay. I know they moved to a much smaller venue…

Now, regarding your friend with the wine tasting and the blindfolding sometimes people will do that, so they have to play the guessing game, not knowing what the bottle is… But you know, when I talked to that master sommelier, I told him about my dark-dining experience, and asked, “Do you think that your sense of taste for wine would be altered” Could you be fooled into mistaking a red wine for a white?”

“Absolutely,” he said. “I am 100% against people not looking at their wine.”

LG: Right, The look of wine is part of their training…

LR: and color should be part of the pleasurable experience—part of the wine-tasting process. And so he was very aware of that. He was not surprised at all about my dining in the dark experience, or about the research showing that color can make a grape-flavor drink taste orange, and all that.

But yeah, sommeliers spend a lot of time talking about color and hue density and all these things. It’s one of his favorite things, and he would never taste wine blindfolded.

LG: right. And I think with my friend up in Napa, I think he’s walking them through the experience, which perhaps the dining in the dark people could take a cue from that and making it into something where you’re paying attention, where you’re learning something, instead of it being sort of just this circus act of eating without sight.

LR: that’s a really cool idea! Maybe I’ll contact the guy—I feel a little guilty for saying such bad things… I bet they are aware of this by now.

LG: If it’s on the Yelp, they know!

LR: Right? If I were that chef, I’d be so disappointed. I hope he’s making a ton of money. Because if people are saying the food is bland, and he knows it’s not—it’s just a function of the sight not being there. They might want something like that. But when I went there, they marketed it as “a place where you could really taste your food,” and boy was that wrong. I think they may have taken that part of the description out of it. But that’s a really good idea that there could be another way of doing it that would be more interesting.

LG: Yeah, I think if you took people on a journey it would be such a great experience. I recently interviewed Mandy Aftel, a natural perfumer in Berkeley, and she has a small museum—the Aftel Archive of Curious Scents—in which she does things like taking apart a perfume so that you can smell each component. And that’s kind of what Hoby does as well with wine. And it just seems like they’re kind of missing an opportunity. Not to mention I think people would be more inclined to return, whereas now it’s likely a one-off experience. I think if you learned to pick out ingredients—coriander for example—out from the dish as a whole, it would be so much cooler.

LR: And they have people who are trained to do that—they train panels to tell whether the cookies are gonna be stale soon. That to me was so fascinating. I became very aware of how familiar but how unidentifiable flavors are—like “I know that flavor, but I can’t name it.” We have familiarity with so many flavors (and smells), but that doesn’t mean we can easily identify them. And I really love that kind of disconnect between those two cognitive skills.

–About the Interviewee–

Lawrence Rosenblum portrait.Lawrence Rosenblum, an award-winning Professor of Psychology at the University of California, Riverside, is the recipient of multiple National Science Foundation and National Institute of Health grants for his research on lipreading and multimodal integration and a grant from the National Federation of the Blind for his research on the audibility of hybrid cars. Rosenblum’s work has been featured in The Economist, the New York Times, the Los Angeles Times and on National Public Radio. He lives in Los Angeles with his wife and two children.

–About the Interviewer–

Leona Godin in sunglasses portrait.M. Leona Godin is a writer, actor, artist, and educator who is blind. She is currently working on Seeing & Not-Seeing: A Personal and Cultural History of Blindness with Pantheon Books. Godin is honored to be a 2019 Logan Nonfiction Fellow. Her writing has appeared in such diverse publications as Playboy, O Magazine, and Catapult, where she writes a column called “A Blind Writer’s Notebook.” She founded Aromatica Poetica as a venue for exploring the arts and sciences of smell and taste.