Carnegie Mellon University

on_humanity.pngDietrich College's Podcast

Episode 1

Scheines, Shinn-Cunningham & Holt

Episode 1: Listen Up with Lori Holt and Barbara Shinn-Cunningham

Auditory neuroscientists Lori Holt and Barbara Shinn-Cunningham talk about their work to understand language learning and the “cocktail party problem.” They both reveal unexpected paths to the field of psychology and a diverse set of interests, from travel to competitive saber fencing.


Full Episode


Richard Scheines: I'm Richard Scheines, dean of the Dietrich College of Humanities and Social Sciences at Carnegie Mellon, and it’s my pleasure to bring you this podcast featuring Dietrich College faculty talking about their research and their journey as people.

Doing podcasts is an idea that really sprung from our alumni. When I became dean and started talking with alumni all over the country, I kept hearing the same message over and over again — “We want more! We wanna hear about the cutting edge research you guys are doing, the great educational programs you're cooking up.”
So, I took two or three faculty to alumni gatherings in L.A., in New York, in the Bay Area, and the response was great. Everyone loved it. But not everyone can get to a Thursday evening gathering in New York City, and I can’t take the faculty out on the road more than a few times each year. So, my Board of Advisors — all of whom also happen to be alumni — suggested we do podcasts, which anyone can listen to any time, from anywhere. Great idea. So, here we are.
This podcast involves two neuroscience professors. It’s around 40 minutes long, and it’s broken down into roughly three parts. In the first, we talk about their research on auditory neuroscience. In the second, we talk about their journey to become professors. And in the third, what it was like to raise children while pursuing a high-powered academic career.
So, it’s my pleasure to introduce Lori Holt, a professor in the Department of Psychology and in the Center for the Neural Basis of Cognition, and Barb Shinn-Cunningham, the director of Carnegie Mellon’s Neuroscience Institute and also a professor in the Department of Psychology. Barb, Lori—welcome.
Lori Holt: Thank you.
Barb Shinn-Cunningham: Thank you.
Richard Scheines: So, the topic at hand, they are famous for is auditory neuroscience. That is, how the brain figures out what sounds you're hearing and what’s around you in the environment. And when we talked about this topic originally, Lori had this wonderful story of why that’s so hard for the brain to do. So, maybe you could start us off with a little bit of that sort of perspective.
Lori Holt: Sounds great. What you're doing right now as you listen to our voices is really what Barb and I study, and it’s effortless, we do it every day. It doesn’t feel like it’s a giant challenge for our brain. But you can really illustrate how difficult it is by, if we were to come out of the basement of the Center for Fine Arts, here —
Barb Shinn-Cunningham: [Laughter]
Lori Holt: - traipse across campus, and head to the Cohon University Center and dip our feet into the edge of the pool. And imagine that you look out onto the pool and you see a number of swimmers doing laps, one guy’s doing a doggy paddle, another one’s doing graceful laps across the pool, someone dives in from the diving board.
Now, I'll ask you to close your eyes, and I switch up all the players in the pool and have them make different strokes, different people coming from different places. And I want you to tell me who’s in the pool, what lap they're doing, what their gender is, and what region of the country they grew up in, just from the waves that are reaching your toes. And that would seem like a pretty hard task, I would venture to say.
Richard Scheines: So, you want me to hear through my toes?
Lori Holt: Exactly. As dean of Dietrich College, I would like to ask that you hear through your toes.
Barb Shinn-Cunningham: You choose left or right.
Richard Scheines: I'm having more and more trouble hearing through my ears. [Laughter] So, that’s a ridiculous challenge.
Lori Holt: It does sound like a ridiculous challenge. But yet, that’s what our ear does all of the time. It solves that ridiculous challenge.
Barb Shinn-Cunningham: To be fair, though, it’s almost like you have 30,000 toes, so it’s a little bit —
Lori Holt: That’s right.

Barb Shinn-Cunningham: - it’s a little bit easier than you might think from just having five toes.

Lori Holt: That’s true. That is true. It is—the ear does have that advantage, but it would still be tough, I would venture to say.
Barb Shinn-Cunningham: It would still be very tough.
Lori Holt: But you have this specialized organ, you know, embedded deep in what we think of as the ear when we look at the outside of our head, and connected to a very complex set of machinery in your brain that’s able to sort out this wave.
And, just like the ear, one of the complexities is that the waves from all of those swimmers add together. They're all overlapping and simultaneous when they reach your toes. So, it’s the job of the brain to sort out the information that’s coming in from the ear, and that’s some of what interests Barb and I.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: So, Barb is famous partly for this problem that’s called the cocktail party conversation.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Where you're having many, many voices in a room and you're paying attention and wanna hear only one of them, and somehow, your brain has to tease apart all those other conversations and focus on the one you care about.
Barb Shinn-Cunningham: Exactly, and you have these 30,000 toes or 30,000 sensors inside the cochlea, inside that inner part of the ear that takes that added up waveform that’s all the sound in the environment from all the different people, all the different places they're coming from. It adds up and then comes into your ear, and then the ear breaks that down into different frequencies.
But even then, even if you have 30,000 different representations that are representing slightly different parts of the sound, that’s the mixture of sound, it’s incredibly hard for a machine to figure out what sound is coming from what person, or what source—it could be not a person, it could be a ball bouncing or a glass shattering. All of that sound, though, we're really good at separating and figuring out which is which, and then focusing attention on the one that you're interested in listening to.
I know the cocktail party, I always end up talking to somebody who’s really boring. Like, I'm the person that’s stuck talking to the guy who’s really excited about the trip he took back in 1972 when he was in his van and he goes on and on for hours, and there’s all this exciting stuff going on around me. And one of the things you, most young adults can do really easily is listen to that guy on the surface, but what they're really doing internally is listening to the really juicy gossip next door. That’s—
Richard Scheines: And shaking their head at just the right time, anyway.
Barb Shinn-Cunningham: Exactly!
Lori Holt: That’s right.
Barb Shinn-Cunningham: And looking engaged and body language is showing that they're listening, but what they're really doing is listening to the people having the discussion about something that happened at work or the fight they had.
Richard Scheines: That explains a lot of my life. [Laughter]
Barb Shinn-Cunningham: Yeah, yeah.

Lori Holt: [Laughter] And it decreases with age, so you get—
Barb Shinn-Cunningham: That’s the problem.
Lori Holt: - less able to tune into that good gossip across the room.
Richard Scheines: Well, that brings us to a topic I know you've worked on, and it’s very interesting. So, as challenging as it is to process the world of sound, especially when there’s multiple sources, somehow your brain learns how to do this from the time you're an infant to the time you're an adult. So, you've done a lot of interesting research on how people learn to hear.
Lori Holt: That’s right. The reason we can listen to a podcast like this is that we have a common code, right? That our brain has tuned up to listen to the sound structure of English. But when you come into the world, you're not preprogrammed to hear any particular language. You have to learn the structure of the sounds that your caregivers are speaking to you, and it takes a long and protracted period of time.
So, when we look at children from the Carnegie Mellon University Children’s School, we can look at kids who are doing just fine in English and they're speaking and talking and even learning to read. But we look into the nitty-gritty of how they're doing that. They're doing it in a way that’s really not mature, even up until 8-1/2 years old. So, there’s a very long trajectory of learning to make sense of these fine-grained differences in the sounds.
Richard Scheines: How does your brain basically do that?
Lori Holt: It’s challenging. And it seems easy, right? Like, as you're hearing me right now, it’s not a problem at all. But I have an example of how difficult it is, right?
Richard Scheines: Yeah. Let’s hear it.
Lori Holt: Let’s hear it.
Male: [Unintelligible conversation]. I had ________ submachine gun in a ________.
Lori Holt: Alright, did you get anything from that?
Richard Scheines: Yeah, it’s total gibberish except for submachine gun, which jumped right out.
Lori Holt: That’s right.
Richard Scheines: How does our brain do that?
Lori Holt: That’s what’s remarkable is that we have all gone through time and learned the patterns and the statistics that are related to English and that are related to words and knowledge in English. But even when our brain is getting lots of signals and information that is gibberish and we have no mapping of that, we're nonetheless constantly monitoring and checking with the world to see what does map onto what we know. And so, when we get to “submachine gun,” it just pops right out. You can’t help but hear it.
Richard Scheines: So, in the early part of your life, you have to understand and learn how to actually parse the sounds coming in and associate them with meaning and learn language. How does the brain do that?
Lori Holt: Yeah, it’s a complicated question, and when you look at a little baby, they don’t look like they're doing much, but by the time—
Barb Shinn-Cunningham: [Laughter]
Lori Holt: - [Laughter] we do know that by the time they're six months old, their brain has already begun to reshape itself to respect the kind of language input that they're getting. So, a Swedish learning infant looks different than an English learning infant versus a Japanese learning infant, all by six months.
So, they don’t appear to be doing it. They're definitely not being instructed by language and getting the kind of tutorials that we would give in a university classroom.
So, we've thought about this kind of learning. It seemed to be kind of a passive absorbing of language, but it turns out that there might be a middle ground in which, as infants are kind of connecting with their world and making behaviors with their caregivers and interacting with objects and events in the world, that kind of behavior can give its own kind of feedback.
And so, we've been mimicking that in the laboratory by putting adult learners into a completely novel environment.
Richard Scheines: Language setting with a game, of sorts.
Lori Holt: Yeah. We put them into a game where we can completely control their sound input. We put them into an alien world where they're flying through space shooting aliens. But just like the real world, there’s structure in this environment, and aliens make different patterns of sound, depending on the kind of behavior that they're going to have.
We never tell these students that there’s anything important about sound to be learned.
Barb Shinn-Cunningham: They're seeing different objects. They think that that’s really the point, right?
Lori Holt: They see different aliens, they shoot different aliens, they fly through different parts of space, and they get paid to play video games, so they're really, really enthusiastic.
Richard Scheines: And so, their brain learns, even if they're not thinking about learning the language.
Lori Holt: That’s absolutely right.
Richard Scheines: And this holds at all ages? So there’s still hope for me?
Lori Holt: There’s hope for you, yeah, absolutely.
Barb Shinn-Cunningham: I don't know if there’s hope for him. Let’s be real. [Laughter]
Lori Holt: [Laughter]
Richard Scheines: Now, I've heard—and many people have, I'm sure, as well—that it’s much more difficult to learn a language after a certain age. Is that puberty, is it 30, 35—what’s that, and what’s happening?
Lori Holt: Well, it is more difficult, but it’s probably not so simple as just having a door close to language learning, right? It’s also the case that adult learners are not nearly as immersed in the input as a child learner. Even the most serious adult language learner is still largely speaking that native language, even after the fact—so, that’s definitely a factor.
And it’s the case that we don’t tend to teach adults language the same way that we are immersed in language as children, either.
Richard Scheines: Right, and when you hear a language, it just seems like one wall of sound. There’s no spaces between the words.
Lori Holt: Mm-hmm.
Richard Scheines: So, one of the tasks your brain has to figure out is, where are the breaks and what are the words and what are the…
Lori Holt: Absolutely.
Barb Shinn-Cunningham: Yeah.
Lori Holt: And that has to be learned, too. Because there’s no kind of unique cue to that in the input, you know? And when you read text, there are these convenient little white spaces between words that help you find it.
Richard Scheines: That’s what I was gonna ask, right. So, that’s—
Lori Holt: That’s right. There’s nothing like that in speech input. If you were to look at a visual representation of what we're saying right now, you wouldn’t see little silences between words.
Richard Scheines: And so, it’s all statistical?
Lori Holt: We don’t speak—
Richard Scheines: Do we actually see the patterns repeat?
Lori Holt: That’s right. And so, and the patterns for English are different than the patterns for Japanese. And so, that’s another learning challenge that needs to happen.
Barb Shinn-Cunningham: And it’s both statistical, but it’s also, learned words themselves will pop out like “submachine gun.” So, the boundaries of words have statistical regularities in different languages that differ.
Lori Holt: That’s right.
Barb Shinn-Cunningham: But also, once you know a particular word, it will pop out even if you don’t have all of those cues for the statistics.
Lori Holt: That’s completely right. Right. And it can be kind of a virtuous cycle, then, right?
Barb Shinn-Cunningham: Yeah.
Lori Holt: So that you learn a few words, it helps you figure out that there is a little unit there and then you can find new things in the continuous input.
Barb Shinn-Cunningham: Yeah. Right. “I didn't know what that one meant—what could that be?”
Lori Holt: That’s right.
Barb Shinn-Cunningham: Mm-hmm.
Richard Scheines: Cool. Okay, so, it’s extremely complicated to learn a language from being a baby, and it seems even more complicated to be hearing many different sounds, sentences, speakers, sources at the same time and effectively separate them so you can focus on just one of them.
Lori Holt: Right.
Barb Shinn-Cunningham: Right. And you asked earlier about what the different parts of the brain are that are doing these different portions of that task, and it really does break down in nice ways.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: And what I study is that process of how you focus on one sound and tune out other sounds. And part of it is learning these statistical regularities. Part of it is figuring out what belongs together—but not just within what makes up a word in a stream of words, for instance, but also what, in a mixture of two sets of words together, which parts of that mixture—
Lori Holt: Yeah. I'll just start talking at the same time Barb is talking.
Barb Shinn-Cunningham: - exactly, exactly.
Lori Holt: And we'll see if you can follow one of us. [Laughter]
Barb Shinn-Cunningham: Yeah. Well—
Richard Scheines: It’s not that hard.
Barb Shinn-Cunningham: - we can play examples of that, too. So, we're really good at separating out the words when there are two people talking at once. And I can play an example, here. If you—this is an example where it’s hyper articulated, it’s called clear speech and it’s hyper articulated, so it should be easy to hear out these words. But I want you to listen for a sentence, and it’s a sentence that starts, “Her shaky”—and tell me what the end of the sentence is. Are you guys ready?
Lori Holt: Mm-hmm.
Richard Scheines: Yep.
Barb Shinn-Cunningham: Here we go.
Male: Her shaky [Cross talk] increases will leap [Cross talk].
Barb Shinn-Cunningham: How’d you do?
Richard Scheines: Not too well.
Lori Holt: I have to say, I've heard this before, and I still can’t do it.
Barb Shinn-Cunningham: You still can’t do it—because I'm evil and mean. What I just played for you is really unnatural. What I played for you is two sentences that are random sentences. They're not meaningful, particularly, so you don’t have any context to help you string together the words. Could you make out words?
Richard Scheines: Increases.
Barb Shinn-Cunningham: Yeah.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: So, you heard words.
Richard Scheines: I could make out words, but I could not extract a sentence with a coherent meaning.
Barb Shinn-Cunningham: Right, and so, there’s two interesting things. One is you fail to string together the correct words, but the word units held together. Now, why did I use hyper articulated speech? I used it because, when you over enunciate, there are gaps.
Richard Scheines: Mm-hmm.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: There are little white spaces. Why is that important? Because increases held together as a word because it never stopped, and your brain heard that as a continuous thing going in time.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: But when there are little gaps and those little gaps align between two people who are the same person in my mixture, your brain has no feature, no way to pull the two sentences apart. So, I'll play them for you. Here’s one.
Male: Her shaky increases will leap on their quarrel.
Barb Shinn-Cunningham: Makes no sense, I know. They're silly sentences.
Lori Holt: [Laughter] That was evil.
Barb Shinn-Cunningham: And I'll play the other.
Richard Scheines: So, your brain has nothing to hang onto, you're saying.
Barb Shinn-Cunningham: Yeah.
Lori Holt: That’s right.
Barb Shinn-Cunningham: And here’s the other example, just for those who are gonna wanna—you know, otherwise, you'll have to go back and play it 17 times to pull it apart. Here it is. Maybe.
Male: The greedy pull ends at the carpet.
Barb Shinn-Cunningham: Makes no sense. There’s no context, nothing for your brain to latch onto.
Richard Scheines: Is that the same speaker?
Barb Shinn-Cunningham: It is the same talker, and grammatically, these sentences have the same grammatically correct structure, but no content meaning that makes sense.
Lori Holt: No way to predict what word might come next.
Barb Shinn-Cunningham: Right.
Richard Scheines: So, if there was two different speakers, it would be a little bit easier?
Barb Shinn-Cunningham: Well, of course, I would never play you an example that didn't work without proving that it could work. Thank you for that beautiful set up, Richard.
Richard Scheines: [Laughter]
Barb Shinn-Cunningham: So, now, let’s play an example where you can do it. So, there’s another phenomenon, here. If you're listening to the podcast and wanna grab a pencil and paper, or pen, feel free. Because there’s a limit to what you can remember in short term memory, and what I'm gonna ask you to do is listen for a phone number in this upcoming sound mixture. But there’s seven digits to this phone number, and that’s right on the hairy edge of what a young adult can remember if it’s unlearned. So, you can write it down if you want as we're going along if you wanna cheat. But Richard does not have a pen. I'm gonna test Richard.
Lori Holt: I can attest to that. He’s not cheating.
Barb Shinn-Cunningham: He’s not gonna write. So, I'm gonna make you listen, and it’s at the hairy edge of what your memory can remember—seven digits.
Lori Holt: Okay. Everything’s on the line for Dietrich College.
Richard Scheines: Okay. I'm ready.
Barb Shinn-Cunningham: So, you're gonna listen for a seven-digit phone number. It’s gonna be a metallic male voice, and here we go. Are you ready?
Lori Holt: No pressure.
Barb Shinn-Cunningham: No pressure.
Richard Scheines: I'm ready.
Barb Shinn-Cunningham: Here we go.
Male: Three five three four three four two.
Female: It’s hard to understand two things at once.
Richard Scheines: Three five three four three two two.
Barb Shinn-Cunningham: Oh, he’s so close!
Lori Holt: So close.
Richard Scheines: What did I miss?
Barb Shinn-Cunningham: Four three four two.
Richard Scheines: Four three four two!
Barb Shinn-Cunningham: Yeah.
Richard Scheines: You know what? My phone number is going into the last four.
Barb Shinn-Cunningham: Well, okay. You heard most of the numbers.
Richard Scheines: I did.
Barb Shinn-Cunningham: And, you know, but here’s the—
Lori Holt: That was pretty good.
Barb Shinn-Cunningham: - yeah, you were pretty good. Can you tell me anything else about what I just played? Was there any other sound in that mixture?
Richard Scheines: Yeah, there was another sound that was combining with that, and I paid no attention to it, so I know nothing about it whatsoever.
Barb Shinn-Cunningham: You know nothing about it?
Richard Scheines: Because I was focusing all my entire ego on remembering that seven-digit phone number.
Lori Holt: [Laughter]
Barb Shinn-Cunningham: I know! And then you didn't even get it right!
Richard Scheines: And I failed anyway!
Barb Shinn-Cunningham: Oh, my God! You know, it’s so funny, because I mean, this example is one of those that I've fine-tuned to make it hard, and I have this little patter that I do. And I, of course, stressed you out entirely by saying, “It’s on the line! It’s on the edge of what you can”—so, you really focused.
Richard Scheines: I did.
Barb Shinn-Cunningham: But there’s something else I—
Lori Holt: [Laughter]
Richard Scheines: And I knew you were duping me, but I didn't care.
Barb Shinn-Cunningham: I know. But there’s another fun thing is—oftentimes, you feel like you can listen to two things at once, but what I'm about to show you is, you really don’t really listen to two things at once.
I'm gonna play the same sound mixture, but now listen not for the phone number, listen for me. Same sound mixture.

Male: Three five three four three four two.
Female: It’s hard to understand two things at once.
Richard Scheines: “It’s hard to understand two things at once.”
Barb Shinn-Cunningham: It is!
Richard Scheines: It is! [Laughter]
Barb Shinn-Cunningham: It really is.
Lori Holt: You know, it’s so telling, too—
Richard Scheines: That’s amazing.
Lori Holt: - because my ego was not on the line, I didn't even try to listen to that phone number, and all I could hear was your voice that was on the masker. So, we were hearing opposite things.
Barb Shinn-Cunningham: Yeah, and it’s me when I was 15 years younger. So, I've used this example hundreds of times to audiences probably in the thousands at this point. And I would say, 95 percent of the people in a big auditorium will have heard most of the phone number. Of those people who hear the phone number, they can’t tell me anything about the other thing—except, maybe it was a woman. Sometimes, they'll be like, “It was a woman.”
The only time they can tell me more than that is (a) they've heard me give the example before because I've given it so many times over the last 15 years, so they know what the trick is. Or (b) they don’t hear the phone number and they listen to the other thing by accident, even though I've instructed them and tried to stress them out to really pay attention.
Richard Scheines: A different problem.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: Yeah. And there’s one actual, other thing going on, which is, there’s a lot of predictability in what I say.
Lori Holt: That’s right.
Barb Shinn-Cunningham: But the male voice—three five three four three four what?
Lori Holt: It could be any numbers.
Barb Shinn-Cunningham: There’s no predictability.
Lori Holt: Right.
Barb Shinn-Cunningham: Yeah. So, you're really forced to pay attention. But what’s really fun is, when you do these kinds of experiments, you can manipulate attention in an experiment, you can see the signature of people listening to one thing or the other thing, just by looking at the sensors that we can put on the scalp, so that—
Lori Holt: That’s right. You can even look at how they switch between two streams.
Barb Shinn-Cunningham: Between them.
Lori Holt: If you're clever about how you present them.
Barb Shinn-Cunningham: And in fact, there are a bunch of—yeah, there are a bunch of people all across the world right now using technology like this to try and build hearing aids that can figure out who it is you're trying to listen to.
Richard Scheines: Well, that’s great. That brings me to the next question, because—
Barb Shinn-Cunningham: Yeah.
Lori Holt: Right. Well, there’s a connection, first, between what we've been talking about.
Barb Shinn-Cunningham: Ooh, ooh!
Lori Holt: Because one of the things Barb and I are really excited about is that our lines of work are merging now that she’s at Carnegie Mellon.
Barb Shinn-Cunningham: Exactly.
Lori Holt: So, her work on attention is merging with my work on learning. Because what we're finding is that we can train people to get better at dealing with multiple streams of input and speech at the same time.
Barb Shinn-Cunningham: Right, and that’s really important—
Richard Scheines: Thank goodness.
Barb Shinn-Cunningham: - because some people are bad at it.
Lori Holt: That’s right. So, there’s whole—
Barb Shinn-Cunningham: Not just older people.
Richard Scheines: Your point, Barb?
Lori Holt: [Laughter]
Barb Shinn-Cunningham: No, none. [Laughter]
Richard Scheines: [Laughter]
Lori Holt: You can’t see pointing on a podcast, Barb.
Barb Shinn-Cunningham: I know. That was a good thing.
Lori Holt: [Laughter]
Richard Scheines: [Laughter] Well, it is true that many people, as they age, have more and more trouble separating the sounds in a conversation, in a crowded restaurant, in a noisy place. And I think many of them look to you with hope.
Barb Shinn-Cunningham: Yeah.
Lori Holt: That’s right.
Barb Shinn-Cunningham: Yeah, so, there’s actually—and there’s another aspect to this. Some of the reasons people are bad at paying attention could be because they have problems with these executive control networks that are in the brain as you normally think of the brain, like, the crinkled up mass that you imagine when I say the word “brain.” That part of the brain is actually fairly new, evolutionarily speaking. There’s a lot of processing of sound that happens in a part of the brain called the subcortical areas that are, that evolved much earlier on.
Lori Holt: Mm-hmm. We have much more in common with other animals.
Barb Shinn-Cunningham: Yeah. So, executive control, controlling, “I'm going to listen to the male” or, “I'm going to listen to the person to the right”—those kinds of decisions are coming from this newer kind of brain area.
Richard Scheines: Well, go back a little bit and talk about what is happening in your brain or in your ear or in the connection from your ear to brain when this capacity decays.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Because everybody I talk to in their 60s, 70s—it’s a different experience going to a restaurant.
Barb Shinn-Cunningham: Yeah, and I guess there’s really good news for people like me, I'm in my 50s and I have trouble hearing in crowded settings now. It’s not that the neocortex is the problem. I mean, everything we've said so far—
Richard Scheines: Phew!
Lori Holt: Well, in most of us. [Laughter]
Barb Shinn-Cunningham: - yeah, I was gonna say. Yeah. It’s not that reasoning part of the brain that’s really the problem for most middle aged, people, it’s really a sensory problem, and—
Lori Holt: And what you mean by that is how the information is getting in and how it’s being conveyed.
Barb Shinn-Cunningham: Right, the ear. Those 30,000 toes that we started out talking about. Like, in the ear itself, in the cochlea that’s taking a soundwave and breaking it down into all of these different channels of representation—
Richard Scheines: Mm-hmm. Like, the 30,000 channels.
Barb Shinn-Cunningham: The 30,000 channels.
Lori Holt: That’s right.
Barb Shinn-Cunningham: Those—that process itself is incredibly complicated and incredibly cool, and incredible fragile. And when cells in the cochlea die, they don’t regenerate. And there’s a lot, there’s two different things that can go on—you were gonna say something. I didn't mean to cut you off.
Lori Holt: Oh, I was just gonna say that it’s the kind of, it’s not just age, it’s the accumulated lifetime of all the rock concerts we've attended.
Richard Scheines: The damage we've done.
Barb Shinn-Cunningham: Yeah.
Lori Holt: And the music we've played at loud venues and the—
Barb Shinn-Cunningham: Yeah. Have you ever gone to a really good concert or a really loud venue and you come out and it feels like there’s cotton in your ears?
Lori Holt: It’s ringing?
Richard Scheines: Completely.
Lori Holt: Yeah.
Barb Shinn-Cunningham: You've damaged your hearing.
Lori Holt: That’s not good.
Barb Shinn-Cunningham: Yeah, sorry. Yeah, you lost some hair cells. So, inside the ear, there are these hair cells, and the hair cells are responsible for taking information up into the brain. But there’s two different kinds. There’s a 3:1 ratio. There’s three sets of outer hair cells for every one inner hair cell.
Richard Scheines: Mm-hmm.
Barb Shinn-Cunningham: You wanna guess—
Lori Holt: Maybe you should say what a hair cell is.
Barb Shinn-Cunningham: - well—oh, yeah.
Richard Scheines: So, it vibrates when the actual wave of sound hits?
Barb Shinn-Cunningham: It actually, there’s mechanical motion, and these cells are cells that literally have little hairs, stereocilia, sticking up.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: And when those stereocilia are moving, it opens a channel that causes voltage—you know, ions to flow into the cell.
Richard Scheines: Action potential?
Lori Holt: Yeah.
Barb Shinn-Cunningham: And the voltage—
Lori Holt: Yeah, it’s really, it’s like—
Barb Shinn-Cunningham: - in the cell changes and it will fire.
Lori Holt: - literally taking mechanical energy from a wave, like in the swimming pool, and converting it into a neural code that the brain can read.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Got it. I wanna over what you see as the interesting problems in the future, but let’s hold off on that for a few minutes and let’s go back and—I'm curious about how you both got into not only the particular field of auditory neuroscience, but academia in general. I mean, all of us, right, probably when we were in 5thh grade or 7thh grade or whatever, we don’t think of ourselves as, “Oh, I wanna be a professor.”
Barb Shinn-Cunningham: Really, you didn't?
Richard Scheines: I didn't, no.
Barb Shinn-Cunningham: [Laughter]
Richard Scheines: It was a whole different kind of profession entirely.
Lori Holt: That’s right.
Richard Scheines: But curiosity actually got me, and here I am.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: And so, I'm really curious to hear your stories.          So, Lori, maybe you can tell us how you came to be—
Lori Holt: I definitely was not thinking about being a professor in 5th grade. I am here quite by accident. I came from this one stoplight town in the middle of Wisconsin and wound up at the University of Wisconsin Madison on a program, a fast track to become a physician. And it took me about six weeks to realize this was probably a big mistake for me. [Laughter]
Richard Scheines: Doctor was not in your future?
Lori Holt: I was not—I was not meant to be a medical doctor. But that left—
Barb Shinn-Cunningham: What in that six weeks convinced—that’s pretty fast!
Lori Holt: It was pretty fast, yeah.
Richard Scheines: So, it wasn’t blood and guts?
Lori Holt: No. We weren’t there yet, we weren’t there yet. But I think, in the construct of that particular program, I was just more curious about why things were happening, you know, rather than kind of getting the basics that prepare you in a pre-med curriculum, right?
And that’s when I found science, because I was reluctant to go home to my one stoplight town for the Christmas vacation, which is a long, extended period in Madison, and the snow is very high. And I sought out a part time job from a faculty member who employed me to work in his lab.
Richard Scheines: In your first Christmas break?
Lori Holt: Yeah, yeah.
Richard Scheines: Wow.
Lori Holt: And the job was not glamorous. It involved working in a lab, seeing very few human beings, and [Laughter] working with an animal called a Japanese quail, that you're probably more familiar with on restaurant menus.
Richard Scheines: [Laughter]
Lori Holt: But they are used in research. And what we were doing is, we were doing auditory experiments with quail. And we were teaching these quail to peck their little beaks at buttons in response to sounds.
Barb Shinn-Cunningham: [Laughter] That sounds so cute.
Lori Holt: It is kinda cute.
Barb Shinn-Cunningham: We should open a quail lab here! It would only cost a few million, Richard. [Laughter]
Richard Scheines: [Laughter] I was gonna make a bad joke. I will refrain.
Barb Shinn-Cunningham: [Laughter]
Lori Holt: [Laughter] Yeah, we have. So, I spent, like, 70 hours a week taking quail out of their little cages and weighing them and bringing them to their experiment to work and helping them to train on learning to distinguish these sounds that we were playing them.
And our reason or doing this research was to look at how a brain as simple as a quail—like, a quail brain is about the size of an almond. It’s really not that extraordinary.
Richard Scheines: Right.
Lori Holt: But at the time in the field, people were making claims that the way that we hear speech is really, fundamentally different than the way we hear other sounds.
Barb Shinn-Cunningham: Yeah.
Lori Holt: So, all these systems that Barb was mentioning, the idea at the time was that speech gets funneled off into one set of brain regions and all other sounds are dealt with in another way. And so, there were kind of a laundry list of reasons people thought this.
And so, the lab I was working in was sort of ticking off on this laundry list and saying, “You know, if you look at it the right way, even a quail can do this.” And thereby saying that some of these processes are simple things about auditory perception that give us the basis for why we can do speech.
Richard Scheines: So, you got really curious and hooked on the—
Lori Holt: I got hooked, and—
Richard Scheines: - incredibly fun process of science when it comes to hearing.
Lori Holt: - yeah, and when it came time for graduate school, I stayed in the same lab and continued there.
Richard Scheines: In Wisconsin.
Lori Holt: That’s right, and—well, quite to my surprise, landed a job interview at Carnegie Mellon before I had begun my dissertation. So, I hurried up, finished my dissertation, and moved to Carnegie Mellon, and I've been here since.
Barb Shinn-Cunningham: Just to be clear, she had started the work for the dissertation, just not the writing of the dissertation.
Lori Holt: Oh, not the writing. That’s right, yes. It wasn’t that accelerated, my goodness.
Barb Shinn-Cunningham: [Laughter] Phew! She did her dissertation in two weeks.
Lori Holt: So, I—
Richard Scheines: Well, it sounds like we were unusually prescient and smart.
Lori Holt: Yeah, that’s right, and I've been here ever since, and it’s been great. So, it’s both a story of no planning on becoming a professor [Laughter]—
Richard Scheines: And Christmas was involved, but not in a good way. [Laughter]
Barb Shinn-Cunningham: [Laughter]
Lori Holt: - but really just being, just getting—yeah. [Laughter] It’s a Christmas story, really.
Richard Scheines: Happy for us.
Lori Holt: Yeah. With no real planning, but found something that was just fascinating that I could just really get into, and I'm still—
Richard Scheines: And I can hear you're still fascinated by it today.
Lori Holt: Yeah! Twenty years later, being at Carnegie Mellon, I'm still fascinated.
Richard Scheines: That’s so cool. And Barb, what about you? How did you find your way to academia?
Barb Shinn-Cunningham: Well, I—I was sure I was gonna be a computer engineer, and I studied engineering as an undergraduate and ended up going to MIT for—
Richard Scheines: And where was that, undergraduate?
Barb Shinn-Cunningham: Excuse me?
Richard Scheines: Where was that undergraduate?
Barb Shinn-Cunningham: Where? At Brown University.
Richard Scheines: Mm-hmm.
Barb Shinn-Cunningham: A very—I have nothing but wonderful, fond feelings for Brown University. But I ended up going to MIT for graduate school, and I didn't know exactly who I wanted to work with. And so, I literally went into a library at MIT that had all of the theses from the last N years, and I pulled out the last two years of Ph.D. theses and Master’s theses and kinda leafed through the titles of these theses to figure out what I could possibly study. Because I had this idea I was gonna be a computer engineer, but I got there and there were people doing all sorts of things in engineering that I never considered.
And I found a bunch of theses on speech research and a bunch of theses on hearing. And I am an oboe player and an English horn player, and I was pretty serious about music for all of my life—in fact, literally considered becoming, trying to become a professional musician when I was in high school and decided engineering was a safer bet.
Richard Scheines: [Laughter]
Barb Shinn-Cunningham: But all of a sudden, I was faced with these books in front of me that combined my engineering and something else that I love, which is sound and music and perception. And I never realized you could do them together.
And I actually had a crisis. I went through a week of feeling like I was gonna be copping out if I did something that felt like so much fun.
Richard Scheines: [Laughter]
Barb Shinn-Cunningham: How could I not be the hardcore engineer and actually apply engineering to something that seemed like it was too much fun to be work? And it took me a week to get over that and I've never looked back, because life is full of fun and that’s how it should be, and here I am at Carnegie Mellon, 30 years later, for me, still doing that. Still having fun and being so engaged by the questions that are interesting and exciting.
Richard Scheines: You found this career in academia, but you also both have interesting side interests.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: And so, one of yours is music. What other interests do you have that are—
Barb Shinn-Cunningham: You would have to bring up my other passion, my other passion that was the one thing that almost made me not come to Pittsburgh was sabre fencing.
Richard Scheines: Sabre fencing!
Barb Shinn-Cunningham: I am a sabre fencer. I started eight years ago, when my son, who’s now a senior in college, started, and I was going to the gym for two weeks, watching him, and it looked like so much fun that I took it up. And he’s quit since he went off to college four years ago. I still do sabre fencing, and it’s really wonderful. And I was worried that I wasn’t gonna find a good sabre fencing environment in Pittsburgh, and it literally was—
Richard Scheines: But lo.
Barb Shinn-Cunningham: - I almost was gonna not come because of that, and then I found the right people and I've been having a blast. So, a couple nights a week, I go and do sabre fencing.
Richard Scheines: Now, I have to tell you, as a dean, when I try to hire people and they have all sorts of interesting side conditions on their lab—
Barb Shinn-Cunningham: Weird, yeah.
Richard Scheines: - or their teaching load or, I've never heard anybody say, “I'll come if you have a good fencing team.”
Barb Shinn-Cunningham: I know.
Lori Holt: I knew—but I knew this would be an issue.
Barb Shinn-Cunningham: Yeah.
Lori Holt: It was the most serious worry I had about bringing Barb to Pittsburgh.
Richard Scheines: But thank God we do.
Barb Shinn-Cunningham: And the first undergraduates I've gotten to know here at CMU were from the fencing team. So, I have buddies on the fencing team here. I don’t fence at CMU every night, some nights I go to a local club, but I'm good friends with the CMU fencing team folks.
Richard Scheines: That’s great. What about you, Lori? [Cross talk]
Lori Holt: Well, I aspire to interests in the future when my young children are a bit bigger.
Richard Scheines: Ah ha.
Lori Holt: But in the meantime, we're spending time traveling and my side interest during that is a lot of photography on the side that I can kinda roll into this without additional time.
Richard Scheines: Nice.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Well, so, can I take a few minutes and ask you both, because you've both been very successful academics and you've both raised children, right? Which is, I know, complicated, hard, and has its own challenges. So, maybe you could just say a few minutes, a few words about what that was like and how hard that is and how you would advise other people confronting those same kinda challenges to take it on.
Barb Shinn-Cunningham: There’s so much to say there.
Lori Holt: Wow. We're gonna need another podcas.t
Richard Scheines: That’s another podcast, but it’s important for people to hear it.
Barb Shinn-Cunningham: So—no, it is. It’s funny, I have a sound example that I give and often I'll do it and show pictures of my children, because I think it’s really important to show to people, especially young women, that it’s possible to have a family and have a successful career.
Richard Scheines: Right.
Lori Holt: That’s right.
Barb Shinn-Cunningham: And it isn’t easy. It’s a compromise.
Lori Holt: That’s right.
Barb Shinn-Cunningham: Everything about it is a compromise, but life is a compromise.
Lori Holt: That’s right. When my kids are babies, I intentionally gave an academic talk in front of an audience while wearing the child.
Barb Shinn-Cunningham: Yep.
Lori Holt: Just so that—
Barb Shinn-Cunningham: I still have people who met me at the first conference—
Lori Holt: That’s right.
Barb Shinn-Cunningham: - where I’d had my son the first conference, and I had him in a Snuggie, and they remember me from—he’s now 24—from meeting me with giving a poster as I was holding him, so yeah.
Richard Scheines: And do you think your kids are now more at ease in front of audiences because of this? [Laughter]
Lori Holt: [Laughter]
Barb Shinn-Cunningham: [Laughter] If you met my older son, you probably wouldn’t ask that. No. [Laughter]
Lori Holt: Yeah.
Richard Scheines: Okay, so, let’s transition—oh, I'm sorry.
Barb Shinn-Cunningham: Well, let me just say—I think we're both kinda waiting, because I think we both think this is such an important topic.
Lori Holt: It is. And it’s one that’s challenging to talk about, because there’s no one right path.
Barb Shinn-Cunningham: But I would say—right. There’s no one right path. I think, for me, personally, and I suspect maybe for Lori, my husband was incredibly supportive and incredibly involved. We were fortunate enough to be able to pay for day care when we needed it, and that was enormous.
But it is really a compromise, and forgiving myself for not being as productive as a scientist as I might have been, and also forgiving myself for not making homemade cupcakes, back when that was still allowed and food allergies were not making them verboten.
Lori Holt: [Laughter]
Barb Shinn-Cunningham: Forgiving myself for what I couldn’t do and being aware that I was making mindful choices was part of how I kept my sanity, because it’s a tradeoff.
Lori Holt: It is.
Richard Scheines: So, you're managing expectations, to some degree.
Lori Holt: On both sides, right?
Barb Shinn-Cunningham: Right, and being aware that, if I do this certain thing for work, it will take time away from my family. And if I spend time with my family, I won’t have that thing from work.
Lori Holt: That’s right.
Barb Shinn-Cunningham: But that’s a mindful choice, and I have balance.
Lori Holt: Well, and we're really fortunate to be in a generation where it’s much more manageable, right? In the sense that—
Barb Shinn-Cunningham: And with the expectations on our husbands were such and they were good enough people that they helped in ways that—
Lori Holt: Yes. Absolutely. We are both extremely fortunate to have husbands and spouses who support us in that way. And also, working in an academic environment is its own blessing of flexible time—
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Mm-hmm.
Lori Holt: - and a real engagement. My kids have grown up on the Carnegie Mellon campus. They came to day care here when they were infants. My daughter went to an AI fun day on Sunday. [Laughter] So, they really feel integrated into this campus.
Richard Scheines: Which is great.
Lori Holt: And that’s been a way that we can have our lives here, as well.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Yeah, my wife and I were in a Ph.D. program together and then we got married and had children while we were still Ph.D. students.
Barb Shinn-Cunningham: Yeah.
Richard Scheines: Which I would recommend, because we had no money.
Lori Holt: That’s right.
Richard Scheines: But we had the flexibility and the common understanding of what our lives were like that it was fairly feasible for a couple years.
Lori Holt: I think that’s key. People always ask when’s the best time.
Barb Shinn-Cunningham: Yeah, there is no good time.
Richard Scheines: There is no good time.
Lori Holt: And there’s no optimal time, and there’s a different path—different tradeoffs at each level.
Barb Shinn-Cunningham: Well, and for me, I was eight months pregnant when I defended my Ph.D. thesis. And instead of going off—the right thing to do is to go off and do a high-powered post doc somewhere new—that wasn’t an option. I could not have been productive. But what I could do is do a part time post doc in the lab that I was doing my Ph.D. in.
Lori Holt: That’s right.
Barb Shinn-Cunningham: And that’s not the right thing to do—
Richard Scheines: So, you were flexible.
Barb Shinn-Cunningham: - except it was the right thing to do for my situation.
Lori Holt: But she’s been fine. [Laughter]
Barb Shinn-Cunningham: It kinda worked out.
Lori Holt: That’s right. [Laughter] It worked out, yeah.
Richard Scheines: It kinda worked out, yeah.
Barb Shinn-Cunningham: So, I mean, people get in their heads that there is only one path, but there’s many paths. And I think being flexible yourself is a huge part of being happy about all this.
Lori Holt: That’s right, and the world is opening up to see different paths, right? I had an extremely different path from either of you. I had my first baby after tenure. And so, it’s completely different, and it would seem easier, on many levels, but it hits at a different time in your career.
Richard Scheines: But then you have to wait until you're finished with tenure, which, for many women, I think, is a complicated thing because of the age factor.
Barb Shinn-Cunningham: Right.
Lori Holt: That’s right.
Barb Shinn-Cunningham: Amen. Yep.
Richard Scheines: And I think that, in some sense, the academic trajectory for women is the worst possible.
Lori Holt: That’s right.
Barb Shinn-Cunningham: It’s hitting right at those—
Richard Scheines: Because, you know, you're typically getting tenure in your early 30s—
Lori Holt: That’s right.
Richard Scheines: - if you're fantastically amazing, or your mid 30s. And so, if you wait ‘til after that, you know, that’s not easy to do that.
Barb Shinn-Cunningham: Yeah.
Lori Holt: That’s right. And I think—I mean, this is something Barb and I also resonate with a lot of trying to help to shape our institutions to be better at recognizing it. It’s better than it was in the past—
Barb Shinn-Cunningham: And find ways to support—
Lori Holt: - we can do better.
Barb Shinn-Cunningham: - to support being a parent—
Lori Holt: That’s right.
Barb Shinn-Cunningham: - and having a good career, because it shouldn’t have to be an all or nothing choice.
Richard Scheines: Totally agree. Okay, so, that was really interesting, and I thank you so much. Before we close, let me ask you both to offer an opinion on the future of the kinda research you're doing, the future of neuroscience, the future of auditory research. Because new equipment is coming on, new instruments are coming on, new knowledge, new theories—and now you have a great group in Pittsburgh, not only the two of you, but a few other people around there, too. What’s in store that we can look for when I have you back on the show 10 years from now?
Barb Shinn-Cunningham: [Laughter]
Lori Holt: You know, when I started in grad school, the term auditory cognitive neuroscience wasn’t a term, at all.
Barb Shinn-Cunningham: Yeah.
Lori Holt: And I think the future of auditory cognitive neuroscience is Pittsburgh.
Barb Shinn-Cunningham: Yeah.
Lori Holt: I think, all of a sudden, we have this confluence of talent who have descended on Carnegie Mellon University and our neighbor, University of Pittsburgh, that we're gonna be able to do really big things here.
Barb Shinn-Cunningham: Yeah.
Lori Holt: So, maybe you wanna say some ideas about what you think is up next, Barb.
Richard Scheines: Yeah, what are the big things? I mean, what are the streams of research?
Barb Shinn-Cunningham: Well, I have two hats, here. One is my personal science hat, which is, auditory neuroscience and cognitive auditory neuroscience here in Pittsburgh is fabulous, because there is this influx of people, enough that the world is noticing. And it’s here at Carnegie Mellon University, but at University of Pittsburg, there’s a whole bunch of new people that have come in and there are still more hires to come.
So, we're having a great time getting together. We have joint lab meetings, Lori and I, along with—
Lori Holt: That’s right.
Barb Shinn-Cunningham: - colleagues of ours from the University of Pittsburgh. We have weekly lab meetings together. I have—my own lab here, physically, isn’t ready, even, yet, but I've been working over at the University of Pittsburgh with our colleagues, so, that’s incredibly exciting.
Lori Holt: That’s right. We're able to train students in brand new ways because of this as well.
Barb Shinn-Cunningham: Right. But I have a second hat, and the second hat is as the Neuroscience Institute Director, and I think that’s also something I have to get a, you know, put in a good plug for.
Richard Scheines: Put in a plug.
Barb Shinn-Cunningham: Yeah. So, one of the things that really brought me here is not just knowing that Lori was gonna be here and my other colleagues here, that that was a really rich and exciting environment for me personally, but as somebody who is an engineer and who really appreciates the wave in neurosciences, we've gotten better and better tools to read out brain information, but we also have technologies that are being developed to increase even beyond what we currently can do to read out these different brain states.
Richard Scheines: And that creates a lot of data.
Barb Shinn-Cunningham: Yeah, it creates huge amounts of data.
Lori Holt: Mm-hmm, absolutely.
Barb Shinn-Cunningham: How do we analyze it? It creates huge amounts of possibilities for technology development—what can we do with that? And what I saw was an enormously exciting opportunity as an engineer at CMU in particular, because we do have such excellence in all of those areas, in technology, in engineering, in data science, in cognitive psychology. All of these areas are coming together right now, right here at CMU in ways that I think are incredibly exciting.
Lori Holt: Mm-hmm.
Barb Shinn-Cunningham: And you and the dean of Mellon College have been incredibly generous in helping to get this new Neuroscience Institute off the ground.
Richard Scheines: Well, for us—
Barb Shinn-Cunningham: The university itself has donated, you know, put in real resources to make this happen, and we are situated—it’s sort of like this confluence of auditory neuroscience.
Lori Holt: Yeah.
Barb Shinn-Cunningham: There’s another confluence, [Cross talk] which is this confluence of science and data and technology and an entrepreneurial spirit that CMU really excels at, that everybody works together across boundaries, across colleges in ways that are gonna really lead to neat, new things that couldn’t happen anywhere else. I really believe that.
Lori Holt: That’s right. Auditory is one example. We could name 9 or 10 others in other areas where there’s that same confluence happening.
Barb Shinn-Cunningham: Yeah. Yeah.
Richard Scheines: Well, that’s great. It makes my heart sing. I mean, I should also mention that my colleague, Rebecca Doerge, who is the Dean of the Mellon College of Science, has been my collaborator in helping stand up this institute, and the two of us jointly hired Barb and the activity going on to build this center is, for us, incredibly exciting. Very rewarding.
Barb Shinn-Cunningham: Yeah. Well, thank you for bringing me here. I'm loving it.
Richard Scheines: Oh, I'm so glad. And thank you, both, for taking time. I know it’s a busy time of year and it’s stressful to do this sort of a thing, but I'm really very, very grateful to you for coming and lending us your stories and insights for a good chunk of time and thank you, again.
[End of Audio]