Episode 33 - Synesthesia
Transcript
David: 0:06
Hi, I'm David Peña-Guzmán.
Ellie: 0:08
And I'm Ellie Anderson. Welcome to Overthink,
David: 0:11
the podcast where two friends,
Ellie: 0:13
who are also professors,
David: 0:15
put philosophy in dialogue with the everyday.
Ellie: 0:18
Because big ideas are within everyone's reach. So I feel like it's a really popular thing to say, I'm synesthetic, almost like a party trick, you know, meeting somebody and talking about what sort of music you like, and then just casually dropping that you have synesthesia.
David: 0:44
Uh, I don't know what parties you're going to, but I've never had that happen to me. I've never been to a party where somebody tried to impress other people by claiming to be a synesthete.
Ellie: 0:55
Okay. I would venture to guess that most of the parties that I've been to, especially back in college, when I was living in the artsy dorm, there was literally a dorm that was like for all of the weirdos and art kids. And that was where I lived senior year of college.
David: 1:09
All the tortured artists with a synesthetic consciousness.
Ellie: 1:13
Right., Like, I'm sure that was mentioned probably at least once a party, but I hear it a lot nowadays, too. I'm wondering David, if this has to do with the fact that I, even to this day, still hang out with like people who work in the film industry and kind of creatives, and you are a nerdy debater.
David: 1:29
Yeah. I only hang out with the ones who brag about being logical and regimented and compartmentalized. That's what really gets you the goods at the party.
Ellie: 1:38
David, you gotta get in on these LA creative type parties. I also need to get into them more. I'm like fronting, like I'm so sceney, it's not at all the case.
David: 1:50
It's because you're not enough of a synesthete, Ellie.
Ellie: 1:53
Right. Okay, for listeners who might not know what synesthesia is, if you're a nerdy debater like David who doesn't hear it as like regular party talk, let's explain it. David, what is synesthesia?
David: 2:05
So synesthesia is basically a subjective experience that some people report that crosses sensory modalities. So most of us are familiar with the senses, you know, you have your vision, you have your touch.
Ellie: 2:19
Most familiar with the senses!?
David: 2:21
Yeah. You know, have you heard of them? There's like a few of them. But there are people who experience the phenomenal world in a really intriguing ways. And one of those ways is synesthesia, which essentially happens when a stimulus is experienced in a way that blends senses in a way that scientists have some trouble explaining. So seeing a color and instead hearing a sound, or a hearing sounds as having colors.
Ellie: 2:52
Yeah, well, and not seeing color and instead hearing a sound but seeing color and also hearing a sound, right? Like it's a mashup or combination of senses. If you think about the etymology of the word, it comes from the Greek word aisthesis, which means sensation, and syn, which means together. So it's basically a joining of the senses.
David: 3:11
Yeah, you're right. So it's not necessarily just a combination of two random phenomenal experiences, let's say one auditory and one visual, but it is the experiencing of a stimulus that is associated with one as always or systematically associated also with another one, again, in a way that raises a lot of questions.
Ellie: 3:30
Yeah, that was one thing that I was struck by in researching this episode is the way that there is a kind of constancy of stimulus for synesthesia, right? The letter A is always read, for instance, that's actually one of those common versions of synesthesia. The most common broad category of synesthesia is what's known as grapheme color synesthesia, basically you see a letter or a number and you associate that with a color. And actually one of the most common versions of this is seeing the letter A as red and not to pull a version of what I was just making fun of those people I partied with in college for doing, but-
David: 4:05
Tell me how you're a synesthete across all the sensory modalities.
Ellie: 4:09
No. I know. I wouldn't claim to have, you know, like technical anesthesia or what researchers call genuine synesthesia, maybe I do. I don't know, but I definitely have a version of grapheme color in. I do see the letter A as red, but it's kind of like a pinky red to me, and then B as yellow, C as blue, D is yellow again, E is pink.
David: 4:31
I mean, that is technical synesthesia. I mean, when you look at a grapheme on a white piece of paper, do you experience it as having a color property?
Ellie: 4:41
No when I think about the letter.
David: 4:43
Ah, okay, so you have imaginary synesthesia. You're like the meta-synesthetic subject.
Ellie: 4:50
Well, that's what some researchers call weak synesthesia, and there are debates about whether that counts as genuine synesthesia or not. So I'm just going to hold off on diagnosing myself and pulling that move of saying, you know, I'm synesthetic, but like maybe I'm a little synesthetic.
David: 5:05
Okay. Fair enough. Fair enough. I accept the weak synesthesia as a form of synesthesia. Today, we're talking about synesthesia.
Ellie: 5:16
What does it feel like to experience this mix up of the senses?
David: 5:23
And what makes this subjective experience not only scientifically interesting, but also philosophically thought provoking?
Ellie: 5:30
Is one born or made a synesthete?
David: 5:47
A lot of people define synesthesia as a neurological condition, but I prefer to speak about it as a subjective experience to avoid pathologizing language. And it's an experience in which a sensory or a cognitive stimulus consistently co activates another sensory or cognitive quality in addition to its usual ones.
Ellie: 6:08
Yeah. One of my favorite examples that I came across for this is that there's this one synesthete who, every time he hears the word jail, he tastes bacon.
David: 6:18
Bacon? Oh my God what, what if he's, what if he's vegetarian though?
Ellie: 6:22
I don't know, even if you're a vegetarian, like bacon still kind of tastes good, right? Like a lot of vegetarians talk about- okay.
David: 6:29
I, I, I cannot handle the taste of meat anymore, even if I tried, um-
Ellie: 6:36
My God. So then jail, jail bad word, right. Tastes bad to you. For me, I'm like, oh, jail, bad word bacon. Ooh.
David: 6:45
Well, I mean, one of the things that I find interesting about synesthesia is that there are some really bizarre forms of synesthesia. Of course, the classical ones are the ones where some of the more commonly known senses mix. So think about something like hearing music as having a specific color or-
Ellie: 7:04
For sure. Like, I totally do that.
David: 7:05
Yeah. Or seeing a color and experiencing a taste or a flavor, but there are some other ones that are not necessarily sensory. So for example, some people say that different letters have different personalities. Like B is really funny and like makes you kind of giggle. But Z is like a total downer and like a wet blanket. And so it's not just a mixing of the classical senses, it's a mixing of categories that we typically experience as compartmentalized. So for example, some people experience different objects as having genders, and it's just part of their experience of the world.
Ellie: 7:45
Yeah. I've heard that there are up to a 150 types of known synesthesia. And one interesting thing about synesthesia research is that the condition or experience as you're talking about it, David, used to be thought of as relatively rare. And now with the advent of the internet in recent decades, a community of synesthetes have come together and started talking about their experiences online. And that has actually led researchers to believe that synesthesia is much more common than was previously thought, which also raises a bunch of questions about whether synesthesia is developmental, as some say it is. Is it something that a certain portion of the population just has and others don't, or is synesthesia a kind of spectrum where we all have a little bit of it, but it's more pronounced in some people than it is in others.
David: 8:32
Yeah. And part of what's happened with the growth of research into synesthesia is that the way in which you define it will, to a large extent, determine how widespread it is in the population. So I've seen a number of estimates and they have a huge range. So some people, for example, will say that synesthetes are one in 200,000, for example. And that's because they're using a very technical, more restrictive definition. But then some researchers use a slightly looser definition that generates a very different estimate of like one in 200 or even one in 20, which is a gigantic difference, right, between one in 20,000 and one in 200. So the definition here does do some of the work and it suggests that even experts are not yet on the same page about how to demarcate this object.
Ellie: 9:27
Yeah. And you know, even beyond this question about its prevalence, whether it's one in 20 or one in 200,000, some people have said that we are all synesthetic. So for instance, a 1996 scientific study by Simon Baron Cohen suggested that we are all synesthetic at birth, but we lose the capacity as we grow older. And philosophers, for instance, Maurice Merleau-Ponty and David Abram have talked about how we actually are all synesthetic, but it is the particularity of our culture that has moved us away from synesthesia. So David Abram hypothesizes in his book Spell of the Sensuous, which I definitely want to talk more about because he has a really interesting account of synesthesia there, that humans are sort of naturally synesthetic and it's only when we get alienated from our connection to nature that we begin to lose our natural synesthesia.
David: 10:18
And so I definitely want to talk more about that because that book is fascinating. It's really good and I think everybody should read it, but it really highlights how difficult it is to pinpoint the nature of synesthesia because researchers disagree, for example, about whether it's genetic, as you mentioned. It has been observed for example, that it runs in families. So there is good reason to believe that it has a genetic component, but there are also a number of environmental triggers that can turn somebody into a synesthete. So think about like LSD or tripping on mushrooms. That's like a synesthetic experience.
Ellie: 10:52
Yeah.
David: 10:53
There are other things that can trigger synesthesia in people who don't think of themselves as synesthetes. So for example, sleep deprivation can cause these weird hallucinations, hypnosis can bring it about as well. And one of the things that we do learn from Abram that we will talk about more in a minute is the way in which culture plays a role, because think about something like reading, right. When I read a book, I'm just seeing words. But according to some people, depending on your phenomenology of reading, I'm also hearing them sounded out. So anybody who is literate would be on that definition a synesthete.
Ellie: 11:35
Yeah. Reading is arguably a form of synesthesia. And you know, when I read some of these scientific studies about people being like, genuine synesthesia is developmental and it's probably genetic and/or has like these neural causes, I just- I got to- I'm inclined to take that with a grain of salt, because I think that is more reflective of the scientific biases of our time and our obsession with finding genetic and neural correlates for everything than it actually is about the nature of synesthesia. And, you know, for one thing, synesthesia itself has posed a lot of problems for scientists and philosophers who are like, this is a contradiction or at least it's a paradox, you know, how do we explain synesthesia? But it's only when you start from the vantage point that there are these completely separate sensory modalities to begin with that synesthesia suddenly seems difficult to explain, right. But the very separation of senses into five senses that are separate, is itself I think at least worth questioning. It's a legacy of Enlightenment/Scientific Revolution theories of perception that a lot of folks are seeing as problematic today, both philosophers and scientists.
David: 12:44
So depending on what model of experience or what taxonomy of consciousness you begin with, then you will interpret the phenomenon of synesthesia as very puzzling, but it's only because you've already projected a certain image onto experience that doesn't grow out of experience, it grows out of a scientific understanding of it. But independently of that, I find the neuroscientific research on synesthesia really interesting because we know that you can generate synesthetic experience in a laboratory. And so I prefer to think about the neuroscientific and the philosophical and the cultural dimension as intermingling one another and showing the way in which experience is neurological, is linguistic, is cultural, is historical all at the same time, right? Synesthesia in particular is an experience that highlights that.
Ellie: 13:36
Yeah. Meanwhile, I'm just imagining an antagonistic dialogue between like a researcher who thinks that synesthesia is only genuine if it's developmental, and by that, they mean that you can never remember a time when you weren't synesthetic. You have had it since you were I dunno if like born or since you can remember, I don't know. Some of these like scientific definitions are fuzzy. Anyway, I'm imagining a dialogue between like that guy and then like somebody who's like just done LSD for the first time and he's like, man, no, this opened up my world, now I'm synesthetic.
David: 14:12
You know, there is now this new wave of research into the neuroscience of psychedelics, which is fascinating. And one of the things that is coming out of this research is that in order to make sense of something like a trip, like a psychedelic trip, you do need to mix these categories. And so there is a dialogue between the scientist and the person that, you know, on shrooms kind of freaking out.
Ellie: 14:36
Oh, yeah, no, for sure. It's just that the scientist's perspective than one I'm imagining is going to be like, you're not experiencing genuine synesthesia, because there are a lot of studies that talk about that.
David: 14:46
True. And so one of the ways in which we can think about making some headway into our understanding of synesthesia is to ask the question: independently of whether it's genetic, independently of whether it's developmental, independently of whether it's environmental or cultural, what are some of the features of all these experiences? What features do they have in common? And it seems like there are three features that people highlight of synesthetic experiences. The first one is that it really is a perception. It's a percept. It's not an imagination. It's not a memory. It really is something in front of you as part of your phenomenal field. So-
Ellie: 15:31
Yeah,
David: 15:31
important.
Ellie: 15:31
chicken doesn't remind you of the color purple, you see the color purple when you taste
David: 15:37
chicken. Yeah. And that's why it's technically inaccurate to call it an association, because it's not as if you're just like remembering something that was connected in your past experience. The second property of synesthesia is that typically it's involuntary, right? You don't control it, you endure it, or you live through it, as opposed to intentionally bringing it about through an act of will. And the third one is that it has to be elicited by a stimulus rather than being random or spontaneous, like a hallucination. So something in the external world triggers it. And so if we limit ourselves to those three criteria, we end up with a relatively capacious category for synesthesia that can encompass synesthetic experiences of various origins. And that's interesting to me.
Ellie: 16:23
So many artists talk about how they're synesthetic, right? Like you have the singer Lorde talking about how she is synesthetic.
David: 16:31
Beyonce has made references to being synesthetic. And also I've-
Ellie: 16:35
God. Of course, I believe Beyonce. I mean, I believe Lorde too, I believe all people who say they're synesthetic.
David: 16:42
Except the people at the party. And, uh, also I think Kanye West has said that he's synesthetic. I believe across various sensory modalities. So it's something-
Ellie: 16:53
Oh, Kanye.
David: 16:53
some people argue is more common in artists, um, because it makes those people sort of already lean towards an aesthetic worldview. And so you're more likely to become an artist if you already talk about the world in a way that other people find intriguing.
Ellie: 17:09
Oh, definitely. I mean, think about, you know, like a painter being inspired by music. I mean, there's a sense in which if you're a synesthete, you're not just going to be inspired to paint by music, but you're literally already going to see the music as color or potentially as shape, too. And then you may just record that in your painting. I mean, this is now like my speculation. I'm moving away from empirical studies and settling into my philosophical armchair. But, you know, I think that being synesthetic gives you an ability to make connections, right, across sensory modalities. And that might also translate into more kind of conceptual or creative connections. For instance, synesthetes are known to have better memories than non-synesthetes because they can say for instance, like, Oh, I don't remember that person's name, but I remember it was a yellow name. And so I think it was Debbie, but it might not be Debbie, it might be a different yellow name. Debbie, by the way, is a yellow name for me.
David: 18:07
Ah, okay. So then the point there is not so much that they have faster or better memories, but rather that their synesthesia acts a mnemonic device. So it's kind of like the same thing that happens when you read a physical book, as opposed to reading on a screen that you kind of remember, I remember that point was in the top right part of the page, about two thirds in. And so the physical experience becomes a mnemonic aid to the experience of reading.
Ellie: 18:34
Yeah, exactly. So their synesthesia helps them with recall.
David: 18:38
Oh, that's interesting.
Ellie: 18:39
Yeah. And I think that is a really important quality in an artist, actually. I think the ability-
David: 18:44
To remember that Debbie is yellow.
Ellie: 18:47
Exactly.
David: 18:48
I wonder what color Karen is, like if you think about it.
Ellie: 18:51
Karen is like light purple.
David: 18:53
Oh, really? That was a very quick answer. So yes.
Ellie: 18:56
I think like I'm literally a
David: 18:57
synesthete. Not that I didn't believe you, like you didn't believe Lorde. Okay. So what's David? What's David?
Ellie: 19:03
David is yellow. But you as a person- the name David is yellow, but you as a person are rust.
David: 19:09
I'm what?
Ellie: 19:10
You're rust colored.
David: 19:12
Is that another way of saying brown?
Ellie: 19:15
No, terracotta! It turns out that my synesthesia just literally like is the people's skin color.
David: 19:23
Just, it's just racial perception. Now we can just say that like all the people who are color blind are like meta-synesthetes where they're like, I just experience all colors as neutral.
Ellie: 19:39
Yeah, no, I love that. Well, actually, there's a working hypothesis from researcher Anina Rich that the opposite of synesthesia is afantasia, which is the inability to imagine. This, I think, is not yet proven or strongly indicated, but that's like a working hypothesis that she's developing, is this idea that synesthesia basically is like a super, super strong version of imagination, right, where you're making all these connections and then afantasia, inability to imagine anything at all-
David: 20:08
Would be the opposite.
Ellie: 20:09
Opposite side of the spectrum, yeah.
David: 20:11
On the one hand, it definitely goes against the consensus that synesthesia is a perception. It's a percept rather than an imagining, but what I like about it is that it highlights the fact that perception and imagination are not separate. And that is my view, that there is no clear way to separate a lot of our cognitive abilities or capacities, philosophers sometimes call the faculties, like reason and emotion are interconnected, so is perception and imagination. And so thinking about it in that way I actually really like, even though it sounds counter-intuitive when you think about the technical definition.
Ellie: 20:44
Yeah. And I think what you're pointing at, David, cause I definitely agree with you there being trained in phenomenology, is this idea that synesthesia presents a lot of challenges to the way that philosophers and scientists usually think about conscious experience. But to some extent, those challenges that it presents I think just kind of reveal the impoverished way that a lot of philosophers and scientists tend to think about perception, for instance, as divided into five different senses and only five different senses, where your auditory sensations are totally separated from your gustatory sensations and that sort of thing. When you think about what challenges synesthesia presents to traditional approaches of consciousness, what are you thinking about, beyond the fact that for instance, it might trouble the distinction between perception and imagination?
David: 21:54
So in the subfield of philosophy known as the philosophy of mind or the philosophy of perception, there are a number of working theories about how to best explain conscious experience. And some of the questions that emerge in this field are some of those perennial philosophical questions that people who are not trained in philosophy think philosophers spend their time ruminating about, and it happens that they're right about that. Like, what's the nature of my consciousness like? How can I tell at any one moment whether I'm awake or asleep?
Ellie: 22:26
Are we living in a simulation?
David: 22:28
And the philosophy of mind is in many ways a very bro-ish sub field of philosophy, precisely because sometimes draws people.
Ellie: 22:37
Who just thinks that they can like sit in their armchairs and reflect on like the essential structures of experience without having any cultural and historical awareness, but that's for another time.
David: 22:46
No, that's so unfair, but maybe a little bit fair. I know, I know. I know. I know. I know. And since I kind of work a little bit in this area, I feel like I've just attacked myself in a very violent way.
Ellie: 22:58
We've, we're, we're doing the stereotype thing where it's like, when you look at an individual philosopher of perception, like there's a lot of really amazing ones, but the field as a whole, we can judge.
David: 23:07
Yeah. And so the point here, to come back to synesthesia, is that because of the kind of object that it is, both a scientific object and a philosophical object, it really raises difficult questions. And depending on what your philosophical commitments are in relation to the field of the philosophy of mind, you will have to answer different questions when confronted with this object. So for instance, there is a hypothesis out there, typically associated with the philosopher Jerry Fodor, called the Modularity of the Mind thesis that holds that the mind is essentially a bunch of separate modules, that different kinds of information. And this is a well-known theory in the philosophy of mind literature. And there is some research that can support it. So it's not as if somebody just came up with this theory and asserted it.
Ellie: 23:57
Some research that can support a lot.
David: 23:59
Of course. It's philosophy, Ellie, that's literally our lives. Um, and according to modularists, there really is a separation, for example, between the way in which we process spatial phenomena and the way in which we process color phenomena. It just happens, not necessarily in different parts of the brain, although there are neurological versions of modularity that actually cut up the brain into sections, but simply there are different processing systems. And again, what synesthesia does is it really calls into question that separation, because there is a phenomenal or experiential hemorrhage between what are typically assumed to be neatly separated modules.
Ellie: 24:44
Well, let me ask you about that, David, because is the modularity thesis different from the thesis that we have these separate faculties, where emotion, reason, will, perception, imagination are sort of different capacities of the human mind that may or may not be activated at different times?
David: 25:01
So there is a historical connection and you can obviously see why the modularity thesis would be sort of like an offspring of that older way of thinking. But it's not exactly the same, because it's not committed to the existence of different faculties altogether. It's rather to the existence of different modules, which are typically defined as domain specific forms of mental processing of stimuli. So just to give you a concrete illustration, you know that viral sensation that happened a couple of years ago, where you would put a cucumber on the floor next to your cat, and then the cat would sort of like look at it and freak out and jump. So one way to interpret that is to say, the cat has a module, a cognitive module, for processing that kind of stimuli that is an effect of evolution, right? Because it would have been advantageous for animals to sort of spot things that look like snakes right away, without having to think about it. And so that's one of the things that really separates faculties from modules, that modules are automatic, their processing happens before entering the field of conscious awareness.
Ellie: 26:10
So they're mental shortcuts.
David: 26:11
Exactly. That's exactly what they are.
Ellie: 26:13
Okay. So the thesis is not that perception's mental shortcuts are distinct in kind from imagination's mental shortcuts. It's just about sort of mental shortcuts in general, and the idea that we have different ones.
David: 26:23
That the mind is nothing but shortcuts across the board. So that's the radical modularity thesis, that there are all these specialized compartments of cognitive processing.
Ellie: 26:33
But when, when we say compartments or modules, like that's obviously a metaphor, right? What do we mean by that?
David: 26:41
It means functions that would attribute differences in processing to actually different areas of the actual brain. So sometimes those go together, but not always, but the point here being that, if you believe in modularity, you're going to have some explaining to do when it comes to synesthesia.
Ellie: 26:57
Which is probably one of many reasons why you shouldn't buy the modularity thesis. But I think, you know, if you're taking it as a metaphor, like, oh, we have these functions or modules in the mind, okay, sure. But a lot of times, I mean, I think part of my impatience with some of these theories is that they just take themselves so seriously. And don't recognize that what they're doing is creating metaphors. They're doing what Gilles Deleuze calls concept creation. And those metaphors are mostly just reflective of like our sort of common, intuitive ways of knowing because of the particular culture that we currently live in, right. We think about the mind as modular or functional, because we are driven by a sort of ideology that emphasizes computers and machines as sort of the standard, right. In a previous era, it would have been the clock as a machine or the sort of movement of the spheres. And so, yeah, that's just to say, like, I think there's a lot of hubris that goes on with a lot of these theories. And I would just want to say, like, we can think about the metaphor of the mind as a module, as a metaphor, but I mean, once we get to the brass tacks of it, like, is there really a lot of reason to believe that the mind is a module? I, as a phenomenologist, am inclined to say no.
David: 28:06
Oh, and I agree with you. So I, myself, am not a modularist, but it's important to note that defenders of the modularity thesis will say two things. They will say, number one, this is not a metaphor because we can isolate these cognitive modules. So again, think about the example of the cat automatically jumping at the sight of what it unconsciously processes as a snake. So it would be kind of hard to attribute that to like a cat culture, to something that changes over time, you know, like, oh, well, 50 years ago, cats wouldn't have done that because it was not in vogue.
Ellie: 28:37
No, no, no, no I'm not cat's response is cultural, like I think it's perfectly intelligible to talk about that as biologically evolutionary. What I'm saying is that the interpretation of that behavior on the basis of a module is culturally inflected, if not culturally determined, right?
David: 28:54
I absolutely agree with you and in general, I am of the view that most of our scientific knowledge, not about the brain, but about consciousness and the mind and experience is purely metaphorical because what we typically do is we reach out for the technologies that dominate our culture, and then we use them as a sieve or as a filter for interpreting ourselves. And so historically the mind has been interpreted through the metaphor of pottery and clay, think about the Genesis story in the Bible, it has been interpreted through the language of hydraulics at a time when hydraulics was the latest thing in technology.
Ellie: 29:33
Or a blank piece of paper, right, in the 18th century that we can sort of write on or stamp with empirical knowledge.
David: 29:40
Yeah, like the tabula rasa and it's no surprise that in the 20th century, during the cybernetic age, we started projecting a computationalist metaphor into our understanding of experience. We agree here. It's just that the people who defend the modularity thesis disagree with our disagree- disagree with us.
Ellie: 30:01
Yeah, I want to throw one other philosophical puzzle into the mix that synesthesia presents for philosophers of perception. And that's the idea of qualia. So qualia are basically subjective conscious experiences, and philosophers have typically thought that you can only have one of these at a time. And synesthesia makes you wonder, well, actually, when I'm hearing the word jail and tasting bacon, those are in principle distinct. And so how is it that those are united under a single quale? Don't we need to be talking instead about the multiplicity of quale at once?
David: 30:39
And to amplify this point, we can think about all forms of synesthesia as raising a difficult question about the nature and origin of qualia, our subjective experience of things, the way in which things feel to us.
Ellie: 30:52
Qualia, qualia. Tomato, tomato. You can say it either way.
David: 30:57
Yeah, I just say quail. There is one particular form of synesthesia that multiplies this problem in a way that really becomes paradoxical and that's color grapheme synesthesia.
Ellie: 31:11
Yeah. The one that I have that makes me see A as a light red.
David: 31:14
Well, but there is a subsection of color grapheme synesthetes who report that they see a grapheme like the number four as having two different colors at the same time. And so this is what it's known as the extra qualia problem in the philosophy of synesthesia. And so they will say, when I look at the number four, it is, let's say, red and yellow.
Ellie: 31:40
Are those next to each other? Are they superimposed?
David: 31:44
This is why it's considered an exotic phenomenal experience because the people who experienced this are very clear in their testimony that when they're talking about two colors, they do not mean superposition. So it's not like the colors mix. They see red and yellow, but not orange. They are very explicit about this. And they also say that it's not alternating. It's not like yellow first and red later. They see both of them at the same time. And moreover, they say that they don't see yellow here and red there, so it's not spatially differentiated. So they see the number as simultaneously red and yellow, but not orange.
Ellie: 32:27
Woah.
David: 32:30
It's
Ellie: 32:30
oh,
David: 32:31
utterly unfathomable from the standpoint of somebody who doesn't share that experience of the world. That's why it's called the extra qualia problem where it's like, you're doubling something that we tend to think of as exclusively singular.
Ellie: 32:45
You're doing such a better job of describing the qualia problem than I was, because I was like over here thinking like, isn't it so weird that they think it's hard to explain the coexistence of the word jail and the taste of bacon, but okay, that does seem like a genuinely interesting problem.
David: 32:59
Well and it, it highlights the extent to which certain forms of lived experience are untranslatable into others, which is something that really motivates my thinking about phenomenology and the philosophy of mind that I'm really fascinated and drawn to these cases of what are called exotic phenomenal qualities, right? Just like, how is that even materially possible? How is it even-
Ellie: 33:23
The word exotic is not canceled?
David: 33:25
Not when you use it about synesthetes, it's fine.
Ellie: 33:29
Okay. Synesthetes, exotic. Ooh, Ooh. Um, okay. Well, this is a really crappy transition now to indigenous perception. Moving away. I know- I know, moving away from the exotic in the technical use that you were using David to, to a completely unrelated non-exotic approach. I think what's really interesting in synesthesia research is this idea that humans have a propensity for synesthesia that we have lost over time because of the specific formation of our culture. So I want to return here to David Abram's book Spell of the Sensuous, because this is what he basically says about our perception. I'm going to go ahead and read a passage from his book because it is really a-
David: 34:14
It really is wonderful.
Ellie: 34:16
If I attend closely to my non-verbal experience of the shifting landscape that surrounds me, I must acknowledge that the so called separate senses are thoroughly blended with one another. And it is only after the fact that I am able to step back and isolate the specific contributions of my eyes, my ears, and my skin. When, for instance, I perceive the wind surging through the branches of an Aspen tree, I am unable at first to distinguish the sight of those trembling leaves from their delicate whispering. My muscles too feel the torsion of those branches bend ever so slightly in the surge and this imbues the encounter with a certain tactile tension, still reading, the encounter is influenced as well by the fresh smell of the autumn wind and even by the taste of an apple that still lingers on my tongue.
David: 35:04
No.
Ellie: 35:04
Our primordial, preconceptual experience is inherently synesthetic. So basically David Abram gives this lyrical description of what it's actually like to experience being in the woods and hearing a tree while simultaneously feeling it and seeing it and concludes here that this kind of commingling of sensory modalities only seems strange to us to the extent that we have been estranged from our direct experience, especially through our focus on written communication and reading.
David: 35:33
Wait, what do you mean especially through writing and reading? What's the argument that he makes, because I've read the book, but it's been a few years. So walk us through that connection here.
Ellie: 35:44
Okay. So basically before human cultures had writing, we, according to Abram, were all synesthetic. We had this kind of intensely attuned perception of ourselves and the world around us that was a kind of concert of the senses. Then, once we develop written communication, especially through the alphabet and especially in traditions where the alphabet is actually cut off from actually inherent meaning, right. So instead of having a hieroglyph that indicates a raven, you would have the word R A V E N. So there's like no inherent connection between the actual thing and the letters.
David: 36:25
So from iconographic to alphabetic language.
Ellie: 36:28
Exactly. Yes, that we start to withdraw our perception from the immediate world around us and kind of channel our synesthetic abilities into reading and writing. Because reading, as you mentioned before, David, requires a kind of synesthesia. When you read letters, you are translating them into sound in your mind, often for people into images.
David: 36:53
So my memory is a little bit vague here, but I remember that in the context of talking about this primordial synesthesia, he mentions some research in linguistic that shows that in a lot of languages, words that have this sound S for example, like sss refer more often than not to objects in the world that themselves make that sound. So for example, the original word for sea or ocean, it has that sound that the ocean itself makes and it's because those early forms of expression embodied or expressed rather than represented things. It's only when we moved to alphabetic language, like the Greek alphabet in particular, that then we get a clear separation and letters start merely representing sounds that themselves represent the world.
Ellie: 37:48
Exactly and that according to Abram, we also get the whole idea that concepts and representations are cut off from their manifestations in the literal world, which you see a lot in ancient Greek philosophy, one of the first, strongly alphabetic cultures. Now in contrast to that type of view, right, so you have Socrates' idea of the forms where the true chair is intangible, and it's just this kind of pure eidos, concept, as opposed to like real chairs in the world. On the other hand, Abram mentions the cultures of Aboriginal Australians. One of the key features of oral cultures in Aboriginal Australia is the idea of naming areas of the landscape. And the idea is that naming is a mnemonic device that allows you to say travel over large distances while keeping track of where you are, because each place has a particular name or a particular story that comes out when you pass over it. And he describes this anecdote of driving the car with an Aboriginal Australian who was going slow over a landscape at one moment and was reciting the names of the landscape while doing that. And then once the car sped up, his recitation of the names of the landscape met the new pace of the car. And so Abram says there's such a close tie here between his physical experience of the landscape and the oral recitation of the names that his speech like literally automatically caught up to the speed of the car and then slowed down again when the car slowed. I think that just paints such a different picture of perception than the one we're used to. And Abram says it's only possible in a culture that does not rely on alphabetic written language.
David: 39:34
I like that he very much makes the development of Western idealist philosophy that creates this other world, like the world of platonic forms, contingent, or he describes that as an effect of the existence of the alphabet, right? So the alphabet alienates us from this primordiality, and once that break happens, he says that's the origin of sort of Western culture with everything that that means later on, including industrialism, the focus on technology.
Ellie: 40:06
Our obsession with concepts, everything that the bro philosophers of mind and perception do, modularity thesis.
David: 40:15
Yeah. But for him that the real break happens with the alphabet.
Ellie: 40:19
Yes. According to Abram, we lose our synesthetic relation to the world by transferring it into this sort of deficient and localized area, which is reading and writing.
David: 40:30
Yeah, the alphabet instead of synesthesizing us, anesthesizes us. Oh!
Ellie: 40:48
Enjoying this episode? Please rate and review us on Apple podcasts, Spotify, or wherever you listen to your podcasts. You can also connect with us and other listeners through our Facebook page or group as well as on Instagram and Twitter at @overthink_pod. I mentioned earlier that consensus in the scientific community about the prevalence of synesthesia is starting to change with the development of online communities who are talking about their experiences of synesthesia and starting to realize how common it is. But there's a long history of research in synesthesia. Over to you, David, want to tell us a little bit about it?
David: 41:28
Well, yeah, because as you know, history of science is a passion of mine. Yeah. I love it. And there is a really interesting history to how synesthesia became an object of scientific interest. So of course, people have written about synesthesia for a very long time. So for example, Aristotle wrote about this already 2.5 millennia ago, but.
Ellie: 41:50
Did he call it synesthesia?
David: 41:51
So he used the word aesthetics, which is ambiguous in the ancient Greek, because it can refer either to sensory experience, but also to art. Now the history of scientific interest in synesthesia really begins in the late 1600s. And it's a story that involves the English philosopher John Locke, one of the fathers of empiricism. In his essay, "Concerning Human Understanding" Locke references a synesthete that he knew. And it was this guy who told Locke that every time he heard the sound of a trumpet, he experienced it as a deep scarlet red. So it was a sound color synesthesia. And after Locke writes about the trumpet guy, it becomes a major debate in Europe and suddenly all these big names start jumping into the fray about how to understand this phenomenon. What kind of theory can we put forth to explain how this guy can possibly experience the sound of a trumpet as a scarlet red? And so, for example, Adam Smith jumps into the debate. He's the father of the metaphor of the invisible hand of the market.
Ellie: 43:06
He takes a break from talking about homo economicus, the way that humans are guided by rational self-interest, in order to just like, make a little claim about synesthesia.
David: 43:15
Trumpet guy side, free market on the other side, but Erasmus Darwin, Darwin's grandfather also gets involved in this debate. So those, uh, Goethe, the German poet, as well as Newton, Isaac Newton, the father of modern physics. And-
Ellie: 43:32
Damn we got some like casual, heavy hitters.
David: 43:35
Yeah, and it all is traced back to, again, this very short passage Locke's essay "Concerning Human Understanding." Now there were a number of theories that were kind of tossed around to try to make sense of this, but the most famous one was this theory that just as sound is a vibration of the medium between you and I, so we make the air vibrate when we make sound waves. What if we think about color perception and light also as a vibration of the medium between us, of the ether between us? And so if we interpret both sound and light as a vibration of a medium that separates subjects, then you just look at the rate of vibration of a color and you map it onto the same rate of vibration for a sound. And so this was the theory. Now, today, we don't think about light in that way. So we don't quite accept that, but at the time this was the best working hypothesis. And so even though the issue was not really settled, Europeans become fascinated with this question. And so it's suddenly like musicians and inventors start hearing about this debate that is happening about-
Ellie: 44:45
Beyonce of the day is like, oh, I have that.
David: 44:47
And so everybody starts hearing about trumpet guy. So there was this whole project amongst musicians and inventors working together to create a musical object that you could play and that would produce sound as color.
Ellie: 45:01
Whoa, synesthesia machine.
David: 45:03
Yes. It was the synesthesia machine and they created all kinds of instruments for this. Some of them look like a piano and you would like pluck at the strings and then it would project colors. So kind of like multimedia art installations. And some of them were really complicated and they look kind of like a church organ.
Ellie: 45:20
Well, I just want to flag too that it's interesting to think about the fact that when these debates were coming up in the late 17th century and then into the 18th century, they're talking about the metaphors of waves, right? They're thinking about this in a very different scientific way than the way that we think about it now, right? The idea of waves kind of flowing between us as opposed to synesthesia as a neurological condition, which is what you find in a lot of the definitions of it today, where it's kind of like located on a personal and even brain-based level.
David: 45:49
Yeah, you're right. Now, we're in a very different place where instead of trying to create musical instruments that prove the reality of synesthesia, we intervene directly on subjects in order to manipulate their experience of the world in different ways to either support or falsify different accounts of synesthesia.
Ellie: 46:10
Yeah. And some synesthesia research today is trying to kind of solve medical problems. For instance, Anina Rich talked about how because synesthetes tend to have better memory than non-synesthetes, researchers are trying to figure out whether we can tap into the sort of power of synesthesia for people who have dementia based memory loss. And so like, can synesthesia teach us something about how we remember and can we even cultivate it in a way?
David: 46:37
Well and the question of cultivation for me is foundational because it indicates that our experience of the world is so plastic that we might be able to, through the proper training, become synesthetic subjects even if we previously didn't experience the world in that way.
Ellie: 46:54
But maybe you like have to stop using the alphabet in order to do that.
David: 46:58
It's like this illusion.
Ellie: 46:59
We want the full picture.
David: 47:01
Yeah. So the solution to our problems is just to forget written language.
Ellie: 47:06
Okay.
David: 47:06
But there is some really fascinating research on the production of synesthetic experience. And one of them is an experiment that was conducted by Jamie Ward and Peter Meijer in 2010 and that was published in a very well-known and respected journal called the Journal of Consciousness and Cognition. And what they did is they tried to show that you can produce synesthesia in a subject by manipulating the way they experienced the world. So what they did is they created this machine called The Voice and it's a machine that they-
Ellie: 47:43
Not to be confused with the TV show.
David: 47:46
Yes. It was not the subject of an article in Consciousness and Cognition.
Ellie: 47:52
That's the one I currently have under review with them.
David: 47:54
Okay. They use this machine specifically with visually impaired research subjects. And so the way the machine works is really fascinating. You basically mount a camera that records what's in front of you on your forehead. The camera records what's in front of the subjects and it produces an image. Now the machine has headphones that then go into the ears of the research subjects and what the machine does is it translates the visual feed of the camera into an auditory stimulus for the subject. So the machine will go down the rows of pixels and translate each pixel into a sound. And so if it's a really, really bright pixel, it will be a kind of louder sound. And so the research subjects who put on this machine get an auditory reading out of the visual scene that they, because they are visually impaired, cannot see.
Ellie: 48:53
And when you say they're visually impaired, David, do you mean that they can partially see or do you mean they're fully blind?
David: 48:57
Yeah, they were completely blind. And what's really fascinating is that initially when subjects put on this machine, it doesn't mean anything, right. It's just like hearing a bunch of random sounds that don't cohere, but, as they got habituated into using this machine and getting an audio feed of whatever the camera records in front of them and that feed changing as they change their position in the world, they over time started to experience the audio sound as visual phenomenology. So they started perceiving shapes and figures and dimensions that are not typically associated with auditory stimulus. And so it's presented as an example of a laboratory induced form of synesthesia where you produce vision through sound. I mean, how intense is that?
Ellie: 49:55
So I'm curious here because, you know, the machine is taking the visual stimuli and translating it into auditory stimuli. And then the subject is taking the auditory stimuli and translating it into visual stimuli, right. So that seems more like a translation than genuine synesthesia. Is that right?
David: 50:12
Well, no, because of course we can talk about the machine doing a translation work, right? The machine translates the visual feed into an auditory feed, but we cannot speak of the subject as doing that translation because subjects are not translation machines as you said yourself earlier, Ellie, not computers.
Ellie: 50:30
Now I am a modularity thesis believer. I don't know if they really think that, but.
David: 50:35
And so, you know, we can use that language metaphorically. We can say that the subject translates the thing that they hear into a visual experience, but that is synesthesia because there is a phenomenological dimension, they experience a visual phenomenon, and it's very difficult to explain how that happens. So sure, it's a translation, but it's a phenomenological reality for the patient. So it's not that they are hearing the sounds and then cognitively thinking about what it could mean visually, it's that they are actually perceiving something that is visual, even though they are blind.
Ellie: 51:11
Um, I think one thing to put in the mix here, because I was just looking this up out of curiosity, is that in the study you're referring to David, it was two subjects and both subjects had gone blind over the course of their life. They were not congenitally blind. And that seems really relevant to me because, you know, they both had previous experience of what sight was like.
David: 51:31
Of course, but that doesn't rule out the possibility of synesthesia.
Ellie: 51:35
No, I'm not saying it does. I'm just saying that, you know, I think it would be like a very different case if somebody who had never seen before was suddenly experiencing audio visual synesthesia through this machine, which isn't to say that like this research isn't really interesting. Cause obviously it is.
David: 51:49
Oh, yeah. So they've done that with people who have lost sight. But they've also done it with sighted subjects or visually non impaired subjects who then are blindfolded. And the point is that there it happens again, but it takes months of using the machine in order for the subject to truly integrate this prosthetic into sort of like it's body image, into its body schema, and really sort of be at one with it. And so it's interesting here to think about how Abram, whom you've talked about earlier, warns us about our possible alienation from the world. And this research indicates that we can become so intimate with an artificial prosthetic machine to the point that that can become part of our own nature after a while.
Ellie: 52:36
Suggesting that we can, in fact, cultivate synesthesia.
David: 52:39
Yeah, that's right. And so I like thinking about that being the kind of work that we should be doing, right? Like broadening our experience of the world, playing at the limits of the phenomenal. That just seems so fascinating to me. We hope you enjoyed today's episode. Please rate and review us on Apple podcasts, Spotify, or wherever you listen to your podcasts.
Ellie: 53:07
You can find us at overthinkpodcast.com, where you can email us with questions, feedback, or even requests for life advice.
David: 53:14
You can also find us on Instagram and Twitter at @overthink_pod. We want to thank our audio editor, Ross Harris, and our production assistants, Sam Hernandez and Lokyi Ho.
Ellie: 53:24
Thanks to Samuel P.K. Smith for the original music and Trevor Ames for our logo. Thanks so much for joining us today.