Discovering the What and the Wherefore: Scents and Sensibility

00:00:14 FL

00:00:57 okay I think we can start I'm at the edner sessan the director of the center uh and this is the uh third round table of the series on the census uh today's is on smell and uh the next one in two weeks will be on sound uh Jerry Hartz who's the associate director will introduce the participants and then we'll get

00:01:28 going good afternoon everyone welcome I have a wonderful list of uh Round Table Round Table participants today we're get very excited about this uh topic today so will you raise your hand please when I call out your name Mark Smith is Carolina distinguished professor of history and Claude Henry nuffer Chair of Southern studies at the University of South Carolina where he is also director of The Institute for southern studies he is a fellow of the royal Historical

00:01:58 Society Smith specializes in the history of the senses and is author of a century history Manifesto and editor of smell and history a reader Claire baddy is associate professor of philosophy at the University of Kentucky and research fellow at the center for all Factory research and applications at The Institute of philosophy University of London her research interest are in the philosophy of perception and in particular the philosophy of all faction

00:02:29 she has published numerous papers on the nature of object representation in all Factory experience including a representational account of ol Factory experience and several others more recently she has turned to issues of property representation those of humans as well as other animals and spatial representation her most recent Publications include scent and the space between us with and with Barry C Smith a world of odors she received her PhD from

00:02:59 MIT in 2007 James Bower is a visiting professor of computational Neuroscience in the biocomputation research group at the University of herfordshire United Kingdom as well as an affiliate professor of biology at Southern Oregon University in Ashland Oregon he was previously a professor at the University of Texas system at the California Institute of Technology Dr Bow's research in computational Neuroscience is focus F on

00:03:30 the physiological and functional organization of cortical structures in the mamalian brain including both the old factory cortex and the cerebellum he has been actively involved in development of scientific in infrastructure including the Genesis neural simulation system as well as founding several scientific meetings and journals including the annual international meeting in the comput in computational neuroscience and summer courses in computational Neuroscience in the United States Europe and Latin

00:04:02 America Andreas Keller is a new york-based academic with phds in neuroscience and philosophy who was interested in olfactory perception he has over a decade of experience in olfactory psychophysics and the clinical aspects of olfaction the results of his of his experiments have shed light on human olfactory capacities on the relation between the structure and smell of odor molecules and on the perceptual consequences of variability in an odorant receptor Gene genes he is the

00:04:33 author of the philosophy of olfactory perception in which he explores the philosophically interesting difference between seeing and smelling and the owner of all Factory art Keller an art gallery in New York's Chinatown that is dedicated to the exploration of scent as a creative medium John McAn is the director of the rutge University Center for Cognitive science and a tene professor of behavioral and systems Neuroscience in the psychology department at

00:05:03 ruter he runs the mean laboratory on the neurobiology of sensory cognition which uses the olfactory system of humans and rodent models to explore how organisms learn about and interpret their sensory World his peer-reviewed scientific work has been published in prominent journals including science neuron and the Journal of Neuroscience his 2017 paper in the journal science arguing that the human sense of smell is excellent and impactful was downloaded 5,000 times in

00:05:35 the first month and featured in discover magazine's top 100 discoveries Dimitri renberg is a professor of Neuroscience and Physiology at the NYU grosman school of medicine and joined the field of Neuroscience after having completed his PhD in physics at the Weissman Institute of science his research comprises Three core domains de deciphering ing the fundamental principles of neural coding exploring olfactory information processing in the brain and harnessing

00:06:06 the olfactory system's remarkable sensitivity as a chemical director the rnberg lab pioneered new theoretical Frameworks for understanding the sense of smell alongside the development of cutting age Technologies for communicating with the brain by combining fundamental and appli research the rimberg lab pushes the limit of our understanding of the signaling of the signal processing in the old factory system while also developing novel applications such as odor-based disease Diagnostics the the list of these uh

00:06:38 these panelists accomplishments goes on from there but I so I truncated a bit but as you can see we've accumulated quite a core of experts on the topic for [Applause] today can you hear me is that is it on now yeah yeah so we put together this five-part series on the senses and of course right off the bat I have to decide or I had to think about what's the order we should do the senses in

00:07:10 right so we did something I think that's sort of intuitive where we started with touch taste and smell was sort of like a toss up and then hearing and sight and we can all go into why that was what I thought of as sort of a natural just I don't really intend to defend it strongly but anyway there's something natural about it but I have to say something interesting about contrasting Tastee and smell which I just acknowledge we're like in a in a fight for second place or third place uh people go oh taste yeah that sounds good I want to go hear about taste and smell

00:07:43 there's something a little on the aesthetic something low low or lowly about smell I think so I'll throw out that sort of aesthetic comment and see what you all think without Al faction there is no taste or in other words the contribution of the older system to taste is the contribution you don't have if you have a bad cold so most of the Nuance I was riding

00:08:17 here on an airplane with a guy who's a big uh real estate lawyer in New York who got me front row tickets to the Rangers game two days ago anyway but and he said I have you know I don't have a sense of smell and I said do you like asparagus he said I love asparagus I said okay then you have a sense I mean I think this this is back going back to the plane theme um it is it is a a common reaction when you sit

00:08:50 beside somebody on the plane and and they they get chatting to you that they ask you you know what do you do I'm a philosopher that can go one of two ways well one of many ways it's either going to go what exactly is philosophy perception or you know okay what do you what do you study and I say all faction you get to oh you know you get a kind of oh okay right right and there's this kind of um assumption this kind of reaction where it's it's oh it's dealing with icky things you know gross things as

00:09:21 opposed to uh beautiful things like perfume that is not the first reaction that I yeah so the the the IL mate reaction is is is seconded in that yeah people people think of smells just as a one dimension from Pleasant to unpleasant if you give people smells and tell them to arrange them they're going to do it from the worst to the best nobody would do that for colors like this is my favorite color this is my least favorite color they would arrange it by the quality of the color and taste

00:09:53 this quality too sour bitter so the qualities are really what's important there and for smell for many people it's just a onedimensional pleasant unpleasant thing so when people come in my gallery and smell something it's like oh I like it oh I don't like this they wouldn't go in a you know Fine Art Gallery and look at paintings and be like this is ugly and this is pretty right they would talk about it in a completely different way so for smell this Dimension it's there some people

00:10:26 can talk differently about it but it's usually ignored there is something quite artificial about dividing the series into five separate modalities I think it's become increasingly clear both from a neuroscientific basis and perhaps even from a philosophical perspective that a lot of these things we have traditionally parsed into separate modalities actually really profoundly interact uh both in the biological sense that you've got you know think about the the taste of a buffalo wing you've got I

00:10:56 don't know five or six senses involved in that right because you've got both the the the sort of true sweet sour salty bitter taste you've got the retronasal smell you've got the orthonasal smells it comes to your mouth but you've also got this trigeminal mediated chemesthetic sense of heat and spiciness you've got the physical warmth or cold if it's a been sitting a little too long um and uh even some of the the bone conduction of the sound of the crunch as you go through it if it's bread it or things like that I mean it's it's true both in our experience that

00:11:27 these that our experience uh intensively crossmodal uh but also in at the level of neural processing it seems like this information is coming together early to make uh to make sort of richly multimodal representations and then also feeding back such that each sensory system potentially knows a lot about what the other sensory systems have or might experience so well I'm I'm the um least qualified to speak on these matters as an historian because historians don't see taste as stable or

00:12:01 as a purely aesthetic question the historian would trace the context in which a smell had a certain meaning and how that is learned over time and your air airplane example is very interesting not least because I think there's a tendency towards habituation right in which smells that are new then become accepted and not worthy upon comment the historian at the challeng is finding the silence in the record cuz

00:12:32 that tells you when the smell is now normalized so depending on when you're on that aircraft how old you are who you are when you're flying there will be a comment on the smell or not so the challenge for the historian is to look at change over time and it's not a stable sense at all so when you talk about the Aesthetics of smell I wrote a chapter on the smell of gettsburg right the smell of the battle of G B is an entirely different experience than

00:13:02 seeing Gettysburg right and there are 6,000 dead soldiers 2,000 dead horses and mules in the July sun in Pennsylvania gettsburg expands its Geographic space not because it's seen but because it's smelled the smell of death is caught and and spread over it lasts until get the Gettysburg addess you can still smell Gettysburg long after it happened yeah I heard they photoshopped out the [Music]

00:13:34 Lincoln I'm not sure what they what that actually does to be honest with you but one of my one of my concerns is how do we treat the historical reproduction of smells by people who experienced them at the time because this is big business right so what does Civil War rein actors do with the smell of Gettysburg what do you do with that well they don't wash right they reenact it every year and they don't wash they want to have an authentic Claim about

00:14:04 reexperiencing the smell of Gettysburg but I have grave reservations about the implications of that can we consume the past through smell even if we could reproduce it are we reproducing the experience of people in 1863 today noses change aircraft change Airlines change all of these things have to be contingent on when and who is doing smelling uh just it's it's super

00:14:34 interesting what you're saying I'm a little bit coming back to the question about uh uh taste and smell probably the most profound differen is one is in remote sense in order to to kind of taste and smell something you need to bring to your mouth you know smell is actually one of the remote senses like vision and uh and uh audition your sense and you actually experience something outside of your your body and through biology through evolution of the senses

00:15:05 it was one of the very important for that reason uh and that's actually uh uh kind of make it different from taste and what has been said about the role of function for taste for food perception of course absolutely but smell is uh has a very special uh different from taste for that reason and on hly speaking I never experienced this effect when somebody asking me what you study says wow mostly the effect was like that

00:15:37 rather than kind of smirking maybe it's the philosophy plus the yeah I think they just think something suspicious is going on yeah it's much more interesting than I'm an historian really ey mask goes onori in the South who has a funny southern accent well yeah that's always the comment it's not about what I do it's like why are you there in the South what are you doing so one so couple of

00:16:07 things and this is first the reason I'm in New York at the moment is because 25 years ago we speculated that the old factory system actually works by detecting the presence of metabolic pathways and that those metabolic and that has something you've learned over revolutionary time so there is a stability we would suggest in fun mentally and all Factor perception that has to do the fact that we think and we have reason to believe this is true that it's dependent on detecting metabolic

00:16:37 pathways okay not alahh alcohols and the sorts of things that chemists like to throw out the olfactory system so that's one thing but the second thing the multi-sensory thing that's interesting about the olfactory system and it's not only Maman it's all olfactory systems as you know you know is that the olfactory system is sort of special in brains in a way because you go directly from the primary in in mammals for example the

00:17:08 primary alector cortex the next structure which is called the endoral cortex is the most multimodal cortex in the brain in insects it's the mushroom bodies so the W factory system in par and then by the way from anal cortex you go to hippocampus so most people in this room know that one of the things about all faction is that it evokes very strong memories and people believe the hippocampus is involved in that so the point is that uniquely for the old

00:17:39 factory system in some ways it is clear that you need multimodal information to be able to distinguish which by the way is also why the old factory system is so heavily context dependent because the the as we probably you know the physicist figuring out what what something is by what it the molecules you get I meaning coffee it's 450 different chemicals figuring that out is tricky difficult computationally

00:18:11 right and you need additional information so the wagor system in particular depends on context from other sensory systems and then but once you have it which is as you were talking about it's sort of a Galt type perception all right then you go straight to the hippocampus and the last thing to say about that is as you know I'm sure everyone here does know that the perfume industry is based on noses these are people that are highly

00:18:42 trained to break down the smell to something other than its honic value which is what he was talking about so to get humans to actually decipher the components of a smell rather than a saying I like it or I don't like it or reminds me of Grandma okay uh you have to train them to be able to actually figure out and once you do you get paid you know $200,000 a year to sit in

00:19:13 Laboratories and identify what oders are so I recommend anyone that wants a career path if that's an interesting one I know yeah but the the context it not not necessarily only helps to figure it out it can also be conflicting the different senses and then smell always loses right so if you have an apple that smells like a banana you show somebody an apple and it smells like a banana and ask them what is this they're going to say an apple they're

00:19:45 going to ignore that they smell a banana if you show them a banana that smells like an apple they're going to be like this is a banana so we trust intrinsically our visual information more than our alory information and so the alory the the visual information and all the other context information can push around our identification of a smell into very very different territories there's interesting studies where the exact same molecule um is presented to people in

00:20:18 different context and it's a molecule that's found in stinky cheese and also in you know dirty sweaty socks it's the same molecule isovaleric acid and if you present it to people making them believe that it's sweat they talk about it very very differently when they get the same thing and you tell them this is a a fancy cheese and so that you know like the the philosophical question that you can answer for us then is does it smell different or does it smell the same but

00:20:50 people put all this other stuff together and come to a different conclusion also it smells the same to that or is that interaction at a perceptual level where it actually modulates the smell of the molecule into something else CL I I didn't mean to put you on the spot like that reminds you what you were saying before about how it it can change also over time how how it's experienced yeah right so so I would pick up on if you tell them something

00:21:22 yeah and I would go back one step depends on who's saying what and from what position of authority they're saying it so if you look at the history of race in this country modern segregation began with the the 1896 py versus Ferguson case right in which a visually ambiguous black man Homer pie sat on a railroad car in New Orleans in order to test whether or not segregation would work so

00:21:54 he sat in the white car he had to tell the conductor that was technically African-American under Louisiana law he was visually ambiguous but Louisiana law was it's this proportion if and they tested it they took it a call you couldn't tell his race visually so the authentication of you know Visual Evidence was highly dubious and they were trying to expose that that case went to court and the prosecutor

00:22:24 responded to the question from the judge the judge said how how can you tell his race if you can't see him cuz if you can't see him you can't possibly have a system of segregation and the prosecutor replied I don't need to see him I can smell his race there is no evidence of course that race is smellable it's a social construction but the point is it was the state saying they could and if you're in the position of authority to authenticate that a group of people smell it doesn't matter if you can

00:22:57 empirically identify it what matters is the authority of the state to underwrite it and that matters a great deal so it's really who's telling you that it smells like a banana is it the authority of science behind it is it the authority of a state and it can have enormous implications because if you look at the beginning of segregation you you can't explain segregation without reference to the deployment of The Stereotype of smell it was not simply a stable visual category

00:23:30 it had to be invoked as an old factory one yeah that's definitely true when I'm at wine tastings you drink the wine and then the person tells you oh that tastes a little bit like banana and then you're like oh yeah yeah now I can taste it right so you go along and the more charismatic and you know certain they are the more you go along with whatever they tell you and I often wonder if you would just do something such a thing and tell people random words what it smells

00:24:01 like if people would just not along there's a lot of these like suggest ability experiments where like you know the teacher opens a botle and tells people it's filled with a horrible smell and people should raise their hand when they smell it so I can tell how it spreads and people start raising their hands and then the people next to it start raising their hands and then like a wave of raised hands go through the classroom and there's no SM in there you have to be a little careful because our experiments with

00:24:32 mice they are much more likely to rely on the old Factory uh percept than the visual of course mice aren't yeah very Visual and although the psychophysicists keep or the neurobiologists keep trying to make them into division Animals by wiping down every cage with alcohol before they actually do the experiment which I pointed out recently to someone from the Allen Institute means you're basically dealing with a PTSD

00:25:03 Mouse uh who's in an environment that they don't know how to decipher because there are nil Factory stimuli and you're flashing visual stimuli at them so you're studying the brain in a very bad state but anyway um so humans you know and also obviously Human Society right giving you a predisposition to go one way or the other and tons of marketing is is based on this as we know especially and but one other thing to say we haven't talked

00:25:33 about the contrast between vision and Al faction you know probably a hundred times more people study Vision than study action maybe a thousand more okay um which is odd for a bunch of reasons but anyway one difference between vision and olfaction is that in olfaction the thing is actually in your nose so it's not an inferential sense and the nervous system knows that that's why scratch and sniff movies don't work

00:26:03 because if you're sitting there in a movie and they tried scratch and stiff movies okay as soon as they put an odor everyone comes out of the movie and assumes that the guy two rows back is doing something they shouldn't be doing okay so you come out of the the presence of the movie and immediately start to interpret and think about what might be going on in the room you're actually in because if the old Factor probably guess the old factory system gets a signal it knows it's real may not know what it is

00:26:35 but it knows it's real uh and so it's hard to that so they don't scratch and stiff movies don't work but conversely it's illegal to use subliminal advertising and vision okay which they also tried in the 50s and it's illegal because it doesn't work uh the perfume industry the factory system which does work is not legal it's a multi- multi-billion dollar

00:27:09 industry so coming back to vision and Al auction I actually believe that part of the mystery of our function is our lack of knowledge and if you think about it uh for example context dependence if we don't know the Dr chromatic vision that we have red green and blue you know looking at the all kind of the illusion when you see different colors will be completely mysterious because the color

00:27:39 perception depends on the context and they recently know blue or gold uh um dress was very famous illusion that kicked the internet and um it's actually similar basically we now know the basis of the of the color Vision it has been more or less discovered at the beginning of the 20th century the color vision and we understand the tromatic vision and now we can understand the context dependence I strongly believe the same thing happening with LA function there is a

00:28:11 Basics which we still don't grasp and on top of that there's a context and all this stuff this is on top of that and until we understand this we can speculate of the role of the you know all these factors but fundamentals is not yet established so and I can speculate why it is it's much more kind of complex system I mean compared to color just because of the variety of the degrees of freedom uh uh but uh and much less

00:28:43 effort was invested in this field as Jim pointed out that only you know maybe 100 or thousand less people working on our function uh but um I don't see big difference well I mean is the context dependence with all faction more related to the say emotional milu as opposed to Vision where for example when they work out you this complexity is the visual system it doesn't seem that applies as

00:29:15 much am I I mean that's that's how I was going to initially answer in part or start to answer your your question was to say that um you know there's there's context dependence in in vision and in so far as we're thinking about way this ways that things might work differently or the same as philosophers and thinking about whether or not sort of what color a a color chip against a different background actually has and whether we go sort of relational on it as we will say um very same questions come up in

00:29:47 the case of w action for for philosophers and so we we I mean I don't think there's many people sort of that have been doing that so far in the in the philosophical literature but one one interesting question is to think about the context dependent context dependence in Al faction which we might not have just enough information yet to really answer the question whether or not it's a kind of honic thing or whether or not it's a quality thing um the way the the color cases present us or whether it's I

00:30:19 don't know in the cases of the chi a matter of of belief or some sort of cognitive state so these are these are super interesting questions that the philosophers are are very or ought to be or are very interested in yeah one one also has to you know consider the possibility we talk about you know how unreliable and context dependent smell is but maybe that's because we use the same things we use for vision same tests for all faction right so if you these the same tests for a system that evolved

00:30:50 to do something else you know it's the giving you know giving giving the wrong test to assess how good it is if all faction's main function is to like you know guide behaviors or modulate emotions mood States or something and not to have naming which you know is a plausible assumption then you know those tests banana or apple is an unfair comparison because that's not what smell does and I think we're pretty reliable in you know

00:31:24 eating something or not eating something depending on the smell right there's not a lot of variability and context right it's like you can vary the visual appearance if it smells rotten it's going to be very difficult for somebody to eat that because that behavior is evolutionary what's being you know Guided by smell and the naming smells probably hasn't been all that important throughout that that development and it's just like a more a more current current thing that we're

00:31:56 doing so can I pick up on your emotion question cuz I think it's very important so emotion to is historically situated right so in a pro asmic or pre-m Theory age smell is rif and Laden with the emotion of fear much more than it is with just disgust another emotion discuss might be a more common emotion in outside of context in which the smell

00:32:29 of something could mean death right so miasma in the 19th century people thought that the smell was the cause of disease it may or may not have been but fear is deeply embedded on what people smell the same is true of what emotional vocabulary was available to people so the emotion of indignation in the 19th century was far more present than it is now indignation doesn't occupy an important emotional space for us lead up

00:33:01 to the Civil War indignation meant a great deal jealousy meant something different in other words it's not just the sensory component that has a historical context it's the emotional register that's attached to it so fear is very important when it comes to smell depending on when you're looking yeah 100 years ago Manhattan smelled like horse manure now it smells like cannabis and I would blood was it that I raise horses so I would prefer horses

00:33:33 frankly uh to the Cannabis um yeah you're right but can we go back to this scratch and sniff thing because I think this is fascinating and I'm learning a great deal from this round table but so historic homes um historic sites they retail and smell to get people in why because seeing things is just not as interesting right if you can smell something there is a a viking Village in yorvik a recreation in England right and the single most popular part of that Village is the Viking latrine and they

00:34:06 will give you a scratch and sniff card and you will smell it and people love it they say well this is fascinating cuz you're smelling the Viking latrine but you're not what you're smelling is a representation of what we think a viking smelled like the Viking would be like smells normal to me just as 100 years ago Horseman ER would have been habituated I don't think I'm quite there with the habituation of the smell of cannabis in New York I bet you I would be if I lived here could be but by the way the best Museum and Paris is the

00:34:37 sewer Museum cuz it appeals to that sense you actually go into the sewer Museum and you're walking over the sewer which is not a SN scratch and sniff experience real thing authenticity matters right and speaking of context you know I don't know if you've ever been to that museum but it's in the sewer and the big thing they talk about of course is the Napoleon Engineers figured out how to make the first modern city because they figured out how to have a sewer system

00:35:08 and as you're walking through the museum surrounded by the smell of uh French sewer okay it makes the experience of the museum that's why I don't know about I didn't know about your Museum but I'm fascinated what they learn to do it under Napoleon the Third well one Napoleon another Napoleon I anyway so yeah one the the the why scratch and sniff movies don't work also points to another um difference between

00:35:40 smelling and hearing and that is that for hearing we can believe that something is a representation so I can show you an image the most horrible image dead people like something that if you would see it in real would Shake You To The Bone but you know it's a movie you know these are actors you watch it and you know you can be pretty detached the smell that doesn't work if I make the smell of rotten

00:36:11 corpses in the lab and I tell you you know this is artificial and I open it you're probably going to throw up or at least leave the room because also some part of your brain knows that this isn't real smell is not influenced by that and it's always perceived as authentic it's very difficult to perceive a smell as a representation of the real smell so that is why you know there's a big difference between doing doing visual entertainment

00:36:41 and smell entertainment in visual entertainment you can do horrible things in smell entertainment if you do it people will leave isn't that a technology issue is it it a technology issue if we can deliver smell at the level how we can deliver uh visual uh pictures or sound picture with the whole Dynamics yeah maybe that problem will be solved because currently you smell the smell lingers you cannot get rid of it

00:37:12 but it's all I mean conceptually solvable if you kind of you know have a image of something and a weave of smell and it passes away it's actually very real and then just if you can deliver it in a proper away which we don't know yet how to do it well the the the failure of the smell movie is not because I believe it's basically because we can deliver proper smell yeah they had smell orama but they had a machine but that's basically the problem is that you cannot

00:37:42 wave out the smell previous smell yeah but when when animals are out in the world okay and it's intrinsically multimodal okay uh and again computationally thinking about this from the point of view of you designing sensory animals um you know one of the things you're trying to determine is what's real and what's not and I really you know all action is real because the thing is in your nose whether you can figure it out or not whether you know what it is or not it's a separate issue

00:38:14 but it's in your nose for sure I I think people n you know animals naturally kind of know that vision is inferential I don't I don't understand what you mean by that I me if I see you you real I see this you're you're seeing me because of a bunch of photons that you're interpreting the same thing photons or or molecules what the difference what's the difference there's an enormous difference between actually having the

00:38:45 thing in your nose and picking it up Photon on your eye sure of course because for example give you a concrete example and by the way we may end up with an argument about this um let's put it this way there are many many optical illusions okay where you fool the visual system to think one thing or another in fact they're they're also heavily used in marketing and everything else there are very few and some would say no all Factory illusions that has a very clear

00:39:18 explanation because uh because of a in some sense the the multi-dimensional the large parameter space of the factories uh world so it's very uh difficult to fool you there and uh in in in Vision you can let's say substitute colors with different stuff or if you're talking about 3D Vision not color vision it's there's a lot of uh things to play to create illusion yeah there are like 47 different visual areas

00:39:49 yeah exactly okay which by the way let me toss one other thing out I'll put on the table so one of the things we proposed many years ago which is the basis for lot of the research we've done is that the olfactory system is actually where the cerebral cortical algorithm was initially evolved and that the entire rest of it in neocortex in particular is about figuring out how to take sensory information from fundamentally non Factory like uh sense you know vision is

00:40:22 very two-dimensional I'll give you three dimensions some velocity you throw in whatever and actually allowing those sensory systems to use what is fundamentally in old factory calculation and if you you can this is a computational argument but it turns out you can look at the genetics and the development say the same thing so I don't want to toss that out given the nature of the conversation and I think that's also one of the reasons that visual illusion Works in some sense and old faction doesn't because it's three

00:40:53 steps from the from the ol Factory recept to the hippocampus three or four steps it's 48 steps from from the from the retina okay but that reflects sort of The evolutionary history of Cortex and so my view is that that hum mammals in particular are deeply old factory that we sense the world in an all factory mode but that sometimes we do it with

00:41:25 vision sometimes we do it with audition sometimes we you know we like music all that stuff but that this is a this is a kind of computation that would not have come around if it had not been the task the old factory system has to to solve so as I said I think one of the reasons that Illusions work in the visual system is it's a it's a complex processing system process to get from something on the retina to identifying an object somewhere in it through 45 five

00:41:57 different steps okay it's exactly three steps and if all Factory receptors are metabolic pathway detectors it turns out to be one step to understand what an all Factor object is so I completely agree with that statement I fully don't do that no no no but I will say sorry sorry we can argue about other stuff but in this respect I fully agree with you and I add even more that probably you know I I I I

00:42:28 look at the AL fuction as the biological sense you know just what what biology tells us about and humans are know some kind of interesting model for studying Al faction not the best one but some one of the model but through Evolution probably one of the ancient sense you know bacteria has Al function bacteria navigate to smell and through Evolution from the very simple organism to mammals actually it's it's amazing how kind of a lot M interacts with the with the with

00:42:59 the with the external World using chemical senses and that's actually absolutely I sorry for being to to agree with you but but yes it was your student two days ago said you need to go down the hall at NYU because I spent three hours aost sizing a student and so go down and fight with him about it but it wasn't a fight oh my goodness I mean I was going to say something um when you were talking about uh the difference between or what I took to you to be saying the

00:43:30 difference between watching a movie and actually presenting somebody with a um you know a chemical or an odor that and and you sort of echoed it when you were saying look the molecules are in your nose and so it it struck me when you were saying that the difference is is that when you're watching the movie it's a representation you know of a visual scene before the eyes but you you give somebody a smell and it it it's there there's no representation it is absolutely there and it's in your nose

00:44:00 so that that struck me as and then you echoed it in what you just said by the way the way that the reason movies work is because the old factory system uh by inventing this algorithm and Compu I don't want to get too far into this but Computing devices a key feature Computing devices are the clocks you cannot build a Computing device without a clock and so we guessed a while ago like 40 years ago that the clocking that the the oscillations let's call them in cortex came from

00:44:32 olfaction and that was what was responsible so for example flicker Fusion is twice the the processing speed of the olfactory system but we predicted think you might have Fusion being how movies work we see discreet images quickly and they I suspect I suspect and I don't know this but it would be nice to know Birds who by the way they're Vol probably came out of the geniculate not the olda factory system I suspect they're very confused by movies okay but we predicted better get

00:45:02 a grand for that believe me I couldn't but we predicted therefore and did this an actual experiment that slow wave sleep which is a very important part of sleep it's where memory consolidation is beli to go on that slowa sleep which is at half a Hertz to 1 and 1/2 Hertz might actually be synced by breathing and it turns out that that's true and it turns out now that there are a bunch of new studies showing that high even

00:45:34 higher level cognition is influenced by the breathing phase so this idea that the I mean a thousand more people work on Vision be because they think we're visual animals okay um although I ask my students often you know they say well faction doesn't really matter much to me and I say how many times did you go brought on a date twice with someone you didn't like how they smell and the answer is zero doesn't happen what they

00:46:05 look like their manners are bad you know no problem but smell very very fundamental that reminds me of something that happened to me recently I was at a concert and and um of course now everybody's watching concerts through tele through you know their phones and um but but people were very good about it and and put them away and um and I and I was trying to be very very good in not having my watch you know sort of go off and there's this this guy sitting next to me and um and he very much smelled like he had had a lot of onions

00:46:36 for dinner right before coming and you know we were sort of like 30 40 minutes into the concert and sort of my clapping was setting off my my watch and he turned to me he said can you please turn your your watch off I thought okay so that that's kind of acceptable here but if I would have said can you smell better please that would not that wouldn't have been accepted and it struck me you know I I was I was kind of annoyed and I thought well I'll get my own back when I go to the round table you know in a couple weeks in New York so there we go um but

00:47:10 but it did strike me in the moment you know the philosopher and thinking about the differences between you know the various senses but also similarities but the differences but also in our attitudes towards them you know we very much in that moment I thought yeah we've this is an indication of you take yourself to be a visual creature cuz that's things that's bugging you and I mean the smell was kind of bugging me but and people don't realize hugging is an old factory Behavior M they don't realize that I mean oh well so there is a there is a

00:47:41 compelling connection between a modest number of molecules get into your nose and it evokes potentially a very complex string of behaviors right so if you're the example L uses you're you're in a shopping mall and uh you smell Cinnabon and you probably weren't expecting to go buy uh a very sugary treat but somehow a few molecules hitting your nose is able to evoke this very complex set of behaviors that involves pathf finding and navigation it requires you to overcome all of your youthful training and talk to a stranger right and then

00:48:11 eat something given to you by a stranger um and it's a few molecules that hit your nose that somehow compel a 100 billion neurons to do something in concert towards a goal um in my lab we do a lot of work on how early Al Factory circuits change and we're increasingly thinking it's not about how to change the perception so much as it's about to change a way to change the coupling between the sensory system and downstream neural circuits which in turn leads to uh potentially complex problem solving and behavior um but in all of

00:48:43 those cases you bring your own personal context with you right I have plenty of colleagues from uh from outside the United States who smell cinnabun and their opposite is the exact opposite right that smells terrible uh so I was once in a panel with the founder of Starbucks yeah and I looked at him and I said why are you manipulating us with smells of coffee right and he looked at me and said that's why we succeeded well this this goes back to my

00:49:14 question earlier I think about is the connection between what we smell and how we experience smells let's say disposition to act is that translatable into to it being closer to our emotional experience than other senses than some senses so some of the demonstrations that we've talked about uh are actual demonstrations I do in some of my courses so the example of uh of the the odor that smells like vomit or it smells like cheese depending on

00:49:46 what you've been told uh really works but I've also I've done it anecdotally on hundreds if not thousands of undergraduates at this point um and in that case there's a very clear emotional comp you'll have someone who practically stick their nose in and go that's a pretty good artificial parmesan cheese scent and then the same person will like wretch and leave but it also works with non-emotional stimul but not to the same degree so I'll do the same thing with a component of a banana odor and I'll you have to kind of hype it up and get into the the the sort of Showmanship of it but you could absolutely persuade a

00:50:17 group of undergraduates that this is an artificial strawberry give them a very distinctive banana and oh yeah yeah no that's strawberry but they say nope but it's actually banana and almost everybody will switch back immediately and won't be able to go back to strawberry once they've gotten that recognition but I will occasionally get somebody in fact one of the angriest I've ever made a student was I got someone who I saw it in his eyes I said it's strawberry it's banana it's strawberry it's banana he got up and he like yelled at me right so there is some individual variability in the ability to

00:50:47 to to ad caveat we know this from studies so feral glucoside which it turns out probably to uh be activate about 50% of we're we're that's why we're visiting fir firage so they can that's what I was doing so they can do the experiment so firal glucos there are three molecules that across many fruits signify ripeness okay so this is a case where the fruit have cooperated if you want to think of it that way to trigger uh and

00:51:20 and mamalian ector receptors may be particularly sensitive to those three so you might think a banana and a fruit and and an apple is different but the banana and the Apple have agreed to share a old factory greed okay to share it was all designed okay so it was agreed well they've shared a trigger that set to the mammal that says

00:51:50 now is the time to eat me so you it's a little tricky if you're you're doing those s of experiments because the fruit themselves have molecules that they commonly have to manipulate us so it turns out a banana and an apple is not as chemically far away as you might necessarily think because one is yellow and one is red yeah it's also you know like hard to imagine that we would ever need to distinguish between banana and

00:52:21 strawberry in you know prehistoric times we're looking for fruit you know we are hungry want some food we're not going to be disappointed if we find a banana instead of a strawberry we want to make sure if it's good to eat well one slapstick was invented exactly so I I found what you said fascinating because it just again reminds me of the politics smell right you're telling a student is banana for well you're the professor you have the

00:52:53 authority to make that claim it's a like when George Orwell supposedly said and it might be apocryphal but I could imagine him saying it there are two words that describe the English working class they smell that is a claim about a class from an elite English leader a thought leader they could never escape the claim not because of what they did if

00:53:24 workingclass women put on perfume it was cheap perfume right uh if workingclass men try to make themselves smell better it never really worked the politics of the claim matters a great deal and I'm in no position to contradict with science here it sounds very persuasive but the moment at which you say it and who says it has to matter right there's this scheme called culture and history that filters what people are

00:53:56 SM smelling and how they're smelling it and what values and this is very dangerous stuff this is not just some frivolous observation I mean we have whole regimes historically that have deployed smell and the claim that certain groups of people smell and need to be marginalized to great effect this is not something that is uh without political implication by the way you know that there's a genetic link between

00:54:26 the histic compatibility complex and pheromones the histo compatibility complex is how you your cells recognize that they're your cells and the immune system therefore mostly doesn't attack them so we now know that the the pheromones in fact the ones that you get from the back of your ear have a genetic relationship a DNA relationship to the hist compatibility complex so as I said before um hugging is actually an old factory Tech ask or an old factory

00:54:57 Behavior next time you hug someone try to Exhale okay so you get them close get the your nose close to the back of their ear and you inhale right and when I do that I say it's so nice to smell you and then they jump back but the point is this it is very like we know this is true in in mice we know it's true in many mammals people argue whether humans have as much of a phonic blah blah blah but my former student Nome soble has shown pretty

00:55:28 clearly that that's nonsense humans do have this strong fonic thing it could be that your the signal you're giving the olfactory signal you're getting is actually telling the receiver something about your genetics so when you talk about the historical use of olfaction for racism okay it's it's it's very likely related to the same kind of concerns about inter reading the same kinds of concerns about purity of

00:55:59 the race because there is probably a relationship between the odors you give off and your genetic his your genetics right I think this goes back to my initial question I don't think we got a I got a satisfactory answer which is why does it seem there's a there's a tend there's a slight bias towards negative a negative feeling about smell like let's say let's grant for a minute that there is perhaps some difference among

00:56:30 different biological groups call them in terms of their smell the question isn't can people be distinguished because they smell differently but why do we how is it so easy to append a negative connotation to it why do we cut the hair we cut why do why do women cut the hair they cut now even more of it than they used to that's how smells are distributed why do we wear perfumes we don't want to be Jud why do you think I understand there are wonderful smells and there's a industry based upon

00:57:00 perfumes and all that but I still say that a lot of our conversation not all of it we've talked about both positive and negative but I'm thinking I'm guessing that there's a little bit of a negative veilance on the general category of smell maybe it has to do with the historical use of it you want to be judged based on your order well but why you judge negatively mostly you're selecting negatively and partly because it's very difficult to argue against right so the

00:57:30 claim and you think about the language think about the vocabulary that is available to us to discuss the topic of smell it's a very impoverished vocabulary you smell what does that mean do you are you smelling do you smell is it a good thing no embedded in the language itself which is historically Associated and conditioned is a claim now you disprove prove to me that you don't smell and you're in a weaker position than I am good luck with

00:58:01 that it the apparatus of the culture and the politics underwriting that culture if I own that apparatus and I identify you as you smell is really hard to push back that's why it's so powerful the language is impoverished it's difficult to be subtle and historically you're right it is negative not always but it that's precisely why it's used it's such a statement of authority also isn't it

00:58:32 because of distance you cannot say somebody doesn't taste good because you have to taste them you can say it's a later stage of the process but you can say that they have no taste as an aesthetic claim as a social claim which is intimately related to what they're eating so that's why enslaved people were fed wretched food because they didn't have the aesthetic ability or the gustatory

00:59:04 ability to distinguish good food from bad food and it also happened to be a lot cheaper by the way my former student who's it s Alfredo Fontanini who you know yeah has been studying this question and and one of the things that he has found is that in order to taste which also involves ction food later that's more to have a more sophisticated ability to distinguish between foods which involves also taste and smell you

00:59:35 have to be exposed to it early so if you're not exposed to a diverse range of foods early then you do not simply have the ability to perceive so the reason that a kid maybe that at age 15 doesn't like broccoli is because they didn't actually get exposed to broccoli when they were young they got exposed to something that Gerber made I you know more about that than I do I'm sure there's also in our society this

01:00:06 tendency to deodorize so it's not just between like a smell being a good smell or a bad smell but the ideal being no smell at all like being completely smelless is an ideal and you know people complain about people wearing perfumes even though they're beautiful wonderful perfumes all the time right so it's not just within smells which ones are good or bad but it's any smell is bad because it's kind

01:00:36 of uncontrollable and it like invades your um invades your your private space you wouldn't say people don't want to stuff stuff up your nose which is what they're doing when when and they make you smell smell them right so it's like just like this ideal of having no odor at all makes a lot of the discourse about odor negative to begin with I mean the words odor and smell if you don't

01:01:07 deliver any other context people assume that's something bad there's an odor here it smells here the assumption would be it's bad I meanor I mean ask a question there's the the deodorizing but then the the perfume industry has a very very firm we also like you know it so it's it's almost like that they sort of perfumes come in yes a lot of people complain well I mean I I actually there's two people in in my

01:01:38 department who wear any sort of perfume or cologne it's me and somebody else there's never been a complaint but I I do worry about it because there is this kind of this this worry that you be bothering somebody headaches Etc but but there is you know with our homes with our spaces this moood to to deodorizing and and and having no smell but then it seems like the perfume industry sort of swoops in into that absence uh to to fill it up again um and it with our homes as well as you know

01:02:11 our bodies um yeah it's there's this there's a sort of tension between I mean I think you're right it's deodorized oh no fill that space deodorize don't fill it with something nice and this this Push Pull kind of thing it's it's about having control of the smell so and it's a rhetorical conceit right it's like the Quest for silence we want there is no such thing as silence you will always end up hearing your own body the idea of odorlessness is a conceit of the 19th

01:02:42 century Elites and then the 20th century reodor ises it but along the lines that are acceptable to those people so it's a rhetorical position rather than a reality that can be produced silence taste least so all of these things are clumsily situated and odorlessness is one of them but it has an historical origin right but isn't a great selection comment on your about taste that is true in English and it

01:03:13 it's true in French it's not true in Armenian it's not true in farc cuz they those that term cannot be applied in the same way yeah so so this is a good example of context right um you know my language skills are very limited I wish they were greater I understand the english- speaking context but that does not mean that it applies to The Armenian speaking context and that's where historical geography historical sociology the

01:03:45 contextual apparatus really matters and what it does is it it can certainly reinforce the universal claim but it can also destabilize it or make it more textured in a way that this particular culture doesn't have that language for this which means there are historical experience is going to be different even though the biological conditioning might be exactly the same I'm basically calling for history

01:04:15 that's it I know it's fascinating so so I I think it's about selection you you don't want to be selected against that poor guy sitting next to you okay you had the French onion French soup at the very very good restaurant where you actually get a lot of onions okay he did not want to be selected against you don't I think you don't want to be selected against based on your odor and and in your case for sure the people that were slaves you

01:04:46 know or people that are in the lower English class would rather not so we decide to be as orderless as possible and furthermore I mean I use on the number five myself that you know you then furthermore decide that we're all going to smell the same right it's a tribal thing right and then the course the perfume industry takes advantage of that and shifts it around every couple just because they're making money but it's better to all smell the same than to go out with somebody and actually have them smell

01:05:17 what you really smell like and decide not to do it again because that is a very very that's a very common thing right so I think we all agree to not smell and then we all agree to smell like the thing that indicates that we're hip and cool and we're not part of the lower English middle class well I'll vote that I was um so I I ended up smelling American I don't know I don't no no you still smell like the lower English oh well thank you you're a good man I'm proud of you um so it's a very

01:05:50 intimate thing isn't it I mean how often you you didn't say to your the champ in the or you smell yeah no no but we wouldn't also we even if we refine it we wouldn't say you smell nice it's very intimate she wouldn't say that no I I mean I wouldn't say that you wouldn't oh I don't think I've ever if you do say it you're sticking your neck out you BL yes you are yes you are that's what I was going to say when you're saying you smell just you don't that's bad that has a negative but we we can supplement that

01:06:20 with you smell nice it will take a a it has def intim that you are sticking your neck out and people are shocked when you say oh you smell really nice today it's like you've invaded invaded their space I didn't yesterday yeah is that what it me when undergraduates take my course I tell them they going to learn things that are really interesting and important and will change their lives and one of them is you go to a bar you hug as many people as possible you're consciously aware of which ones smell best and then when you hit someone that smells good there's a good chance you smell good to them too so you actually then spend more

01:06:51 time on that person and then eventually you say I like how you smell and then say is history obviously a need to take your class um you need to go to the bars that you go to and see learn my vocabulary a bit better I guess there's a company in New York that make a dating uh by uh sending each other smells so you wear the t-shirt for 5 days then you cut this t-shirt and send different and if there's a match between two of us they organize the they

01:07:23 organize the date it's it's kind of all blind you smell a bunch of piece of shortt that you previously wear that the other person previously weed and uh great idea I don't know how successful they are it's easier it's easier than hugging everyone in the bar exactly exactly exactly exactly the scalability of smell here the bars and ashlander small I think we're going to open up for a question shortly but I wanted to I

01:07:54 thought it was I wanted to hear a little bit more about this idea about the old factory system possibly being a sort of a template for the other senses and I wonder if you could we take that up and maybe talk about that so here's the argument it's the what you I don't know someone else wants to to show this I'll start the very fundamental right so ultimately what we're doing in the olfactory system is detecting chemicals and uh that's one of the most absolutely fundamental things in any biological system which is in ultimately chemistry and physics uh and there's been uh

01:08:27 increased understanding over the last few decades that the biological apparatus that evolved to detect chemicals in the world is also increas also used internally in the body to detect chemicals in places like the kateed body and other and other places where sort of a a a basic chemical detector uh and so that kind of begins the process of it's a it's a fundamental sense but it extrapolates out in many other ways and could the same sort of

01:08:57 recog the same computational principles that a system like that might have to use to be specific to the particular chemical in question to have some sense of intensity or concentration uh that could be used to feed into a decision-making process how do I change my cell this way in response to that chemical that I detected uh that actually turns out to be a broader set of computational principles from which you can build other sensory systems and and ultimately minds and behaviors this a very specific specific hypothesis which is that uh in reptiles

01:09:30 for example um like I said there's this multi you need this multimodal input so the vigal system the auditory system the SM sensory system visceral pain all of them are connected into this very highly multim multile U highly multimodal structure that's right next to the old factory system and that interacts with the old factory system so then what happens well if you can build more uh uh steps to make the signal it comes from

01:10:03 the retina more amenable to an old factory like calculation by building subsequent uh uh uh processing stages between the retina between visual cortex and it then you sort of build out the system that allows the visual system to use a fundamentally old Factory calculation much more in a much more sophisticated way the implication of that most people think that the neocortex uh sort of

01:10:35 somehow came out of vision okay and they're very confused about the fact that V1 has a very different structure across mammals all right but if you believe as we have proposed that actually this is this process of building stages in between it means that V1 should have very different structures across very different manels the core idea is that only the old factory system because it had this demand requirement

01:11:06 computational requirement to do this kind of Gestalt multi-sensory calculation was in a position to actually evolve that type of computation and that the other systems took advantage of it and that is what neocortex is is taking advantage of basically all Factory processing so uh people often you know Gordon Shepard and others said many times that that the old factory system is like the visual system in fact the visual system

01:11:38 is more like the old factory system uh again kind of agree with you but wanted to add something that's so um I'll say something from perspective what I'm studying I'm studying everything after what happening after The receptors so how we process the smell and if you think about it if you present a subject and smell of apple and then smell of orange you kind of know that very different smells but then you present a

01:12:09 smell of lemon you immediately sell lemon probably closer to the orange so somebody in the brain tells you the proximity the relationship and this computation happening probably in the cortex I'm still trying to understand where they happening and it's very mental computation because if you think about it if you show you one face and another phas and the third phase you can say oh this face are more similar to that on that they're probably you know siblings or no they're from different race completely different so you build

01:12:40 the space of the faces and it's actually very similar computation happening in Al function you you you build this space of orders I mean consciously subconsciously that's I don't touch this subject but you can ask ask the this question something what is computed behind the nose is very simple and basic computation that our function may lead us to understand okay well I think um that was

01:13:11 wonderful and I wonder if there are folks who want to come up and ask questions at the microphone please it seems to me that there's something uh very important to me about the senses that uh really haven't been addressed and it seems to me that this is among uh the most important the most one that needs it the most which is this notion

01:13:43 of intimacy in other words what you it is something that you experience at close range and that is the time when when it is the most powerful in terms of uh directing your behavior not only the way you think but how how you behave so this I'm talking about intimacy right not not just you know a physical

01:14:14 distance the old factory system is the anti-free will sense that's why we don't like it it's the anti-free will sense the the old factory system that's why we don't like it why we don't like to talk about why we don't like to study it so you're right the intimacy and the fact that you actually kind of don't know what's exactly going on in that you know your intimate response is really really fundamental in the whole factory system and the way it dictates Behavior see I I

01:14:46 was thinking about it right as very similar to you know the phys physically touching as well and and I see that as right very much on on the same or very close plan please thank you for a fascinating panel uh I've been coming to this room for 55 years and this has been one of the most interesting hours uh I'm

01:15:17 primarily interested in human pathology and uh right now in human uh degenerative disease uh and I'm interested in degenerative disease as its effects the old factory system and one of the most striking human diseases is aging so uh and the other thing that has struck me is the increasing amount of genetic

01:15:47 information that's now becoming available about human beings in the UK they're going for a million it's difficult to collect uh genetic material and correlated with phenotype in humans in the United States it's now about 250,000 I'm convinced that a lot of the things that we talk about in human disease and human function varies tremendously by genotype uh some and we are the rare

01:16:21 diseases that we're stumbling into uh really require computer communication and huge genotype pools uh it's striking that we test hearing and vision very early do we test ol ofaction at all in human beings it's likely be the first indication of um we actually published this a long time ago it's l to be a first indication of uh Alzheimer's

01:16:53 actually is the inability to distinguish between uh odors especially ones that are structurally quite similar and one of a little story I was once on a panel with um Spock with Leonard deoy and um I said by the way you know how that thing worked that they they scanned over the body uh you know that McCoy the the right I'm aging myself but McCoy scan he said how that work he said no it was a TV show I said no I can tell you how it worked no was a TV show I said it worked

01:17:24 because detected molecules and eventually and you know this historically Physicians used to be trained to smell their patients to actually do diagnosis and they stopped being trained that way right but actually it's you know anyway the and and nemoy looked at me and said God it's just a TV show yeah the with with with Co the the smell test thing has become a a bigger

01:17:56 topic because especially early on loss of smell was a big symptom um of the infection and then quite some money um came into for funding to develop smell tests that would be deployed clinical um I I have have developed one myself and try to push it into the clinic and now after covid a lot of people who were affected say like oh I have my sense of smell back I don't think is it's good anymore I think it's different but you

01:18:27 don't know because there was no Baseline Des for because unlike with vision or with hearing you don't do a regular testing of it so if after uh you know after a disturbance you test it you don't really know um what happened and the downside of most of the tests available is that they are identification tests so they are cultural biased you have to know what cinnamon smells like to pass that test right and so the new wave of tests that's being developed tries to avoid

01:18:58 that so it's a nonverbal type of test and it has to be very quick and cheap of course to be adopted but there is a I was at a meeting a few months ago where there's a push to you know make a make it a universal smell test so that most people in their life will be tested for their sense of smell to to speak to the Aging component a little bit more um one of the sort of biological quirks of the olfactory system is that there's a real sense in

01:19:29 which the the neurons that are detecting the odors are on the outside of the body and they're exposed to the environment uh and if you were to look at the biochemistry of the of the nose what you might find is actually it's it's layered in defenses to try to have all sorts of enzymes that are present that seem to be designed to detoxify things that might come in and in fact some sense of our smell is actually confusing because because those enzymes break down odors as well and so when we smell something certain things we're actually smelling

01:20:01 both the original molecule and its metabolites in the nose um but perhaps because those cells are constantly exposed to a a universe of potential toxicants they die and are replaced throughout your life from a population of stem cells that exists in your nose and it's constantly growing new neurons that wire into the circuit and connect back to the brain uh and so it's absolutely true that there's a loss of smell statistically about the population level with age I've seen uh I think the

01:20:31 the worst number I've ever seen which I can't vouch for is something like 40 50% of the population over age 65 has got uh weaker than than typical uh olfactory function um and one model is that there might actually be sort of the accumulative damage of exposure to all these things in the outside world perhaps that regenerative function uh degrades over time time or conveys a certain vulnerability and then that same uh process potentially could share a mechanism with loss of uh loss of uh

01:21:03 neural function elsewhere though that's more speculative yeah I I actually want to pick up also in something come on up that microphone uh that Andreas was just saying about smell and having a baseline smell test um and also in terms of what implication might have for uh incipient dementia that is one of the problems with doing a smell test and just say oh your smell you have anosmia is that um it there's a lot of false negatives for false positives for that rather right so there could be things other than

01:21:34 dementia that accounts for it but perhaps if we refined it or had Baseline to compare to a good example would be what we do with hearing tests so if you think you're losing your hearing I said if you think you no if you think you're losing your hearing and it's from old age and it can be and maybe you're not that old yet and you're concerned about it if you go and get an Audiology test they will see oh if it's quote unquote normal part of aging the higher frequencies will be lost the rest is okay and they'll be able to tell you based on that profile that you don't

01:22:04 need to worry or at least this is normal aging right if it comes out with a very different pattern and profile that's very meaningful so one wonders whether that would be something in smell if we could refine the sorts of sensitivities that are gained or lost over time perhaps it would be able it would enable us to predict outcomes right yeah so two things that are tested are sensitivity to a smell what's the lowest concentration one can smell and ability to tell two cents apart and there is

01:22:36 some data that shows that if the smell problems are related to you know neuro degeneration then the Discrimination is more affected than the sensitivity whereas other things for example smoking affects the sensitivity but not so much the Discrimination so one can you know find different tasks to make a differential diagnosis there's also some theory that like large molecules the

01:23:06 sensitivity to large molecules and small molecules act a little differently but that's very speculative so I don't know where that will be going this goes back to the problem of not having a good metric uh for the old factory system and this thing that we're proposing is a metric this metabolic detection and it makes specific predictions which we've been able to show for example one of the funny things about the old factory system is if you smell one thing and smell another thing sometimes smelling

01:23:38 the first thing changes the perception of the second thing up until re well there's no way to predict that we predicted that if two molecules were on the same metabolic pathway that they would cross adapt and that turned out to be exactly the case case so structure doesn't do it percept doesn't do it if the two molecules are on the same metabolic pathway they cross adapt so knowing more about the receptors okay is going to help build

01:24:08 the tests but without that you know you're sort of just shotgunning it which is how the old factory system has worked for years or studies the factory here thank you thank you for these uh very rich and informative panel as some of other people we've been here many years and it is rare that it is so precise and so good now two things one I was I've been for many years a professor

01:24:39 of architecture and indeed to reinforce your comments in Chicago in the famous SC done by Salan there is the structure that mean that you know is about same height as the feet of the line above you and I was in a great concert by janier Ral and I couldn't enjoy it because the gentlemen behind me typically Chicago Working Class People they JS up for the

01:25:12 occasion which mean that they use chap or the colon and they bash their te with a certain strong face and combination of this adult meant that I couldn't enjoy the concert and I had to leave in the middle but this is now not why I stood up to speak reason I to have to speak is totally different and much more painful and difficult and that is 911 because those of you have been here in New York at at the time following the

01:25:44 events when you cross 14th Street you would have a terrible smell which was a combination of course de was was certainly part of it and it went on for a while but after about 25 minutes it died out and that really brought to my mind the experience of the people around concentration camps and gas Chambers much have it must have been a terrible

01:26:15 smell how come they did not react to it how come nobody mention it I think it's the same thing that we witness here in New York that after a while we are insensitive to our own body burning whether be this terrible wordss it's an unfortunate truth that when you leave your house and you go on vacation and then you come home and your house smells weird maybe bad it always smells like that you're just not used to

01:26:46 it we know this at the level of receptors we know it at the olfactory bulb we know at the ol Factory cortex uh the ol factory system adap dep very rapidly um what it's really looking for is change and because of the complexity of detecting old factory stimuli and how many are out there if you want to pick something up that's going to be significant to you you have to adapt out the Baseline otherwise it would get completely overwhelmed so we know adaptation is what you're talking about is adaptation it's very very strong in

01:27:19 the well that's why women that wear perfume for example tend they get older to put more and more and more on cuz they can't smell it and then when you're walking down Madison Avenue as I was recently like today and someone walks by and you just go oh my God you know that they've been using that perum for way too long so and so I caught up to her and I said please change your per the the young the young men are doing it why then overdosing with cologne even after adaptation I'm want this may the answer

01:27:50 may be no that'd be great uh even with adaptation that is may be having an effect is that a possibility well now you're getting into attention and complicate sitting there and go oh yeah what is that smell but I it does seem to disappear so your neurons know it's there but um but there's less response to it in terms of just numbers of spikes and things like that in your neurons I sense it goes away I mean with sounds like we've been hearing this

01:28:21 little bit of work not far away we could filter it out but then if you stop and pay attention you go yeah what is that right and I I don't find that with sense the same thing you know we we we we we're sitting here and somebody walks in and said oh there's a burning smell and you immediately start sensing it yeah so it's it's it's a fundamental stuff it's I I think Al function disr not different the the environment slightly different the stimula is different but the principle of

01:28:51 adaptation are very very much similar because you ignore the the noise the the buzz the everything if somebody tells you oh you start hearing it yeah similar thing happening I mean there's two processes adaptation at the level of the receptor and then habituation as a central brain process so adaptation it can't have an effect anymore because you just kind of tie out the sensory neurons and they don't fire that much anymore but habituation is more that thing when

01:29:22 you direct the attention to it again and then it's there again it's like the ticking clock in the room you know you hear it when you first come in then it goes away but if somebody says that clock is loud it it comes right back so it's two different processes I mean I can't direct my attention to the the smell of our our our house in the in the summer because we get the sort of very humid Kentucky uh Summers and and the the basement sort of will start and then it I'll go away and I'll come back and have that experience thinking oh God

01:29:53 what's going to happen happen when we have to sell this we'll sell it not in the summer cookies um but yeah that's right right um but I can't direct my attention back to it once I'm once I'm home for a while yeah I think I think we keep sort of uh dancing around this today but um I continued to think uh during the talk about the the imprints that that sense oders make on our memory I mean for years if I smelled Ralph Len Polo cologne right back to my senior from

01:30:24 it's probably just cuz it's not in fashion anymore that I I don't recall that but I would give a more complex example of of the training for um for somier or for the training for these um noses in the par perfume houses and they make it very romantic that these noses are just um sort of divined somehow to do this do this work but in fact they they' probably grown their F A lot of them are family businesses they've grown up doing this they've imprinted um these scents um these odors in their memory

01:30:56 and I think they just and and that combined with the vocabulary is is their profession and that's sort of my what I'm throwing out to the table between between the use of memory and and trying to do this whether whether it's you're a somier or or someone who works for for G you you um you can develop this and and some of the best so is the first thing you'll hear about them is they have a great memory and and of course we're assuming that the the ol of faction is integrally related with the with the taste yeah that's the first first year

01:31:29 of perfumer training is just recognizing all the raw materials that perfumers use and then when you know the labels you recognize them in mixtures so you can detect them there so that's really you know what's what's required to do that that's the most important part and you know when you do smell testing in terms of like how sensitive to Smells they are then there usually no difference between professional perfumers and other people when you make them name or recognize

01:32:00 smells and mixtures then they're off the charts better because that's what they've been training and working for by the way this is sort of built into our culture so you know this the reason that you have ginger and sushi is because you're supposed to have the ginger between eating the different Sushi and the reason is that that resets you know in some sense it resets your p your well factory system back so that you can actually taste the difference in the next one so we this

01:32:30 this kind of thing we have a knowledge of this the I'm write I write books now and the last book I'm going to write is titled um what science has told us that we already knew and uh this is one a lot of wine Tasties and I'm standing next to people who have done it before and they're just speechless you need the vocabulary experience you need to have developed it there's no difference they can do it they like it I actually kind of would

01:33:03 like to challenge a little bit this notion about the connection of the smell to the memory we all kind of like this idea that you smell something it immediately bring brings you to the to the prom or you know you smell the kitchen of your grandmother classical examples I wonder if I show you the picture of the same thing you have the same emotional resp response the my think is difference is that probably and that's I'm going to the feel that I'm not an expert so maybe somebody who

01:33:33 thinks about it from the human perspective it's partly because you don't verbalize it you don't have a language when you smell something you cannot verbalize it it immediately brings you some emotional memory oh this is my grand uh grandmother kitchen but if I show you the grandmother uh kitchen table oh this is a table you internally verbalize it and then you go to the memory so so probably that's why we think that our function is so close to the memory because of the lack of the

01:34:05 language I'll sooner smell a particular impressionistic painting that it it will have made some sort of impression on me impression on in terms of the the first time I saw it or where I was when I saw that that visual thing doesn't correspond with that same memory experience Maybe I think the theory is that the V that the alory induced memories are more Vivid because of the connection to emotion like emotional memories are vivid right if you remember back a car crash or your wedding it's

01:34:37 very detailed and Vivid those details are probably wrong but they're there in your memory and because kind of like similar brain structures and processes are used for smell there's also an extra vividness to those smell memories but it's extreme difficult to test that in an experiment that's exactly my point that we don't have feel personally that you have vivid smell memory well there's also the lack of accessibility it's not that often someone's going to walk by and go oh yeah I got this photo of your

01:35:08 grandmother's kitchen exactly where it's a smell can you might have that smell it's a little bit more they're interesting I've been thinking a lot about this question a lot lately but I think they're interesting at least some of them are interesting in so far as they they sort of take you back to a location in in a significant sense um and and maybe that's loaded with emotion but but I when I experience those things it's it's often that I'm taken to a place and very you know and not necessarily very particular there's not

01:35:38 a lot of detail but it's like a broad location sort of like my childhood home or you know uh a certain country or so on and so forth with vegetation in a certain way um and so that's why I I think they're so striking at times for me because you're not actually there but you you feel as if in a significant sense you are there um and so I don't know I I mean I'd have to look at the empirical stuff about this and what what

01:36:09 others say about it but at least I mean you can't really it's not really good to argue out from your own case and just say this is the way it is but for me at least it's they are striking because of that sense of place so and not necessarily because of the emotional content so this is another long this is 2hour lecture I can't give and you don't want to hear but the hippocampus which people many people think is a generic memory space is actually a mapping space yeah and so and the hippocampus is very close and the

01:36:40 argument this is a long thing I want to go into is that in in in finding food right which is one of the things the old factory system is definitely involved in doing one of the things you need is is spatial mapping to find the location of the fruit tree okay so I actually think that the miman hippocampus is also derived from the derived from the old factory system to provide that mapping so I think your your perception that it that it's the spatial location that you

01:37:12 get transformed to is very perceptive and very deep about how the hippocampus works and how it works with respect to the factory system and how both of them developed in a particular ecological you know uh uh uh selection environment and this would be a case of a kind of Illusion too because the I mean the thing is so weird or striking or whatever word you want to use um about those kinds of experiences is the fact that you're not there that's yeah um

01:37:44 yeah so for me it's never been about sort of I mean if it's you know my childhood home there's might be a bit of emotion but mostly it's like there is the initial thought yeah by the way 95% of the people that stud the hippocampus use the alcohol to get rid of the odors uh before they do it and if you ask them why are you doing that they say cuz I can't make sense of the neural signals unless we get rid of the odors and then you say well but but but you're turning the animal into something it isn't and you want to figure out how

01:38:15 something that isn't a real animal Works go right ahead um but I'd rather not I want to welcome this question about memory because fundamentally it's historical right I mean fundamentally it's a historical question and I work on the sensory history of natural disasters such as hurricanes tsunamis and depending where you are obviously there are two sensory signatures for recovery from hurricanes especially in the American South it's

01:38:46 the sound of the chainsa and it's the smell of diesel from generator and sewage which backs up and those are the things that trigger memories about environmental disasters just like the 911 example they're extraordinarily powerful but they're always historical right always historical hi I'm just an avatar for the uh YouTube comments and questions so we

01:39:18 have two one of which I'll kind of add my own uh uh addition to sort of Flesh it out so the first question is from Eve Haron thank you Eve for bring this in so they wrote years ago I live in Taiwan and learned that Chinese people are often repulsed by the way non-chinese smell I thought maybe diet related maybe genetics so obviously it ties into what we sort of heard today about certain elements of genetics and also with the onion guy and other smells at concerts that people visited and so the other thing I was thinking of is is this just

01:39:48 is this just another chicken versus the egg situation of jeans vers diet like how would you rank those two and the further Dimension I'll add is that within diet do you think it's just a self-fulfilling epigenic phenomenon I guess the flesh I mean like you know you have groups of people eating the same diet and given any genetic changes that arrive from that eating that diet won't necessarily lead to germ cells being mutated is it just because the groups of people eat the same food it's just leading to the same genetic changes Generation by generation

01:40:23 so you know I was much happier when we all thought Lamar was nonsense frankly um although I always thought that that was wrong personally that there was some uh sense in which we we can acquire a traits but also diets over centuries there some cultures where the diets have been distinct for for many centuries diet is fascinating um uh for a bunch of great reasons especially because real diets

01:40:54 are designed to give your body the right chemistry and in the United States where we eat Thai one day and Italian the next day and whatever it's a problem but the other thing that that ties into and it again goes back to this metabolic idea is one of the big changes in science in the last 10 years is our understanding of the biome and so one of the things that doesn't come up here at all is how much olfactory detection is actually a consequence of detecting the microbes that are involved and and that turns out to

01:41:27 change the way you think about things as well if you're detecting metabolic pathways what you're really doing is detecting the microbes that are operating on the the the the sewer and whatever else so but I I don't maybe you want to take on epigenetics in this case I look uh humans are only one species that we're discussing actually biology has a huge evolution in history and if you think about it our function was not didn't involve to uh to for Somalia or

01:42:01 you know how enjoying very very fancy food it enjoy basically the communication among species and actually smell are you are you from my tribe or from a foreigner are you eating the same food actually food preferences is a huge so actually animal smell another animal knowing to know what to eat that's a known phenomena in biology kind of transmission of the food preferences and we as the other biological creatures

01:42:32 inherited a lot of all this stuff maybe subconsciously and that's I think the biology of our F system tells us you know we have sensitivity to you know to diet to this to to to different you know culture to different environment but it all comes way before you know humans uh comes to to to play and also previously you know the the modern hygiene started you know 100 years ago madebe 200 years ago before we just were

01:43:04 smelly creatures and we you our noses get kind of information from that and I think what you asking is yes you consciously subconsciously can smell your diet okay um so the next one is from science Cathedral uh thank you science Cathedral um I guess this relates to the previous question about memory but they wrote is there varied preferences of smell related to our childhood

01:43:35 memories childhood experience absolutely memories that's like I said I mean the by the way when was when were chemical when was chemical sense the most important in in living systems was actually in the first cells 4.6 billion years ago so chemical sense has been around as a fundamental feature of how how how biological systems work since the first cells

01:44:07 formed so it is really fundamental to how biology works we think of it in terms of smell and taste and vision and stuff but if you really want to understand biology you got to understand chemical sense cuz that's you know kind of what it's all about at a base but yeah Alfredo Fontanini if you look at they can look at some of his work showing how exposure as a young person to different types of foods changes the way you perceive food later um so it's

01:44:39 it is an important thing great can I ask one more question I don't mean the hogy but I have one more on my own not from YouTube this is more I guess looking at history history so uh give him the talk about how we try to become more orderless or know with perfume we try to smell nicer I sort of thought about a few examples in history so plyy the Elder talked about Ty and purple and how to make that color which is generally a sign of luxury or royalty you would murder or like kill thousands

01:45:12 of these mollusks that lived in the Eastern Mediterranean to extract their glands to make the purple die and it smelled awful we take about a thousand just to make one gram of the substance and then the other example I was thinking about sort of related was um the Hindenburg was like a transatlantic flight by blimp they had no showers or anything so these very rich people would be able to travel from Europe to to New York but they'd smell awful after because they haden't showered for a week and then we recently I thought about the um the people trying to visit the

01:45:42 Titanic they're in that small tube I can only imagine what it smell like before it imploded uh but I guess what I'm just asking is like it seems to be obviously to when you're really rich and have a lot of resources you're able to do things that go beyond what other people could do but still seems to be no matter what you do you still can't avoid the fact that you're just going to smell bad so is that is that the Last Frontier you know just spend get out SP not smell B while we go up the great equal um well far bit for me to give you

01:46:14 the Last Frontier on anything but the point is that it's those people who get to Define what's smells good that's what matters so if they they might smell of the Hindenburg and recreate as hey this is the smell of wealth because I could go across the Atlantic on the Hindenburg and there are other things besides my body odor the smell of the food that I ate the smell of the wine that I ate that is thefactory signature

01:46:47 of wealth in this particular moment other words it matters who's saying it and it doesn't have to be provable in a kind of emphatically scientific sense the the words and the person who is articulating whose descriptions to whom they're applying has a great deal of weight and without recognizing that we are often in danger of repeating some of the mistakes we've made in the

01:47:17 past so maybe someone here knows I don't know I know people would know but what's the difference between cheap perfume and good perfume cuz I've been told I've been told that the difference is that good perfume actually mixes your natural body odor with the perfume and so it becomes more individualized whereas cheap perfume just sort of covers you up and makes you smell like something do you know does anyone know so I don't think it's only

01:47:49 the class says this is the right smell but my understanding from perfumers that I've talked to is that it's actually the nature of the perfume and how it interacts they sell it by saying take this you don't cover yourself up you enhance yourself and so I don't know the answer the same from experts but I don't probably more might be an example that can buy you can buy just musk and just and that's just a raw of

01:48:19 musk whatever that is animal fat or something and just rub it on yourself and your clothes and it becomes it becomes you but I I would extend also again a ha wian example the most authentic wines are the least manipulated so possibly by anal analogy to perfumes they're the most natural and most organic that that in turn take on your scent personality and this does to some extent filter back to the issues around metabolism of chemicals once they're in contact with you and so there is some Evolution to any compound that

01:48:51 gets onto you as a going to be uh determined in part by your particular body chemistry and whether the metabolites themselves are volatile and so forth yeah yeah well I think that it was just absolutely an amazing uh conversation to be a part of and I want to thank you all all of our Round Table members and I guess I'll close by saying Ari Aroma we did a good job what's up we did a good job

01:49:24 [Music] oh amazing that was like 10 years ago something