1 00:00:03,120 --> 00:00:06,000 Speaker 1: Welcome to Stuff to Blow Your Mind from how Stuff 2 00:00:06,000 --> 00:00:14,000 Speaker 1: Works dot com. Hey, welcome to Stuff to Blow your Mind. 3 00:00:14,000 --> 00:00:16,400 Speaker 1: My name is Robert Lamb and I'm Julie Douglas. You know, 4 00:00:16,440 --> 00:00:18,560 Speaker 1: we've spent a lot of time on this podcast talking 5 00:00:18,560 --> 00:00:22,639 Speaker 1: about the senses, breaking down the senses and getting down 6 00:00:22,640 --> 00:00:26,800 Speaker 1: to not only the scientific underpinnings of our sense experience, 7 00:00:26,840 --> 00:00:29,400 Speaker 1: but also the sort of mysteries of it that we 8 00:00:29,440 --> 00:00:33,640 Speaker 1: take for granted every day. That's true, and uh sent 9 00:00:33,800 --> 00:00:36,159 Speaker 1: is one of those things that we often take for granted, 10 00:00:36,200 --> 00:00:38,600 Speaker 1: but it turns out to be the hum dinger of 11 00:00:38,640 --> 00:00:40,839 Speaker 1: the senses. And we're going to talk about that today. 12 00:00:40,840 --> 00:00:43,960 Speaker 1: And we thought, well, heck, while we're rolling out sense 13 00:00:44,040 --> 00:00:48,400 Speaker 1: and smells, we might as well roll out a little proost. Yeah. 14 00:00:48,479 --> 00:00:53,159 Speaker 1: Marcel Proust eighteen seventy one through French novelist, critic and says, 15 00:00:53,200 --> 00:00:55,840 Speaker 1: best known for his novel In Search of Lost Time 16 00:00:56,000 --> 00:00:59,440 Speaker 1: a k a. The Remembrance of Things Past. Yes, because 17 00:00:59,520 --> 00:01:01,920 Speaker 1: in this novel he has what is now known as 18 00:01:01,960 --> 00:01:06,600 Speaker 1: the Proust moment, this sort of memory that is evoked 19 00:01:06,760 --> 00:01:10,720 Speaker 1: by a food and in particular scent, which is as 20 00:01:10,760 --> 00:01:13,520 Speaker 1: we know, bound up with food. Now This is him 21 00:01:13,520 --> 00:01:17,160 Speaker 1: describing the shell shaped cookie called Madeline. He says, quote, 22 00:01:17,200 --> 00:01:19,720 Speaker 1: I raised to my lips a spoonful of the tea 23 00:01:19,760 --> 00:01:22,080 Speaker 1: in which I had soaked a morsel of the cake. 24 00:01:22,760 --> 00:01:26,200 Speaker 1: No sooner had the warm liquid mixed with the crumbs 25 00:01:26,200 --> 00:01:28,880 Speaker 1: touched my palette than a shutter ram through me, and 26 00:01:28,920 --> 00:01:33,040 Speaker 1: I stopped intent upon the extraordinary thing that was happening 27 00:01:33,040 --> 00:01:37,560 Speaker 1: to me. An exquisite pleasure invaded my senses. M hmm. 28 00:01:38,040 --> 00:01:39,880 Speaker 1: You know, I think we we've all had those moments 29 00:01:40,040 --> 00:01:43,520 Speaker 1: in our lives where some some scent or some taste 30 00:01:43,520 --> 00:01:46,919 Speaker 1: associated with the scent, uh finds. Maybe we're just walking 31 00:01:46,959 --> 00:01:49,240 Speaker 1: down the street and it just we end up just 32 00:01:49,320 --> 00:01:52,080 Speaker 1: time traveling in our mind back to some some moment 33 00:01:52,120 --> 00:01:55,120 Speaker 1: in the past that we we maybe don't even think 34 00:01:55,120 --> 00:01:58,080 Speaker 1: about all that often, you know, and we tend to 35 00:01:58,160 --> 00:02:00,760 Speaker 1: not even think about how it's acting on our behavior. 36 00:02:00,800 --> 00:02:03,720 Speaker 1: We've brought this up before. There was a study on 37 00:02:03,880 --> 00:02:08,360 Speaker 1: altruism and freshly baked bread, and I won't go into 38 00:02:08,400 --> 00:02:12,040 Speaker 1: that because it's it's a bit lengthy, but basically, people 39 00:02:12,040 --> 00:02:16,800 Speaker 1: who were smelling the scent, we're much more inclined to 40 00:02:16,840 --> 00:02:21,359 Speaker 1: help other people. Yeah, uh, Now, Prost goes on to 41 00:02:21,280 --> 00:02:23,440 Speaker 1: to to summarize things a little bit, and he says, 42 00:02:23,919 --> 00:02:27,320 Speaker 1: when nothing else subsists from the past, after the people 43 00:02:27,360 --> 00:02:30,680 Speaker 1: are dead, after the things are broken and scattered, the 44 00:02:30,720 --> 00:02:33,840 Speaker 1: smell and taste of things remain poised for a long time, 45 00:02:34,040 --> 00:02:39,040 Speaker 1: like souls bearing resiliently on tiny and almost impalpable drops 46 00:02:39,080 --> 00:02:43,520 Speaker 1: of their essence. The immense edifice of memory. Indeed, and 47 00:02:43,560 --> 00:02:45,800 Speaker 1: that is that's the sort of thing that's behind the 48 00:02:45,840 --> 00:02:48,720 Speaker 1: wall of smell, And that's what we're gonna look at today. Yeah, 49 00:02:48,760 --> 00:02:51,080 Speaker 1: it is weird, how like even the most comforting smells 50 00:02:51,080 --> 00:02:53,600 Speaker 1: in the world, you know, the smell of you know, 51 00:02:53,639 --> 00:02:56,560 Speaker 1: of a loved one's hair or skin, or or you know, 52 00:02:56,680 --> 00:02:59,760 Speaker 1: just the sort of house smells that that give you 53 00:02:59,800 --> 00:03:01,920 Speaker 1: that warn't feeling inside of yourself, well you know, your 54 00:03:02,000 --> 00:03:04,680 Speaker 1: favorite to meal, what have you? Something with you with 55 00:03:04,800 --> 00:03:08,920 Speaker 1: rich connections. They're not something that you end up just 56 00:03:09,000 --> 00:03:11,760 Speaker 1: craving all the time. But but it's only when you 57 00:03:11,800 --> 00:03:15,960 Speaker 1: actually encounter them that you that they really take hold. Yeah, 58 00:03:16,000 --> 00:03:19,520 Speaker 1: because it's light taking a book off the shelf of memory. Now, 59 00:03:19,760 --> 00:03:22,680 Speaker 1: before we kind of get into these more specifics of 60 00:03:22,760 --> 00:03:25,919 Speaker 1: memory and smell, let's look at a little cent one 61 00:03:25,960 --> 00:03:30,919 Speaker 1: oh one, because think about all of these possible smell surrounding. 62 00:03:30,919 --> 00:03:33,760 Speaker 1: You might say possible, because this sense have to be 63 00:03:33,919 --> 00:03:37,440 Speaker 1: volatile enough to spew out microscopic particles in the air 64 00:03:37,480 --> 00:03:41,920 Speaker 1: and then get on your noses radar system. Right. Um, 65 00:03:42,040 --> 00:03:45,040 Speaker 1: so your kitchen countertops or even this table that we're 66 00:03:45,080 --> 00:03:48,920 Speaker 1: podcasting at that is not a volatile material. But let's 67 00:03:48,960 --> 00:03:51,120 Speaker 1: say nol our producer brings in a little bit of 68 00:03:51,120 --> 00:03:53,760 Speaker 1: warmed over cabbage. Then all of a sudden, that is 69 00:03:53,800 --> 00:03:59,240 Speaker 1: a huge volatile funk. Now. In the book A Natural 70 00:03:59,280 --> 00:04:01,840 Speaker 1: History of the Sense of by Diane Ackerman, she writes, quote, 71 00:04:02,440 --> 00:04:05,920 Speaker 1: each day, we breathe about twenty three thousand, forty times 72 00:04:05,960 --> 00:04:08,960 Speaker 1: and move around four hundred and thirty eight cubic feet 73 00:04:08,960 --> 00:04:12,080 Speaker 1: of air. It takes us about five seconds to breathe, 74 00:04:12,240 --> 00:04:15,520 Speaker 1: two seconds to inhale, and three seconds to exhale. And 75 00:04:15,640 --> 00:04:19,240 Speaker 1: in that time molecules of odor flood through our systems. 76 00:04:19,680 --> 00:04:23,760 Speaker 1: Inhaling and exhaling, we smell odors. Smells code us, swirl 77 00:04:23,839 --> 00:04:27,200 Speaker 1: around us and enter our bodies, emanate from us. We 78 00:04:27,360 --> 00:04:31,680 Speaker 1: live in a constant wash of them. And get this, 79 00:04:31,680 --> 00:04:37,000 Speaker 1: this is really interesting According to research by Stanford University scientists, 80 00:04:37,120 --> 00:04:41,120 Speaker 1: which was published in a November fourth issue of Nature, 81 00:04:42,200 --> 00:04:46,159 Speaker 1: each nostril of the human nose is tuned to smell 82 00:04:46,320 --> 00:04:50,760 Speaker 1: some odors better than others, and the specialization moves back 83 00:04:50,800 --> 00:04:54,120 Speaker 1: and forth from one nostril to the other, so one 84 00:04:54,640 --> 00:04:56,799 Speaker 1: a certain smell might be more of a left nostril 85 00:04:56,839 --> 00:04:59,440 Speaker 1: smell as opposed to a right nostril smell. Yeah. So 86 00:04:59,600 --> 00:05:02,440 Speaker 1: there's turns out that there's a difference in airflow of 87 00:05:02,600 --> 00:05:06,599 Speaker 1: nostrils and that effects scent detection, which kind of gets 88 00:05:06,680 --> 00:05:09,839 Speaker 1: you to the question maybe you never even wondered about 89 00:05:09,880 --> 00:05:12,560 Speaker 1: why do we have two nostrils anyway? Yeah, well it 90 00:05:12,600 --> 00:05:17,480 Speaker 1: turns out there's two different systems detecting different odors. Huh. Yeah. 91 00:05:17,560 --> 00:05:19,760 Speaker 1: I was kind of, without really thinking about it, thought 92 00:05:19,760 --> 00:05:21,880 Speaker 1: it was just so that if snot clogged up one, 93 00:05:22,240 --> 00:05:23,680 Speaker 1: you still had another one. You know. It's kind of 94 00:05:23,720 --> 00:05:26,719 Speaker 1: like having a double barrel shotgun. Right. Indeed, all right, so, 95 00:05:26,760 --> 00:05:29,880 Speaker 1: as we've discussed, you have these airborne molecules peeling off 96 00:05:29,920 --> 00:05:32,640 Speaker 1: of things. A lot of molecules peeling off of something 97 00:05:32,760 --> 00:05:36,200 Speaker 1: like freshly baked pie. Uh, not so much with say 98 00:05:36,200 --> 00:05:40,800 Speaker 1: a lump of steel. Okay. So these molecules are floating around, 99 00:05:41,360 --> 00:05:45,039 Speaker 1: they enter the nostrils and then they hit the olfactory 100 00:05:45,240 --> 00:05:49,440 Speaker 1: epithelium is the center of the of olfactory sensation. Now 101 00:05:49,440 --> 00:05:52,240 Speaker 1: it takes up we're talking about a mirror one square 102 00:05:52,279 --> 00:05:55,599 Speaker 1: inch of the superior portion of the nasal cavity. Mucas 103 00:05:55,640 --> 00:05:59,200 Speaker 1: coats the epithelium surface and it helps dissolve these odorance 104 00:05:59,320 --> 00:06:02,839 Speaker 1: so they can all they gonna be properly uh taken in. Okay, 105 00:06:02,880 --> 00:06:06,839 Speaker 1: Then these highly specialized olfactory receptor cells come into play. Uh. 106 00:06:07,000 --> 00:06:11,120 Speaker 1: These are neurons with knob shaped tips called dendrites and 107 00:06:11,200 --> 00:06:13,560 Speaker 1: old factory here's that bind with the odorants cover each 108 00:06:13,560 --> 00:06:17,520 Speaker 1: of these dent drives. Next, with the odorant having successfully 109 00:06:17,600 --> 00:06:21,200 Speaker 1: stimulated the receptor cell, the cell send an electrical impulse 110 00:06:21,400 --> 00:06:24,359 Speaker 1: to the old factory bulb. And that is part of 111 00:06:24,400 --> 00:06:26,760 Speaker 1: the brain's limbic system. That's gonna be key here in 112 00:06:26,760 --> 00:06:33,320 Speaker 1: a moment because of the olympic systems relationship to memory. Okay. Now, specifically, 113 00:06:33,320 --> 00:06:36,520 Speaker 1: each olfactory receptor type sends its electrical impulse to a 114 00:06:36,600 --> 00:06:40,800 Speaker 1: particular microregion of the olfactory bulb. So we've gone from 115 00:06:40,880 --> 00:06:43,359 Speaker 1: molecule on on all the way up into the brain. 116 00:06:43,440 --> 00:06:46,040 Speaker 1: And then this is where the sensation of smell as 117 00:06:46,080 --> 00:06:50,080 Speaker 1: we experience it uh in our minds emerges. Now to 118 00:06:50,200 --> 00:06:53,920 Speaker 1: underscore how important smell is, let me just point out 119 00:06:54,000 --> 00:06:56,400 Speaker 1: that if you destroy a neuron in the brain, it's 120 00:06:56,440 --> 00:06:59,880 Speaker 1: finished forever. It won't regrow. If you damage neurons and 121 00:06:59,880 --> 00:07:03,400 Speaker 1: your or eyes or ears, both organs will be irreparably damaged. 122 00:07:04,120 --> 00:07:07,240 Speaker 1: But the neurons and the nose uh, those are replaced 123 00:07:07,320 --> 00:07:12,520 Speaker 1: about every thirty days. And according to Diane Ackerman, unlike 124 00:07:12,600 --> 00:07:15,400 Speaker 1: any other neurons in the body, they stick right out 125 00:07:15,480 --> 00:07:18,880 Speaker 1: and wave in the air current like animonees on a 126 00:07:19,000 --> 00:07:22,200 Speaker 1: coral reef. And I thought this is such a great 127 00:07:22,320 --> 00:07:26,240 Speaker 1: similar especially if you consider some research that was done 128 00:07:26,240 --> 00:07:30,280 Speaker 1: by the Cavalry Institute for Systems Neuroscience. They found that 129 00:07:30,360 --> 00:07:33,600 Speaker 1: when it came to scent, there are synchronized brain waves 130 00:07:33,720 --> 00:07:38,440 Speaker 1: of twenty to forty hurts moving through the brain and 131 00:07:38,680 --> 00:07:41,760 Speaker 1: these are signals from the nose that translate and they 132 00:07:41,840 --> 00:07:45,760 Speaker 1: connect to memories in this sort of orchestrated symphony of 133 00:07:45,840 --> 00:07:48,400 Speaker 1: signals in your brain. And the reason they know that, 134 00:07:48,440 --> 00:07:51,880 Speaker 1: of course is rats. Because we've discussed in an earlier 135 00:07:51,960 --> 00:07:56,000 Speaker 1: episode to give us a good amount of information about 136 00:07:56,000 --> 00:07:58,400 Speaker 1: these types of things and systems in the brain. Now, 137 00:07:58,440 --> 00:08:02,160 Speaker 1: the researchers took seen to twenty electrodes. They place them 138 00:08:02,160 --> 00:08:04,760 Speaker 1: in the hippocampus in the different areas of the into 139 00:08:04,880 --> 00:08:08,480 Speaker 1: rhinal cortex and rats, and this allowed them to observe 140 00:08:08,560 --> 00:08:13,280 Speaker 1: this wave like action and synchronousity happening during the scent 141 00:08:13,640 --> 00:08:17,600 Speaker 1: memory acquisition in rats. Now I mentioned that the olfactory 142 00:08:17,600 --> 00:08:20,240 Speaker 1: bulb is part of the brain's limbic system, again area 143 00:08:20,240 --> 00:08:23,800 Speaker 1: associated with memory and feeling. That the bulb has intimate 144 00:08:23,800 --> 00:08:27,200 Speaker 1: access to the amygla, which processes emotion in the hippocampus, 145 00:08:27,520 --> 00:08:32,040 Speaker 1: which is responsible for associative learning. And this this is key, okay, 146 00:08:32,120 --> 00:08:36,360 Speaker 1: because it's why smell can call up those memories and 147 00:08:36,400 --> 00:08:42,679 Speaker 1: powerful responses almost instantaneously, cutting out we're almost cutting out conscience, remembrance. 148 00:08:42,920 --> 00:08:45,679 Speaker 1: And the key triggers here are conditioned responses. You smell 149 00:08:45,760 --> 00:08:49,160 Speaker 1: something and this links to an event, person, thing, or moment. 150 00:08:49,160 --> 00:08:52,440 Speaker 1: The brain forges the link between smell and memory, and 151 00:08:52,440 --> 00:08:55,520 Speaker 1: then when you smell it again, even years later, decades later, 152 00:08:55,679 --> 00:08:59,079 Speaker 1: the link is already there lights up again. Now, since 153 00:08:59,120 --> 00:09:01,640 Speaker 1: we encounter most of these new odors in our youth, 154 00:09:01,840 --> 00:09:03,560 Speaker 1: because I mean, you know, there are a lot of 155 00:09:03,559 --> 00:09:05,439 Speaker 1: smells out there, but you're gonna hit something. Most of 156 00:09:05,480 --> 00:09:08,160 Speaker 1: the key ones, you know pretty early on, since you 157 00:09:08,160 --> 00:09:10,640 Speaker 1: smell most of them in your youth. Smells often some 158 00:09:10,720 --> 00:09:14,320 Speaker 1: of these strong feelings of nostalgia, mental time travel, taking 159 00:09:14,400 --> 00:09:17,079 Speaker 1: us back to bake pies of our youth, or or 160 00:09:17,120 --> 00:09:22,360 Speaker 1: even it's not even necessarily a positive, you know, or 161 00:09:22,400 --> 00:09:25,600 Speaker 1: at least subjectively positive smell that we end up having 162 00:09:25,600 --> 00:09:28,680 Speaker 1: these positive associations with. Uh. It could be something like 163 00:09:29,480 --> 00:09:33,480 Speaker 1: chlorine in a pool, something that is harsh chemical uh. 164 00:09:33,520 --> 00:09:35,880 Speaker 1: And to some people with a different association, and they 165 00:09:35,920 --> 00:09:37,920 Speaker 1: might they might not have the same kind of positive 166 00:09:37,920 --> 00:09:41,000 Speaker 1: swelling of emotion around it. But once that's forged in 167 00:09:41,040 --> 00:09:43,720 Speaker 1: the brain, that's the connection we take when we smell 168 00:09:43,720 --> 00:09:47,160 Speaker 1: it again. Uh. And interestingly enough, we even begin making 169 00:09:47,200 --> 00:09:51,240 Speaker 1: these emotional connections to smells before we're even born. Infants 170 00:09:51,280 --> 00:09:54,199 Speaker 1: who have been exposed to alcohol, cigarette smoke, or garlic 171 00:09:54,200 --> 00:09:57,199 Speaker 1: in the womb actually show a preference for these smells 172 00:09:57,280 --> 00:10:02,280 Speaker 1: later on. And that's really interesting of her. Before that, Um, 173 00:10:02,320 --> 00:10:05,240 Speaker 1: some of your food choices can influence the diet of 174 00:10:05,280 --> 00:10:08,600 Speaker 1: your child later on. But who knew that even smoke 175 00:10:09,160 --> 00:10:12,320 Speaker 1: would be something that would be incorporated into the landscape 176 00:10:12,320 --> 00:10:15,760 Speaker 1: of smell for an infant um. Now we're going to 177 00:10:15,840 --> 00:10:18,839 Speaker 1: take a quick break. When we get back, we are 178 00:10:18,880 --> 00:10:22,000 Speaker 1: going to look at how smell influenced the formation of 179 00:10:22,040 --> 00:10:32,439 Speaker 1: the primitive brain. All right, we're back. We're talking about smell. 180 00:10:32,480 --> 00:10:35,640 Speaker 1: We're talking about and be a very primal sense, if 181 00:10:35,679 --> 00:10:38,400 Speaker 1: not the most primal sense. Yeah, and if you veer 182 00:10:38,400 --> 00:10:40,679 Speaker 1: away from humans for a moment and you look at 183 00:10:40,720 --> 00:10:43,920 Speaker 1: smell and its role in the animal world, will you 184 00:10:43,920 --> 00:10:48,559 Speaker 1: see that it becomes maybe ten or fifteen episodes spirhirling 185 00:10:48,600 --> 00:10:50,200 Speaker 1: out of this. So we're not going to go way 186 00:10:50,200 --> 00:10:52,560 Speaker 1: deep into this, but we wanted to mention some of 187 00:10:52,559 --> 00:10:56,400 Speaker 1: the ways that sensory world is interacting um with scent 188 00:10:56,600 --> 00:11:02,520 Speaker 1: in organisms. And that's because it really plays a bigger role, 189 00:11:02,679 --> 00:11:07,120 Speaker 1: a more integral role in identification and communication. So, for instance, 190 00:11:07,400 --> 00:11:09,960 Speaker 1: if you think about a tobacco leaf that's being munched 191 00:11:09,960 --> 00:11:14,000 Speaker 1: on by a caterpillar, well, that tobacco leaf will emit 192 00:11:14,120 --> 00:11:17,439 Speaker 1: something called a green leaf volatile and this is a 193 00:11:17,520 --> 00:11:20,360 Speaker 1: chemical that once it's airborne, it acts as a kind 194 00:11:20,360 --> 00:11:26,120 Speaker 1: of s o s two predators of the caterpillar, like wasps, 195 00:11:26,520 --> 00:11:29,720 Speaker 1: and it's essentially saying to those wops, hey, there's something 196 00:11:29,760 --> 00:11:32,520 Speaker 1: there's there's this blood sucker on me or this you know, 197 00:11:32,640 --> 00:11:36,520 Speaker 1: leaf sucker on me, and it is completely distracted right now. 198 00:11:36,559 --> 00:11:38,880 Speaker 1: And I know you love a good juicy caterpillar to 199 00:11:38,920 --> 00:11:41,640 Speaker 1: swoop down and eat it. And that in and of 200 00:11:41,679 --> 00:11:45,079 Speaker 1: itself is amazing, this kind of chemical communication. But then 201 00:11:45,120 --> 00:11:49,320 Speaker 1: you consider the research that's been done on rodents, and 202 00:11:50,160 --> 00:11:53,880 Speaker 1: that we can see that rodents can actually detect fear 203 00:11:53,960 --> 00:11:58,200 Speaker 1: through scent alone, or even considering something like a silver 204 00:11:58,320 --> 00:12:02,520 Speaker 1: tip grizzly, which can smell a carcass up to eighteen 205 00:12:02,559 --> 00:12:04,960 Speaker 1: miles away, which would be really important to aggressively right 206 00:12:05,000 --> 00:12:07,600 Speaker 1: because that could be a second lunch, a second breakfast, 207 00:12:07,640 --> 00:12:10,800 Speaker 1: a snack, you know, any sort of leftovers. And these 208 00:12:10,800 --> 00:12:14,880 Speaker 1: are just just a tiny bit of examples of the 209 00:12:14,960 --> 00:12:17,040 Speaker 1: rich roll of scent in the animal world. But it 210 00:12:17,080 --> 00:12:20,720 Speaker 1: gets even more micro than that. Yeah, And and in 211 00:12:20,800 --> 00:12:23,560 Speaker 1: doing so, it gets even more telling about just this 212 00:12:23,679 --> 00:12:26,640 Speaker 1: idea of smell as this primary sense of the connection 213 00:12:26,640 --> 00:12:31,000 Speaker 1: between smell and survival, because in the you know, your 214 00:12:31,000 --> 00:12:33,920 Speaker 1: average day, we're not smelling out our dinner. We're not saying, 215 00:12:33,960 --> 00:12:36,040 Speaker 1: all right, you know, time to get some food on 216 00:12:36,080 --> 00:12:37,800 Speaker 1: the table, let me go stick my nose out in 217 00:12:37,800 --> 00:12:41,040 Speaker 1: the air. But we see this, we we see this 218 00:12:41,120 --> 00:12:45,200 Speaker 1: even in bacteria. According to a two thousand and ten 219 00:12:45,280 --> 00:12:50,040 Speaker 1: study from the University Medical Center Utrecht in the Netherlands, UH, 220 00:12:50,240 --> 00:12:55,240 Speaker 1: bacteria can detect ammonia. Ammonia is an important source of 221 00:12:55,320 --> 00:12:58,760 Speaker 1: nutrients for bacteria, and it causes bacteria to form slimy 222 00:12:58,800 --> 00:13:04,199 Speaker 1: colonies called bio films UH and smelling it. Identifying ammonia 223 00:13:04,320 --> 00:13:07,640 Speaker 1: may help the microbes to locate their food sources and 224 00:13:07,679 --> 00:13:12,800 Speaker 1: avoid competitors. Now, critics of this study, you know, easily say, well, 225 00:13:12,800 --> 00:13:15,000 Speaker 1: that's not smell. You're just you're you're talking about something 226 00:13:15,120 --> 00:13:17,840 Speaker 1: far more primitive. But if you break down smell, if 227 00:13:17,840 --> 00:13:21,559 Speaker 1: you define smell, it's just simply sensing a volatile molecule, 228 00:13:21,840 --> 00:13:24,680 Speaker 1: sensing key molecules that are peeling off. As as we 229 00:13:24,720 --> 00:13:27,160 Speaker 1: mentioned at the beginning, then that's exactly what's going on 230 00:13:27,240 --> 00:13:31,560 Speaker 1: with these bacteria. They're not smelling oxygen because it doesn't 231 00:13:31,559 --> 00:13:33,800 Speaker 1: have a smell. It's always there around them. But they 232 00:13:33,800 --> 00:13:37,760 Speaker 1: can smell an important gas that signals food, which I 233 00:13:37,800 --> 00:13:42,319 Speaker 1: think is really root to all animals, right, because this 234 00:13:42,400 --> 00:13:45,040 Speaker 1: is the simplest and most ancient form of life from 235 00:13:45,080 --> 00:13:48,520 Speaker 1: which everything else evolved. In this sort of food detection 236 00:13:48,559 --> 00:13:52,800 Speaker 1: device would really play into how the primitive brain would develop. 237 00:13:52,960 --> 00:13:56,400 Speaker 1: So Diane Ackerman's book, again, A Natural History of Senses, 238 00:13:56,440 --> 00:13:59,440 Speaker 1: goes into this. She writes that chemical detection was so 239 00:13:59,480 --> 00:14:03,240 Speaker 1: important that the scent sensitive tissue sitting atop the nerve 240 00:14:03,320 --> 00:14:06,920 Speaker 1: cord developed into a primitive brain. Moreover, and this is 241 00:14:06,960 --> 00:14:10,600 Speaker 1: probably the most mind blowing part of this. Our cerebral 242 00:14:10,640 --> 00:14:16,200 Speaker 1: hemispheres were originally buds from the old factory stocks. Huh. 243 00:14:16,520 --> 00:14:19,000 Speaker 1: So it's it's one of the prime primal scoops of 244 00:14:19,000 --> 00:14:22,440 Speaker 1: ice cream on which our our additional brain scoots were placed. Yeah, 245 00:14:22,480 --> 00:14:24,520 Speaker 1: I mean these are sort of the original blueprints, right. 246 00:14:24,680 --> 00:14:29,800 Speaker 1: That called back to this ability to detect detect chemicals 247 00:14:29,920 --> 00:14:32,240 Speaker 1: that is like the base stock of the brain here. 248 00:14:32,680 --> 00:14:34,240 Speaker 1: So much of it is fascinating, and that there's a 249 00:14:34,320 --> 00:14:38,120 Speaker 1: certain level of understanding that we have conscious understanding about 250 00:14:38,120 --> 00:14:40,040 Speaker 1: what's going on with our our sense of smell, and 251 00:14:40,080 --> 00:14:42,280 Speaker 1: then there's all this other stuff that's going on under 252 00:14:42,320 --> 00:14:45,080 Speaker 1: the surface. And a great example of This comes from 253 00:14:45,160 --> 00:14:49,760 Speaker 1: a two thousand and fourteen study from Manl Chemical Sensus Center. Uh, 254 00:14:49,920 --> 00:14:53,720 Speaker 1: show that that people can actually smell differences in dietary 255 00:14:53,800 --> 00:14:57,760 Speaker 1: fat in foods. In other words, the nose nose when 256 00:14:57,800 --> 00:14:59,640 Speaker 1: you try to pull a fast one on it with 257 00:15:00,000 --> 00:15:04,720 Speaker 1: oh fat alternatives. Yeah. So have this breakdown, well, eight 258 00:15:04,720 --> 00:15:09,600 Speaker 1: participants in two locations, Philadelphia and the Netherlands. Uh. And 259 00:15:09,680 --> 00:15:12,400 Speaker 1: that's key here because we're gonna be dealing with with 260 00:15:12,520 --> 00:15:15,480 Speaker 1: milk and uh, individuals in the Netherlands consume a lot 261 00:15:15,480 --> 00:15:20,320 Speaker 1: more milk than individuals in Philadelphia. Um, they have cream cheese. 262 00:15:20,360 --> 00:15:22,720 Speaker 1: Even that. Yeah, even though they have cream cheese. Uh, 263 00:15:22,880 --> 00:15:25,880 Speaker 1: the Netherlands are still they're still they're still coming out 264 00:15:25,880 --> 00:15:28,800 Speaker 1: on top, all right. So these participants, uh, they were 265 00:15:28,800 --> 00:15:32,360 Speaker 1: made to smell samples of milk with varying amounts of fat, 266 00:15:33,080 --> 00:15:36,000 Speaker 1: and they found that participants could actually distinguish among the 267 00:15:36,040 --> 00:15:39,400 Speaker 1: samples based on their fat content. And and really this 268 00:15:39,400 --> 00:15:42,080 Speaker 1: this makes perfect sense. It's that means as simple as this, fatty, 269 00:15:42,200 --> 00:15:45,920 Speaker 1: high calorie foods equal energy and energy equal survival. So 270 00:15:45,960 --> 00:15:48,840 Speaker 1: it makes perfect sense from evolutionary standpoint. You want to 271 00:15:48,840 --> 00:15:52,760 Speaker 1: be able to sniff out the best source of nutrients. Um. 272 00:15:52,800 --> 00:15:56,600 Speaker 1: Now it's not learned behavior, it's it's in bread behavior. UM. 273 00:15:56,680 --> 00:15:59,440 Speaker 1: I already mentioned that the Dutch drink more milk than Americans, 274 00:15:59,440 --> 00:16:03,480 Speaker 1: but both were equally good at sniffing out the fatty goodness. Likewise, 275 00:16:03,480 --> 00:16:07,240 Speaker 1: participant weight didn't play into the results either, and they 276 00:16:07,280 --> 00:16:09,840 Speaker 1: made sure that they were isolating just the fat by 277 00:16:09,920 --> 00:16:13,400 Speaker 1: using powdered milk rather than fresh. Now, there's still some 278 00:16:13,560 --> 00:16:17,880 Speaker 1: lingering questions here that the researchers are looking into. UM. 279 00:16:18,000 --> 00:16:21,040 Speaker 1: For starters, fat molecules and milk are not very volatile. 280 00:16:21,040 --> 00:16:23,320 Speaker 1: They don't peel off and float around as easily, and 281 00:16:23,360 --> 00:16:26,280 Speaker 1: therefore shouldn't be that easily smelled. But they think they 282 00:16:26,320 --> 00:16:30,240 Speaker 1: might be attaching to other compounds that are huh yeah, 283 00:16:30,320 --> 00:16:32,920 Speaker 1: especially powdered milk right, because it doesn't have anything to 284 00:16:32,920 --> 00:16:36,840 Speaker 1: help dissolve and create a vapor. UM. I think what 285 00:16:37,000 --> 00:16:40,760 Speaker 1: that points to to me is that humans ability to 286 00:16:40,840 --> 00:16:43,520 Speaker 1: suss out smell is you know, a little bit more 287 00:16:43,560 --> 00:16:45,800 Speaker 1: complex than we thought. I mean, not dog complex. We 288 00:16:45,840 --> 00:16:48,360 Speaker 1: don't have that kind of sensory world available to us, 289 00:16:49,000 --> 00:16:52,200 Speaker 1: but certainly a little bit more enhanced than we thought. 290 00:16:52,640 --> 00:16:56,520 Speaker 1: And I wanted to point to this idea um that 291 00:16:57,640 --> 00:16:59,920 Speaker 1: or this previous idea that it was thought that we 292 00:17:00,040 --> 00:17:03,080 Speaker 1: could sniff out about ten thousand smells. Well, in two 293 00:17:03,120 --> 00:17:06,320 Speaker 1: thousand and fourteen, researchers from the Rockefeller University and the 294 00:17:06,359 --> 00:17:10,800 Speaker 1: Howard Hughes Medical Institute put together an experiment that would 295 00:17:10,840 --> 00:17:14,320 Speaker 1: blow that ability to detect ten thousand smells out of 296 00:17:14,320 --> 00:17:17,600 Speaker 1: the water. And the researchers started with bottles of one 297 00:17:17,680 --> 00:17:22,040 Speaker 1: hundred and twenty eight distinct smells, so think about grass 298 00:17:22,240 --> 00:17:26,080 Speaker 1: or citrus, right, and they mixed up to thirty different 299 00:17:26,119 --> 00:17:29,360 Speaker 1: chemicals with it to create unfamiliar smells. And they did 300 00:17:29,359 --> 00:17:32,119 Speaker 1: that because they wanted to really obscure what it was 301 00:17:32,840 --> 00:17:35,480 Speaker 1: and really have people work with their sense of smell 302 00:17:35,600 --> 00:17:38,560 Speaker 1: to suss out what sort of chemicals or odors they 303 00:17:38,640 --> 00:17:42,840 Speaker 1: were sniffing. And so they took three bottles and two 304 00:17:43,000 --> 00:17:45,679 Speaker 1: of those bottles were the same and one was different 305 00:17:45,680 --> 00:17:50,119 Speaker 1: from it, and they had twenty six study participants quaffing 306 00:17:50,560 --> 00:17:54,439 Speaker 1: these odors. And what they did is they calculated the 307 00:17:54,480 --> 00:17:58,560 Speaker 1: percentage of these mixtures that participants could distinguish, and then 308 00:17:58,640 --> 00:18:02,719 Speaker 1: they handed that data over to a mathematician who figured 309 00:18:02,760 --> 00:18:06,240 Speaker 1: out the number of possible unique odors that could be 310 00:18:06,320 --> 00:18:09,880 Speaker 1: made from the mixtures of the chemicals. Okay, I'm gonna 311 00:18:09,880 --> 00:18:22,520 Speaker 1: guess it's it's no dan no, how many one trillion? Yeah, 312 00:18:22,960 --> 00:18:25,440 Speaker 1: So okay, here's the thing, though, this doesn't mean that 313 00:18:25,680 --> 00:18:32,200 Speaker 1: now one connoisseurs need to start using one trillion descriptors exists, right. 314 00:18:32,240 --> 00:18:35,720 Speaker 1: They are trying really hard, uh, but because this is 315 00:18:35,760 --> 00:18:40,880 Speaker 1: more about distinguishing rather than identifying the smells, and it's 316 00:18:41,000 --> 00:18:45,879 Speaker 1: really no indication that we're actually able to pick up 317 00:18:45,920 --> 00:18:47,840 Speaker 1: on a trillion smells, because you think about you may 318 00:18:47,840 --> 00:18:50,920 Speaker 1: not even be met with one trillion smells in your lifetime. 319 00:18:51,640 --> 00:18:55,000 Speaker 1: It's uh, it's more just that that that's the upper 320 00:18:55,040 --> 00:18:59,600 Speaker 1: limit of possible sense. And the reason why they did 321 00:18:59,600 --> 00:19:02,879 Speaker 1: this study is they wanted to discredit that idea of 322 00:19:02,920 --> 00:19:06,560 Speaker 1: tenos smells because it's from the early twentieth century and 323 00:19:07,000 --> 00:19:10,879 Speaker 1: it's not really tied to any specific data set. Is 324 00:19:10,920 --> 00:19:13,080 Speaker 1: just one of some one of those ideas that arose, 325 00:19:13,960 --> 00:19:17,000 Speaker 1: and so this was that, um, this was their chance 326 00:19:17,080 --> 00:19:20,800 Speaker 1: to say, no, smell is so much more complicated and 327 00:19:21,000 --> 00:19:25,040 Speaker 1: nuanced than that, and our ability to detect it. We've 328 00:19:25,080 --> 00:19:26,840 Speaker 1: been kind of given it short shrift for a while. 329 00:19:27,160 --> 00:19:29,199 Speaker 1: We have and uh, you know, I mean as far 330 00:19:29,240 --> 00:19:30,959 Speaker 1: as the senses go, you can sort of look at 331 00:19:30,960 --> 00:19:33,760 Speaker 1: our technology as a good, uh, a good way to 332 00:19:33,800 --> 00:19:36,480 Speaker 1: gauge how much emphasis we put on on it, right 333 00:19:36,800 --> 00:19:38,560 Speaker 1: because right now I can we either of us can 334 00:19:38,600 --> 00:19:41,280 Speaker 1: pick up our smartphone and we can we can send 335 00:19:41,359 --> 00:19:45,159 Speaker 1: visual information, we can send auditory information. We've discussed all 336 00:19:45,160 --> 00:19:48,320 Speaker 1: the different haptic technologies in place where we're we're a 337 00:19:48,359 --> 00:19:50,080 Speaker 1: lot of a lot of people are working really hard 338 00:19:50,200 --> 00:19:55,520 Speaker 1: on being able to transmit feeling and touch across the internet. Hugs, 339 00:19:55,520 --> 00:19:58,080 Speaker 1: We've talked about that. But but where's the smell, where's 340 00:19:58,119 --> 00:20:04,119 Speaker 1: the where's the stank? Well. On June fourteen, the first 341 00:20:04,200 --> 00:20:09,040 Speaker 1: ever transatlantic scent message was transmitted from New York City 342 00:20:09,040 --> 00:20:12,399 Speaker 1: to Paris, and Harvard professor David Edwards and his co 343 00:20:12,520 --> 00:20:17,520 Speaker 1: inventor Rachel Field. They they sent an image, an electronic 344 00:20:17,600 --> 00:20:21,359 Speaker 1: image tagged with a scent, to Le la Boutoire, a 345 00:20:21,359 --> 00:20:24,760 Speaker 1: contemporary art and design center in Paris, and they're a 346 00:20:24,880 --> 00:20:29,040 Speaker 1: device called an O phone decoded the message and reproduced 347 00:20:29,080 --> 00:20:33,199 Speaker 1: the scent using its aromatic cartridges. Yeah, and that the 348 00:20:33,280 --> 00:20:35,920 Speaker 1: scent message that is sent, by the way, is the 349 00:20:35,920 --> 00:20:38,800 Speaker 1: the scent email. If you will. The scent text message 350 00:20:38,920 --> 00:20:41,399 Speaker 1: is called an O note, just just to get the 351 00:20:41,480 --> 00:20:46,040 Speaker 1: lingo out there. UM. This uh, this is a technology 352 00:20:46,080 --> 00:20:50,160 Speaker 1: that is still very much in its infancy. Um. Basically 353 00:20:50,280 --> 00:20:52,200 Speaker 1: like where they are now with it is they're they're 354 00:20:52,240 --> 00:20:55,040 Speaker 1: they're looking at being able to capture somewhere in the 355 00:20:55,080 --> 00:20:58,679 Speaker 1: area of three thousand unique scents. Uh. And it's and 356 00:20:58,880 --> 00:21:00,840 Speaker 1: you'd have to go to an O phone hotspot to 357 00:21:00,920 --> 00:21:02,920 Speaker 1: pick one up if somebody sent one to you, Because 358 00:21:02,920 --> 00:21:06,520 Speaker 1: it ultimately gets into that area of printing smells, of 359 00:21:06,600 --> 00:21:11,120 Speaker 1: using primary odors as a palette, and then using combining 360 00:21:11,160 --> 00:21:14,280 Speaker 1: those to try and create at least an approximation of 361 00:21:14,280 --> 00:21:16,440 Speaker 1: what you're going for with what you're trying to scent. 362 00:21:17,000 --> 00:21:20,560 Speaker 1: And so the exciting part of this is that scent 363 00:21:20,840 --> 00:21:26,040 Speaker 1: could begin to be woven into uh, these different types 364 00:21:26,080 --> 00:21:28,800 Speaker 1: of media that we consume. And so right now we 365 00:21:29,080 --> 00:21:32,080 Speaker 1: have music right is being woven into the media that 366 00:21:32,160 --> 00:21:34,399 Speaker 1: we enjoy, and a lot of times we don't think 367 00:21:34,400 --> 00:21:36,960 Speaker 1: about how powerful that is. That even if it's just 368 00:21:37,040 --> 00:21:40,840 Speaker 1: background music, it changes the mood. It gives your brain 369 00:21:40,880 --> 00:21:43,359 Speaker 1: a little bit something else to hook onto and reframe 370 00:21:43,680 --> 00:21:46,520 Speaker 1: the information you're getting. So just imagine if right now 371 00:21:46,880 --> 00:21:48,840 Speaker 1: you guys were listening to us and we were just 372 00:21:48,920 --> 00:21:53,040 Speaker 1: piping through some cabbage or or freshly baked bread, and 373 00:21:53,080 --> 00:21:57,359 Speaker 1: how that might change the way that you're considering the information. Yeah, 374 00:21:57,480 --> 00:21:59,600 Speaker 1: or even even more than that. It's like, and when 375 00:21:59,600 --> 00:22:01,919 Speaker 1: I think of out our, our our use of music, 376 00:22:02,680 --> 00:22:04,800 Speaker 1: if we're listening to music, whe we're listening to a 377 00:22:04,840 --> 00:22:07,520 Speaker 1: complete composition with various notes to kind of take us 378 00:22:07,520 --> 00:22:11,439 Speaker 1: on a sonic journey. So I can easily imagine a 379 00:22:11,520 --> 00:22:14,840 Speaker 1: time when you plug in I guess your nostril plugs 380 00:22:14,920 --> 00:22:17,840 Speaker 1: or whatever. And uh, and instead of printing with just 381 00:22:17,880 --> 00:22:19,959 Speaker 1: a single smell, without it, without it just being a 382 00:22:19,960 --> 00:22:23,760 Speaker 1: matter of bread or cinnabon or a certain flower, you 383 00:22:23,840 --> 00:22:26,560 Speaker 1: go on a smell journey, say through a garden or 384 00:22:26,600 --> 00:22:30,439 Speaker 1: through the French countryside or a spice market and Marrakesh 385 00:22:30,640 --> 00:22:34,840 Speaker 1: or something of that nature. Like it. Once the technology 386 00:22:34,880 --> 00:22:37,880 Speaker 1: is there and more available, like I feel like we'll 387 00:22:37,920 --> 00:22:41,440 Speaker 1: sort of discover its uses more so than we can 388 00:22:41,560 --> 00:22:44,479 Speaker 1: sort of predict them. Yeah. Indeed, a scratch and sniff 389 00:22:44,600 --> 00:22:50,800 Speaker 1: podcast in right, and already there is some use of smells. 390 00:22:51,000 --> 00:22:54,159 Speaker 1: Um and I'm talking in particular with these scent artists 391 00:22:54,160 --> 00:22:58,800 Speaker 1: Setel tol Us who used sense as a study aid 392 00:22:58,840 --> 00:23:01,439 Speaker 1: for students, which I other we brilliant because we already 393 00:23:01,440 --> 00:23:03,720 Speaker 1: know that when you're trying to learn information that your 394 00:23:03,720 --> 00:23:06,359 Speaker 1: brain is tagging things in its mind like a map, right, 395 00:23:06,359 --> 00:23:10,159 Speaker 1: because it's very spatial, and layer upon that some some 396 00:23:10,440 --> 00:23:13,439 Speaker 1: smells and you can really get the thumb tacks in 397 00:23:13,480 --> 00:23:16,520 Speaker 1: a little bit deeper. I think, Yeah, she's she's wonderful. 398 00:23:16,600 --> 00:23:18,680 Speaker 1: She's the the artist that we we both caught it 399 00:23:18,800 --> 00:23:21,960 Speaker 1: the World Science Festival whild Back if I remember correctly. Um, 400 00:23:22,240 --> 00:23:25,680 Speaker 1: and it's big into like don't call it stinky, like 401 00:23:25,680 --> 00:23:29,960 Speaker 1: like like with children starting early, and trying to frame 402 00:23:30,080 --> 00:23:35,439 Speaker 1: our our linguistic understanding of of of scent in a 403 00:23:35,480 --> 00:23:38,159 Speaker 1: more nuanced way, like more than just the smell is 404 00:23:38,200 --> 00:23:40,240 Speaker 1: good and the smells bad, Like what does it actually 405 00:23:40,280 --> 00:23:43,360 Speaker 1: smell like? Well? And she's really challenging people with smells 406 00:23:43,400 --> 00:23:45,320 Speaker 1: and what it means to them and what sort of 407 00:23:45,359 --> 00:23:49,479 Speaker 1: framework it's it's creating for existence. Um. We've mentioned her 408 00:23:49,560 --> 00:23:53,359 Speaker 1: before with the m I T exhibit that she had 409 00:23:53,440 --> 00:23:57,240 Speaker 1: a wall painted with the sweat of fearful men. You 410 00:23:57,280 --> 00:23:59,720 Speaker 1: would go and smell that wall and smell the fear. 411 00:24:00,320 --> 00:24:02,119 Speaker 1: And then there was another one that she did. It 412 00:24:02,160 --> 00:24:05,760 Speaker 1: was with donated coats and she did the smell profile, 413 00:24:05,840 --> 00:24:08,720 Speaker 1: and I believe that one of them contained, like Chanelle 414 00:24:08,800 --> 00:24:13,320 Speaker 1: number five, dog crap and soy sauce. Yeah, I mainly 415 00:24:13,320 --> 00:24:16,679 Speaker 1: remember the dog crap. I think was just that her 416 00:24:16,720 --> 00:24:19,200 Speaker 1: findings where there's a certain amount of of poop smell 417 00:24:19,280 --> 00:24:21,720 Speaker 1: to a certain number of coats, well, and I love 418 00:24:21,760 --> 00:24:24,520 Speaker 1: that it's contrasted with the Chanel number five. You know, 419 00:24:24,560 --> 00:24:27,480 Speaker 1: it's a fancy lady, and yet she could not escape 420 00:24:27,520 --> 00:24:31,800 Speaker 1: the fine patina a feeces covering us in the world. Indeed, 421 00:24:31,800 --> 00:24:33,560 Speaker 1: you gotta scoop it up. That's the that's the law, 422 00:24:34,840 --> 00:24:40,320 Speaker 1: all right. Well, there you have it, smell, how it works, 423 00:24:40,320 --> 00:24:43,080 Speaker 1: how ancient it is, and when, indeed, what the future 424 00:24:43,200 --> 00:24:46,600 Speaker 1: of smell might consist of. Now, if you check out 425 00:24:46,640 --> 00:24:48,840 Speaker 1: the landing page for this episode on stuff to Blow 426 00:24:48,880 --> 00:24:51,160 Speaker 1: your Mind dot com, you'll also find links to previous 427 00:24:51,200 --> 00:24:53,680 Speaker 1: episodes we've done that have dealt with with scent as 428 00:24:53,680 --> 00:24:57,439 Speaker 1: well as other primary human senses. You'll also find all 429 00:24:57,440 --> 00:24:59,720 Speaker 1: sorts of videos, blog posts, linkside to our social media 430 00:24:59,720 --> 00:25:02,240 Speaker 1: accoun all sorts of good stuff at stuff to blow 431 00:25:02,240 --> 00:25:06,840 Speaker 1: your Mind dot com the mothership of this podcast, and 432 00:25:07,000 --> 00:25:09,800 Speaker 1: I bet you have thoughts um Specifically, we'd love to 433 00:25:09,840 --> 00:25:12,159 Speaker 1: know about whether or not you would be open to 434 00:25:12,240 --> 00:25:15,080 Speaker 1: having a scratch and sniff podcasts, or really any sort 435 00:25:15,160 --> 00:25:18,359 Speaker 1: of media that would deliver some sort of pungent odor 436 00:25:18,400 --> 00:25:21,000 Speaker 1: to your nostrils. You can let us know your thoughts 437 00:25:21,040 --> 00:25:23,720 Speaker 1: by emailing us that blow the mind at how stuff 438 00:25:23,720 --> 00:25:29,439 Speaker 1: works dot com for more on this and thousands of 439 00:25:29,440 --> 00:25:37,600 Speaker 1: other topics. Is it how stuff works dot com