Speaker 1: Hey, you welcome to Stuff to Blow Your Mind. My
Speaker 1: name is Robert Lamb and I'm Joe McCormick, and it's Saturday,
Speaker 1: so we are heading into the vault for an older
Speaker 1: episode of Stuff to Blow Your Mind. This one originally
Speaker 1: aired on April fourteenth, twenty twenty two, and it's part
Speaker 1: two of our series on whether or not plants have
Speaker 1: memories or anything analogous to memory. So we hope you
Speaker 1: enjoy Welcome to Stuff to Blow your Mind, a production
Speaker 1: of iHeartRadio. Hey, welcome to Stuff to Blow your Mind.
Speaker 1: My name is Robert Lamb and I'm Joe McCormick, and
Speaker 1: we're back for part two of our series on the
Speaker 1: possible evidence for memory and learning in plants. Now, this
Speaker 1: is one of our series where if you haven't listened
Speaker 1: to part one yet, you really should go back and
Speaker 1: do that one first, since we clear a lot of
Speaker 1: the ground for what we're going to be talking about today.
Speaker 1: This is one that I think is going to be
Speaker 1: kind of hard to jump in in the middle. But
Speaker 1: in that past episode, for a refresher, we talked about
Speaker 1: a plant called known as the sensitive plant or the
Speaker 1: humble plant, the shame plant that touched me not scientific
Speaker 1: name Mimosa pudica, which is one of the few plants
Speaker 1: in the world that displays rapid movement or movement on
Speaker 1: the time scale usually associated with animal life, and we
Speaker 1: talked about experiments from twenty fourteen that appeared to show
Speaker 1: a form of rudimentary learning called habituation in these plants,
Speaker 1: where for example, if you take a potted Mimosa pudica
Speaker 1: and you drop it the exact same way over many
Speaker 1: training sessions, it will adapt so that it no longer
Speaker 1: closes its leaves defensively in response to a drop, but
Speaker 1: it will still close its leaves in response to other
Speaker 1: types of disturbance. So if this type of finding holds
Speaker 1: up to scrutiny and replication, it would be evidence that
Speaker 1: even though this plant has no brain, it has some
Speaker 1: kind of internal mechanism for learning from experience in order
Speaker 1: to maximize its fitness. And of course, at some level,
Speaker 1: learning requires a form of what we would think of
Speaker 1: as memory. In order to learn from the past, you
Speaker 1: have to have some way of being changed by the past,
Speaker 1: to store the past within you in an organized way
Speaker 1: that can influence future behavior, which, of course we do
Speaker 1: with our brains. But if plants in some cases also
Speaker 1: do this, it's a great question what is the mechanism
Speaker 1: They obviously don't have brains. And finally, in the last episode,
Speaker 1: we tried to disentangle different claims about so called plant cognition,
Speaker 1: which is a controversial concept. We noted that memory is
Speaker 1: not the same thing as reasoning, which is not the
Speaker 1: same as consciousness, which is not the same as emotion
Speaker 1: or communication or or or plant like psychic plant mind reading,
Speaker 1: which some people have also claimed evidence oft without much justification,
Speaker 1: and with the final point being that evidence for one
Speaker 1: of these traits is not necessarily evidence for others. But
Speaker 1: today we're going to look at some more research that
Speaker 1: has been interpreted as showing plant memory or plant cognition
Speaker 1: in the past decade, as well as some reaction and
Speaker 1: criticism to that. Yeah. Now, in the last episode I
Speaker 1: mentioned some music. I mentioned both Celtic Frost's metal album
Speaker 1: to Megatherian Uh and mort Garson's Plantasia, and both were
Speaker 1: kind of offhand references, and afterwards I was looking into
Speaker 1: it a little bit more, and I was first of
Speaker 1: all delighted to see that Plantasia is more widely regarded
Speaker 1: as a classic than I thought it was. Um, I
Speaker 1: was familiar with mort Garson's work, and um, you know,
Speaker 1: I was delighted that his work had recently been reissued
Speaker 1: by Sacred Bones Records. I think I had to make
Speaker 1: do with some some some some bad copies back in
Speaker 1: the day. Sorry, we refresh on the on the mort
Speaker 1: Garson album, it was so mort Garson. It was a
Speaker 1: pioneer of electronic music and synth work. And he had
Speaker 1: a few different monikers that he used. He did some
Speaker 1: like some occult sounding sounds and so forth. But he
Speaker 1: also put out this album Plantasia, which was music to
Speaker 1: be played for your plants very much. Jumping in on
Speaker 1: this The Secret Lives of Plants one, I don't want
Speaker 1: to say hysteria, We'll say popularity during the nineteen seventies.
Speaker 1: And as we discussed in that episode, and we'll discuss
Speaker 1: a little bit here. Yeah, this album is not actually
Speaker 1: going to help your plants out in any of your plants.
Speaker 1: Do not care about Mark Garson's discography as much as
Speaker 1: you do or I do, But it is a very
Speaker 1: nice album for human listeners. Sure, And hey, as I
Speaker 1: said in the last episode, even if it doesn't actually
Speaker 1: do anything for your plants, which it probably doesn't no
Speaker 1: reason not to play it for your plants. I mean
Speaker 1: that sounds fun. Yeah, so I was delighted to see that,
Speaker 1: even though there was a New York Times article about
Speaker 1: this album's popularity and increased popularity I think in part
Speaker 1: due to the reissue, but also they were making the
Speaker 1: point due to the resurgence and interest in houseplants during
Speaker 1: the pandemic, you know, don't. I don't know about about you,
Speaker 1: but I think I don't know if we actually picked
Speaker 1: up that. No, we did pick up more house plants.
Speaker 1: I think some of them were gifted to us. But
Speaker 1: we have all sorts of little succulents like hanging out
Speaker 1: all over the house that we accumulated over the past
Speaker 1: couple of years. I don't know the name for them.
Speaker 1: At Rachel has some kind of houseplant that repeatedly produces buds,
Speaker 1: like I guess, stalks will come off of it, and
Speaker 1: you can separate them and turn them into their own
Speaker 1: new potted version of that same plant, kind of like
Speaker 1: getting a grimlin wet or something. Just you know, they
Speaker 1: repopulate and go all over the place. So I think
Speaker 1: we have had at least proliferation of existing plants. Yeah,
Speaker 1: and house plants are great, no doubt about it. But
Speaker 1: on the other hand, I was looking around for stuff
Speaker 1: on this, and I was kind of taken aback at
Speaker 1: just how much content there is out there on the
Speaker 1: Internet regarding playing music for plants. And while I didn't
Speaker 1: find anyone actually exalting the benefits of playing Celtic Frost
Speaker 1: for your philodendrons, there are pages talking about the merits
Speaker 1: of different musical genres alleged merits, i should say, for
Speaker 1: plant growth, including the idea that heavy metal can improve
Speaker 1: plant mass and fruit taste, provided that it's not too
Speaker 1: noisy or presumably too heavy beautiful. What is the best
Speaker 1: thrash metal for your plants? I've got to assume downstream
Speaker 1: of this, some people who believe in this, really they
Speaker 1: think their plants have individual tastes, like my plants really
Speaker 1: love motor Head. Yeah. I mean, I think we said
Speaker 1: before death metal bands need to get in on beans
Speaker 1: and realize that in the folklore it canon, bean plants
Speaker 1: are closely associated with the world of the dead and
Speaker 1: this should be embraced. Sure, Now, all this being said, yeah,
Speaker 1: not every source popping up on the subject is something
Speaker 1: that I would take to the bank at all. But
Speaker 1: plants do produce vibrations and can respond to sound vibrations.
Speaker 1: Now I got interested in this idea thinking about plants
Speaker 1: responding to sound, and I started wondering about a question.
Speaker 1: I think this is always something good to wonder about.
Speaker 1: When you hear a claim about a life form, you think,
Speaker 1: what would be the original ecological relevance of this, like
Speaker 1: in the actual environment, not in a in a house
Speaker 1: or a lab or something. Why would this kind of
Speaker 1: stimulus be relevant? So I looked it up in the
Speaker 1: scientific literature and I did find some interesting examples. One
Speaker 1: of them was a paper published in Ecologia in twenty
Speaker 1: fourteen by HIGDM Apple and Reginald B. Cocroft called plants
Speaker 1: respond to leaf vibrations caused by insect herbivore chewing. And
Speaker 1: this study found that if you reproduce the sounds made
Speaker 1: by a caterpillar feeding on a leaf and then expose
Speaker 1: those sounds to what's known as a thail cress plant,
Speaker 1: the plant will respond by producing higher level of glucosinolate
Speaker 1: and anthocyanin, which are defensive chemicals. So, if this finding
Speaker 1: is sound, then the plant does actually detect sound, and
Speaker 1: it is ecologically relevant. Sound is an indicator of nearby predation.
Speaker 1: The plant is it is being threatened by what is
Speaker 1: producing this caterpillar eating sound. Yeah, and there's another study
Speaker 1: that I believe came out the same year, conducted by
Speaker 1: Italian botanist Stefano Mancuso, who found that roots could seek
Speaker 1: out buried pipes of running water seemingly attracted to the sound.
Speaker 1: So again, if if these results hold up. Basically, the
Speaker 1: idea here is you have water running through a pipe
Speaker 1: that is otherwise, you know, completely set apart from the dirt,
Speaker 1: from the dirt from the soil, and yet the roots
Speaker 1: are moving towards the water anyway, how would they know
Speaker 1: the water? Is there? The ideas that they're picking up
Speaker 1: on the sound, picking up on the vibrations, right, and
Speaker 1: so again you could wonder how would that be ecologically relevant?
Speaker 1: It seems plausible to me. I mean, they're all kinds
Speaker 1: of like underground water flows and so and those would
Speaker 1: of course produce vibrations right now, And you might then wonder, well, okay,
Speaker 1: if there's a sound of running water and my ambient music,
Speaker 1: does that mean my plant wants it. I think that's
Speaker 1: a more Maybe that's a kind of a simple, simplified
Speaker 1: argument to make. I think you get into a lot
Speaker 1: of discussions about like the differences between how the plant
Speaker 1: is quote unquote hearing and how we are quote unquote
Speaker 1: hearing something, right, I mean, I would say it's hard
Speaker 1: to imagine that there's a evolutionarily justified reason a plant
Speaker 1: would respond to music in particular, But of course there
Speaker 1: are probably good reasons for plants to respond to certain
Speaker 1: types of noise. So to be very generous, I guess
Speaker 1: it's possible that in some cases, some types of music
Speaker 1: might accidentally trigger something like a tropism or a stress
Speaker 1: response in a plant, where it might make the plant,
Speaker 1: I don't know, look different in some way that the
Speaker 1: owner would be able to detect. It's possible. I'm sort
Speaker 1: of skeptical even as far as that goes like the
Speaker 1: accidental byproduct of certain types of music. But as I
Speaker 1: said in the last episode, again, if you want to
Speaker 1: play music for your plants, go for it. You know,
Speaker 1: I don't think it makes sense to literally believe it's
Speaker 1: doing anything for the plant itself, but it sounds like
Speaker 1: a perfectly wonderful activity. Yeah, especially prints. Everybody loves prints,
Speaker 1: so it makes sense that plants would love prints as well.
Speaker 1: Now this is just one of the senses that plants
Speaker 1: seem to possess. I've read that plants have somewhere between
Speaker 1: fifteen and twenty distinct senses, and some of these can
Speaker 1: be compared to our basic set of human senses. In
Speaker 1: addition to sound, as Michael Pollen points out in his
Speaker 1: wonderful article The Intelligent Plant from The New Yorker in
Speaker 1: twenty thirteen, we have, of course, on the human side,
Speaker 1: smell and taste, and plants do seem to sense and
Speaker 1: respond to chemicals in the air or on their bodies.
Speaker 1: We have sight, and plants react differently to various wavelengths
Speaker 1: of light as well as to shadow. So plants like
Speaker 1: us live in a world of periodic light and darkness,
Speaker 1: and of course they depend heavily upon the light because
Speaker 1: of photosenses, So it makes sense that this would be
Speaker 1: in place. And then we have the sense of touch,
Speaker 1: and a vine or root seems to know when it
Speaker 1: encounters a solid object. So plant roots have been found
Speaker 1: to be able to sense gravity, moisture, light, pressure, firmness,
Speaker 1: so you know it's like they're encountering something that seems
Speaker 1: to be a solid as opposed to something they can
Speaker 1: continue to grow in into volume, nitrogen, phosphorus, salt, various toxins.
Speaker 1: A lot of times, Pollen points out that the roots,
Speaker 1: the toxins are going to be first encountered by those
Speaker 1: roots microbes as well as chemical signals from other plants,
Speaker 1: and in that just a little bit, you get into
Speaker 1: the realm of communication. Yeah, And so my read on
Speaker 1: this domain is that while a lot of the other
Speaker 1: things in so called plant cognition could be considered pretty controversial,
Speaker 1: even some of the stuff with better evidence for it,
Speaker 1: like the memory stuff we're talking about, that's still somewhat controversial.
Speaker 1: But plant sensation, the plants being able to gather information
Speaker 1: about all kinds of different things in their environment, that
Speaker 1: seems to me to be utterly uncontroversial. That's just they
Speaker 1: clearly do that right now. A lot of the more
Speaker 1: controversial and it's just flat out unbelievable stuff you encounter
Speaker 1: out there about plants listening to music and so forth.
Speaker 1: This is still st stemming from that nineteen seventy three
Speaker 1: The Secret Life of Plants book by Tompkins and Bird
Speaker 1: that we we talked about in the first episode, popular
Speaker 1: work of mostly pseudoscience. That was also a huge setback
Speaker 1: for legitimate research. And we should also point out that
Speaker 1: make the point here too that there was of course
Speaker 1: movement in the field of plant research into plants senses
Speaker 1: and and you know, potentially plant intelligence decades earlier before Baxter,
Speaker 1: before these these authors wrote this book. For instance, decades
Speaker 1: before this, scientist jagades Chandra bows demonstrated the plants were
Speaker 1: aware of their environment and that they responded to electrical stimulation. Sure,
Speaker 1: but then comes The Secret Life of Plants, and it
Speaker 1: was interesting. I was reading what Paullen had to say
Speaker 1: about it in the in that article, and he points
Speaker 1: out that this book may have resulted in the self
Speaker 1: censorship of researchers that were touching on areas of plant
Speaker 1: cognition or anything that hinted at similarities between plant and
Speaker 1: animal senses. Paullen writes, quote, Americans began talking to their
Speaker 1: plants and playing Mozart for them, and no doubt many
Speaker 1: still do. This might seem harmless enough, there will probably
Speaker 1: always be a strain of romanticism running through our thinking
Speaker 1: about plants. Luther Burr Bank and George Washington Carver both
Speaker 1: reputedly talk to and listen to the plants they did
Speaker 1: such brilliant work with. But in the view of many
Speaker 1: plants scientists, the science the secret life of plants has
Speaker 1: done lasting damage to their field. Yeah, and you can
Speaker 1: understand how this would happen. So there is a there
Speaker 1: is a very culturally popular work of largely based on
Speaker 1: pseudoscience or not well founded claims about the about the
Speaker 1: intelligence or cognition of plants, and then for decades after
Speaker 1: that you would have some reticence to get into thematically
Speaker 1: similar research areas, even if you did have a better
Speaker 1: evidential grounding for them. Yeah, I have to say it
Speaker 1: reminds me a little bit of the situation with dolphin
Speaker 1: communication research coming out in the sixties and seventies, with
Speaker 1: its reputation somewhat tarnished or at least endangered by some
Speaker 1: perspectives by John C. Lilli's work. And also it reminds
Speaker 1: me a bit of the state of psychedelic research coming
Speaker 1: out of the same time period, though of course, here
Speaker 1: with psychedelics there was the added situation of these substances
Speaker 1: becoming federally outlawed so no one was outlawing speaking to
Speaker 1: plants or playing music for them after the Secret Life
Speaker 1: of Plants came out, But we can see how the
Speaker 1: whole affair became somewhat distracting and off putting to serious researchers.
Speaker 1: You know, you're very this is your life's work. You
Speaker 1: don't want it to be associated with this work of pseudoscience,
Speaker 1: with this popular conception of what plants are doing, etc. Yeah,
Speaker 1: I can totally see the parallel to psychedelic research because, yeah,
Speaker 1: in recent years there's been a thaw on psychedelic research
Speaker 1: and there's more legitimate experiment being done with them. But
Speaker 1: I think for a long time, yeah, it wasn't just
Speaker 1: the law. There was a I think a scientific stigma
Speaker 1: about them because there had been a lot of the
Speaker 1: early work on psychedelics was clearly done by people who
Speaker 1: were not practicing unbiased objectives science, but had become sort
Speaker 1: of psychedelic evangelists. And we're we're dedicated proponents of psychedelics,
Speaker 1: and we're just like, how can I make them look good?
Speaker 1: I'll do anything. Yeah, Ti Timothy Learry to be out
Speaker 1: there being the major figure that fits that classification, and
Speaker 1: I have to say, in my very brief survey of
Speaker 1: some of this plant cognition stuff, one thing that does
Speaker 1: make me a little suspicious, perhaps unfairly, of even the
Speaker 1: more legitimate seeming plant cognition research, is that plant cognition
Speaker 1: concepts seem to attract partisans who, at least as far
Speaker 1: as I can tell, sometimes overextend what can be concluded
Speaker 1: based on a piece of research. Like you could look
Speaker 1: at a single study about you know, habituation or something
Speaker 1: that looks like learning or memory and plants and conclude
Speaker 1: from that that this means plants are conscious, they can think,
Speaker 1: they can read my mind, they have a soul, or
Speaker 1: so something like that, you know, over extrapolating from actually
Speaker 1: what is a fairly contained result, or I think also
Speaker 1: you see examples of some people and I'm not accusing
Speaker 1: the researchers themselves of this, but more like people who
Speaker 1: are excited about this research proponents, people who want to
Speaker 1: use plant cognition research to prove ideas they've already acquired elsewhere,
Speaker 1: like ideas about like a universal life spirit permeating all
Speaker 1: things or something, or who take on a kind of
Speaker 1: intellectual martyr persona like the closed minded academy wants to
Speaker 1: destroy the truth, all of which are major red flags.
Speaker 1: But of course it's something I've noticed more in the
Speaker 1: fans of plant cognition research than in the research itself,
Speaker 1: So I wouldn't hold that against the studies we're about
Speaker 1: to talk about. Yeah, anytime science is used to advance
Speaker 1: a non scientific you know, say a theology or some
Speaker 1: sort of an ideology, you get into murky territory, even
Speaker 1: if said theology or ideology isn't, at least on the surface,
Speaker 1: something that's particularly harmful, even if it's yet something like, oh,
Speaker 1: all life forms are connected on Earth, you know, Oh,
Speaker 1: nothing wrong with believing that, is just like this study
Speaker 1: does not show that, right, right, But the situation is
Speaker 1: there is a lot of wonderfully impressive evidence on the
Speaker 1: different ways that the plant, since their environment, they compete
Speaker 1: with each other, communicate, and much more. And so this
Speaker 1: research did continue and and continues to this day. A
Speaker 1: pollen points to a shifting point around the year two
Speaker 1: thousand and six. This is when an article came that
Speaker 1: came out in Trends and Plant Science by six scientists
Speaker 1: who were active in this field of research, and they
Speaker 1: proposed a new field be established plant neurobiology, and Pollen
Speaker 1: writes that more than a decade after this term was
Speaker 1: first proposed, the plant science community was still somewhat split
Speaker 1: on all of this, with some arguing that this was
Speaker 1: a necessary step in the right direction of reconsidering what
Speaker 1: institutes intelligence, and indeed this is something we see similar
Speaker 1: discussions going on regarding the likes of ants and slime molds,
Speaker 1: the ideas of you know, emergent intelligence, intelligence without brains,
Speaker 1: you know, getting outside of the sort of you know,
Speaker 1: basic human and animal conception of what intelligence is. Right
Speaker 1: and of course this is also important when we get
Speaker 1: into discussions of artificial intelligence and contemplations of what alien
Speaker 1: intelligence could consist of. Well, this also recalls other types
Speaker 1: of research along these lines, not in plants, but in say, animals,
Speaker 1: are parts of animals in which a brain is not present.
Speaker 1: You know, we did a couple of episodes about the
Speaker 1: research perhaps indicating that certain types of flatworms could learn
Speaker 1: without a brain, or that part of their body, when
Speaker 1: cut off, could retain memories without the brain present. It's
Speaker 1: an older series, so I know I'm forgetting some details,
Speaker 1: but if you want the full story on that, the
Speaker 1: pair of ses we did. I think we're called devourer
Speaker 1: of memories. So anyway, plant neurobiology, some people, some researchers
Speaker 1: in this field, very much behind the idea of this classification,
Speaker 1: while others considered it kind of a backslide to the seventies,
Speaker 1: you know, saying, look, we're trying to get past the
Speaker 1: stigma of the secret life of plants. This just judges
Speaker 1: it all back up again. Though though to be clear,
Speaker 1: none of these plant neurobiology proponents were making these outrageous
Speaker 1: claims about telepathy or plants having emotions, and the sort
Speaker 1: of intelligence they're proposing is more in line with the
Speaker 1: emergent modes of intelligence that we're discussing here now. One
Speaker 1: of the key arguments for reconsidering the lives of plants
Speaker 1: actually comes down to big revelations made through time lapse footage,
Speaker 1: or if not key to the arguments, key to a
Speaker 1: way of illustrating and studying the plants in question. By
Speaker 1: speeding up long shots of growing stems and leaves and vines,
Speaker 1: were able to sort of translate that timescale of plants
Speaker 1: into the time scale of human beings. And it's not
Speaker 1: just a matter of oh, look, if you speed up
Speaker 1: the footage, it looks like a vine is crawling. Now
Speaker 1: the vine is kind of like a snake and a
Speaker 1: snakes and animal. And now I'm viewing the plant as
Speaker 1: more of a you know, a rational being sort of thing.
Speaker 1: I guess that's inherently part of it, at least to
Speaker 1: the you know, the casual viewer. You're flipping around on
Speaker 1: the TV and you happen to come across, you know,
Speaker 1: one of these Planet Earth documentaries, and you see brilliant
Speaker 1: footage like that. But in various experiments, it actually allows us,
Speaker 1: this kind of footage allows us to better consider environmental interactions.
Speaker 1: So one example that bald has brought up before, I
Speaker 1: believe he I think he brings it up in if
Speaker 1: not in this article, he brings it up in some
Speaker 1: of his books, but brings it up in some video
Speaker 1: view footage that was there to the World Science Festival
Speaker 1: several years back. But you have bean plants that are
Speaker 1: competing for a single pole on which to grow. And
Speaker 1: when you when you speed up that footage and you
Speaker 1: watch the time laps of it, you can see them competing.
Speaker 1: You can see them both going after the same pole.
Speaker 1: You can see one claiming the pole, and then the
Speaker 1: other retreating, giving up the fight, saying all right, fair enough,
Speaker 1: you've got it. And so this, you know, this sort
Speaker 1: of reaction to competition, h you know, rather than inanimate
Speaker 1: objects is key to many of these studies like this
Speaker 1: seems to be an area where plants are even more
Speaker 1: likely to have this sort of rapid response. Yes, though,
Speaker 1: of course this invites I think highly relevant and interesting
Speaker 1: questions about what intelligence actually is. Intelligence is a concept
Speaker 1: that is notoriously difficult to define, because I mean, just
Speaker 1: think about it for a second, how would you define intelligence.
Speaker 1: It's clear like there are some things it seem very
Speaker 1: clearly suggested by the concept. And one of them, I
Speaker 1: think is interesting has to do with speed. Intelligence clearly
Speaker 1: has something to do with the rate of things, because
Speaker 1: like a you know, an animal that solves ama is quickly,
Speaker 1: we look at that behavior and we say, yeah, that's
Speaker 1: indicative of intelligence. But a slime mold that solves amas slowly,
Speaker 1: we look at that and say, yeah, that that doesn't
Speaker 1: so much look like intelligence. So our intuitions have something
Speaker 1: to do with speed. But I would also say another
Speaker 1: part is I think we tend to assume that intelligence
Speaker 1: involves the selection of behaviors or acquisition of goals in
Speaker 1: ways that are not strictly instinctually programmed, but are somehow
Speaker 1: adaptive to individual situations. Though then again, that's often difficult
Speaker 1: to detect, Like when you see time lapse footage of
Speaker 1: a beanstock competing for a pole and then reacting to
Speaker 1: the pole already being claimed. Don't is that a purely
Speaker 1: genetically programmed instinctual reaction or should you think of that
Speaker 1: as in some way individually adaptive or reactive to the
Speaker 1: specific situation? Yeah? Absolutely, I mean some ut regarding intelligence
Speaker 1: and certainly cognition. You know, it comes back to the
Speaker 1: old idea that's just so hard to put aside the
Speaker 1: human perception of the thing. It's so hard to uh
Speaker 1: to even think about say intelligence in our household pets
Speaker 1: without comparing it to ourselves. Yeah, it's it's it's tricky now,
Speaker 1: this this you know, coming back to the idea of
Speaker 1: of neurobiology plant neurobiology. Those opposed to this notion um
Speaker 1: have frequently stated, well, okay, plants just simply do not
Speaker 1: have neurons, synapses, or a brain. Those pollen points out.
Speaker 1: Legitimate scientists in this field are not making that claim
Speaker 1: they're only suggesting that there might be something analogous to
Speaker 1: a brain, to to neurons, etc Um. So Pollen speaks
Speaker 1: with plant biologists Lincoln Tays who opposes the idea of
Speaker 1: plant neurobiology as a sort of animism which takes the
Speaker 1: realities of both short and long term electrical signaling and
Speaker 1: neurotransmitter like chemicals and plants, and then the argument is
Speaker 1: over interprets these realities, ultimately leading to quote anthropomorphizing, philosophizing,
Speaker 1: and wild speculations. Yeah, and I suppose I can see
Speaker 1: like the valid point to be made between these two sides, right,
Speaker 1: I mean, for instance, we often talk about evolution on
Speaker 1: the show, and it's very easy to fall into the
Speaker 1: trap of anthropomorphizing evolution, discussing it as if it has
Speaker 1: a will. You know, this is the sort of thing
Speaker 1: that can make it easier to comprehend what we're talking about.
Speaker 1: It can make it easier to explain some of what's happening,
Speaker 1: drive home what makes it interesting and making it make
Speaker 1: it exciting, But you can also do injustice to the
Speaker 1: appreciation of what it actually is, either subtly or overtly. Yeah, exactly,
Speaker 1: And likewise seems to me that, Yeah, comparing plants to animals,
Speaker 1: it can help explain, it can help excite, It can
Speaker 1: force us to reconsider outdated notions and limitations about what
Speaker 1: plants are and what they're capable of. But you can
Speaker 1: also potentially get into those murky waters. So I'm not
Speaker 1: saying I think either side is totally in the right here,
Speaker 1: but I can see why there is an issue. Yeah,
Speaker 1: but pollen drives something that. Yeah, there are some very
Speaker 1: strong feelings among plant biologists about all of this, which
Speaker 1: actually results in at least a little more heat in
Speaker 1: name calling than usually encounter in the sciences. But perhaps
Speaker 1: it's not all bad. Pollen writes quote. The controversy is
Speaker 1: less about the remarkable discoveries of recent plant science than
Speaker 1: about how to interpret and name them. Whether behaviors observed
Speaker 1: in plants which look very much like learning, memory, decision making,
Speaker 1: and intelligence deserve to be called by those terms, or
Speaker 1: whether those words should be reserved exclusively for creatures with brains. Yeah,
Speaker 1: that absolutely tracks with my experience reading about a lot
Speaker 1: of this plant cognition stuff. That either way, you have
Speaker 1: some very interesting experimental results, but a lot of the
Speaker 1: conflict seems to be in arguing about what those results
Speaker 1: mean and what is a reasonable way to characterize them. Yeah, now,
Speaker 1: on the topic of plants and brains, you might wonder,
Speaker 1: why don't they have a brain. Perhaps you've played a
Speaker 1: video game before where you have to blast the vital
Speaker 1: organs out of some sort of monster plant in order
Speaker 1: to defeat it. Why does that not seem to be
Speaker 1: the case. Why is the reality instead that a plant
Speaker 1: can lose up to around ninety percent of its body
Speaker 1: without being killed. I mean, this all comes down to
Speaker 1: the fact that plants are are stationary. They stay in
Speaker 1: one spot. I mean, with some you know, they are
Speaker 1: rooted to the ground. We have some situations where yes,
Speaker 1: plants can travel and to varying degrees, but for the
Speaker 1: most part, where the plant takes root, the plant stays.
Speaker 1: The plant can't run away. It's got to be ready
Speaker 1: to sacrifice large portions of its body, and so it
Speaker 1: simply doesn't make sense for it to evolve some sort
Speaker 1: of a centralized, irreplaceable and insensitive organ like this. The
Speaker 1: sessile lifestyle requires different approaches to problem solving, and it
Speaker 1: also ends up being one of the reasons that you
Speaker 1: have such a robust biochemical weapons. Why it has such
Speaker 1: a such a robust biochemical arsenal and the plant the
Speaker 1: power here, for plants are famous, you know, far more
Speaker 1: opponent than anything you'll find in animals. And it's why
Speaker 1: so much of human medicine is based in Okay, I
Speaker 1: have this ailment, which plant should I eat? And how
Speaker 1: much of that plant should I eat in order to
Speaker 1: fight it? Yeah. Another way to put that is just
Speaker 1: that the plant kingdom is full of internal chemicals that
Speaker 1: have potent effects on the physiology of animals. Yeah. And
Speaker 1: of course Pollen has written about this quite a bit,
Speaker 1: including the book The Botany of Desire that In this
Speaker 1: New Yorker article he summarizes the biochemical arsenal quite quite nicely.
Speaker 1: He says, unable to run away, plants deploy a complex
Speaker 1: molecular vocabulary to signal, distress, deter, or poison enemies, and
Speaker 1: recruit animals to perform various services for them. So, yeah,
Speaker 1: I think he puts it quite well there. It's almost
Speaker 1: like sort of asking yourself, well, okay, I have a
Speaker 1: computer system. Why doesn't the computer system have a knife.
Speaker 1: Why does it have a club? It should? It should? Right? Well, no,
Speaker 1: it has these other things, and it has them to
Speaker 1: you know, all these other defenses are in place because
Speaker 1: it's it's fighting a different type of battle on a
Speaker 1: different scale. So again, yeah, it's so much of the
Speaker 1: of what makes the plant different. You know. We can
Speaker 1: look at the time scale certainly as a huge factor,
Speaker 1: but also the fact that it is a sessile organism. Yeah,
Speaker 1: and so if a plant does indeed contains something that
Speaker 1: is it could legitimately be considered intelligence. It would need
Speaker 1: a different kind of substrate to conta that intelligence then
Speaker 1: the human brain, which is a centralized command center, you know,
Speaker 1: because again, like you said, the plant might get ninety
Speaker 1: percent of it might get eaten, and then it needs
Speaker 1: to be able to grow back. So if you allow
Speaker 1: for the concept of plant intelligence, it would probably need
Speaker 1: to somehow be more modular or distributed rather than housed
Speaker 1: in a command center like the human brain. And so
Speaker 1: what would some of these these physical substrates or systems
Speaker 1: be I think that is largely unknown, though there are
Speaker 1: some interesting ideas. Like in the previous episode, one of
Speaker 1: the papers we looked at, the one that looked at
Speaker 1: habituation in Mimosa pudica, it hypothesized one of the possible
Speaker 1: substrates of plant memory formation could be what are called
Speaker 1: calcium ion channels within the plant's tissues, which can form
Speaker 1: these kind of sensory chains throughout the plant's body. But
Speaker 1: it's it's still unknown. But but but I guess we
Speaker 1: should look at least one more study. Look, it's more
Speaker 1: lab research. So in the previous study, we looked at
Speaker 1: the one from twenty fourteen. In the last episode, it
Speaker 1: found apparent demonstration of a very rudimentary form of learning
Speaker 1: known as habituation in these sensitive plants that could close
Speaker 1: their leaves. And habituation could be defined as the diminishment
Speaker 1: of a programmed reaction to a repeated stimulus. So maybe
Speaker 1: you jump with fright when you hear a sudden clattering
Speaker 1: sound behind you. Most people would, But if that clattering
Speaker 1: sound is repeated every five minutes, you will eventually stop
Speaker 1: jumping with fright. You will become accustomed to it. You
Speaker 1: will just start ignoring it because you've become habituated. And
Speaker 1: this doesn't require conscious effort. It just happens unconsciously naturally.
Speaker 1: When you're exposed to the same salient stimulus over and
Speaker 1: over again. What seems salient at first has been encountered
Speaker 1: enough times that your body's just been trained to no
Speaker 1: longer regard it as salient. It's just noise, it's background.
Speaker 1: But of course there are other types of learning and
Speaker 1: memory that could of course be considered more complex. So
Speaker 1: could plants actually demonstrate any of these other forms of
Speaker 1: memory as well? The next study I want to talk
Speaker 1: about looked at whether you could find evidence of classical
Speaker 1: conditioning in plants. Classical conditioning is one of the big
Speaker 1: concepts in behavioral psychology. I'd say it is one of
Speaker 1: the biggest discoveries of psychology in the last I don't
Speaker 1: know about the last of the twentieth century. It is
Speaker 1: a type of unconscious learning, usually observed in animals, in
Speaker 1: which you repeatedly pair a salient stimulus with a neutral stimulus,
Speaker 1: and over time the animal will eventually respond to the
Speaker 1: previously neutral stimulus the way they respond to the salient one. So,
Speaker 1: if you concrete examples, the original one is the story
Speaker 1: of Pavlov's dogs. This goes back to the Russian physiologist
Speaker 1: von Pavlov, who lived eighteen forty nine to nineteen thirty six.
Speaker 1: He was studying digestion in dogs, and he started to
Speaker 1: notice that the dogs in his lab would drool not
Speaker 1: only when their food was in sight, but when they
Speaker 1: saw the specific lab assistant who always fed them. So
Speaker 1: the production of saliva and the presence of food is
Speaker 1: a natural, unconditioned response, that's just something that makes sense
Speaker 1: for the body to do. The saliva will be useful
Speaker 1: once you start eating, but the dogs come to associate
Speaker 1: the assistant with food, so their glands start jacking up
Speaker 1: the saliva when they see and smell that specific person
Speaker 1: who feeds them, even though the person themselves is not
Speaker 1: actually food, And it of course can be any stimulus.
Speaker 1: The classic example is a sound such as a bell
Speaker 1: or a metronome. So if I give you a painful
Speaker 1: electric shock every time I start playing we Built this
Speaker 1: City by Starship, you will start to have a reaction
Speaker 1: to the song without the shock. Even if there's no shock,
Speaker 1: you hear that first line and you'll probably freeze or WinCE. Anyway,
Speaker 1: given that there is some preliminary evidence that at least
Speaker 1: some plant species can exhibit habituation, would it be possible
Speaker 1: to show this other kind of memory based learning in plants.
Speaker 1: Can plants be classically conditioned? To associate a neutral queue
Speaker 1: with a biologically salient queue. So the study I want
Speaker 1: to mention was published in Nature Scientific Reports in twenty
Speaker 1: sixteen by Monica Gagliano, Vladislav Vasovski, Alexander Borbelli, Mavra Grimonprez
Speaker 1: and Martial Deptchinsky. And it's called learning by association in plants.
Speaker 1: So the authors justify their investigation by explaining that they
Speaker 1: think there would in fact be evolutionary pressure on plants
Speaker 1: to show associate of learning. So, much like the question
Speaker 1: we asked earlier about sounds and stuff in plants, it's
Speaker 1: worth thinking is there actually an ecologically relevant reason for
Speaker 1: the creature you're studying to have the ability you're looking for?
Speaker 1: And so they write quote. Incomplex and ever changing environments,
Speaker 1: resources such as food are often scarce and unevenly distributed
Speaker 1: in space and time. Therefore, utilizing external cues to locate
Speaker 1: and remember high quality sources allows more efficient foraging, thus
Speaker 1: increasing chances for survival. Associations between environmental cues and food
Speaker 1: are readily formed because of the tangible benefits they confer,
Speaker 1: while examples of the key role they play in shaping
Speaker 1: foraging behaviors are widespread in the animal world. The possibility
Speaker 1: that plants are also able to acquire learned associations to
Speaker 1: guide their foraging behavior has never been demonstrated. Okay, so
Speaker 1: the same ability to discern and make these associations would
Speaker 1: potentially be useful for plants, we just haven't documented evidence
Speaker 1: of it yet. And this study explored the question with
Speaker 1: the use of a different plant than the other one.
Speaker 1: We're not talking about Mimosa pudica anymore. In this case,
Speaker 1: they looked at seedlings of the garden p plant or
Speaker 1: Pisum sativum. Now it's worth clarifying that the plant behavior
Speaker 1: studied in this experiment occurs on a different timescale than
Speaker 1: the ones we talked about in the previous episode. In
Speaker 1: the last episode, there were examples of the few plants
Speaker 1: with the ability to move rapidly, such as the venus
Speaker 1: flytrap or Mimosa putica, and these rapid movements were examples
Speaker 1: of what are called nastic reflexes, reflexes that are independent
Speaker 1: of the direction of the stimulus and they're just guided
Speaker 1: by the plant's body form. Nastic movements were contrasted with
Speaker 1: what are called tropisms, which tend to be slower movements,
Speaker 1: but are stimulus directed. And the most common plant tropism
Speaker 1: you will have observed pretty much everybody's seen this is
Speaker 1: phototropism growing towards a light source, which totally makes sense
Speaker 1: for a plant because light provides the energy that powers photosynthesis.
Speaker 1: So you can roughly think of a plant growing toward
Speaker 1: light much like an animal moving toward a source of food.
Speaker 1: And that's what this twenty sixteen experiment was studying, not
Speaker 1: nastic reflexes, but tropisms growth in the direction of a
Speaker 1: biologically salient stimulus, in this case light. So the first
Speaker 1: experimental setup looked like this the author's right quote. In
Speaker 1: the first experiment, p seedlings, forty five of them were
Speaker 1: entrained to an eight hour light sixteen hour dark cycle
Speaker 1: for five to eight days. In the subsequent three day
Speaker 1: training period, they were kept in darkness with the exception
Speaker 1: of one hour light exposures during the three daily training sessions.
Speaker 1: And during this training period the seedlings, they would place
Speaker 1: them in what's known as a y maze. So to
Speaker 1: picture this, you think of a Y shaped pipe. The
Speaker 1: seedling is down at the bottom in the single channel
Speaker 1: part of the tube, and then above it the tube
Speaker 1: forks off into two arms, and then there are two
Speaker 1: different training conditions, one in which the seedlings are exposed
Speaker 1: to a light source from one of the tube with
Speaker 1: a fan blowing on them from the same arm, and
Speaker 1: then there's another test condition in which they are exposed
Speaker 1: to a light source from one arm and a fan
Speaker 1: blowing on them from the opposite arm. So we have
Speaker 1: the light associated with a fan or a light associated
Speaker 1: with being opposite the fan. So if the plants are
Speaker 1: capable of classically conditioned associations, one group should learn that
Speaker 1: the airflow from a fan is positively correlated with food,
Speaker 1: so it should start to associate a fan with food,
Speaker 1: and then the other will learn that the airflow is
Speaker 1: negatively correlated with food, and it should associate going in
Speaker 1: the opposite direction of the fan with food. And to
Speaker 1: make the direction of the incoming light unpredictable, its direction
Speaker 1: was repeatedly switched around during the training period, though its
Speaker 1: association or lack of association with the fan was kept
Speaker 1: consistent with each plan. And after this training period, the
Speaker 1: plants were further subdivided to put some in test groups
Speaker 1: in the other in the control group, and the two
Speaker 1: test groups would be exposed to a fan from one
Speaker 1: direction or the other without the light source along with
Speaker 1: it the author's right quote. In this group, to control
Speaker 1: for the influence of innate phototropic response, the fan was
Speaker 1: placed in the arm opposite to last light exposure in
Speaker 1: the fan plus light group and on the arm of
Speaker 1: the last light exposure in the fan versus light group,
Speaker 1: So that was the second is when they were on
Speaker 1: opposite sides of the y maze quote. The seedlings of
Speaker 1: the control group were left undisturbed. On the morning after
Speaker 1: the testing day, we visually inspected the seedlings and recorded
Speaker 1: the arm of the maze they had grown into. So
Speaker 1: what did they find. Well, in the control group, this
Speaker 1: is the group that got no fan exposure in the
Speaker 1: test phase, so no fan, one hundred percent of the
Speaker 1: plants grew in the direction of the most recent light exposure,
Speaker 1: wherever the light came from last that's where they went.
Speaker 1: But in the test groups, the authors report that the
Speaker 1: majority of seedlings did indeed show a conditioned response. So
Speaker 1: in the group that it been trained with the fan
Speaker 1: and the light on the same side, sixty two percent
Speaker 1: of them grew toward the fan without the light, And
Speaker 1: in the group that had been trained with the fan
Speaker 1: and the light on opposite sides, sixty nine percent grew
Speaker 1: away from the fan. So if this holds up, it
Speaker 1: would appear to show associate of learning in plants, a
Speaker 1: type of learning that in the majority of cases prevails
Speaker 1: over the basic reflexive tropism to grow in the direction
Speaker 1: of wherever the light came from last. But of course
Speaker 1: it's a good question does this study actually hold up?
Speaker 1: Will come and come back to that in a minute. Here.
Speaker 1: One more thing I wanted to mention, though, is that
Speaker 1: there were also subsequent experiments in the same study, and
Speaker 1: the authors found that the associat of learning only succeeded
Speaker 1: when it took place during the quote daytime from the
Speaker 1: plant's perspective given its training regimen, which the authors suggest
Speaker 1: means that there are metabolic demands on the learning process. Quote.
Speaker 1: This experiment, in which plants were trained at three different
Speaker 1: time periods within twenty four hours, revealed that the learning
Speaker 1: effect disappears when training occurred during the evening hours, when
Speaker 1: light would not normally be available. This finding is particularly
Speaker 1: intriguing and bolsters the argument that associative learning is an
Speaker 1: adaptive response that is only utilized during daylight hours when
Speaker 1: it is most useful vin internal circadian clock, which is
Speaker 1: interesting because that also invokes a sort of second order
Speaker 1: type of thing that some people would have called a
Speaker 1: type of plant intelligence, which is its ability to measure
Speaker 1: spans of time. Anyway, in the end, the authors of
Speaker 1: this study, they say, quote, our results show that associative
Speaker 1: learning is an essential component of plant behavior. We conclude
Speaker 1: the associative learning represents a universal adaptive mechanism shared by
Speaker 1: both plants, animals and plants. Now, this was in twenty sixteen,
Speaker 1: and I did find a study following up on this
Speaker 1: and attempting a replication and failing. So the attempted replication
Speaker 1: was by Casey Marcole published in ELFE called lack of
Speaker 1: Evidence for associate of Learning in p Plants. The year
Speaker 1: was twenty twenty. Pretty straightforward. The author tried to repeat
Speaker 1: the twenty sixteen experiment. They repeated the protocol described in
Speaker 1: the first experiment, and they write quote, However, a replication
Speaker 1: of the protocol failed to demonstrate the same result, calling
Speaker 1: for further verification and study before mainstream acceptance of this
Speaker 1: paradigm shifting phenomenon. This replication attempt used a larger sample
Speaker 1: size and fully blinded analysis, and of course both of
Speaker 1: those things are always good. Larger samples are good, blinded
Speaker 1: analysis is always good. I wasn't one hundred percent sure
Speaker 1: exactly what that meant in this case, but I think
Speaker 1: it would mean that whoever compiled and analyzed the results
Speaker 1: of the experiment had no way of knowing which groups
Speaker 1: the subjects were in, which would help prevent any possible contamination,
Speaker 1: intentional or unintentional by experiment or bias. So we're in
Speaker 1: the middle ground here. One study gets a positive result,
Speaker 1: a follow up attempt does not, So how do we
Speaker 1: sort it out? Well? Actually, the authors of the original
Speaker 1: study replied, publishing a follow up comment in the same journal.
Speaker 1: They essentially to summarize their argument. They essentially say that
Speaker 1: the experiment may not have worked in the replication attempt
Speaker 1: because of some crucial differences in methodology, mainly that the
Speaker 1: unconditioned stimulus in this case light was not tightly controlled enough,
Speaker 1: and that they criticize some things about the plants had
Speaker 1: been mounted inside their growth case, and the idea that
Speaker 1: light from one tube may have been penetrating into other tubes,
Speaker 1: making a kind of light noisy environment. That there were
Speaker 1: too many light sources and this would introduce randomness into
Speaker 1: the results. So to put it in terms of the
Speaker 1: Pavlov's dog example, this might be a kind of rough comparison,
Speaker 1: But the unconditioned stimulus in Pavlov's dogs would be food.
Speaker 1: So if you were to have a poor control of
Speaker 1: the unconditioned stimulus in that case, it would be kind
Speaker 1: of like imagining that the dogs had constant ambient access
Speaker 1: to food. They were just food bowls constantly full throughout
Speaker 1: the room they're in. In that case, would they salivate
Speaker 1: when they saw an assistant coming in to put some
Speaker 1: more food in one of the bowls, Well, if they've
Speaker 1: just always got food anyway, probably not right. I don't know.
Speaker 1: I don't know enough about dogs. Sometimes I feel like
Speaker 1: sometimes my cat can be kind of like that, where
Speaker 1: it's like, really that you have food, and here's more food.
Speaker 1: Now you're excited for this. How about the food you
Speaker 1: already have? I trust the research or something. Right, Well,
Speaker 1: if they've just got food anytime they want it, right,
Speaker 1: then they wouldn't associate the assistant coming in to fill
Speaker 1: the food bowls with them getting the food. It would
Speaker 1: just you know, they would just get the food whenever
Speaker 1: they want. True. True. So that's what the authors of
Speaker 1: the original study argued. But then there was a response
Speaker 1: to the response in the same journal again where Markel
Speaker 1: came back and argued, for a number of technical reasons
Speaker 1: that the differences they highlighted are unlikely to explain the
Speaker 1: different outcomes. Quote. Despite considerable effort to match the experimental
Speaker 1: details of the twenty sixteen experiment, the application attempt did
Speaker 1: not find evidence for associate of learning in PEP plants.
Speaker 1: Of course, this does not rule out the existence of
Speaker 1: such learning, and I sincerely hope that future research demonstrates
Speaker 1: the phenomenon to be reproducible. So I feel like we're
Speaker 1: kind of in a middle ground here. Personally, I don't
Speaker 1: have the expertise or judgment to reach a conclusion on
Speaker 1: the technical points they're arguing about in the experiment here,
Speaker 1: So I guess I would just say I'd have to
Speaker 1: consider the twenty sixteen results very interesting, but heavily caveated
Speaker 1: until we see successful replication. Yeah. Now, I will say
Speaker 1: that the lead author on this paper, Monica Gagliano, I've
Speaker 1: seen her. She was part of a panel discussion at
Speaker 1: the World Science Festival back in twenty nineteen, I Believe
Speaker 1: Intelligence Without Brains. That also featured ants scientist Mark Moffatt,
Speaker 1: whose work we've discussed in the show before. Oh yeah yeah.
Speaker 1: Monica Gagliano's research Associate professor in Evolutionary ecology the Biological
Speaker 1: Intelligence Lab at Southern Cross University in Australia. Her primary
Speaker 1: areas of research or marine ecology and plant cognitive ecology.
Speaker 1: She also has a book out which I was not
Speaker 1: aware of until I was looking back into her work here,
Speaker 1: but the book is thus Spoke the Plant. Yeah. She
Speaker 1: seems to be one of the leading figures in the
Speaker 1: plant cognition domain these days. She wrote another article in
Speaker 1: twenty eighteen summing up some of this recent stuff in
Speaker 1: ecologia called Plants Learn and Remember, Let's get used to it.
Speaker 1: Actually sorry, that had three authors. She was the first
Speaker 1: listed author. Well, I will say she did seem to
Speaker 1: have a good sense of humor about about herself and
Speaker 1: about her area of research when I saw her gift
Speaker 1: that talk. And by the way, if you want to
Speaker 1: see that talk for yourself, you can find it at
Speaker 1: the World Science Festival's website. Just look for Intelligence Without brains.
Speaker 1: They have the full talk up there now. I guess
Speaker 1: we've already covered this a good bit earlier on, so
Speaker 1: I won't get into too much detail. I did have
Speaker 1: a few notes about some other articles I was reading,
Speaker 1: for example, by one author you already cited who came
Speaker 1: up in Pollen's New Yorker piece, Lincoln Tiez, who has
Speaker 1: been a critic of so called plant cognition or plant neurobiology,
Speaker 1: and comments by researchers from this camp, though a lot
Speaker 1: of this seemed aimed at the kind of thing you
Speaker 1: were talking about, where they're objecting to certain extrapolations or characterizations,
Speaker 1: extrapolations from or characterizations of this research, rather than the
Speaker 1: research itself, like rejecting the idea of plant consciousness and
Speaker 1: so forth, And of course that opens its own cannon worms,
Speaker 1: because of course, you know, there's no actual test for consciousness,
Speaker 1: even in humans. Consciousness can only be experienced directly in
Speaker 1: the self and then inferred to exist by analogy and
Speaker 1: other humans, and possibly in non human animals. But they've
Speaker 1: got a number of arguments based on the the just
Speaker 1: physical anatomical qualities of plants that say, you know, it's
Speaker 1: very unlikely they would have the whatever kind of computational
Speaker 1: complexity the I don't know, calcium channels or anything like that,
Speaker 1: and plants might possess it would be unlikely to possess
Speaker 1: the level of complexity that we see in animal brains
Speaker 1: and that we assume to be the necessary basis for consciousness.
Speaker 1: But anyway, I mean, so, I think where we're left
Speaker 1: right now, at least from my point of view, is
Speaker 1: that we're still in the middle of a research program.
Speaker 1: There's still like a you know, a lot of basic
Speaker 1: research in plant cognition going on that maybe in five
Speaker 1: or ten more years we will have a better idea
Speaker 1: of what the direct evidence is about what plants can
Speaker 1: actually do, and then it might we might be more
Speaker 1: well equipped to argue about whether it actually counts as X,
Speaker 1: y or z that we you know, words we use
Speaker 1: to associate with the mental phenomena of humans. Yeah, yeah,
Speaker 1: or I don't know, maybe we'll have different terminology at
Speaker 1: that point that it's yeah, we end up in the
Speaker 1: same situation where we're trying to divorce the study of
Speaker 1: intelligence and content and even potentially consciousness, you know, across
Speaker 1: multiple species and multiple organisms. Despite the fact that we
Speaker 1: have this this this experience of these things, and this
Speaker 1: this concept of these things that's you know, closer than
Speaker 1: our own breath. One thing that's got me thinking about
Speaker 1: again this is this is we're in the speculative realm. Now,
Speaker 1: this is not what's necessarily justified by the existing evidence.
Speaker 1: But if you were to discover, for example, that maybe
Speaker 1: you can't justify the claim that plants can think, but
Speaker 1: you could justify the claim that plants can learn, it
Speaker 1: would be an important reminder to not blur all different
Speaker 1: types of mental phenomenon together into one single substance, Like
Speaker 1: there may be important differences between, for example, remembering and
Speaker 1: reasoning that make one but not the other possible given
Speaker 1: any physical substrates, say like the kinds of I don't know,
Speaker 1: computational chemical pathway that would exist in plant stems and
Speaker 1: roots versus in the neural tissue of a human being
Speaker 1: or an animal. Maybe human brain tissue can do both,
Speaker 1: but plant tissue can only do one. And this has
Speaker 1: interesting implications for speculating about alien intelligence. If there are
Speaker 1: other types of intelligence out there in the galaxy, we
Speaker 1: would tend to assume those intelligences to bundle together all
Speaker 1: the myriad functions performed by our own primate brains, but
Speaker 1: it's important to remember those are like specifically primate brains.
Speaker 1: We've got a very particular type of meat in our heads,
Speaker 1: and the type of intelligence we're familiar with is what
Speaker 1: that meat can do. So what if, like there's another
Speaker 1: physical substrate that's unfamiliar to us and that constitutes what
Speaker 1: we would think of as the alien brain, whatever that is,
Speaker 1: should we be trying to think of it as capable
Speaker 1: of some of the subdivided parts of intelligence what we
Speaker 1: think of as intelligence, but not others. Yeah, that's a
Speaker 1: great point. And uh, you know, I guess I would
Speaker 1: hope that we're at least reaching towards a point where
Speaker 1: we're going to have a more you know, complicated understanding
Speaker 1: of what memory and learning are because we're already having
Speaker 1: to contend not just with human and animal memory and learning,
Speaker 1: but also machine learning and machine memory and you know,
Speaker 1: potentially plant analogs as well, and so yeah, it just
Speaker 1: it kind of hopefully forces to push the human experience
Speaker 1: and the human model a little further aside and realize that, yeah,
Speaker 1: this is this is an example of a broader thing,
Speaker 1: and it is not the thing itself, Like I'm imagining
Speaker 1: a sci fi concept of story about encountering aliens that maybe,
Speaker 1: if this makes any sense, what if they could do
Speaker 1: something that looks like intelligence because they can learn and adapt,
Speaker 1: but they can't do what we would think of as reasoning. Yeah,
Speaker 1: like they can learn, but they can't think. I don't know,
Speaker 1: I'm not sure that even makes sense. But uh, I
Speaker 1: don't know. It gets my gears cranking. All right, we
Speaker 1: just had a brief conversation off Mike. Are we gonna
Speaker 1: Are we gonna cap this series here? Are we going
Speaker 1: to go more with the interesting hidden lives of plants,
Speaker 1: plant cognition, so called plant communication, things like that. Maybe
Speaker 1: we'll just leave it a mystery. You'll be surprised next Tuesday,
Speaker 1: which whether we're onto something else or whether the plants continue. Yeah,
Speaker 1: and in the meantime, you've you've got some hanging out
Speaker 1: to do with your various house plants and plants in
Speaker 1: the yard, maybe plants out in the wild. Um, you know,
Speaker 1: if if they're within your house, maybe maybe play them
Speaker 1: a little Starship, play them a little some prints and
Speaker 1: some of the other musical examples we mentioned these episodes.
Speaker 1: We're not saying it's going to do anything, but it
Speaker 1: might be fun to hang out with your plan and
Speaker 1: listen to Starship. You know, I think of it like
Speaker 1: the the semantic contents of talking to your dog, Like
Speaker 1: if the dog's mostly just going to be responding to
Speaker 1: the tone of your voice. If I tell my dog
Speaker 1: he's a he's a bad boy and a good boy voice,
Speaker 1: he's probably gonna be super happy. But you know, I
Speaker 1: want to say good boy anyway because that makes me
Speaker 1: feel good. All right, Well, we're gonna go and close
Speaker 1: it out here, but as always, you can find episodes
Speaker 1: core episodes of Stuff to Blow Your Mind in the
Speaker 1: Stuff to Blow Your Mind podcast feed every Thursday and Tuesday.
Speaker 1: You will also find our short form Artifact or Monster
Speaker 1: Fack episodes on Wednesdays, Listenermail on Mondays, and on Friday,
Speaker 1: well we do a little Weirdout Cinema. That's when we
Speaker 1: set aside most serious concerns and just talk about a
Speaker 1: strange film. And then on the weekend we have a
Speaker 1: vault episode that is a rerun from yesteryear. Huge thanks
Speaker 1: as always to our excellent audio producer Seth Nicholas Johnson,
Speaker 1: though he is out this week. So big thanks to
Speaker 1: our excellent guest audio producer Paul deckand huge thanks for
Speaker 1: stepping in this week, Paul. If you would like to
Speaker 1: get in touch with us with feedback on this episode
Speaker 1: or any other, suggest a topic for the future, or
Speaker 1: just to say hello, you can email us at contact
Speaker 1: at stuff to Blow your Mind dot com. Stuff to
Speaker 1: Blow Your Mind is production of iHeartRadio. For more podcasts
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