November 21, 2019 • 49 mins
“You are what you eat,” the saying goes -- but does that apply to memories as well? In this Stuff to Blow Your Mind two-parter, join Robert and Joe on a journey through the world of Planaria worms, controversial research, regineration, behaviorism and even the machinations of the unabomber.
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Episode Transcript
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Speaker 1 (00:00):
My Welcome to Stuff to Blow Your Mind, a production
of I Heart Radios How Stuff Works. Hey, welcome to
Stuff to Blow Your Mind. My name is Robert Lamb
and I'm Joe McCormick, and we're back with part two
of our exploration of planarians, memory, learning and conditioning, and
(00:23):
of course today we're going to get to the cannibalism.
That's right. If you did not listen to part one,
do go back and listen to it, because we lay
the groundwork. We discussed these organisms, why they're interesting. We
discussed their regenerative powers. We talk about McConnell himself. We
talk about his personal and professional history as well as
his run in with the unit Bomber. Right. Uh, so
(00:44):
that figure, of course is James V. McConnell, the American psychologist.
But if you listen to the last episode, as you
should before this one, you already know that. So we're
picking up after McConnell's initial research demonstrating in the nineteen
fifties that despite conventional wisdom that in vertebrates could not learn,
could not be trained through classical conditioning or any other
(01:04):
kind of associate of learning. Uh. McConnell and colleagues did
in fact demonstrate that that's not true, at least for planarians,
these flatworms that that could be trained to react to
something like a light stimulus. And we also discussed how
it's just generally known to be true today that invertebrates
can learn. The conventional wisdom at the time was wrong.
(01:25):
But so to pick up with McConnell's career. After completing
his graduate degree at the University of Texas, I almost
said Jerry O'Connell, not Jerry O'Connell. James McConnell moved on
to the University of Michigan, where he continued his research
into flatworms. So the team that came to be known
as the Pollinarian Research Group or pr G. So another
(01:45):
piece of context for this research is a sort of
quest for the holy Grail within twentieth century psychology and neuroscience,
and this was the hunt for the elusive Ingram. It
was believed by men in the mid century that a researcher,
that the first researcher to actually pinpoint something known as
(02:06):
the ingram, would receive the Nobel Prize for their work.
But what was the ingram? The short version is that
the ingram was believed to be the fundamental physical unit
of memory represented in the body. In order for an
animal to learn an association between two things, that memory
has to be accompanied by some kind of physical change
(02:28):
inside the body. But what is the fundamental unit of
that change? Is it a structural change in the brain
that can be located, or is it something else. So
the idea is that you would see the physical evidence
of learning and then potentially like that is physical evidence
that could be then manipulated. Of course, yeah, it's sort
of like searching for the atom. What the atom is
(02:50):
to matter? The ingram would be to memory, what is
the fundamental unit that that physically indicates in the body
a memory has been formed. And of course motivation for
studying whether simpler organisms like worms and other invertebrates could
in fact learn associations through classical conditioning was that this
might help move along the search for the ingram. If
(03:12):
a biological phenomenon seems too complex to understand in one organism,
you know, if you can't find it in a rabbit,
everything is just too complicated. Maybe you can get a
foothold to understanding by looking for analogous phenomena in simpler
organisms and then build your way back up, and this
is a sensible way to go about it, of course.
Uh So, research in the middle of the twentieth century
(03:33):
tried to locate the ingram two changes in a specific
part of the brain and a rat, but these efforts failed.
In fact, rat brain memory research he demonstrated that there
was no one location or structure in which the fundamental
unit of memory association was to be found. Instead, learning
seemed to involve wide swaths of the rat cortex, and
(03:56):
today we know that certain regions of the brain are
especially important for memory. Is, for example, fear based conditioning,
like if you condition somebody to respond to a stimulus
through conditioning due to an electric shock. This seems to
strongly implicate the amygdala, not just fear actually, but other
types of emotional memory as well. I think, while memory
of spatial locations and physical maps seems especially to implicate
(04:20):
the hippocampus, but memories for complex actions maybe finding your
way around a maze, as was often tried with rats,
will involve lots of different parts of the brain at once,
so you can't point to the memory in one specific
part of the brain. It's using the whole brain. Basically,
in the nineteen fifties. This wasn't yet clear it was.
(04:40):
It was just clear that memory, contrary to the expectations
of many psychologists, couldn't be located in one particular structure
or single point physical change in the brain. And because
of the failure of researchers to locate a structural ingram
at a single point in the brain, some researchers began
to turned to other explanations, and McConnell was one of them.
(05:03):
McConnell wondered, what if memories were not stored exclusively in
structures in the brain. Could you have memories in your hands,
in your blood, in your guts. Was there a deeper
chemical rather than structural basis for our memories? And here's
where the Planarians again become an invaluable research tool in
(05:25):
looking into could you have memories outside the brain? Could
there be such a thing as a memory chemical or
a memory molecule found throughout the body? And yeah, this
we come back to the regenerative powers of the Planarian.
We described this in the first episode as being something
like The Sorcerer's Apprentice, the old Disney animation from Fantasia
(05:47):
in which the uh what what is it? It's a
broom that is brought to life to do a particular task,
to carry water from a well. I think, and yeah,
it was, it's a well. And then and then Nikki,
the sorcerer's apprentice in this case uh In is up
having to to destroy it, so he chops it into
a million pieces with his axe, and then all those
millions of pieces, each little sliver of the broom comes
(06:09):
back to life and grows into a whole new fresh
of broom with that walks around on two legs and
carries buckets of water. Right, And this connects to the
regenerative powers of planaria, because if you cut a planarian
in half one of these flatworms, just chop it in
half crosswise, separating the head from the tail. Each half
of the worm would grow back the part it lost,
(06:32):
So the decapitated head could regrow a tail, and the
decapitated tail could regrow ahead, which means regrowing a brain.
So McConnell's question was, if I condition a flat worm
to learn something, maybe have a response to a stimulus
like a flashing light, and then I cut it in half,
(06:52):
which half of the worm will retain the response. If either,
Now you might think the answer is obvious, right, Well,
obviously the head half is where the brain is, so
the head half will retain the conditioning if either side
does and the tail half won't, Right that that seems
like the obvious conclusion, Right, Yeah, that's what you would assume.
That's what like a basic understanding of monster movies would
(07:13):
have you assumed. Yes, McConnell found this was not exactly
true in his experiments on freshwater flat worms called dogs
a Dorado cephala. If you classically condition the worm to
respond to a light and then you cut the flat
worm into two halves, both halves retained the conditioning, and
in a few cases the tail retained the conditioning more
(07:34):
strongly than the head. So you could cut the head off,
the tail would regrow ahead and it would still respond
like the way it had learned to respond when it
had its original head. So if all the learning was
in the brain, how could that be possible? Right? This
would seem to indicate that there's some sort of memory
retention or memory storage going on within the body itself, right,
(07:59):
And these was else were eventually published in the Journal
of Comparative and Physiological Psychology. But then it gets even
weirder because we're going to start playing flatworms Ship of Theseus?
Uh so refresher on the Ship of Theseus? Thought experiment, Robert,
do you want to do the honors here? Oh? Sure?
This is the basic idea. If you you have this ship,
for this legendary Ship of Theseus, you're celebrating it across
(08:22):
the decades. Think about it. Is a ship that is
docked for decades tends to fall apart piece by piece,
so you replace it piece by piece. Eventually you reach
the point where you have replaced every single piece of
this vessel. The question is, is the Ship of Theseus
any longer? The Ship of Theseus? Is it? It's it's
not physically the same ship it was before, but it
(08:44):
is the same shape. It's just all the pieces have
been at this point replaced. Now, what if you in
fact do this with flatworms since they can regenerate, And
this is exactly what they tried. In a series of experiments,
McConnell and the Planarian Research Group showed that if you
cut a worm, like, for example, you cut a flat
worm's head off after it's been conditioned and trained, so
(09:06):
it has this memory response and then that tail regrows ahead,
and then you cut the original tail off, so the
regenerated head regrows a tail. Now you've got no original
part of the worm left. So you've been through these
multiple generations of cutting a worm apart and letting it regenerate.
And yet their experiments found that some learning training memory
(09:30):
was retained across the multiple generations where there was no
original part of the worm left. Again, how would this
be possible, Like, if memories are stored exclusively in the brain,
how could a memory necessary to establish a conditioned response
still operate within a tail that had its head cut off,
or a segment of a worm grown from a segment
(09:51):
of a worm grown from a segment of a worm
that had been through the conditioning. And this led McConnell
to suppose that he had evidence that memory may have
strong chemical whole components. They're not limited to activity within
the brain. There could be actual molecules of chemical memory
coursing through the worm's body. Now, if this were true,
(10:12):
this would of course be a revolutionary discovery right right right,
because of course, and it would conceivably apply to other organisms.
I mean, that's that's the thing. It might force us
to completely rethink what we thought we knew about memory, right,
and of course if it were true of flatworms, as possible,
it would only be true of flatworms. But yeah, you
don't know where else this would lead. Could it even
(10:33):
be true of more complex animals. So it was this
line of research about cut up flatworms retaining memories that
led actually to the founding of the magazine we talked
about in the last episode, The Worm Runners Digest. This
was McConnell's magazine that quite strangely combined both real research
on on planarians. It was like real flatworm research published
(10:57):
alongside weird poems and and joke articles and satirical articles
and stuff. It's such a weird title. The worm part
clearly relates to the worm experiments, but it also brings
to mind like blade Runner, except it's worm Runner. And
it also makes me think of various Gary Larson far
Side cartoons which a worm is perhaps, you know, wearing
(11:17):
sweatpants and linn running. That's good, But the joke and
title in the title is actually a reference to like
common terms used by psychologists of this period, lots of
research about learning and memory involves rats and mazes, and
so researchers who did this kind of work referred to
themselves jokingly in the nineteen fifties as rat runners. McConnell's
(11:38):
variation is self explanatory. Jerry the worm runner. Okay, not Jerry, Jarry,
Jerry O'Connell, James Ry myself there, James the worm runner then,
but yeah, actually so coming back. So this led to
the founding of this strange magazine that he became very
well known for. The story has summarized by Larry Stern,
(11:59):
and I mentioned and several sources at the beginning of
the last episode. We're still referring to those sources in
this episode. One was an article by Larry Stern that
that talked about the founding of this magazine. So in
nineteen nine, McConnell presented some of this work, uh, this
work about chopping up flatworms and then supposedly retaining memories
to an annual convention of the American Psychological Association the
(12:20):
a p A. And this included results collected by a
member of the Planarian Research Group named Riva Jacobson. And
again this research showed that not only could a decapitated
flatworm retain associate of learning, but essentially the ship of
theseus flatworm containing no tissue of the original worm could
also retain learning, and after the presentation, Newsweek published an
(12:41):
article summarizing the research. This led to a huge surge
of popular interest in McConnell's work, and so Larry Stern
writes quote. Shortly after the Newsweek coverage, McConnell was inundated
with letters from high school students from around the country
asking where they could obtain worms for their projects and
how they should go about caring for and training them.
(13:02):
Some students, according to McConnell, demanded that he sent them
a few hundred trained worms at once, as their projects
were due within days. It sounds a little familiar, right,
Students don't do things like this, but McConnell did want
to help students conduct their own flatworm research. I get
the feeling he was into this idea, but he realized
very quickly that it didn't make sense to try to
(13:23):
respond to each letter individually, so instead he decided to
publish a manual on how to replicate the experiments performed
by the PRG, and he titled this document The Worm
Runners Digest. However, after publishing this manual under that title,
McConnell started getting submissions to appear in future issues. So
(13:43):
he began publishing this so called journal on a regular basis, again,
including both real research and psychological in jokes, cartoons, poems,
and all that kind of stuff interwriting. So it's kind
of accidentally became a continuing publication. Yeah. Now, as you
can magine, some people didn't take kindly to this mix
of subject matter. In nineteen sixty four, after some readers
(14:06):
complained that they couldn't tell the real research from the
jokes and the satire, they started publishing the satirical elements
upside down in the back half of the journal. So
there was some attempt there to clear up the confusion.
But I think for a lot of scientists the pure
proximity of the different material was was a problem no
matter how clear the division. Well, I think that's understandable.
(14:26):
We talked before about the Ignoble Prizes, for instance, about
most of the individuals involved and honored by these prizes
that celebrate, you know, scientific studies that are legitimate scientific studies,
but that are on some level humorous or amusing. But
you still have some individuals in the scientific world who
do not see the value of that. So if they're
(14:48):
so if feathers are ever ruffled by the ignoble prizes,
obviously something like this would ruffle feathers as well. Yes,
uh so, Then in nineteen sixty seven there came another
split where the serious half of the journal was just
formally cleaved and renamed, in fact cloven in half like
a flatworm, uh, chopped right off, decapitated. The serious half
(15:08):
was renamed the Journal of Biological Psychology, and the worm
runners Digest became the soul Haven of Humor, and it
continued publishing that way until all Right, on that note,
we're going to take a quick break, but we will
be right back. Than alright, we're back, alright, So to
jump back into the progression of James McConnell's research, we're
(15:30):
we're brought back to this question of a non brain
chemical basis for memory. Couldn't memory, or at least some memory,
some types of memories be stored chemically rather than structurally
dispersed in the body in molecules, And here's where we
get to the cannibalism. So, if there were in fact
molecules within an animal representing some kind of chemical memory,
(15:53):
such as memory of how to navigate a maze, could
this be demonstrated? Could those molecules be shared from one
animal to another? And this makes sense. That's what creatures do.
They take molecules from each other, from other organisms and
put them into themselves. Sure, we absorbed the molecules existing
in other organisms for nutrition. Uh, so maybe you could
(16:15):
molecules be absorbed from one organism to another four memory transfer.
So the first method they tried, uh and this is
based on the reporting of one of those Larry Stern articles.
The first method they tried was to splice the head
of a conditioned worm onto the tail of an unconditioned
worm to see if it would share molecules right, to
force them to exchange the alleged memory molecules. But the
(16:38):
transplant did not work. The head would not stay attached.
Then they tried to liquefy fully conditioned flat worms and
inject their juice into untrained worms, but this was also difficult.
The planarians were too small to be injected basically, and
sometimes they exploded when injected. In Larry Stern's words quote
it was like trying to impay all a prune with
(17:01):
a javelin a lot of horrific things done to to
planarians in these experiments. I guess they are a simple
enough organisms that we have to be so upset about them,
I guess, But it's still one can't help it. Pause
a little on some of these, right, some of the grinding, Yeah,
the sauce, the gravy, the flatworm sauce. So how do
(17:23):
you get those hypothetical memory molecules in there? If you
can't inject them, you can't transplant ahead on. So the
next route they tried, and this was in the year
nineteen sixty, was experimental planarian cannibalism. This would be the
old fashioned way of getting molecules from one organism into
the other. Sure, so apparently the idea came from a
flatworm researcher named Jay Boyd Best who communicated to McConnell
(17:46):
about the fact that one particular species of planarian was
known for cannibalistic behavior. So here's the answer. You train
the worms to respond to to a maze or to
the light, whatever the conditioning stimulus is, and then they
learn the conditioning and then you grind them up into
worm gravy, and then you feed the worm gravy to
the untrained naive worms, and you see what happens, and astonishingly,
(18:10):
their early experiments with this method looked very promising, including
a number of early replication attempts with blinding procedures to
remove the possibility of experiment or bias, supposedly confirming their
early results. So, if it were true that memory molecules
are being exchanged through this strange cannibalistic ritual, could I,
(18:32):
you know, with this extend to humans? Could could I
drink your flesh and gain your memories? And how was
it happening? What was the chemical basis here? So one
interesting line of reasoning here followed from the still somewhat
recent discoveries about genetic information being stored in and mediated
by nucleic acids DNA and RNA. Remember, you know, we're
(18:55):
not too far from from the discovery of the double
helix here. So if DNA and RNA could be involved
in an information management process passing genetic information across generations
from parents to offspring, could the same molecules also in
code and mediate other types of information? I mean information
(19:16):
is in the DNA. So specifically, could the information content
of memories somehow be coded into DNA or RNA and
then dispersed through the body, but also transferred from one
body to another. And so this is the line they took.
McConnell and his team conducted experiments and published results that
(19:37):
seemed to back up the idea, at least for a while,
that RNA played some important role in facilitating memory, and
that RNA could be used to chemically inoculate naive worms
with the memory associations of their more worldly predecessors. And again,
just consider how revolutionary this would be if it turned
out to be true. You'd be forced to wonder how
(19:58):
far the principle could be taken. Did this only apply
to planarians or did it extend to other more complex animals.
Would there be ways in which humans could undergo chemical learning?
Could you train the mind in some way with an
injection alone, or even a pill? Even if it only
worked for like broad associative learning such as you know,
the kind of things you get through classical conditioning with
(20:21):
an electric shock and a single stimulus, you could still
possibly imagine profound benefits. Just one idea comes to mind, like,
say you're struggling with a drug addiction. Could you seek
out an injection of of memory molecules to establish a
strong averse reaction to your drug of choice such that
you wouldn't want to take it anymore. Yeah, Or to
(20:41):
get into some of the behavioral his ideas that we
discussed in the first episode, some of those ideas that
that that McConnell's very outspoken about it, even later in life.
You could have some sort of a cocktail that could
be injected into an individual that had a history of
violence and history of of you know, breaking the law
(21:03):
and rebelling against authority figures, and you could can potentially
fix them with this injection. Yeah. And of course there
you get into the more nefarious possible thing, Like you
can probably instantaneously imagine so many horrible, insidious uses for
injectable conditioning if such a thing were possible. Oh yes,
I mean, as with any science, many many fabulous uses
(21:25):
come to mind, but so many nightmares as well. But
we should stop and be real for a second here,
that even if these findings had turned out to be
totally solid for planaria and more on, that in a moment,
we should know better than to freely extrapolate from worms
to humans. I think this is one of the most
classic traps that people fall into and interpreting biological research.
(21:47):
I'd say more often as people extrapolating from like rats
to humans. But this isn't a much larger jump. This
isn't even a vertebrate animal. Yeah, I mean, you can't help.
I often find that I can't help, but but at
least think about that on some when I read a
science headline, I can't help it. Put myself into into
it somehow and imagine myself as the creature, right, And
it's often, I mean, it's just done right there in
(22:08):
the press. Again, it's fine to wonder about what possibilities
could be implied by studies in rats for humans, but
you can't just, you know, conclude from one to another.
We can't help but anthropomorphize virtually any creature, and if
that creatures in a study, we're also going to end
up anthropomorphizing that as well. But James McConnell, true to form,
(22:31):
as we know from the last episode, was not one
to be shy or cautious about interpreting his findings. He
loudly proclaimed them to the public, advertising his results on
TV programs. He apparently embraced the nickname mccannibal uh, and
he predicted an era of memory pills like we just discussed,
So you might be thinking, like, wait a minute, he
(22:52):
should know better than to extrapolate from planarian even if
you assume the planarian research to be solid and will
introduce some caveats to that. But even if you did
assume that, how could you jump from that to human
memory pills? That seems like a you know, a leap
of miles of assumptions. Yeah, very much though, And it
(23:13):
does seem from from what I was reading, especially in
Rilling's paper about McConnell, that it seemed like to him
he sort of had a sense of humor about talking
about memory pills, like as if he were sort of
joking when he talked about memory pills. But that was
not clear to the popular audience that was listening on
the TV. You know, they weren't psychologists. They didn't understand
(23:36):
that he was kind of kidding when he said. That
makes sense, oh, certainly. And then also, they're going to
be like a few different levels, so I could like,
he may joke about it here in this paper, or
joke about it to this individual, but then you're gonna
have different levels of coverage, and it's going to get
out of out of control pretty quickly. Yes, So Rilling
writes that quote McConnell's work on retention following regeneration and
(23:58):
planaria provides a case study in sensational journalism and illustrates
how his media work escaped the normal mechanisms of peer review.
So the idea is that McConnell and colleagues would do
an experiment, they would obtain a very strange and interesting
result that looked solid enough to get published in an
academic journal, and then McConnell would immediately want to engage
(24:21):
in quote, wild sounding conjectures interpreting the meaning of his
results and how they would be applied in the future,
and scientific journals generally like one example was the editor
Harry harlow Uh generally refused to publish these wild interpretive
or speculative addendums to the research. They just say, well,
we'll publish your study, you gotta cut out this section
(24:42):
about memory pills that doesn't belong in here. But of
course there's no peer review in the popular media, so
he could go on TV and say memory pills as
much as he wanted, And it turned out that that
kind of thing on TV gets you booked on TV
again because it's exciting right. I mean, that's like something
that people in picture, it's not hard to understand, and
it's it's very like what revolutionary. That's what you want
(25:05):
in a science segment on your your news programs. You
want something relatable, and here's this guy that is making
it relatable and exciting with promises that are not at
all implied by the research being discussed. Even if the
research itself is a solid and and retrospectively that may
be in doubt. So just one example, in nineteen fifty nine,
an article in Newsweek covering McConnell and the PRG research
(25:29):
claimed it may be that in schools of the future,
students will facilitate the ability to retain information with chemical injections. Apparently,
there was also a lot of misunderstanding in the media,
misunderstanding the fact that multiple generations of regenerated Planaria could
retain training, and they misunderstood this is the fact that
(25:49):
memories can be inherited in apparent to child sense, which
led to all kinds of Lamarckian interpretation. So I think
there there's all. There was also just confusion stemming from
the use of the word inherited and generations he was
talking about like generations being chopped up and regenerating, which
is quite different than what we understand, right, And again
he's coming down. He's talking about memories here. There are
(26:12):
other things that you know, there's certainly things that affect
that have generational effects in biology and in human biology.
I think we've talked about studies before and about body
size following periods of starvation, that sort of thing. But
but again we're talking about memories here. He is explicitly
talking about memory. Yes, And another one that that was
(26:33):
quoted in Rilling was regarding cannibalistic memory transfer, the one
where you eat the worm gravy and you gain that
worm's memories. Supposedly, there was a nineteen sixty four article
in the Saturday Evening Post that claimed we quote might
someday enable us or it might someday enable us to
learn the piano by taking a pill, or to take
calculus by injection, which at that point is is very crude,
(26:55):
gross kind of like over interpretation of what the memories
here all are. And the you know, the leap from
one organism to another, you just like do a line
of ground up Beethoven, And yeah, I mean this is
this is so outrageous that like I, I feel like
I would I would feel like I was over stretching
to use this as an outrageous example of a possibility,
you know, like earlier I I did the the far
(27:18):
future example of of criminals being treated like this seems
even this is even seems crazier, but on the same hand,
also attractive the idea of being able to uh, say,
master calculus by simply injecting something into your body. Yeah,
though I hope Also our questions about potential applications if
this were true were heavily caveat. So in the mid
(27:39):
nineteen sixties there were even studies following up on this
cannibalism research claiming to bear out chemical memory transferring other species,
such as in rats. Again, that's kind of hard to believe,
and so like. For a few years there in the sixties,
things looked incredibly promising with this research. But fortunately or unfortunately,
depending on how you look at it, it was not
(27:59):
too lad. There was a problem with the p RGS
cannibalistic memory transfer research, and it was just that it
didn't hold up to sustained scrutiny over time. Over time,
properly blinded and controlled efforts to replicate McConnell's results. A
few of them came in saying yeah, we replicated, but
a lot did not produce the same effects for cannibalism
(28:21):
or other chemical methods of memory transfer. According to Rilling
in nineteen seventy one, I guess this would be as
a result of some of these failures, the Plenaryan research
group lost its grant support, and this led McConnell to
change focus. And after this in the seventies he went
on to write a very influential and from what I
can tell, mostly well regarded textbook for introductory psychology. Apparently,
(28:45):
one thing that set it apart in the field was
that it used a lot of fiction. It introduced students
to psychological research methods with the use of stories and
like fictional framing narratives to explain the principles that were
discussed in each chapter. UH, even including one chapter about memory.
It seems to begin with a fictionalized version of the
story of his research with Thompson in nineteen fifty four
(29:09):
or so, UH, though incorporating lessons about control groups that
he had not learned very well back then, and as
we discussed more in the previous episode. Later in his career,
I think he was known more maybe for being a
fierce public advocate of the powers of behavior modification through conditioning. Again,
this was an era in which behaviorist psychology was seen
by many as a potentially revolutionary scientific tool for minute
(29:33):
control of human minds and lives. This is the birth
of the modern concept of brainwashing. Right and McConnell wrote
and appeared on TV arguing that behavioral conditioning would fundamentally
alter the nature of criminal justice in democratic society itself.
I think there was one article he wrote that was
titled something like we must brainwash criminals. Now, well, that's
(29:54):
a great headline though, no doubt about it. Yeah, certainly
if you want to get the clicks. Uh, yeah he
was maybe he maybe he was clickbait before the Internet.
He does, he does seem very CLICKBAITYU. And this is
something some of his colleagues said about them. Is quoted
in the Rilling paper that he wanted to shock people.
He wanted to say things that would make people say,
(30:15):
what what's this guy talking about? That can't be true?
And he said, you know, the idea was you you
bring people in by shocking them, and then you educate
them with the science. And you know, I guess that
can be an okay method if what you if what
you say in order to shock people isn't fundamentally dishonest
in some way, right, Yeah, I mean it's it's kind
of it kind of gets into a similar of like
(30:37):
leading with an example, you know, and sometimes it's an
outrageous example. Sometimes, like on this show, we we bring
up a monster, something fantastic, and we use that to
talk about something that is that is real and talk
about actual scientific studies or actual biology that somehow matches
up to that. But well, I hope we never do.
I hope if we start with god Zilla, we don't
leave you with the impression at the end of the
(30:58):
episode that god zills real and true. But it is
interesting how it seems like some of the things that
did make him such a great communicator and ultimately like
a great author of an introductory psychology book. Uh, those
are also some of the things that got him in trouble. Yeah,
that totally seems to be true based on everything I've read.
But but coming back to the the memory transfer issue,
(31:21):
I just want to say that I think the conclusion,
unfortunately at the end is that the cannibalistic memory transfer
saga is widely regarded now as a dead end. Despite
a few reports of moderate replication successes, McConnell's results ultimately
did not hold up to widespread scrutiny and the rigorous
application of controls by others. And it looks like his
(31:42):
supposed discoveries about memory transfer through injection or cannibalism were
probably wrong, but not all of his conclusions were necessarily wrong.
I mean again, One of the points of Rilling's article
seems to be that despite the ultimate failure of the
memory transfer through cannibalism theory, McConnell did make truly important
(32:02):
contributions to research on invertebrate learning in the nineteen fifties.
And while the memory transfer the memory molecule transfer through
cannibalism is almost definitely a dead end, more recent studies
have sort of raised the question of whether his like
decapitation and transplantation research might have been on the right track.
All right, we're gonna take one more break. When we
(32:24):
come back, we're going to discuss some of these modern
follow ups regarding polanaryan decapitation and brain transplant Thank alright,
we're back so we discussed through through the end of
the career of of James V. McConnell, who studied planarians
memory memory transfer our memories outside of the brain, and
(32:47):
we we brought up the idea that this subject has
been revisited by researchers just in the past few years
who think that while McConnell was probably wrong about like say,
eating flat worms and gay in their memories, there may
be some truth to the idea of memories somehow being
stored outside the brain or transferred without a full brain. Yeah. So,
(33:09):
for instance, it has been demonstrated that if you transplant
the planarians brain into another worm's body, uh, it will
result in at least partial recovery of function, even if
the brain is put in backwards or transplanted across species. Uh.
The author Pagan, who we brought up earlier, who wrote
the first brain UH, he points this out, and he
(33:31):
points out that basically the cross species transplants held, meaning
there was no rejection and forty eight hours later the
worm retained mostly normal behavior. I mean, that's pretty weird,
but again it's worms. Like Yeah. One of the big
take comes from all of this is that planarian brains
and plinarian in general are strange, right, So a lot
(33:51):
of what we determine what a lot of what we
learned from this research you could interpret as some fascinating
deeper inside about biology g as a whole, or you
could interpret it as fascinating specific facts about these flatworms. Absolutely.
Uh so in particular, though a gun and there's are
referring to a study by Davies at all, and they
(34:15):
were working with a species of planarium that actually can't
regenerate brain tissue, but a transplanted brain will take root
and quote nerves exiting the brain tended to join with
the peripheral nerves closest to them, which I think is
a wonderful image of the brain being implanted in this creature.
And then like the like the like roots forming, like
(34:37):
the vein, he connects itself. It hooks itself up like
a car battery that has been placed in the inside
another via a new vehicle, and all the things just
kind of hook up automatically, plug and play. Yeah. Well,
or like like mistletoe or some other kind of parasite
that like sticks it's little it's how stori um or whatever,
the little spikes down into the host. Yeah, it's it's
(34:59):
it's weird. It's definitely not the human experience. I mean
not to not to discuss, you know, the whole body
transplant or human brain and head transplant much in this episode,
but basically it's very complicated, if not impossible in humans. Yeah. Well,
and again to look at memory more broadly, neuroscientists today
(35:19):
mostly broadly understand memories to be neural networks, right, networks
within the brains, sort of strings of reinforced connections between
neurons and brain regions that specify memories by their cross
linked structure. A memory is in some way a series
of connections between neurons and the brain. Uh. Though that
(35:41):
does seem to be the case. Beyond that broad picture,
there's still a lot we don't know about the physical
basis of memory, and so even in especially in organisms
like flatworms, there are ways in which memory could be
operating and that are still mysterious to us right now.
Of course, the quest to solve these mysteries continues. Uh.
Great deal of pollinarian research is still going on, and
(36:03):
you see quite a bit of it come out of
Tufts University, and you'll see um, a researcher by the
name of Michael Levin often is a is a head
author or co author or contributing author on these papers. Yeah,
and there was one big study that got some press
being connected back to McConnell's research that Levin was at
least one of the authors on UM and and basically
(36:26):
it had to do with replicating a version of the
decapitation experiment showing that somehow it appeared memory if the
study was designed properly and there wasn't some kind of
flaw that people didn't notice in there, that memories maybe
were somehow being transferred through the decapitation process. Right. This
is a two thousand thirteen Tough University study that found
(36:46):
that a decapitated flat worm that grows a new head
keeps its old memories. Uh. For instance, the Sarahsing article
about this it appeared in Nautilus, carried the title decapitation
but not cannon is um might transmit memories without context.
That's a pretty weird title, right, But then within context
the article refers back to McConnell's work quite a bit.
(37:10):
And the idea here is that some trace of the
of memory might be stored in neural circuits outside the
brain and certainly when you take that and you compare
it to these you know, these other into this previous study. Uh,
with with one brain being dropped into a new creature,
a new a new individual and seeing it, you know,
take root and uh and seemingly bounce back. Uh, that
(37:31):
becomes all the more interesting. Yeah. One of the things
that has clearly been the case, and this was discussed
in that article in the Verge we talked about in
the last episode, is that Levin's research has been focused
on trying to eliminate some of the problems that could
have existed in the original McConnell research. One example is
that that he helped create um and a thing called
(37:52):
an automatic training apparatus. Basically, it's a robot for conditioning
the flatworms, take the human element element out of the
training process to eliminate any kind of bias or error
that could be introduced that way. But I love the
idea in general of a robot for training worms. So
that that two thousand thirteen study especially generated quite a
(38:13):
bit of interest, and at the time there was there
was mixed response from the scientific community. Now, I do
want to drive home that it is not my interpretation
that Michael Levan is anything like a McConnell figure. He seems.
He seems to be a very suffected researcher. And most
of his work, like I said, he's seeing on a
lot of studies for his general planaria research right now,
(38:35):
I mean, I don't. I haven't seen anything where Michael
Levin is going on TV and saying memory pills right right,
uh and uh and and by and large it seems
like most of his work just deals with with regeneration,
uh in these planaria worms. But yeah, so you had
plenty of people that that were supportive and thought that,
you know, they might be onto something. Others were a
(38:55):
little critical at the time. Robert Kintridge, I say it
was a psychologist at Durham University, and he pointed out
in a two fifteen Verge article that Verge article we
cited earlier that it might be simply related to quote
behavior induced by a stress hormone itself triggered by the
textualized petrie dishes unquote. And to clarify, they're part of
(39:19):
what the study looked at to see conditioning in the
flatworms was you'd have these textured petrie dishes where they
would be swimming around the food they were going to eat,
and how fast they approached the food in a newly
textured Petrie dish environment was taken as a signal of
their memory or familiarity with the environment. Like you put
(39:39):
a new flatworm in a textured Petrie dish, its circles
for a while before going for the food because it's
exploring its environment. It doesn't know. But after it's been
trained with the texture and a Petrie dish, it goes
straight for the food because it already knows the environment. Right. Yeah.
So so basically a number of individuals UH said, well,
there there are aspects of the study that could have
(40:01):
been better designed. Sure. Now again, Michael Levin, his research continues.
He and you you'll find a number of studies from
very recently that he's been involved with. He was an
author on a study earlier this year neural control of
body plan access in regenerating planaria. And in two thousand
fifteen he put out a paper on the planarian regeneration
(40:21):
model as deciphered by artificial intelligence. And uh that same
year he was also a co author on another study
UH that included the growth of extra heads. Yeah, I've
seen also that I think both within and outside of planaria.
He's just generally studied regeneration. Yeah, and with the poplinaria,
of course, it's it's just such an amazingly regenerative creature.
(40:42):
You get things like like this. Uh, the second study
that I mentioned from fifteen, they were able to induce
one species of flat worm to grow heads and brains
characteristic of another species of flat worm without altering genomic sequence,
and then the individual later regenerated to the appropriate head shape.
Now quickly, I guess one thing worth discussing is if
(41:04):
the research associated with with Michael Levin is in fact correct,
the results are valid, there's not some kind of flaw
we're missing in the design of the study. And uh,
and this is really going on. The memories are surviving
the regeneration without an original brain. How would you interpret this, Like,
what does it mean if this is in fact true? Uh?
So a couple of ideas are given in the Verge article.
(41:28):
Leven hYP quote hypothesizes that memories could spread beyond the
brain thanks to electrical charges generated by cells and the
rest of the body. So there's some kind of information
encoding that's just like coming from cells in the other
body that are electrically stimulating something like a memory response.
But then there's another thing cited in the same piece
(41:49):
by Ava Jablanca, a developmental biologist at Tel Aviv University,
and she offers a speculative explanation involving particles called small RNAs,
which are short copies of DNA, but they don't turn
into proteins. They don't generate proteins. So when a flatworm
(42:10):
learns an association or an episode, something in this model
about the brain chemistry would change, and then these changes
alter the small RNA is present in the body, which
of course are not confined to the brain because they
migrate around between cells. And by migrating around between cells,
she says, perhaps they end up in stem cells that
(42:32):
remain in the body. After the worm's head is cut off,
and to read from the article quote, when the worm's
head grows back, the small RNA's migrate back to the head,
changing the brain's chemistry and allowing it to learn certain
behaviors more quickly. Um If true, the memory that Levin
thinks is stored outside the brain wouldn't be memory at all. Rather,
(42:53):
the small RNAs would allow the flatworm to recover a
brain environment that helps them learn a specific behavior more quickly.
So the idea there is that if this speculative idea
is correct, and again she she's very clear to stay
this this isn't something we know. Is just a speculative interpretation.
Maybe it works this way, then what would be happening
is these little chemical molecules don't transmit the memory prepare
(43:18):
the new brain to learn a memory that was previously
learned more quickly. Okay, so at least we have a
hypothetical model of how this would actually work, which or
at least here's one model presented anyway, Sure, but ultimately
we don't know for sure. And again another thing that
we don't know for sure is if these results do
(43:39):
hold up. Is this something that's specific to planaria? Is
it flatworms only that can transfer memories in this way
or could this be more applicable beyond flatworms to other organisms,
because that's the thing. Other organisms can't regenerate like a
like a planaria can. But at the same time, we
one of the one of the things that's often cited
for researching an area regeneration is that we might learn
(44:01):
something that could be appliable to humans. Of course, especially
and with not even getting into memory implantation, just the
idea that they have such impressive neural regenerative powers, the
ability to regenerate like damaged brain cells. You know, if
we could, if we could develop some better method of
doing that based on our studies of these organisms, then
that would be tremendous. Of course. I mean though it
(44:24):
when you introduce the idea of brain regeneration or anything
like that to a human context, things emerge that don't
necessarily seem to be of concern. When you're talking about planaria.
Planaria don't seem to have extremely distinct personalities. Uh, you
know humans do you know, however much we want to
joke about humans acting like sheep and all being the
(44:46):
same we you know, we we've got a lot of
different stuff going on in our heads. If you cut
your head off and regrow it, what indication would you
have that the new head would be you in any
sense other than sharing your d n A. Well, I
guess as long as it's said all the right things
and I mean just get along just fine, it would
be like a p zombie perhaps, Well, I mean, would it?
(45:10):
I guess it would be a question of whether it
would retain any memories from your life, you could you
talk about whether that might be stored in the body somehow,
or even if you assume it, okay, it retains no
memories whatsoever because those are just stored in the brain.
Whatever may or may not be happening in flatworms doesn't
happen and all at all in humans. Even if you
assume all that, you'd also have to ask, like, would
(45:30):
its personality be the same as yours personality is so
shaped by life experience? I don't know. It makes me
wonder has anyone ever considered creating a like a science
fiction yarn in which you look at what would human
society be like if we had regenerative properties like this?
Like what would war be like? What would what would
(45:51):
reproduction and society be like? I mean, granted, I think
the obvious answer, it would absolutely change everything. But the
fun thing about science fiction is you don't you don't
have to go all the way. You can just sort
of like tweak it, like what would this if we
if I were to look at this particular vision for
a totally regenerative plnary in human species, then what could
(46:11):
I perhaps unravel about our actual human condition? Well? I mean,
I think we pretty much all at some state, at
some point or other, get into a get into a
place where not very happy with our own brain. We
don't like the emotional patterns were feeling. Maybe we're ruminating
in bad ways. I mean, this happens pretty often to people.
So what if you had the option to you get
(46:31):
into a bad state like that, you know, you can
just cut your head off and grow a new one.
These are exactly what the horrifying orange creatures in Labyrinth
they're all about when they come up to Sarah and
they encourage your Hey, take your own head off, throw
it around, try on a different head, Let your head
try it out, try itself out on a different body,
see how it shakes out. Just you know, have to
(46:52):
have a little fun. You're not a flat worm. Don't
try it people. All right, We're gonna go ahead and
close this out then, but we hope you have enjoyed
and then learned from this exploration. Perhaps you'll think of
flat worms in a new light now, and perhaps you
will even second guest memory a little bit as well.
In the meantime, if you want to check out other
(47:13):
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(47:34):
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(47:55):
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(49:00):
Radio is a the i heart Radio app, Apple Podcasts,
or wherever you listen to your favorite shows.
My Welcome to Stuff to Blow Your Mind, a production
of I Heart Radios How Stuff Works. Hey, welcome to
Stuff to Blow Your Mind. My name is Robert Lamb
and I'm Joe McCormick, and we're back with part two
of our exploration of planarians, memory, learning and conditioning, and
(00:23):
of course today we're going to get to the cannibalism.
That's right. If you did not listen to part one,
do go back and listen to it, because we lay
the groundwork. We discussed these organisms, why they're interesting. We
discussed their regenerative powers. We talk about McConnell himself. We
talk about his personal and professional history as well as
his run in with the unit Bomber. Right. Uh, so
(00:44):
that figure, of course is James V. McConnell, the American psychologist.
But if you listen to the last episode, as you
should before this one, you already know that. So we're
picking up after McConnell's initial research demonstrating in the nineteen
fifties that despite conventional wisdom that in vertebrates could not learn,
could not be trained through classical conditioning or any other
(01:04):
kind of associate of learning. Uh. McConnell and colleagues did
in fact demonstrate that that's not true, at least for planarians,
these flatworms that that could be trained to react to
something like a light stimulus. And we also discussed how
it's just generally known to be true today that invertebrates
can learn. The conventional wisdom at the time was wrong.
(01:25):
But so to pick up with McConnell's career. After completing
his graduate degree at the University of Texas, I almost
said Jerry O'Connell, not Jerry O'Connell. James McConnell moved on
to the University of Michigan, where he continued his research
into flatworms. So the team that came to be known
as the Pollinarian Research Group or pr G. So another
(01:45):
piece of context for this research is a sort of
quest for the holy Grail within twentieth century psychology and neuroscience,
and this was the hunt for the elusive Ingram. It
was believed by men in the mid century that a researcher,
that the first researcher to actually pinpoint something known as
(02:06):
the ingram, would receive the Nobel Prize for their work.
But what was the ingram? The short version is that
the ingram was believed to be the fundamental physical unit
of memory represented in the body. In order for an
animal to learn an association between two things, that memory
has to be accompanied by some kind of physical change
(02:28):
inside the body. But what is the fundamental unit of
that change? Is it a structural change in the brain
that can be located, or is it something else. So
the idea is that you would see the physical evidence
of learning and then potentially like that is physical evidence
that could be then manipulated. Of course, yeah, it's sort
of like searching for the atom. What the atom is
(02:50):
to matter? The ingram would be to memory, what is
the fundamental unit that that physically indicates in the body
a memory has been formed. And of course motivation for
studying whether simpler organisms like worms and other invertebrates could
in fact learn associations through classical conditioning was that this
might help move along the search for the ingram. If
(03:12):
a biological phenomenon seems too complex to understand in one organism,
you know, if you can't find it in a rabbit,
everything is just too complicated. Maybe you can get a
foothold to understanding by looking for analogous phenomena in simpler
organisms and then build your way back up, and this
is a sensible way to go about it, of course.
Uh So, research in the middle of the twentieth century
(03:33):
tried to locate the ingram two changes in a specific
part of the brain and a rat, but these efforts failed.
In fact, rat brain memory research he demonstrated that there
was no one location or structure in which the fundamental
unit of memory association was to be found. Instead, learning
seemed to involve wide swaths of the rat cortex, and
(03:56):
today we know that certain regions of the brain are
especially important for memory. Is, for example, fear based conditioning,
like if you condition somebody to respond to a stimulus
through conditioning due to an electric shock. This seems to
strongly implicate the amygdala, not just fear actually, but other
types of emotional memory as well. I think, while memory
of spatial locations and physical maps seems especially to implicate
(04:20):
the hippocampus, but memories for complex actions maybe finding your
way around a maze, as was often tried with rats,
will involve lots of different parts of the brain at once,
so you can't point to the memory in one specific
part of the brain. It's using the whole brain. Basically,
in the nineteen fifties. This wasn't yet clear it was.
(04:40):
It was just clear that memory, contrary to the expectations
of many psychologists, couldn't be located in one particular structure
or single point physical change in the brain. And because
of the failure of researchers to locate a structural ingram
at a single point in the brain, some researchers began
to turned to other explanations, and McConnell was one of them.
(05:03):
McConnell wondered, what if memories were not stored exclusively in
structures in the brain. Could you have memories in your hands,
in your blood, in your guts. Was there a deeper
chemical rather than structural basis for our memories? And here's
where the Planarians again become an invaluable research tool in
(05:25):
looking into could you have memories outside the brain? Could
there be such a thing as a memory chemical or
a memory molecule found throughout the body? And yeah, this
we come back to the regenerative powers of the Planarian.
We described this in the first episode as being something
like The Sorcerer's Apprentice, the old Disney animation from Fantasia
(05:47):
in which the uh what what is it? It's a
broom that is brought to life to do a particular task,
to carry water from a well. I think, and yeah,
it was, it's a well. And then and then Nikki,
the sorcerer's apprentice in this case uh In is up
having to to destroy it, so he chops it into
a million pieces with his axe, and then all those
millions of pieces, each little sliver of the broom comes
(06:09):
back to life and grows into a whole new fresh
of broom with that walks around on two legs and
carries buckets of water. Right, And this connects to the
regenerative powers of planaria, because if you cut a planarian
in half one of these flatworms, just chop it in
half crosswise, separating the head from the tail. Each half
of the worm would grow back the part it lost,
(06:32):
So the decapitated head could regrow a tail, and the
decapitated tail could regrow ahead, which means regrowing a brain.
So McConnell's question was, if I condition a flat worm
to learn something, maybe have a response to a stimulus
like a flashing light, and then I cut it in half,
(06:52):
which half of the worm will retain the response. If either,
Now you might think the answer is obvious, right, Well,
obviously the head half is where the brain is, so
the head half will retain the conditioning if either side
does and the tail half won't, Right that that seems
like the obvious conclusion, Right, Yeah, that's what you would assume.
That's what like a basic understanding of monster movies would
(07:13):
have you assumed. Yes, McConnell found this was not exactly
true in his experiments on freshwater flat worms called dogs
a Dorado cephala. If you classically condition the worm to
respond to a light and then you cut the flat
worm into two halves, both halves retained the conditioning, and
in a few cases the tail retained the conditioning more
(07:34):
strongly than the head. So you could cut the head off,
the tail would regrow ahead and it would still respond
like the way it had learned to respond when it
had its original head. So if all the learning was
in the brain, how could that be possible? Right? This
would seem to indicate that there's some sort of memory
retention or memory storage going on within the body itself, right,
(07:59):
And these was else were eventually published in the Journal
of Comparative and Physiological Psychology. But then it gets even
weirder because we're going to start playing flatworms Ship of Theseus?
Uh so refresher on the Ship of Theseus? Thought experiment, Robert,
do you want to do the honors here? Oh? Sure?
This is the basic idea. If you you have this ship,
for this legendary Ship of Theseus, you're celebrating it across
(08:22):
the decades. Think about it. Is a ship that is
docked for decades tends to fall apart piece by piece,
so you replace it piece by piece. Eventually you reach
the point where you have replaced every single piece of
this vessel. The question is, is the Ship of Theseus
any longer? The Ship of Theseus? Is it? It's it's
not physically the same ship it was before, but it
(08:44):
is the same shape. It's just all the pieces have
been at this point replaced. Now, what if you in
fact do this with flatworms since they can regenerate, And
this is exactly what they tried. In a series of experiments,
McConnell and the Planarian Research Group showed that if you
cut a worm, like, for example, you cut a flat
worm's head off after it's been conditioned and trained, so
(09:06):
it has this memory response and then that tail regrows ahead,
and then you cut the original tail off, so the
regenerated head regrows a tail. Now you've got no original
part of the worm left. So you've been through these
multiple generations of cutting a worm apart and letting it regenerate.
And yet their experiments found that some learning training memory
(09:30):
was retained across the multiple generations where there was no
original part of the worm left. Again, how would this
be possible, Like, if memories are stored exclusively in the brain,
how could a memory necessary to establish a conditioned response
still operate within a tail that had its head cut off,
or a segment of a worm grown from a segment
(09:51):
of a worm grown from a segment of a worm
that had been through the conditioning. And this led McConnell
to suppose that he had evidence that memory may have
strong chemical whole components. They're not limited to activity within
the brain. There could be actual molecules of chemical memory
coursing through the worm's body. Now, if this were true,
(10:12):
this would of course be a revolutionary discovery right right right,
because of course, and it would conceivably apply to other organisms.
I mean, that's that's the thing. It might force us
to completely rethink what we thought we knew about memory, right,
and of course if it were true of flatworms, as possible,
it would only be true of flatworms. But yeah, you
don't know where else this would lead. Could it even
(10:33):
be true of more complex animals. So it was this
line of research about cut up flatworms retaining memories that
led actually to the founding of the magazine we talked
about in the last episode, The Worm Runners Digest. This
was McConnell's magazine that quite strangely combined both real research
on on planarians. It was like real flatworm research published
(10:57):
alongside weird poems and and joke articles and satirical articles
and stuff. It's such a weird title. The worm part
clearly relates to the worm experiments, but it also brings
to mind like blade Runner, except it's worm Runner. And
it also makes me think of various Gary Larson far
Side cartoons which a worm is perhaps, you know, wearing
(11:17):
sweatpants and linn running. That's good, But the joke and
title in the title is actually a reference to like
common terms used by psychologists of this period, lots of
research about learning and memory involves rats and mazes, and
so researchers who did this kind of work referred to
themselves jokingly in the nineteen fifties as rat runners. McConnell's
(11:38):
variation is self explanatory. Jerry the worm runner. Okay, not Jerry, Jarry,
Jerry O'Connell, James Ry myself there, James the worm runner then,
but yeah, actually so coming back. So this led to
the founding of this strange magazine that he became very
well known for. The story has summarized by Larry Stern,
(11:59):
and I mentioned and several sources at the beginning of
the last episode. We're still referring to those sources in
this episode. One was an article by Larry Stern that
that talked about the founding of this magazine. So in
nineteen nine, McConnell presented some of this work, uh, this
work about chopping up flatworms and then supposedly retaining memories
to an annual convention of the American Psychological Association the
(12:20):
a p A. And this included results collected by a
member of the Planarian Research Group named Riva Jacobson. And
again this research showed that not only could a decapitated
flatworm retain associate of learning, but essentially the ship of
theseus flatworm containing no tissue of the original worm could
also retain learning, and after the presentation, Newsweek published an
(12:41):
article summarizing the research. This led to a huge surge
of popular interest in McConnell's work, and so Larry Stern
writes quote. Shortly after the Newsweek coverage, McConnell was inundated
with letters from high school students from around the country
asking where they could obtain worms for their projects and
how they should go about caring for and training them.
(13:02):
Some students, according to McConnell, demanded that he sent them
a few hundred trained worms at once, as their projects
were due within days. It sounds a little familiar, right,
Students don't do things like this, but McConnell did want
to help students conduct their own flatworm research. I get
the feeling he was into this idea, but he realized
very quickly that it didn't make sense to try to
(13:23):
respond to each letter individually, so instead he decided to
publish a manual on how to replicate the experiments performed
by the PRG, and he titled this document The Worm
Runners Digest. However, after publishing this manual under that title,
McConnell started getting submissions to appear in future issues. So
(13:43):
he began publishing this so called journal on a regular basis, again,
including both real research and psychological in jokes, cartoons, poems,
and all that kind of stuff interwriting. So it's kind
of accidentally became a continuing publication. Yeah. Now, as you
can magine, some people didn't take kindly to this mix
of subject matter. In nineteen sixty four, after some readers
(14:06):
complained that they couldn't tell the real research from the
jokes and the satire, they started publishing the satirical elements
upside down in the back half of the journal. So
there was some attempt there to clear up the confusion.
But I think for a lot of scientists the pure
proximity of the different material was was a problem no
matter how clear the division. Well, I think that's understandable.
(14:26):
We talked before about the Ignoble Prizes, for instance, about
most of the individuals involved and honored by these prizes
that celebrate, you know, scientific studies that are legitimate scientific studies,
but that are on some level humorous or amusing. But
you still have some individuals in the scientific world who
do not see the value of that. So if they're
(14:48):
so if feathers are ever ruffled by the ignoble prizes,
obviously something like this would ruffle feathers as well. Yes,
uh so, Then in nineteen sixty seven there came another
split where the serious half of the journal was just
formally cleaved and renamed, in fact cloven in half like
a flatworm, uh, chopped right off, decapitated. The serious half
(15:08):
was renamed the Journal of Biological Psychology, and the worm
runners Digest became the soul Haven of Humor, and it
continued publishing that way until all Right, on that note,
we're going to take a quick break, but we will
be right back. Than alright, we're back, alright, So to
jump back into the progression of James McConnell's research, we're
(15:30):
we're brought back to this question of a non brain
chemical basis for memory. Couldn't memory, or at least some memory,
some types of memories be stored chemically rather than structurally
dispersed in the body in molecules, And here's where we
get to the cannibalism. So, if there were in fact
molecules within an animal representing some kind of chemical memory,
(15:53):
such as memory of how to navigate a maze, could
this be demonstrated? Could those molecules be shared from one
animal to another? And this makes sense. That's what creatures do.
They take molecules from each other, from other organisms and
put them into themselves. Sure, we absorbed the molecules existing
in other organisms for nutrition. Uh, so maybe you could
(16:15):
molecules be absorbed from one organism to another four memory transfer.
So the first method they tried, uh and this is
based on the reporting of one of those Larry Stern articles.
The first method they tried was to splice the head
of a conditioned worm onto the tail of an unconditioned
worm to see if it would share molecules right, to
force them to exchange the alleged memory molecules. But the
(16:38):
transplant did not work. The head would not stay attached.
Then they tried to liquefy fully conditioned flat worms and
inject their juice into untrained worms, but this was also difficult.
The planarians were too small to be injected basically, and
sometimes they exploded when injected. In Larry Stern's words quote
it was like trying to impay all a prune with
(17:01):
a javelin a lot of horrific things done to to
planarians in these experiments. I guess they are a simple
enough organisms that we have to be so upset about them,
I guess, But it's still one can't help it. Pause
a little on some of these, right, some of the grinding, Yeah,
the sauce, the gravy, the flatworm sauce. So how do
(17:23):
you get those hypothetical memory molecules in there? If you
can't inject them, you can't transplant ahead on. So the
next route they tried, and this was in the year
nineteen sixty, was experimental planarian cannibalism. This would be the
old fashioned way of getting molecules from one organism into
the other. Sure, so apparently the idea came from a
flatworm researcher named Jay Boyd Best who communicated to McConnell
(17:46):
about the fact that one particular species of planarian was
known for cannibalistic behavior. So here's the answer. You train
the worms to respond to to a maze or to
the light, whatever the conditioning stimulus is, and then they
learn the conditioning and then you grind them up into
worm gravy, and then you feed the worm gravy to
the untrained naive worms, and you see what happens, and astonishingly,
(18:10):
their early experiments with this method looked very promising, including
a number of early replication attempts with blinding procedures to
remove the possibility of experiment or bias, supposedly confirming their
early results. So, if it were true that memory molecules
are being exchanged through this strange cannibalistic ritual, could I,
(18:32):
you know, with this extend to humans? Could could I
drink your flesh and gain your memories? And how was
it happening? What was the chemical basis here? So one
interesting line of reasoning here followed from the still somewhat
recent discoveries about genetic information being stored in and mediated
by nucleic acids DNA and RNA. Remember, you know, we're
(18:55):
not too far from from the discovery of the double
helix here. So if DNA and RNA could be involved
in an information management process passing genetic information across generations
from parents to offspring, could the same molecules also in
code and mediate other types of information? I mean information
(19:16):
is in the DNA. So specifically, could the information content
of memories somehow be coded into DNA or RNA and
then dispersed through the body, but also transferred from one
body to another. And so this is the line they took.
McConnell and his team conducted experiments and published results that
(19:37):
seemed to back up the idea, at least for a while,
that RNA played some important role in facilitating memory, and
that RNA could be used to chemically inoculate naive worms
with the memory associations of their more worldly predecessors. And again,
just consider how revolutionary this would be if it turned
out to be true. You'd be forced to wonder how
(19:58):
far the principle could be taken. Did this only apply
to planarians or did it extend to other more complex animals.
Would there be ways in which humans could undergo chemical learning?
Could you train the mind in some way with an
injection alone, or even a pill? Even if it only
worked for like broad associative learning such as you know,
the kind of things you get through classical conditioning with
(20:21):
an electric shock and a single stimulus, you could still
possibly imagine profound benefits. Just one idea comes to mind, like,
say you're struggling with a drug addiction. Could you seek
out an injection of of memory molecules to establish a
strong averse reaction to your drug of choice such that
you wouldn't want to take it anymore. Yeah, Or to
(20:41):
get into some of the behavioral his ideas that we
discussed in the first episode, some of those ideas that
that that McConnell's very outspoken about it, even later in life.
You could have some sort of a cocktail that could
be injected into an individual that had a history of
violence and history of of you know, breaking the law
(21:03):
and rebelling against authority figures, and you could can potentially
fix them with this injection. Yeah. And of course there
you get into the more nefarious possible thing, Like you
can probably instantaneously imagine so many horrible, insidious uses for
injectable conditioning if such a thing were possible. Oh yes,
I mean, as with any science, many many fabulous uses
(21:25):
come to mind, but so many nightmares as well. But
we should stop and be real for a second here,
that even if these findings had turned out to be
totally solid for planaria and more on, that in a moment,
we should know better than to freely extrapolate from worms
to humans. I think this is one of the most
classic traps that people fall into and interpreting biological research.
(21:47):
I'd say more often as people extrapolating from like rats
to humans. But this isn't a much larger jump. This
isn't even a vertebrate animal. Yeah, I mean, you can't help.
I often find that I can't help, but but at
least think about that on some when I read a
science headline, I can't help it. Put myself into into
it somehow and imagine myself as the creature, right, And
it's often, I mean, it's just done right there in
(22:08):
the press. Again, it's fine to wonder about what possibilities
could be implied by studies in rats for humans, but
you can't just, you know, conclude from one to another.
We can't help but anthropomorphize virtually any creature, and if
that creatures in a study, we're also going to end
up anthropomorphizing that as well. But James McConnell, true to form,
(22:31):
as we know from the last episode, was not one
to be shy or cautious about interpreting his findings. He
loudly proclaimed them to the public, advertising his results on
TV programs. He apparently embraced the nickname mccannibal uh, and
he predicted an era of memory pills like we just discussed,
So you might be thinking, like, wait a minute, he
(22:52):
should know better than to extrapolate from planarian even if
you assume the planarian research to be solid and will
introduce some caveats to that. But even if you did
assume that, how could you jump from that to human
memory pills? That seems like a you know, a leap
of miles of assumptions. Yeah, very much though, And it
(23:13):
does seem from from what I was reading, especially in
Rilling's paper about McConnell, that it seemed like to him
he sort of had a sense of humor about talking
about memory pills, like as if he were sort of
joking when he talked about memory pills. But that was
not clear to the popular audience that was listening on
the TV. You know, they weren't psychologists. They didn't understand
(23:36):
that he was kind of kidding when he said. That
makes sense, oh, certainly. And then also, they're going to
be like a few different levels, so I could like,
he may joke about it here in this paper, or
joke about it to this individual, but then you're gonna
have different levels of coverage, and it's going to get
out of out of control pretty quickly. Yes, So Rilling
writes that quote McConnell's work on retention following regeneration and
(23:58):
planaria provides a case study in sensational journalism and illustrates
how his media work escaped the normal mechanisms of peer review.
So the idea is that McConnell and colleagues would do
an experiment, they would obtain a very strange and interesting
result that looked solid enough to get published in an
academic journal, and then McConnell would immediately want to engage
(24:21):
in quote, wild sounding conjectures interpreting the meaning of his
results and how they would be applied in the future,
and scientific journals generally like one example was the editor
Harry harlow Uh generally refused to publish these wild interpretive
or speculative addendums to the research. They just say, well,
we'll publish your study, you gotta cut out this section
(24:42):
about memory pills that doesn't belong in here. But of
course there's no peer review in the popular media, so
he could go on TV and say memory pills as
much as he wanted, And it turned out that that
kind of thing on TV gets you booked on TV
again because it's exciting right. I mean, that's like something
that people in picture, it's not hard to understand, and
it's it's very like what revolutionary. That's what you want
(25:05):
in a science segment on your your news programs. You
want something relatable, and here's this guy that is making
it relatable and exciting with promises that are not at
all implied by the research being discussed. Even if the
research itself is a solid and and retrospectively that may
be in doubt. So just one example, in nineteen fifty nine,
an article in Newsweek covering McConnell and the PRG research
(25:29):
claimed it may be that in schools of the future,
students will facilitate the ability to retain information with chemical injections. Apparently,
there was also a lot of misunderstanding in the media,
misunderstanding the fact that multiple generations of regenerated Planaria could
retain training, and they misunderstood this is the fact that
(25:49):
memories can be inherited in apparent to child sense, which
led to all kinds of Lamarckian interpretation. So I think
there there's all. There was also just confusion stemming from
the use of the word inherited and generations he was
talking about like generations being chopped up and regenerating, which
is quite different than what we understand, right, And again
he's coming down. He's talking about memories here. There are
(26:12):
other things that you know, there's certainly things that affect
that have generational effects in biology and in human biology.
I think we've talked about studies before and about body
size following periods of starvation, that sort of thing. But
but again we're talking about memories here. He is explicitly
talking about memory. Yes, And another one that that was
(26:33):
quoted in Rilling was regarding cannibalistic memory transfer, the one
where you eat the worm gravy and you gain that
worm's memories. Supposedly, there was a nineteen sixty four article
in the Saturday Evening Post that claimed we quote might
someday enable us or it might someday enable us to
learn the piano by taking a pill, or to take
calculus by injection, which at that point is is very crude,
(26:55):
gross kind of like over interpretation of what the memories
here all are. And the you know, the leap from
one organism to another, you just like do a line
of ground up Beethoven, And yeah, I mean this is
this is so outrageous that like I, I feel like
I would I would feel like I was over stretching
to use this as an outrageous example of a possibility,
you know, like earlier I I did the the far
(27:18):
future example of of criminals being treated like this seems
even this is even seems crazier, but on the same hand,
also attractive the idea of being able to uh, say,
master calculus by simply injecting something into your body. Yeah,
though I hope Also our questions about potential applications if
this were true were heavily caveat. So in the mid
(27:39):
nineteen sixties there were even studies following up on this
cannibalism research claiming to bear out chemical memory transferring other species,
such as in rats. Again, that's kind of hard to believe,
and so like. For a few years there in the sixties,
things looked incredibly promising with this research. But fortunately or unfortunately,
depending on how you look at it, it was not
(27:59):
too lad. There was a problem with the p RGS
cannibalistic memory transfer research, and it was just that it
didn't hold up to sustained scrutiny over time. Over time,
properly blinded and controlled efforts to replicate McConnell's results. A
few of them came in saying yeah, we replicated, but
a lot did not produce the same effects for cannibalism
(28:21):
or other chemical methods of memory transfer. According to Rilling
in nineteen seventy one, I guess this would be as
a result of some of these failures, the Plenaryan research
group lost its grant support, and this led McConnell to
change focus. And after this in the seventies he went
on to write a very influential and from what I
can tell, mostly well regarded textbook for introductory psychology. Apparently,
(28:45):
one thing that set it apart in the field was
that it used a lot of fiction. It introduced students
to psychological research methods with the use of stories and
like fictional framing narratives to explain the principles that were
discussed in each chapter. UH, even including one chapter about memory.
It seems to begin with a fictionalized version of the
story of his research with Thompson in nineteen fifty four
(29:09):
or so, UH, though incorporating lessons about control groups that
he had not learned very well back then, and as
we discussed more in the previous episode. Later in his career,
I think he was known more maybe for being a
fierce public advocate of the powers of behavior modification through conditioning. Again,
this was an era in which behaviorist psychology was seen
by many as a potentially revolutionary scientific tool for minute
(29:33):
control of human minds and lives. This is the birth
of the modern concept of brainwashing. Right and McConnell wrote
and appeared on TV arguing that behavioral conditioning would fundamentally
alter the nature of criminal justice in democratic society itself.
I think there was one article he wrote that was
titled something like we must brainwash criminals. Now, well, that's
(29:54):
a great headline though, no doubt about it. Yeah, certainly
if you want to get the clicks. Uh, yeah he
was maybe he maybe he was clickbait before the Internet.
He does, he does seem very CLICKBAITYU. And this is
something some of his colleagues said about them. Is quoted
in the Rilling paper that he wanted to shock people.
He wanted to say things that would make people say,
(30:15):
what what's this guy talking about? That can't be true?
And he said, you know, the idea was you you
bring people in by shocking them, and then you educate
them with the science. And you know, I guess that
can be an okay method if what you if what
you say in order to shock people isn't fundamentally dishonest
in some way, right, Yeah, I mean it's it's kind
of it kind of gets into a similar of like
(30:37):
leading with an example, you know, and sometimes it's an
outrageous example. Sometimes, like on this show, we we bring
up a monster, something fantastic, and we use that to
talk about something that is that is real and talk
about actual scientific studies or actual biology that somehow matches
up to that. But well, I hope we never do.
I hope if we start with god Zilla, we don't
leave you with the impression at the end of the
(30:58):
episode that god zills real and true. But it is
interesting how it seems like some of the things that
did make him such a great communicator and ultimately like
a great author of an introductory psychology book. Uh, those
are also some of the things that got him in trouble. Yeah,
that totally seems to be true based on everything I've read.
But but coming back to the the memory transfer issue,
(31:21):
I just want to say that I think the conclusion,
unfortunately at the end is that the cannibalistic memory transfer
saga is widely regarded now as a dead end. Despite
a few reports of moderate replication successes, McConnell's results ultimately
did not hold up to widespread scrutiny and the rigorous
application of controls by others. And it looks like his
(31:42):
supposed discoveries about memory transfer through injection or cannibalism were
probably wrong, but not all of his conclusions were necessarily wrong.
I mean again, One of the points of Rilling's article
seems to be that despite the ultimate failure of the
memory transfer through cannibalism theory, McConnell did make truly important
(32:02):
contributions to research on invertebrate learning in the nineteen fifties.
And while the memory transfer the memory molecule transfer through
cannibalism is almost definitely a dead end, more recent studies
have sort of raised the question of whether his like
decapitation and transplantation research might have been on the right track.
All right, we're gonna take one more break. When we
(32:24):
come back, we're going to discuss some of these modern
follow ups regarding polanaryan decapitation and brain transplant Thank alright,
we're back so we discussed through through the end of
the career of of James V. McConnell, who studied planarians
memory memory transfer our memories outside of the brain, and
(32:47):
we we brought up the idea that this subject has
been revisited by researchers just in the past few years
who think that while McConnell was probably wrong about like say,
eating flat worms and gay in their memories, there may
be some truth to the idea of memories somehow being
stored outside the brain or transferred without a full brain. Yeah. So,
(33:09):
for instance, it has been demonstrated that if you transplant
the planarians brain into another worm's body, uh, it will
result in at least partial recovery of function, even if
the brain is put in backwards or transplanted across species. Uh.
The author Pagan, who we brought up earlier, who wrote
the first brain UH, he points this out, and he
(33:31):
points out that basically the cross species transplants held, meaning
there was no rejection and forty eight hours later the
worm retained mostly normal behavior. I mean, that's pretty weird,
but again it's worms. Like Yeah. One of the big
take comes from all of this is that planarian brains
and plinarian in general are strange, right, So a lot
(33:51):
of what we determine what a lot of what we
learned from this research you could interpret as some fascinating
deeper inside about biology g as a whole, or you
could interpret it as fascinating specific facts about these flatworms. Absolutely.
Uh so in particular, though a gun and there's are
referring to a study by Davies at all, and they
(34:15):
were working with a species of planarium that actually can't
regenerate brain tissue, but a transplanted brain will take root
and quote nerves exiting the brain tended to join with
the peripheral nerves closest to them, which I think is
a wonderful image of the brain being implanted in this creature.
And then like the like the like roots forming, like
(34:37):
the vein, he connects itself. It hooks itself up like
a car battery that has been placed in the inside
another via a new vehicle, and all the things just
kind of hook up automatically, plug and play. Yeah. Well,
or like like mistletoe or some other kind of parasite
that like sticks it's little it's how stori um or whatever,
the little spikes down into the host. Yeah, it's it's
(34:59):
it's weird. It's definitely not the human experience. I mean
not to not to discuss, you know, the whole body
transplant or human brain and head transplant much in this episode,
but basically it's very complicated, if not impossible in humans. Yeah. Well,
and again to look at memory more broadly, neuroscientists today
(35:19):
mostly broadly understand memories to be neural networks, right, networks
within the brains, sort of strings of reinforced connections between
neurons and brain regions that specify memories by their cross
linked structure. A memory is in some way a series
of connections between neurons and the brain. Uh. Though that
(35:41):
does seem to be the case. Beyond that broad picture,
there's still a lot we don't know about the physical
basis of memory, and so even in especially in organisms
like flatworms, there are ways in which memory could be
operating and that are still mysterious to us right now.
Of course, the quest to solve these mysteries continues. Uh.
Great deal of pollinarian research is still going on, and
(36:03):
you see quite a bit of it come out of
Tufts University, and you'll see um, a researcher by the
name of Michael Levin often is a is a head
author or co author or contributing author on these papers. Yeah,
and there was one big study that got some press
being connected back to McConnell's research that Levin was at
least one of the authors on UM and and basically
(36:26):
it had to do with replicating a version of the
decapitation experiment showing that somehow it appeared memory if the
study was designed properly and there wasn't some kind of
flaw that people didn't notice in there, that memories maybe
were somehow being transferred through the decapitation process. Right. This
is a two thousand thirteen Tough University study that found
(36:46):
that a decapitated flat worm that grows a new head
keeps its old memories. Uh. For instance, the Sarahsing article
about this it appeared in Nautilus, carried the title decapitation
but not cannon is um might transmit memories without context.
That's a pretty weird title, right, But then within context
the article refers back to McConnell's work quite a bit.
(37:10):
And the idea here is that some trace of the
of memory might be stored in neural circuits outside the
brain and certainly when you take that and you compare
it to these you know, these other into this previous study. Uh,
with with one brain being dropped into a new creature,
a new a new individual and seeing it, you know,
take root and uh and seemingly bounce back. Uh, that
(37:31):
becomes all the more interesting. Yeah. One of the things
that has clearly been the case, and this was discussed
in that article in the Verge we talked about in
the last episode, is that Levin's research has been focused
on trying to eliminate some of the problems that could
have existed in the original McConnell research. One example is
that that he helped create um and a thing called
(37:52):
an automatic training apparatus. Basically, it's a robot for conditioning
the flatworms, take the human element element out of the
training process to eliminate any kind of bias or error
that could be introduced that way. But I love the
idea in general of a robot for training worms. So
that that two thousand thirteen study especially generated quite a
(38:13):
bit of interest, and at the time there was there
was mixed response from the scientific community. Now, I do
want to drive home that it is not my interpretation
that Michael Levan is anything like a McConnell figure. He seems.
He seems to be a very suffected researcher. And most
of his work, like I said, he's seeing on a
lot of studies for his general planaria research right now,
(38:35):
I mean, I don't. I haven't seen anything where Michael
Levin is going on TV and saying memory pills right right,
uh and uh and and by and large it seems
like most of his work just deals with with regeneration,
uh in these planaria worms. But yeah, so you had
plenty of people that that were supportive and thought that,
you know, they might be onto something. Others were a
(38:55):
little critical at the time. Robert Kintridge, I say it
was a psychologist at Durham University, and he pointed out
in a two fifteen Verge article that Verge article we
cited earlier that it might be simply related to quote
behavior induced by a stress hormone itself triggered by the
textualized petrie dishes unquote. And to clarify, they're part of
(39:19):
what the study looked at to see conditioning in the
flatworms was you'd have these textured petrie dishes where they
would be swimming around the food they were going to eat,
and how fast they approached the food in a newly
textured Petrie dish environment was taken as a signal of
their memory or familiarity with the environment. Like you put
(39:39):
a new flatworm in a textured Petrie dish, its circles
for a while before going for the food because it's
exploring its environment. It doesn't know. But after it's been
trained with the texture and a Petrie dish, it goes
straight for the food because it already knows the environment. Right. Yeah.
So so basically a number of individuals UH said, well,
there there are aspects of the study that could have
(40:01):
been better designed. Sure. Now again, Michael Levin, his research continues.
He and you you'll find a number of studies from
very recently that he's been involved with. He was an
author on a study earlier this year neural control of
body plan access in regenerating planaria. And in two thousand
fifteen he put out a paper on the planarian regeneration
(40:21):
model as deciphered by artificial intelligence. And uh that same
year he was also a co author on another study
UH that included the growth of extra heads. Yeah, I've
seen also that I think both within and outside of planaria.
He's just generally studied regeneration. Yeah, and with the poplinaria,
of course, it's it's just such an amazingly regenerative creature.
(40:42):
You get things like like this. Uh, the second study
that I mentioned from fifteen, they were able to induce
one species of flat worm to grow heads and brains
characteristic of another species of flat worm without altering genomic sequence,
and then the individual later regenerated to the appropriate head shape.
Now quickly, I guess one thing worth discussing is if
(41:04):
the research associated with with Michael Levin is in fact correct,
the results are valid, there's not some kind of flaw
we're missing in the design of the study. And uh,
and this is really going on. The memories are surviving
the regeneration without an original brain. How would you interpret this, Like,
what does it mean if this is in fact true? Uh?
So a couple of ideas are given in the Verge article.
(41:28):
Leven hYP quote hypothesizes that memories could spread beyond the
brain thanks to electrical charges generated by cells and the
rest of the body. So there's some kind of information
encoding that's just like coming from cells in the other
body that are electrically stimulating something like a memory response.
But then there's another thing cited in the same piece
(41:49):
by Ava Jablanca, a developmental biologist at Tel Aviv University,
and she offers a speculative explanation involving particles called small RNAs,
which are short copies of DNA, but they don't turn
into proteins. They don't generate proteins. So when a flatworm
(42:10):
learns an association or an episode, something in this model
about the brain chemistry would change, and then these changes
alter the small RNA is present in the body, which
of course are not confined to the brain because they
migrate around between cells. And by migrating around between cells,
she says, perhaps they end up in stem cells that
(42:32):
remain in the body. After the worm's head is cut off,
and to read from the article quote, when the worm's
head grows back, the small RNA's migrate back to the head,
changing the brain's chemistry and allowing it to learn certain
behaviors more quickly. Um If true, the memory that Levin
thinks is stored outside the brain wouldn't be memory at all. Rather,
(42:53):
the small RNAs would allow the flatworm to recover a
brain environment that helps them learn a specific behavior more quickly.
So the idea there is that if this speculative idea
is correct, and again she she's very clear to stay
this this isn't something we know. Is just a speculative interpretation.
Maybe it works this way, then what would be happening
is these little chemical molecules don't transmit the memory prepare
(43:18):
the new brain to learn a memory that was previously
learned more quickly. Okay, so at least we have a
hypothetical model of how this would actually work, which or
at least here's one model presented anyway, Sure, but ultimately
we don't know for sure. And again another thing that
we don't know for sure is if these results do
(43:39):
hold up. Is this something that's specific to planaria? Is
it flatworms only that can transfer memories in this way
or could this be more applicable beyond flatworms to other organisms,
because that's the thing. Other organisms can't regenerate like a
like a planaria can. But at the same time, we
one of the one of the things that's often cited
for researching an area regeneration is that we might learn
(44:01):
something that could be appliable to humans. Of course, especially
and with not even getting into memory implantation, just the
idea that they have such impressive neural regenerative powers, the
ability to regenerate like damaged brain cells. You know, if
we could, if we could develop some better method of
doing that based on our studies of these organisms, then
that would be tremendous. Of course. I mean though it
(44:24):
when you introduce the idea of brain regeneration or anything
like that to a human context, things emerge that don't
necessarily seem to be of concern. When you're talking about planaria.
Planaria don't seem to have extremely distinct personalities. Uh, you
know humans do you know, however much we want to
joke about humans acting like sheep and all being the
(44:46):
same we you know, we we've got a lot of
different stuff going on in our heads. If you cut
your head off and regrow it, what indication would you
have that the new head would be you in any
sense other than sharing your d n A. Well, I
guess as long as it's said all the right things
and I mean just get along just fine, it would
be like a p zombie perhaps, Well, I mean, would it?
(45:10):
I guess it would be a question of whether it
would retain any memories from your life, you could you
talk about whether that might be stored in the body somehow,
or even if you assume it, okay, it retains no
memories whatsoever because those are just stored in the brain.
Whatever may or may not be happening in flatworms doesn't
happen and all at all in humans. Even if you
assume all that, you'd also have to ask, like, would
(45:30):
its personality be the same as yours personality is so
shaped by life experience? I don't know. It makes me
wonder has anyone ever considered creating a like a science
fiction yarn in which you look at what would human
society be like if we had regenerative properties like this?
Like what would war be like? What would what would
(45:51):
reproduction and society be like? I mean, granted, I think
the obvious answer, it would absolutely change everything. But the
fun thing about science fiction is you don't you don't
have to go all the way. You can just sort
of like tweak it, like what would this if we
if I were to look at this particular vision for
a totally regenerative plnary in human species, then what could
(46:11):
I perhaps unravel about our actual human condition? Well? I mean,
I think we pretty much all at some state, at
some point or other, get into a get into a
place where not very happy with our own brain. We
don't like the emotional patterns were feeling. Maybe we're ruminating
in bad ways. I mean, this happens pretty often to people.
So what if you had the option to you get
(46:31):
into a bad state like that, you know, you can
just cut your head off and grow a new one.
These are exactly what the horrifying orange creatures in Labyrinth
they're all about when they come up to Sarah and
they encourage your Hey, take your own head off, throw
it around, try on a different head, Let your head
try it out, try itself out on a different body,
see how it shakes out. Just you know, have to
(46:52):
have a little fun. You're not a flat worm. Don't
try it people. All right, We're gonna go ahead and
close this out then, but we hope you have enjoyed
and then learned from this exploration. Perhaps you'll think of
flat worms in a new light now, and perhaps you
will even second guest memory a little bit as well.
In the meantime, if you want to check out other
(47:13):
episodes of stuff to blow your mind, you'll find them.
It's Stuff to Blow your Mind dot com. That's the mothership.
And you can also find our podcast Tack just about
everywhere else anywhere you get the podcast, though, we do
ask that you leave us a nice review, leave us
some stars, that sort of that makes you subscribed. That
kind of thing really helps us out in the long run. Also,
if you want other shows who were involved with there
(47:34):
is Invention. Invention is a journey through human techno history,
one invention at a time. Go check that out. It's
an invention pod dot com and you can also find
it anywhere you get your podcasts. Just look up Invention.
If you want a little serialized horror sci fi for
your holiday season, check out the second oil age that
is out as well. And I'm also told that the
(47:55):
Stuff to Blow your Mind t shirt shop UH is
not only still around it, it is been around uh
and it still has all those wonderful squirrel and Vasilisk
and buy Camera and Mind designs, as well as their
logo designs. But there's gonna be a new logo for
the Thanksgiving Ish holiday, and there's gonna be some sort
of a sale coming up. Right. If you've got a
friend or family member who's a fan of the show.
(48:17):
You want to get him a holiday gift. Maybe you
should get them a Sphere Catastro feat shirt or a
Squirrels Are Not What They Seem shirt, any one of
the many wonderful offerings we've got for you right in
the merch place. So go into the merch pit, come out,
come out with treasures anyway. Huge thanks as always to
our excellent audio producer Seth Nicholas Johnson. If you would
(48:38):
like to get in touch with us with feedback on
this episode or any other, to suggest a topic for
the future, or just to say hello, you can email
us at contact at stuff to blow your Mind dot com.
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