Free Transcript for BS 203: 16th Annual Review Episode

Aired December 23, 2022

[Music]

Welcome to Brain Science, the podcast that explores how recent discoveries in neuroscience are unraveling the mystery of how our brain makes us human. I'm your host, Dr. Ginger Campbell, and this is episode 203.

Today, is our 16th annual review episode, and the free transcript of this episode is available along with complete show notes at brainsciencepodcast.com. You can also send me feedback at brainsciencepodcast@gmail.com.

I will be sharing highlights from 2022 in chronological order, and scatter brief announcements throughout. These announcements will be particularly useful to newer listeners, which is one reason I mention that the transcript for this episode is free.

Before I talk about the individual episodes, I want to give a brief overview of the past year. Some of the topics we explored were entirely new. We talked about hearing and the grieving brain. We talked about brain development for the first time since 2007, and we continued our ongoing exploration of the neuroscience of consciousness.

Finally, we considered two topics that have often been covered on Brain Science: the role of emotion and the importance of embodiment. Our discussion of embodiment included a new look at the importance of embodied cognition in education and learning.

I'll share some additional reflections on 2022 at the end, but now, let's jump into our review.

REVIEW

BS 192 featured Nina Kraus, author Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World. I was surprised when I realized that this is only the second time I've talked about hearing. Back in episode 140, I described a talk I attended about the role of hearing loss in the development of dementia.

The bottom line is that if you have hearing loss, it's critical to your brain health to get hearing aids that really work. This includes working with a professional to make sure that they are adjusted properly.

Kraus pointed out that people tend to take hearing for granted, even though hearing loss is actually much more socially isolating than vision loss. Vision is also the most heavily studied of the senses, but hearing presents some interesting contrasts that relate to the differences in the signal.

Visual inputs are relatively static, while sound is extremely time sensitive. Sound is not only time sensitive, but very rapidly changing. Again, this is something we seldom notice unless we try to listen to someone talking another language, and then it sounds like they're talking way too fast. And speech is actually faster than other sounds, including music.

It takes about a hundred milliseconds to tell the difference between two notes, but for consonants, the change is like 20 milliseconds. I emphasize this timing element because it's one of the keys to understanding how sound is processed in the brain.

Despite all the supposed powers of the cortex, the cortex is way too slow to process sound. Most of the processing actually occurs subcortically, and of course, unconsciously. These are ancient circuits because hearing is shared by virtually all vertebrates even though many lack vision.

The decoding of the timing of sounds including speech and music, occurs at the level of the brainstem and midbrain. This is discussed in more detail in the book.

Dr. Kraus emphasized that everything we hear changes our brain, and in the case of noise, these changes can be damaging, while learning languages and music is highly beneficial. I encourage you to read Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World by Nina Kraus.

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[Music]

Next, BS 193 asked the question, what does it mean to say that the mind is embodied? Embodied cognition is a topic that I discussed often in the early years of Brain Science, but I realized that newer listeners might need an introduction to the topic.

This episode was unusual in two ways. There was no guest and although it was inspired by the book Out of the Cave: A Natural Philosophy of Mind and Knowing by Mark Johnson and Don Tucker, my goal was to give a broader introduction to the concept known as embodied cognition.

This term actually refers to a family of approaches that share an emphasis on embodiment over so-called representational approaches. The key idea of embodied cognition is that the mind is embodied, which means that the mind is a natural process of a brain within a body interacting with its environment.

This is an anti-dualistic approach because rather than seeing the mind as something non-physical, embodied cognition acknowledges the mind's absolute dependence on the brain and its interactions with the body and the world.

More mainstream approaches thought of the mind as something computational. Sometimes the mind was even called the software of the brain. It's difficult to let go of our intuition that the mind is something non-physical. We seem to be natural dualists.

This disembodied view is deeply entrenched in both Western and Eastern thought. Neuroscientist Michael Graziano probably put it best when he observed that the brain gives us a cartoon version of reality. It doesn't need to tell us what it's up to since that's not important to our survival. So, naturally, we have this intuition or feeling that our thinking mind is something non-physical.

Recognizing that the mind is embodied means more than moving past computer metaphors. It has many interesting consequences including appreciating that the properties of an organism's body limit or constrain the concepts it can acquire.

It points to the use of a dynamic systems approach that recognizes that cognitive processes are not discreet, but continuous. And possibly, most important, the body or world plays a constitutive role rather than merely a causal role in cognitive processing. What does that mean?

To say that the body is a constituent of cognition is to say that it's like oxygen is a constituent of water as opposed to a causal role, which like oxygen, is a cause of an explosion. There is also a whole field called cognitive linguistics that explores how embodiment influences our language.

It basically says that our language is a reflection of how we experience the world. Cognitive linguistics also introduces an idea that some may consider controversial, which is the idea that thinking and cognition precede language. Language enhances both our ability to communicate and our ability to think, but it did not come first as is traditionally assumed.

This might seem obvious to younger listeners who've grown up with the overwhelming evidence that non-human animals and non-verbal humans can be intelligent, but the data for this has only emerged in the last 50 years or so.

The show notes for this episode include links to previous episodes about embodied cognition, and in the episode, I actually did refer back to quite a few of the earlier episodes. I'll be talking more about embodied cognition later in this episode.

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Now, this seems like a good time to mention a problem that I've recently discovered on my website at brainsciencepodcast.com. Brainsciencepodcast.com is hosted on Squarespace, which provides what used to be a very effective search function. However, it now appears that their algorithm does not work well for sites containing many years of content.

Thus, if you were to put in the term “embodied cognition,” you might not get anything back. I'm looking into purchasing a third party solution to this problem, so I'd appreciate your feedback to give me a sense of how many of you would use search if it actually worked correctly. Obviously, being able to do a reliable search is crucial for a site containing 16 years of content.

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Okay, now, let's talk about BS 194 with Mary-Frances O’Connor, author of The Grieving Brain: The Surprising Science of How We Learn from Love and Loss.

This book is intended for readers of all backgrounds, but you're more likely to find it interesting if you've actually experienced the loss of a loved one.

Dr. O'Connor noted that during the pandemic, many people suffered grieving in isolation and that is one reason why I felt this was an extremely timely topic. I always talk about how our brains make us human, and grief and grieving are universal experiences of being human.

Before I read The Grieving Brain, I didn't even know anyone was studying the neuroscience of bereavement. It's a very young field, but researchers like Dr. O'Connor are already making discoveries that may help those that are suffering. Let's start with a brief review of the difference between grief and grieving.

Grief is an in-the-moment wave of feeling that's overwhelming and horrible, while grieving is a process that occurs over time as we adapt to the loss of our loved one. When it comes to the so-called normal grief, there are two key ideas.

First, from the standpoint of the brain, grieving is about learning that your loved one is really gone forever, and because we are a social species, we appear to devote significant brain resources to tracking our loved ones, not just in terms of their location in space and time, but also, their psychological closeness. So, when someone close to us dies, our brain struggles with this sudden change.

A good analogy might be phantom limb pain. Even if a person knows their limb is gone, they can't just will the pain to go away. Ironically, our difficulty with grieving may also reflect the limits of our brain's plasticity.

The second key idea is that all the seemingly crazy things people experience during grief and grieving make sense if we remember that learning this new reality represents a significant challenge to our brain’s predictions. We need to give ourselves and others time. Don't expect to just get over it by the force of mental will.

Dr. O'Connor wrote on page 22, “You cannot force yourself to learn overnight that your loved one is gone.” Fortunately, most people are able to cope with grief in a resilient manner, and return to meaningful lives.

Those with complicated or prolonged grief can benefit from treatment based on our increasing understanding of what happens in the brain during grief and grieving.

I appreciate those of you who took the time to send me feedback about this episode. Brain Science is not a self-help show, but this was definitely an episode with practical applications, and I highly recommend this book, The Grieving Brain: The Surprising Science of How We Learn from Love and Loss by Mary-Frances O’Connor.

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Let me change to sort of a more upbeat topic. The same day that Brain Science 194 was released, I was actually inducted into the Podcast Hall of Fame. This was a great honor because there are currently only 32 podcasters in the Hall of Fame, and I'm only the second science podcaster. The other one is my friend, Dr. Pamela Gay from Astronomy Cast.

Best of all, several listeners were able to join me for the ceremony in Los Angeles. If you'd like to hear my acceptance speech, it's still available on YouTube. I'll put the link into the show notes. The link will take you to the 10-minute mark, which is right before I take the stage.

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Now, let's go to Brain Science 195 with David Anderson, author of The Nature of the Beast: How Emotions Guide Us. This is a great book if you're interested in learning more about how science is really done, but I'm just going to share a few of the key ideas.

One issue that we addressed was how to study emotion in animals. A somewhat controversial question because there are respected scientists who feel that this is by definition, impossible because animals can't share their subjective experience, and it's not science to jump to conclusions based on our intuition.

Dr. Anderson argued that it is essential to separate the brain states and what he calls emotion primitives from subjective feelings. This allows us to study animal models which gives us access to many techniques that we can't use in humans.

I can only hit the high points of our conversation, but I do want to emphasize the importance of that idea. Rather than focusing on the conscious aspects of the problem. Dr. Anderson said, “We're concerned with emotions as a brain function like decision-making, learning and memory.”

I want to repeat that quote: “We are concerned with emotions as a brain function like decision-making, learning, and memory.”

This might seem like a strange approach, but it really comes down to saying that emotion should not be studied any differently than any other basic brain function that's been successfully studied in animals, including vision, olfaction, decision-making, learning, memory, motivation, reward, and motor control. Every one of these has a subjective component.

The key step is the removal of the subjective feelings from the equation. This is where the concept of emotion primitives comes in. This concept was actually introduced in the neuroscience of emotion, which I discussed back in episode 151, but when I read this earlier book, I did not appreciate why these emotion primitives are so important.

Things like persistence and scalability are what allows us to say that a behavior being observed is not a reflex, but it is being caused by a specific brain state. If you're reluctant to accept this approach, consider the fact that we don't say we can't study vision because it has subjective aspects.

If you read The Nature of The Beast: How Emotions Guide Us, you will learn a lot about how the experiments are designed to establish causality.

I asked Dr. Anderson to talk about how proving causality is very different from correlation. This is a key issue because we constantly hear the mainstream press conflating the ideas. According to Dr. Anderson, demonstrating causality involves two things; necessity and sufficiency.

Necessity means that if A is necessary for B, removing A prevents B. So, in the case of an experiment, you're asking if getting rid of the electrical activity, does the behavior disappear?

An example of something that's necessary but not sufficient is that your car needs gas to run, but that's not enough. Sufficiency means demonstrating that the brain activity causes the behavior even in situations where it wouldn't normally occur, so you could use a technique like optogenetics to turn the neurons on directly.

Now, prior to optogenetics, precision was often an issue. But with optogenetics, they have the extreme precision right down to single neurons.

An example of correlation rather than causation is the fact that ice cream ingestion and crime both go up during the hot summer months, but there's no causation between the two.

Dr. Anderson has studied both fruit flies and mice, but we only had time to talk about the fruit flies. Fruit flies have many fascinating behaviors, and they have these little, tiny brains of about a hundred thousand neurons compared to our 86 billion.

There are now wonderful genetic tools that allow researchers to tinker with the specific neurons in the brain of the fly, and since flies are easier to work with than mice, it's a great system for studying how genes control behavior.

At this point, researchers actually have a complete wiring diagram for the female fly brain, and they're working on the male brain. So, let's review a few of the key things that they learned from flies.

First, they do have persistent internal states just like mice. Persistent activity of certain neurons leads to persistent fighting behaviors, so they're not just little robots. Male and female flies behave differently.

Dr. Anderson has a student who found this neuron that appears to control head butting in females and lunging in males. Some of you may remember that Dr. Joseph LeDoux came on Brain Science back in episode 161, and he said that he had not been studying fear all these years — that what he had been studying was what he called defensive behavior.

I asked Dr. Anderson for his take on LeDoux's claim that scientists should not use the term “emotion” because the everyday use of the term implies subjective conscious feelings. And since animals can't talk to us, we don't really know their experience.

Anderson responded that part of LeDoux’s argument seems to come down to how scientists should use words that may have different meanings in everyday speech, but he argued that as long as we're clear about how we're using a term, that should be a non-issue.

That's why he made a clear distinction between subjective conscious feelings, and the use of the term “emotion” to refer to internal brain states that guide animal behavior.

He also referred to other scientists who have been arguing for separating the term, using feeling to describe the thing that we can only study in humans, but the key is that the brain states can be studied.

He also mentioned Lisa Feldman Barrett's book, How Emotions Are Made, which argues that feelings emerge in the cortex. Anderson is not contesting the role of the cortex in feelings. Instead, he refers to the evidence that subcortical structures including the amygdala have a role in subjective experience. If you're interested in Barrett's interview, I refer you back to episode 135.

I agree with Dr. Anderson's view that the cortex is monitoring what's happening in the subcortical regions along with the rest of the brain, and this ultimately, leads to our conscious subjective experience.

Anderson also said, “I think that it's important for your listeners to know that it's unequivocal that the amygdala is necessary for the subjective experience of at least some kinds of fear in humans, but it's not sufficient.”

I asked Anderson how emotions are different from motivation, drive, and arousal since these are the sorts of things that all neuroscientists, including LeDoux agree, can be studied. Motivation is scalable. You can feel more or less motivated, but it's not necessarily persistent.

Drives are not persistent because as soon as you get a reward, the drive goes away. And this is one of the reasons for defining emotional primitives so that we can help distinguish them from things like motivation and drive.

Another primitive is generalizability versus the specificity of a drive such as hunger or thirst. Different external signals can generate the same sorts of defensive behaviors in contrast to hunger, which is specifically generated by the need for food.

Thus, emotions provide more flexibility, and they allow the brain to organize behavior. They are adaptive and remind us of the key idea that emotions are something that have evolved to help us, and other animals survive.

In reviewing this episode, I realized that this is actually different from what many people assume since we've often been told that emotions are something that humans should overcome. However, thanks to the work of people like Antonio Damasio, we've learned that emotions are essential to normal decision-making.

Even though Dr. Anderson has spent his career studying emotion in animals, he emphasized that his primary motivation is to help develop better treatments for mental illness.

He shares the late Jaak Panksepp’s belief that it is critical that neuroscience be carried out on multiple levels because there are things we can only learn directly from humans, and other things we can only learn from animals.

Panksepp was a pioneer in the field of affective neuroscience and he too, believed strongly that understanding emotions in animals would be critical in developing better treatment for human mental illness.

A main goal of Brain Sciences to give you a taste of these different levels of research, but I also want you to appreciate why this work is relevant to you. That's why I continue to talk about emotion.

We now know that emotion is created by the brain, and it can never be separated from activities that seem more cognitive. It is an intimate part of decision-making even for those who aspire to Spock-like logic.

I highly recommend The Nature of the Beast: How Emotions Guide Us by David J. Anderson, especially if you're interested in how studying animals is contributing to our understanding of emotions.

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I want to take a moment to talk about episode transcripts and how you can get them. I started producing transcripts in year two, right after I discovered that many listeners were unable to understand my first interview with Jeff Hawkins.

The transcripts make a great reference and a tool for review. Listeners who are not native English speakers find them especially helpful. Even though I do use the transcripts to generate income, I've tried to keep them very inexpensive. You can buy individual transcripts at brainsciencepodcast.com.

But if you use them regularly, I recommend that you explore one of the subscription options, MyLibsyn Premium or Patreon. You can learn more about these at brainsciencepodcast.com/donations.

I say this in every episode, but today, I want to clear up something that seems to confuse people. If you subscribe to MyLibsyn Premium or Patreon, you do not get your transcripts at brainsciencepodcast.com. You get them from MyLibsyn or Patreon, or from the respective mobile app. I'll talk more about this later, but let's get back to our review.

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BS 196 features Hakwan Lau, author of In Consciousness We Trust: The Cognitive Neuroscience of Subjective Experience. This book is really aimed at workers and students in the field of consciousness research.

That's why in my original review of this episode, I reminded critical listeners to read the entire book. It's never possible to do justice to a book in a short interview, but this was particularly true for the book In Consciousness We Trust.

Some of Lau's ideas conflict with those of previous guests. So, following the style of my original review, I'll start with a summary of the key ideas that Lau shared, but I'll also contrast his ideas with other approaches, and I'll try to be clear about when I'm expressing my personal opinion.

Lau's book takes a critical stance toward the current state of consciousness studies as a scientific discipline. On the podcast Brain Inspired, he complained that there are too many theories, and in his book, he complained that the media inflates the importance of certain theories because they're championed by established authorities.

I invited Lau on Brain Science, not because I agree with everything he said, but because I want to provide a sense of the diversity of voices among those who are trying to understand how the brain generates consciousness.

The one thing that all my guests have in common, is that they believe that consciousness requires the brain, and that it's a legitimate area of scientific endeavor. Lau is quite critical of the work of others in the field. Such criticism is an important part of the endeavor. If your theory can't stand up to the withering criticism of other scientists, you shouldn't be sharing it with the rest of the world.

To simplify his attack, Lau describes most theories as variations on two main extremes: global approaches and localist approaches.

An extreme local view, places subjective experience in the sensory cortex. While the well-known Global Workspace Theory says that consciousness requires a widespread broadcast of information. Of course, there isn't anyone who currently says that it requires the entire cortex, which would be the logical opposite of the extreme localist view.

Lau's main point is that neither view accounts for all the experimental data, which he says implies the need for a more centrist view. He proposes what he calls the Perceptual Reality Monitoring Theory (PRM for short). This is an example of a higher order theory of consciousness because it involves hierarchical information processing.

Lau proposes that reality monitoring is the mechanism by which we get a subjective experience. Not that consciousness is reality monitoring. He still agrees that consciousness is subjective experience, but his proposal says that if you look into the brain mechanisms, the process that gives you subjective experience will turn out to be the circuits for reality monitoring.

To be perfectly honest, I did not find his argument persuasive. I can see how reality monitoring is important to metacognition, and even to our ability to know the difference between real-time experience and imagination. But my biggest problem with Lau's approach is that not only does it fail to explain the qualitative nature of conscious experience, it restricts consciousness to a limited number of mammals.

And this is not because he accepts LeDoux’s argument that we can't know if animals are conscious, but it's because he limits consciousness to animals that appear to have the necessary cortical circuitry to implement his Perceptual Reality Monitoring.

One important point Lau made was that experimental confounders are always a challenge. If you are unfamiliar with the idea of confounders, I refer you back to the original episode 196. In his book, Lau emphasized the importance of recognizing confounders, and the importance of converging evidence.

This refers to the idea that if you have several different experimental approaches with different confounders and they converge on the same conclusion, it helps overcome confounders that can't be removed.

The reason I mentioned confounders, is that in his book, this seems to be one of Lau's primary arguments against Global Neuronal Workspace Theory.

Lau's take on Dehaene’s work does not always match what I took away from reading Dehaene’s book, Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts, which I described briefly in episode 160.

However, I would rather concentrate on several bigger issues. First, all the theories considered by Lau are what Mark Solms who I interviewed in episode 184 called cortic0centric. This may be why he has difficulty incorporating both the qualitative aspects of consciousness and emotions.

Antonio Damasio has famously come around to accepting the late Jaak Panksepp’s claim that both emotion and consciousness begins subcortically. This has huge implications for answering the question of which non-human animals are conscious.

Also, I refer you back to episode 128 where I talked with the co-author of a book called The Ancient Origins of Consciousness. This book argues that all vertebrates and maybe, even insects, have primary sensory consciousness. It should also be noted that even those who restrict the possibility of consciousness to mammals are beginning to recognize the role of subcortical circuits.

The other objection I have to Lau's approach is his functionalism. He never acknowledges the role of the embodied cognition movement. This contrasts sharply with his contemporary Anil Seth, who was interviewed last year in episode 188.

I have no particular allegiance to any theory of consciousness, but based on my reading, a credible theory must include findings from outside the narrow confines of consciousness studies. It must accommodate the evidence that many processes that were once considered conscious, for example, visual processing, are largely unconscious.

Maybe there isn't such a sharp divide between consciousness and all the other brain processes like we once assumed. A credible theory must also include the role of embodiment and the fact that emotions are fundamental to having subjective experience.

These ideas also impact the questions that appear at the end of almost every book about consciousness, such as are animals conscious? and Could computers become conscious?

It is extremely rare for me to criticize the position of my guests, but given how openly Lau criticizes his colleagues, I don't think he was offended.

I can't keep up with all the literature in this or any other subfield of neuroscience, so I rely on academic texts to give me an overview of the current issues. With this in mind, I highly recommend In Consciousness we Trust: The Cognitive Neuroscience of Subjective Experience for students and anyone else working in this field.

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[Music]

BS 197 is an encore of the interview with Frank Amthor, author of Neuroscience For Dummies and Neurobiology For Dummies. This episode originally aired in the summer of 2014, and it's definitely a great episode for newbies.

I'm going to review a few of the key ideas from the interview, but I want to emphasize that there's a lot more material in both books, such as discussion of the senses like vision, hearing, smell, taste, and touch, as well as the various parts of the brain, including the spinal cord and the cortex.

If you like the Dummies’ approach, you will enjoy Frank's books. If you want more detail, I recommend his textbook, Essentials of Modern Neuroscience, which came out in 2020.

So, we started out talking about neurons, and what makes them special. Ironically, we didn't talk about the synapse, which is the gap between the neurons where a lot of important stuff happens. Of course, this is discussed in the book and there's also an episode 186 that especially focuses on what happens in the synapse.

We talked about the difference between neurotransmitters and hormones. The same substance in the body can be either one depending on where it is. A good example is epinephrine, but the key difference is that neurotransmitters act in a more targeted way because they're released into the synapse and affect nearby neurons.

In contrast, hormones are released into the bloodstream and have more distant and diffuse targets. They both require interaction with receptors, which means that what they do depends on the receptors they interact with.

I want to emphasize this point because this is one reason why trying to create a drug that blocks or facilitates a particular neurotransmitter can have unintended side effects. That's why modern neuropharmacology is focusing on drugs that target the specific receptors instead, but the problem is we still don't know where all these receptors are located or what they do.

The key take-home message is that it is really an oversimplification to identify any neurotransmitter with a particular action, such as calling dopamine the reward chemical is a gross oversimplification.

We spent time talking about the NMDA receptors, which are thought to be important in memory. These are fairly unique because they actually act like AND gate. The NMDA receptor gate is usually blocked by a magnesium ion. This magnesium is only removed if an adjacent non-NMDA receptor is activated by glutamate, which then allows the NMDA receptor itself to be activated by another molecule of glutamate.

Essentially, two receptors have to be activated, which is why it's AND gate. This triggers a flux of both sodium and calcium. These receptors are thought to be important for mediating synaptic plasticity, so it's not surprising that NMDA receptors are particularly abundant in the hippocampus, which is important to memory.

I also asked Dr. Amthor to talk about how brains are different from our current computers. The most obvious way is that our brains are massively parallel compared to computers which usually operate serially. This means our brains are usually doing a lot of things at once while computers do things in sequence, though this is usually not obvious because they’re much faster than we are.

But a much more fundamental difference is that biological memory is reconstructive. There aren't any full memory stored in specific locations like they are in a computer.

I know this is not a new idea for regular listeners, but many people still don't appreciate the dynamic nature of memory or its implications. The fact that memory involves recreating the context in which the original event occurred, probably explains why when we go to certain locations, our memory of past events that happened at that same place are triggered.

I've talked in the past about how eyewitness memories can be altered so that they're no longer accurate. Things like leading questions can exaggerate this tendency. That's why we shouldn't assume that someone is lying if they remember an event differently than we do, or even if we think they've changed their story.

As Dr. Amthor pointed out, you really can't distinguish which memory is right. Obviously, this reconstructive nature of memory has profound implications, especially in our judicial system.

Elizabeth Loftus is probably the world's leading researcher in showing how volatile memory is and how easy it is to plant false memories. I saw her do a demonstration once where she showed us a series of pictures and got half of us to misremember which one we saw at the beginning. It was a really impressive demonstration, but I don't know how long it's going to take before we really deal with the implications of the reconstructive nature of memory.

Returning to my conversation with Frank Amthor, we spent some time talking about the neocortex, which is that thin layer that covers the cerebral hemispheres. This is what distinguishes mammalian brains from those of other vertebrates, and many scientists believe that it's our massive neocortex that makes us so smart.

Before the evolution of the neocortex, each brain structure was unique and pretty much committed to a specific dedicated function. With the emergence of the six-layered cortex and its columnar structure, we have something that reminds me of the invention of the integrated circuit because now we have a structure that can do different things depending on who it talks to.

Obviously, whole books have been written about the importance of the structure of the neocortex, but Amthor did a great job of introducing this important concept.

For example, let's consider the association areas, where the information from various parts of the body is integrated. This is how we know that a sight and sound, for example, go together, and it's because all these different cortical areas are able to communicate with each other.

Finally, we talked about the spinal cord and Dr. Amthor said that it's a brain in its own right. He emphasized that even the spinal cord, which is virtually identical across vertebrates, is much more complex than we usually realize. He also talked about the importance of the cerebellum, which is another ancient structure that doesn't get much attention.

Obviously, I've only hit a few high points from our conversation, but I want to encourage you to share this episode with others and check out Neurobiology for Dummies or the second edition of Neuroscience for Dummies by Frank Amthor. For a good introductory textbook, I recommend Essentials of Modern Neuroscience, which he edited in 2020.

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Now, I'm going to take a few moments to explain the MyLibsyn Premium subscription, which I launched in January 2014, and until recently, called the Premium subscription.

I finally came to realize that many people get confused when they try to sign up and then see the MyLibsyn interface. That's why I'm going to start calling it MyLibsyn Premium. My Libsyn Premium is a great way to support Brain Science. It's only $10 a month and less if you pay by the year, and you can cancel at any time.

Premium subscribers have unlimited access to all episodes of Brain Science going back to December 2006, as well as all episode transcripts. Unfortunately, subscribers can not access this content at brainsciencepodcast.com. Although I started adding episode transcript links to the individual show notes.

The easiest way to access this content is via the free Brain Science Mobile app, but you can also access the content via your web browser, but you do have to log into MyLibsyn. I'm hoping that changing this name to MyLibsyn Premium will help clear up some of the confusion.

Listeners often ask me whether they should choose MyLibsyn Premium or Patreon. Usually, they want to know which one pays me the most since both Libsyn and Patreon take a cut. I would prefer that you pick the one that fits your needs.

MyLibsyn Premium is the best choice for anyone who wants or needs access to older episodes and transcripts. However, I realize that many subscribers don't access these things and just want to support my work. I don't thank you often enough.

I could not live off my income from MyLibsyn Premium, but it has definitely kept me going over the years. Thanks, again.

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BS 198 is an interview with Evan Thompson, author of Mind in Life: Biology, Phenomenology, and the Sciences of Mind.

This interview was originally aired back in the fall of 2012, and I chose it as an encore episode because it was very popular with listeners when it first aired, and because I want to give newer listeners a sense for the diversity of content available to MyLibsyn Premium subscribers.

The first two years of Brain Science, which was December 2006 through 2008, contains a lot of basic neuroscience. But as the show matured, I began to mix up the technical level, and it's fair to say that this was one of the more challenging episodes. My goal is to make these more challenging topics accessible to listeners of all background.

So, as I review the key ideas of this episode, I encourage you to check the show notes for links to additional episodes and resources about embodied cognition.

Dr. Thompson was the co-author of one of the pioneering books about embodied cognition, The Embodied Mind, which was published back in 1991. This interview was about his follow-up book Mind in Life.

We actually started by reviewing some of the key ideas from The Embodied Mind. The key concept of embodied cognition is that our mind is shaped by our body and the way it interacts with the world around us. We are not passive recipients of sensory information.

Perception is shaped by how we move in the world. Cognition, particularly perception, is an active or enactive process because it depends on having a body with certain kinds of sensory motor skills and habits. The word “enactive” emphasizes the importance of action.

According to Thompson, the enactive approach has two important threads. One is the idea that the mind has an active or interactive relationship to the body. The second is that the mind is not representational: that is the mind is not acting on some representation of the world that exists in the head because the mind of the animal or person is not a passive representor of the environment. So, the enactive approach is a movement away from representation toward action or interaction.

The term umvelt was coined in the early 20th century to represent the idea that every animal's experience is a direct result of how it interacts with the world.

My favorite example is, of course, a dog because the dog's world is so different from ours because his world is dominated by smell while ours is dominated by sight, usually.

Thompson quoted Lawrence Shapiro, who I interviewed back in episode 73 as describing embodied cognition as having the working assumption that our cognition and interaction with the world is strongly shaped by the kind of bodies we have.

One of the problems with the early approaches of cognitive science that is computationalism and connectionism, was that they both tended to be pursued independently from biology. We spent quite a bit of time talking about phenomenology.

In the context of embodied cognition, phenomenology points to the importance of subjective experience. What is it like to have a mind? While phenomenology might seem rather esoteric, the main theme of mind in life is not esoteric.

As Thompson noted, the core idea is that we can trace a continuous path from the emergence of life into the emergence of mind, and the emergence of consciousness and subjectivity. One of the guiding ideas that runs through this book is the idea of self-organization and how using the tools from the study of self-organizing systems can help us understand cognition and perception.

This led us to a conversation about autonomous systems. Thompson defined an autonomous system as one that creates a self through interactions with its environment. We didn't really have a chance to emphasize how important this is in terms of understanding why the mind is different from the computational model, envisioned by early cognitive scientists.

But we did talk about autopoiesis, which is a special kind of autonomy exemplified by a living cell. An autopoietic system is one that creates its own boundary. This matters because now, we have the beginnings of self, long before the emergence of awareness.

I wish we could have spent more time talking about the use of dynamic systems theory and how that relates to autonomous systems, but we did touch briefly on the fact that dynamic systems theory is a tool that allows us to get our handle on systems that are non-linear. That is systems that are highly dependent on initial conditions. Living systems are dynamic systems. That's what allows them to be resilient and adaptable.

Returning once again to this theme of continuity, I asked Thompson about cognition, and he said, “I would say living systems are sense making systems, and cognition is a form of sense making.”

If we look at cognition as a form of sense making, it isn't best understood according to the representational model; input, representation, output. However, it is important to note that Thompson does not propose that all life is conscious.

He wrote on page 162 of Mind in Life, “It is important to situate consciousness in relationship to dynamic unconscious processes of life regulation. This effort becomes difficult, perhaps impossible if one projects consciousness all the way down to the cellular level.”

This book, Mind in Life: Biology, Phenomenology, and the Sciences of Mind is not light reading, but I do think it's a must-read for students of neuroscience, especially those who are interested in the philosophy of mind, and I particularly recommend it to those with some familiarity with embodied cognition, because it takes the discussion to a much deeper level.

I'm going to stop my review there because I realize that I've gotten really carried away with too much detail. Obviously, no interview can do justice to any book, and that's especially true for a book with the depth of Mind in Life.

But I wanted to give you a sense of how Mind in Life fits into our ongoing exploration of the brain, mind and consciousness. When I read this book, I was struck by Thompson's vision of the deep continuity between the emergence of life and the emergence of mind. In fact, I came away with a strong sense that another level of explanation was not required.

*****

I don't like to ask for money, but because Brain Science is independently produced, it relies on the financial support of listeners like you. You can donate via PayPal or by going to brainsciencepodcast.com/donations. But the two main ways listeners support Brain Science is via MyLibsyn Premium and Patreon.

I've already described MyLibsyn Premium, so now I'm going to talk about Patreon, which is popular with many podcasters, musicians, and other creators.

Unlike MyLibsyn, which has a set monthly rate, with Patreon, you can choose whatever amount fits your budget. If you give at least $4 a month, you'll have access to new episode transcripts. You will get an email when one of these is posted, and you can also access content via the Patreon mobile app.

For $10 a month, you can get both new episode transcripts and an ad-free version of each new episode. Thus, if you don't need access to older episodes or you prefer the flexibility of choosing how much you contribute each month, Patreon is probably the best choice for you. Thanks so much for your support.

*****

BS 199 is an interview with Batja Mesquita, author of Between Us: How Cultures Create Emotions.

This really compliments episode 135 with Lisa Feldman Barrett, author of How Emotions Are Made. I recommend both of these books to anyone interested in emotion no matter what your background.

I've always considered understanding emotion to be one of the primary topics of Brain Science because it’s something that affects everyone. As I review this episode, I will try to touch on how my own thinking has evolved over the years.

My first discussion of emotion was back in episode 11, which I posted way back in 2007. I don't remember much about that episode except that I did introduce the famous experiments by Paul Ekman that claimed to show that people across cultures can recognize emotion via facial expressions. I'll come back to the evidence against that conclusion in a few minutes

Around 2010, I discovered the work of Jaak Panksepp who argued that emotion has subcortical origins, and there are subcortical origins that are shared across mammals. He argued for the existence of several universal affective circuits.

Although his work has not been replicated, he made key contributions to the field, including realizing that animals do have feelings even if they are different from our own, and that the origin of affect appears to be subcortical.

Then along came Lisa Feldman Barrett. She challenged Panksepp’s interpretations as well as the assumption that emotions are something innate and universal. She and her coworkers have produced convincing evidence that emotions or feelings (depending on how you define your terms) are learned and therefore, culturally based.

In How Emotions Are Made, Barrett debunked much of the presumed evidence for universal innate emotions. Here are two examples.

One is the idea that there are reliable physiological markers for particular emotions. This is important because it forms the basis for things like the lie detector test. Here is a simple example of how this assumption fails.

Consider the experience of your heart racing; based on context, you might experience several emotions, not just fear or anxiety. You might feel excited or even sexually attracted to someone. Now, let's return to Paul Ekman's famous experiments with the natives of Papua New Guinea.

These natives allegedly recognized emotions from a set of staged pictures. They actually had to choose from a list of emotion words that had been translated from English. When the experiment was repeated without the list so that they could spontaneously choose, the results were completely different.

It turns out that when we judge emotions from facial expression, context is critically important. That's why I worry about the use of artificial intelligence or AI tools to supposedly pick out suspicious people based on their facial expressions.

With all that background in mind, let's consider the key ideas from Dr. Mesquita's interview. The first key idea was that how we experience emotion is not only learned, but that there is diversity across cultures.

As her experience showed, this diversity exists even among western cultures that seem fairly similar. Based on this realization, she shared two different ways of thinking about our emotions; the MINE Model and the OURS Model.

MINE stands for Mental INside the person, and Essentialist, which means that emotions always have the same properties. This contrasts with the OURS model, which is Outward, Relational and Situational, so emotions take on different shapes depending on the situation. It's important to realize that both aspects of emotion occur in all cultures, but the emphasis may be different.

So, in the West, we tend to be inside/out or MINE-oriented. How we view emotions has consequences, especially in a world that is becoming increasingly diverse. We considered some examples such as teachers misunderstanding the body language of their students.

The biggest take-home point is this; don't assume you know what someone else is thinking or feeling. And if you ask, believe their answer! Don’t discount their experience because it is different from what you consider to be normal or expected.

That's why it's important to understand that based on mounting evidence, emotions are not innate and universal. They are learned from our culture, and each of us has a slightly different experience. I really want to encourage everyone to read Between Us: How Cultures Create Emotions by Batja Mesquita.

*****

I've been talking about how you can support Brain Science financially, so I want to take a moment to remind you that even if you can't afford to contribute monetarily, you can still help Brain Science grow and prosper.

I don't do any advertising and to be honest, I'm not good at using social media. I rely on your word of mouth, which means talking to friends, family, or colleagues, or posting on whatever social media you enjoy. Also, if you'd like to help me promote Brain Science via social media, please email me at brainsciencepodcast@gmail.com.

*****

Let's move on to episode 200, which was an exploration of embodied cognition in education and learning. This episode featured Sheila Macrine and Jennifer Fugate, editors of Movement Matters: How Embodied Cognition Informs Teaching and Learning.

I picked this book for two reasons. First, I've been interested in embodied cognition since I discovered it back in 2007, and I really think that appreciating how our mind is embodied shifts the way we see ourselves and our place in the world.

The other reason I chose this book is because I know that many of you are involved in education, but even if you don't have any formal connection to the field, I think it's important to understand how embodied cognition impacts how we learn.

If you are new to the idea of embodied cognition, I encourage you to consult the show notes in your audio app or go to brainsciencepodcast.com — I mean, the complete show notes for episode 200 because I've got links to previous episodes about embodied cognition.

One reason that I consider embodied cognition to be one of the core themes of Brain Science is that it challenges the traditional dualistic approach to the mind. It's one thing to claim that science has moved beyond the separation of mind and body, but dualism is so embedded in our cultural approaches to education, it can persist almost without our awareness.

This is reflected in the fact that classrooms, for the most part, look just like they did a hundred years ago, and adding laptops or tablets might actually exacerbate this tendency to see students as brain-bound learners.

Ironically, body-based approaches to learning are generally seen as inferior. They get restricted to special education or seen as something that students should outgrow, and this is actually contrary to the growing evidence that all cognition involves interaction between the body and the environment. This interaction is crucial to learning.

So, for those of you who are many years past your school days, think back and see if you can remember an example of hands-on learning. What do you remember about it, and how was that different from trying to learn things from just listening to somebody lecture or reading a textbook?

Movement Matters: How Embodied Cognition Informs Teaching and Learning edited by Sheila Macrine and Jennifer Fugate is highly recommended if you're an educator or work in the field. It's also a great primer for introducing embodied learning to others, and you can get it free on the MIT website.

*****

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When you sign up, you'll get a free gift entitled, Five Things You Need To Know About Your Brain. Just text BrainScience (all one word) to 55444.

*****

BS 201 is an interview with Bill Harris, author of Zero to Birth: How the Human Brain Is Built.

Brain development is a complicated subject, and this book is a great introduction to how we know what we currently know. It's not a beginner level book, but I recommend it to everyone working in other areas of neuroscience or medicine. I'm going to try to emphasize just a few key ideas.

Before I talk about brain development. I want to talk about a few other points. One of the themes that comes from this book is the idea of evolutionary continuity. We have so much in common with other species. Even single-celled paramecia generate action potential or voltage spikes even though they use calcium channels instead of sodium. They also use signaling proteins, the exact same ones that are now neurotransmitters in our nervous system.

Seth Grant was the first one who made me aware of this way back in episode 51. We also have continuity with invertebrates like fruit flies, and our basic nervous system and our body plan is shared with all vertebrates. How did this happen?

Well, every cell in our body contains the entire genome. It's which genes are turned on that matters. Some genes code for transcription factors that turn on other genes so they can have a much bigger impact, especially if they turn on many other genes. So, a transcription factor is a protein that turns on another gene.

So, let's go through the basic steps of brain formation. I'm going to leave out most of the terminology so we can focus on what happens.

We start out as a ball of pluripotent cells, that is cells that can become anything. These cells develop into three layers that are going to become the main tissues of the body. The outer layer is called the ectoderm and it will become skin or nervous tissue.

During a process called gastrulation, a section of the ectoderm called the neural plate gets pushed inside the ball of cells and forms the neural tube, which will become the brain and the spinal cord. This happens in all vertebrates.

Once this basic plan is established, the neural stem cells divide into a combination of more stem cells or neurons. So, at birth we have most of the neurons we will ever have. The brain continues to grow after birth mainly due to the growth of both connections and glial cells.

Once the neurons have formed, they begin to make connections, and that's the process that continues after birth and obviously, throughout life. Finally, neurons begin to send action potentials to each other and tissues like muscles.

It's ironic that once the synapses are formed, the neurons actually have to compete for survival. I want to go through this again so you can get it solid in your head.

The pluripotent cells become part of the ectoderm, and then the neuroectoderm, which is what will become the nervous system. During gastrulation, a structure called the neural plate is pushed inside the embryo and becomes the neural tube.

The brain and the spinal cord develop from the neural tube. Once this basic structure is in place, the neural stem cells begin to become neurons. The neurons send out axons to connect to other neurons or tissues like muscle.

Some neurons actually die before birth either because they don't form successful synapses or because they were part of a scaffold for building the brain and are no longer needed. We actually have the most neurons we will ever have before we are born, and we get very few additional neurons after this because neurons can't divide or reproduce. Glial cells and synapses will continue to form and that's why the brain gets bigger after birth.

Brain development is a very complex subject, but we had a chance to explore a few key questions like how does the body plan, including the brain and spinal cord come about? What determines the identity of any particular neuron, and how do the axons reach the right target? You will have to listen to the episode to get the answers to these questions.

However, Harris mentioned some of the scientists who have worked on these questions, going back to the early days of embryology, before we had the complex tools of molecular biology that we now have. These allow actual manipulation of genes to see what will happen.

One of my favorite parts of his book is the description of some of the groundbreaking experiments that have been done sometimes under extremely challenging conditions. Another cool thing is the surprises.

For example, for years, it was assumed that neural stem cells needed a particular signal to become neurons, but it turns out that ectodermal cells will become neurons unless they get a signal that tells them to become skin cells. Sort of like the way a fetus will become female unless it gets a signal to make male sex organs.

Another surprise was the recent evidence that rather than evolving many times in the past, the key components of vision may have a common origin that goes back to the genes for photosensitive proteins that are present in bacteria. Harris mentioned the experiment that shows that the human PAX6 gene can be inserted into a genetically blind fly, and its compound eyes will form normally.

This seems almost unbelievable given how different human eyes are from the compound eyes of flies. Even though this is a podcast about neuroscience, I think it's important to have a basic understanding of how the tools of molecular biology and genetics are integral not just to neuroscience, but to every life science.

What does it mean to say that we share our genetic makeup with other animals like fruit flies and single-celled organisms like bacteria? The key is remembering what genes actually do. They code for making proteins, and proteins have a huge variety of functions.

Some become parts of complex structures, but others are transcription factors, which means they turn other genes on and off. Some of these transcription factors seem to turn on whole cascades of other genes. This means that they can have similar but different functions in different examples.

An example of this is the Hox family of genes, that's spelled H-O-X. We talked a little about this Hox family of genes, which is arranged in a sequence that corresponds to the head-to-toe structure of the body. They were first discovered in fruit flies, and a scientist named Ed Harris showed that if the Hox genes were inserted into other cells, you could grow extra wings or extra legs in places where they wouldn't normally be located.

Bill Harris emphasized that those Hox genes don't code for chemical signals, they actually code for proteins that are transcription factors that may turn on thousands of other genes.

Unless you work in this field, it's not necessary to worry about the details, but I picked the Hox gene as an example because it's one of the ones that is found in invertebrates like fruit flies, but they only have one set of eight Hox genes, while vertebrates have four sets.

This is because the sets were apparently duplicated twice during early vertebrate evolution. I first learned about this gene duplication, which I think occurred about 250 million years ago from Seth Grant, and I think it is a very under appreciated element of why vertebrates were able to evolve into more complex and diverse species than existed before.

The last idea I want to highlight is a comment Harris made near the end of his interview. He said, “At birth, each baby's brain is unique. It's not a blank slate.” Obviously, as I said, brain development is extremely complex and in our conversation and in this review, we've just barely touched on some of the fascinating discoveries about how it works.

If you're interested in learning more, I highly recommend this book, Zero to Birth: How the Human Brain Is Built by William A. Harris.

*****

Don't forget that my 2020 book, Are You Sure? The Unconscious Origins of Certainty is available in both paperback and eBook formats. You can get it from your favorite online book seller, but if you'd like to have an autographed copy, just email me at brainsciencepodcast@gmail.com.

*****

The last new episode of 2022 is BS 202 with Evan Thompson. We explored the question, Is meditation a Mind Science? This is the same Evan Thompson that I talked to in episode 198, and was inspired by Thompson's more recent book, Why I Am Not a Buddhist.

In my attempt to stay within the expected content of this podcast, we actually skipped over a large chunk of the book, jumping straight to the question of whether meditation is a mind science.

Instead of rehashing this episode since it was just last month, I want to provide some additional context because I fear some listeners misunderstood the goal of the episode.

I may have unfairly given listeners the idea that Thompson's book is an attack on meditation, which it is not. He began meditating as a young teenager and as far as I know, he still finds the practice meaningful.

However, as the title of his book indicates, despite long exposure, he does not consider himself a Buddhist, and I found his reasons to be very enlightening. His book challenges two claims that are very common, at least here in the United States.

One is the claim that Buddhism is more scientific than other religions, and the second is the claim that Buddhism is not a religion. If you think either of these statements are true, I recommend his book, Why I Am Not a Buddhist for the counter arguments.

So, where does meditation come in? Western Buddhists tend to see meditation as the essence of Buddhism and make varying claims about the importance of its other teachings. Thus, the claim that meditation is a mind science is an important foundation to the claim that Buddhism is more scientific than other religions.

To me, Thompson is the best person to address this claim for several reasons. His background in Asian studies gives him a much broader foundation than the average American Buddhist, and his grounding in phenomenology and embodied cognition, allows him to approach meditation from a different perspective.

Meditation is a subjective experience. It does not represent a neutral method to access what the mind is doing.

Now, I'm going to diverge from what Thompson wrote to consider how my own attitudes toward meditation have evolved.

I used to consider myself a Buddhist, but I now see most of what I have read as more consistent with dualism than our current understanding of the mind as an embodied process that requires a brain that is interacting with the body and the environment.

Meditation may be a powerful tool for dealing with stress and the challenges of life, but it does not give us access to objective knowledge. Given what we now understand about both the role of unconscious processes and the importance of embodiment, I think it is important not to exaggerate the role of meditation.

There is one point that Thompson made that I want to review.

He addressed the claim that neuroscience has proven the Buddhist claim that the self does not exist. The key idea is that even if there is no permanent unchanging self, this does not mean that the self that the brain constructs is unreal or an illusion.

Modern physics has taught us that solid objects are mostly empty, but that doesn't mean that the objects are an illusion or unreal. The fact that our conscious experience of our inner world is unreliable does not negate the experience, but we can't look to it for an objective understanding of what the mind is doing.

At the end of the interview, we talked very briefly about cosmopolitanism. This is the idea that we are citizens of the world, but that this doesn't mean we all have to have the same beliefs or ways of life. Cosmopolitanism offers a ray of hope in our divided world. That's why I included several references in the show notes for this episode.

I closed BS 202 with several themes that have been running through Brain Science over many years. First, since most of what our brain does is not accessible to introspection, we cannot use meditation or any other introspective technique including psychoanalysis to determine how it works.

More importantly, the mind is embodied. This means that it's embedded in a body that interacts with its environment. You are not a brain in a vat, and because the brain is not the mind, studying the brain alone is not enough.

I make this last point because even though this podcast is called Brain Science, I've tried not to fall prey to “neuromania.” We are also wired to be social, so being human means being part of cultures, and these cultures, are also constantly changing our brains as well as our minds.

*****

Looking back on 2022, I am grateful to all the guests who have taken the time to talk with me. We explored some new topics such as hearing and what happens when the brain grieves. We also revisited key themes such as embodiment and consciousness.

I strongly believe that understanding how our brains really work can help us become more tolerant toward others and ourselves. I appreciate each of you who have taken the time to write to me, and I would encourage more of you to send me feedback at brainsciencepodcast@gmail.com.

I look forward to exploring these topics and many more with you in 2023. Please do subscribe to Brain Science in your favorite audio app. Visit brainsciencepodcast.com, and please share Brain Science with others.

Thanks again for listening. I look forward to talking with you in 2023.

[Music]

Brain Science is copyrighted by Virginia Campbell, MD. You may share the show with others, but for any other uses or derivatives, please write to brainsciencepodcast@gmail.com for permission.

The theme music for Brain Science is “Mind Fire,” written and performed by Tony Cotraccia. You can find his work at syncopationnow.com.