Transcript Excerpt from BS 195
with David J Anderson
Author of The Nature of the Beast: How Emotions Guide Us
Aired April 29, 2022
Excerpts from full transcript
Dr. Anderson: What we are really concerned about here is not, again, the conscious feeling aspect of emotion. We're concerned with emotion as a brain function, like decision-making, learning, and memory. It's a biological function that evolved over time through natural selection like other biological functions. And we are trying to understand the neurobiological underpinnings of those emotion states. So, it's really driven by a biological approach to the problem.
I feel strongly that the study of animals and causal neuroscience are critical if we're ever going to improve medicines for the Mind.
Closing Remarks/ Episode Summary
Dr. Campbell: I want to thank David Dr. Anderson for taking the time to talk with me about his fascinating book, The Nature of the Beast: How Emotions Guide Us. If you're interested in the nitty gritty of how neuroscience is really done, I highly recommend this book.
Our goal today was to hit the key ideas. The first issue we addressed was how to study emotion in animals. This is 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 is not science to jump to conclusions based on our intuitions.
That is why Dr. Anderson argues 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 can't be used in humans. This was a very dense conversation.
So, I want to emphasize the importance of this 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.”
At first, this might seem like a strange approach, but it really comes down to saying that emotion should not be studied any differently from any other basic brain function that has been successfully studied in animals, including vision, olfaction, decision-making, learning and memory, motivation, reward, and motor control. Everything I just listed has a subjective aspect. The key step is the removal of subjective feelings from the equation.
The concept of emotion primitives was actually introduced in The Neuroscience of Emotion. But I have to admit that when I read this earlier book, I didn't really appreciate why these are so important. Things like persistence and scalability are what allows us to say that a behavior being observed is not a reflex, but is caused by specific brain states.
During the interview, I commented that we don't say we can't study vision just because it has subjective aspects. If you read The Nature of the Beast, you will learn a lot about how experiments are designed to establish causality.
So, I asked Dr. Anderson to talk about how proving causation is very different from correlation. This is a key issue because we constantly hear the mainstream press conflating these 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 you get rid of the electrical activity, does the behavior disappear?
An example of something that's necessary but not sufficient, is that your car has to have gas to run, but that's not enough. Sufficiency means demonstrating that if you show the brain activity causes the behavior, even in situations where it normally wouldn't occur. So, you use a technique like optogenetics that turns the neurons on directly.
Now, prior to optogenetics, precision was often an issue, but with optogenetics, they have 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 hot weather, but there's no causation between the two.
We did not have an opportunity to talk about what Dr. Anderson has learned from studying mice, but we did briefly talk about fruit flies.
Fruit flies have many fascinating behaviors and they have these little tiny brains of about a hundred thousand neurons. Remember, we have 86 billion. We also have great genetic tools that allow us to tinker with the specific neurons in the brain of flies. And flies, of course, are easier than working with mice. So, it’s a great system for studying how genes control behavior.
They even have a complete wiring diagram for the female brain, and the one for the male brain is expected to be finished soon. So, what are some key things that have been learned from the flies?
They have persistent internal states just like mice. Persistent activity of certain neurons leads to persistent fighting behaviors. So, they're not just little robots. And male and female flies behave differently. Dr. Anderson has a student who has found this neuron that appears to control head-butting in females and lunging in males.
Some of you may remember that when Joseph LeDoux came on Brain Science back in episode 161, he said that he had not been studying fear all these years, that what he's been studying should be called defensive behavior.
So, 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 what they're experiencing.
According to Dr. Anderson, 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 has 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 terms, using feelings to describe the thing that we can only study in humans. But the key idea is that brain states can be studied.
He also talked about Lisa Feldman Barrett's book, How Emotions Are Made, which argues that feelings emerge in the cortex. And he said he’s not contesting the role of the cortex in feelings, instead, he referred to the evidence that subcortical structures, including the amygdala, do 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.
There was another thing that he said that I thought was important. He 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 him about how emotions are different from motivation, drive, and arousal. These are the sorts of things that all neuroscientists agree can be studying it, including LeDoux.
Motivation is scalable. You feel more or less motivated, but it's not necessarily persistent. Drives are also not persistence, since as soon as you get the reward, the drive goes away. This is one of the motivations 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 say, a drive like hunger or thirst. Different external signals can generate the same sorts of defensive behaviors as opposed to, needing food leads to hunger.
So, emotions provide more flexibility and they allow the brain to organize behavior. That is what he called most adaptive. And this goes along with recognizing that emotions are something that has evolved to help us and other animals survive.
There is much more to The Nature of the Beast: How Emotions Guide Us by David J Anderson. So, I recommend it to anyone who's interested in how studying animals is contributing to our understanding of emotion. As Dr. Anderson observed, this understanding is critical to developing better treatments for mental illness.
Early in the interview, I mentioned the work of Jaak Panksepp. If you’re new to the show, I recommend you check the show notes for the link to the encore presentation of his first interview. Panksepp is considered by most to be a pioneer of affective neuroscience. And even if some of his work does not hold up under the precision of modern techniques, he was the first to argue that we can learn about emotion by studying animals.
One of the points he (Panksepp) made during our last conversation before his death, was that neuroscience must be carried out at multiple levels because there are things we can only learn directly from humans and other things, we can only learn from animals.
A main goal of Brain Science is 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's an intimate part of decision-making even for those who aspire to Spock-like logic.
To just close with a few brief announcements, I want to thank those of you who sent me emails about my induction into the Podcast Hall of Fame. You can still watch my speech on YouTube if you search under 2022 Podcast Hall of Fame. I recommend skipping the first 10 minutes, and then you'll almost be near to where my part is.
As always, you can get complete show notes and episode transcripts at brainsciencepodcast.com. You can send me email at brainsciencepodcast@gmail.com. And we also have a fan page on Facebook.
You can get show notes automatically each month when you sign up for the free Brain Science newsletter. Just text BrainScience (all one word) to 55444. There's also a link to the newsletter at brainsciencepodcast.com.
When you sign up, you will get a free gift entitled, Five Things You Need to Know About Your Brain. That's BrainScience (all one word) to 55444.
Because Brain Science is independently produced, it relies on the support of listeners like you. You can learn more at brainsciencepodcast.com/donations.
For transcripts to ALL EPISODES sign up for MyLibsyn Premium.
Patreon supporters ($4/month minimum) get new transcripts every month.
