The Science of Everything Podcast - Episode 135: The Science of Emotion

Episode Date: March 31, 2023

An introduction to the scientific study of emotion, including a discussion of the difficulties in defining emotions, discrete and dimensional methods of classifying emotions, the functional and representational roles of emotions, and an overview of major psychological theories of emotion, including the James-Lange and Cannon-Bard theories. We also examine the neurobiological basis of emotion, including the roles of the orbitofrontal cortex, the ventromedial prefrontal cortex, the cingulate cortex, and the amygdala. Recommended pre-listening is Episode 134: Hormones and the Endocrine System. If you enjoyed the podcast please consider supporting the show by making a PayPal donation or becoming a Patreon supporter. https://www.patreon.com/jamesfodor https://www.paypal.me/ScienceofEverything

you're listening to The Science of Everything podcast episode 135, The Science of Emotions. I'm your host, James Fodor. In this episode, we're going to talk about the difficult and rather and rather, in some sense, unscientific topic of emotions. In particular, we're going to talk about what are emotions and the thorny issue of defining what we mean by emotion. I'm then going to cover classifications of emotions, and then we're going to talk about

different psychological theories of emotions and the neurobiology of emotion. Recommended pre-listening is the immediately previous episode 134, hormones and the endocrine system, which will provide a little bit of background help for understanding certain aspects of what we talk about today. So let's jump straight in and begin by talking about defining emotions. Everyone knows in some sense what emotions are, but if someone asks you to define what is an emotion, it turns out to be rather more difficult than you might have thought. course, we can give examples of emotions. Happiness, sadness, anger, fear are some of the most

common examples, but it's hard to say exactly what all these things have in common. And it's hard also to distinguish emotions from other related phenomena, such as pain or discomfort or hunger, or moods, and so forth. So we'll talk about some of that in these initial remarks here. I think one of the first things that I want to discuss is the idea that can we even study emotions scientifically? Many people think of emotions as ultimately. subjective and therefore not amenable to scientific inquiry. And I think that this is mistaken. Depending on your point of view, emotions are just part of the physical world, just like other phenomena that we study in science, like chemicals and the nervous system and digestion

and the weather. So although emotions may be more familiar to us being psychological beings than these other phenomena, nevertheless, they're just as much part of the physical world and therefore just as amenable, at least in principle, to scientific study. Of course, your own philosophical mileage may vary there about whether you think that emotions are purely the product of the physical world, but that's what I'm going to assume in this episode today. Another point that should be made is that I'm going to approach emotions from the point of view of psychology and neuroscience research. The usage of the term emotion here is not exactly the same as the way we use emotion, or at least the way some people use the term emotion,

in kind of everyday context or in our folk psychological language. So bear in mind there that some of the usage may be a little bit different, although I think it's broadly similar. So with those caveats out of the way, let's start by trying to provide a framework for how we understand emotions. In psychology and also in philosophy generally, emotion generally refers to a subjective conscience experience of a person or an animal, but we'll focus mainly on people here.

and this type of subjective conscious experience is characterized by certain physiological expressions, so changes to the body, including those mediated by the endocrine system that we talked about in the previous episode, as well as mental states. So there's a physiological component to emotion as well as a cognitive or a mental component, and those aspects will become more important over the course of our discussion. So pretty much everyone agrees that emotions are multifaceted, phenomena. Emotions aren't a single thing that you can point to and precisely define. They include multiple aspects and we'll sort of talk about some of these. One common way of describing emotions

in a bit more detail, which I took from a leading textbook on cognitive neuroscience, says that emotions are valenced responses. Valence means that it can be basically positive or negative, so good or bad. Emotions are valenced responses to stimuli, could be an external stimuli, or internal mental stimulation, that have the following properties. So first, they involve changes across multiple response systems. So that means that it includes behavioral responses, physiological responses, and so forth. Two, they're distinct from moods. So moods are more longer lasting, whereas emotions have more identifiable objects or triggers

and don't last for as long as, say, a mood or a general psychological disposition. 3. Emotions can either be innate or they can be learned in association with different types of stimuli. So like an innate fear response to a sudden loud noise versus a learned fear response to a particular sound or image. And fourth, emotions depend on different neural subsystems. So we'll talk more about that later. So the key components here is that emotions are generally thought to be valenced. We'll discuss that in more detail later. and that they occur in response to some kind of stimulus,

or this can be like a memory, so it can be kind of an internal stimulus, that there's multiple aspects of their response, so including experiences, behaviors, physiological changes, that they're relatively short-lasting, compared to moods or personality dispositions, that they can be either innate or learned, and that they're dependent on particular neural subsystems,

especially in the brain. So that gives us something to work with, but it's still a bit vague, and not very specific, but let's try to unpack this and go into a little bit more detail. One view called the component process model of emotion breaks emotions down into five different elements, and this is sort of related to what we just discussed, but is a bit of a different way of expressing it. So one is cognitive appraisal. So this is the evaluation of some event or object or evaluation of a stimulus. Because emotions are typically thought to be valenced, often this is going to be an evaluation of something as positive or negative to some degree.

So there's a cognitive appraisal component. Secondly, there's a bodily symptom or a physiological component. So much of this relates to the arousal of the sympathetic and parasympathetic nervous system via the endocrine system. Again, we talked about that in the previous episode. So I won't go into details of that here, but that's sort of arousal, adrenaline, flight or flight, rest and digest. That's the physiological or bodily aspect of emotions. Third, there is a behavioral or action tendencies.

So this is related to a motivational component, a preparation for a certain type of action and a disposition to act in a certain way. So we might think of a startle response following fear or desire to sort of hit something or tendency to sort of lash out in response to a stimulus that causes anger, or an approach response in following some sort of stimulus that makes us happy, and so forth. So these are the behavioral aspects of emotion, the tendencies or motivation and preparations for certain types of motor responses. Fourth is facial expressions and vocal expressions. So, I mean, this is sort of a behavioral component, but it's a highly specialized behavioral component.

So this is the tendency often subconscious to make certain vocal and facial expressions that nearly always accompany emotions, especially basic emotions. So I think everyone knows that one can distinguish a happy face from a sad face, an angry face, a surprised face, and so forth. I'll discuss that a little bit more later, but those emotional expressions, at least for basic emotions are very robust cross-culturally and appear to be innate or largely innate, although the specific manner in which they are expressed and the social approval, of course, is culturally dependent, but at least the basic underlying facial and vocal expressions, things like laughter or grunts of annoyance,

those appear to be substantively innate. And the final component of these five key aspects of emotion are feelings. Now, this is an important distinction here because many people quaint or convey. inflate feelings and emotions, but in the psychological and neuroscience literatures, these are distinguished. So emotion in this way of describing things is the whole package, right? It's all of these aspects. It's the cognitive aspect, the physiological aspect, the motivational aspect, the expression, and all of those things that go into it, right? It's this combination of features or components. Feelings are just one of these components or aspects of emotion, and the feeling

is the subjective experience of the emotional state as it occurs. So an emotion is not just the feeling. It's not just the subjective experience. To understand the difference, it's useful to recognize, first of all, that there are other aspects to emotions beyond simply the feeling. So there's the facial expressions, there's the behavioral tendencies, there's the arousal, parasympathetic and sympathetic nervous systems. And there's the cognitive appraisal, like whether something is good or bad, so the valence and linkage to other memories and associations and so forth. So that's a tied in with emotions as well, those aren't feelings in and of themselves, right? They may support the feeling or go along with it, but they're different from the actual subjective experience,

at least conceptually, right? The other thing is that we can have feelings without emotions, and there are many, many different types of feelings that aren't emotional, or at least that don't appear to be emotional. I mean, it does depend on how you define it. So, again, if we just understand a feeling as some kind of subjective experience, then feelings extend well beyond emotion, So there's a feeling of hunger, feelings of cold, feelings of itchiness, feelings of general discomfort, a feeling of knowing or of understanding or of something being familiar. There's feelings associated with laughter, and it's unclear whether that counts as an emotion. There's feelings that are associated with perception, tactile or gustatory or otherwise. So the point is there are many, many types of feelings, if we understand that as simply a type of subjective experience.

But only some of those are emotional feelings. Others are perceptual or maybe we even say cognitive in terms of like understanding or familiarity or visceral like the feeling of hunger or the feeling of the need to urinate. So there are many types of feelings elicited and produced by different cognitive and bodily systems. Only some of those are emotional. The emotional ones are those that are associated with these multifaceted valence responses that include behavioral tendencies, action tendencies, the physiological arousal, facial expressions, and cognitive appraisal.

So what we're trying to do here with the idea of an emotion is to identify key components and then identify kind of a cluster of similar types of cognitive slash bodily states or psychophysiological states, as the fancy term is, and draw a fuzzy border around them and identify a set of things that are sort of roughly similar and we're calling these emotions, right? and we want to exclude things which are kind of different, although, of course, exactly where you draw the boundary is going to be a bit tricky and a bit subjective, and there's not a lot of agreement precisely how to do that.

So that leads us to the next issue, which is how to distinguish emotions from other similar states. So as I've just discussed, emotions are typically understood as multifaceted psychophysiological states or expressions, which involve feelings, behavioral tendencies, cognitive appraisal, valence, etc., right? So that's what an emotion is. or at least that's how we're characterizing it here, and that they're relatively short-lasting. You don't go on feeling the same emotion for like weeks on end, or that's highly unusual at best. So we distinguish emotions from feelings, which are the subjective experience, and there are many types of feelings that are not emotions, and we've just talked about some example of those.

And finally, we also distinguish emotions from moods. So moods are more diffuse affective states. So affective essentially means that there's a feeling component to it, and often also a valence component, so good or bad. but they're much longer lasting than emotions. They're also usually less intense, though not always. Moods can be very strong, like depression being an example of that. I would say depression is a mood rather than an emotion, although they can intermingle

there. For example, when you're feeling a mood, you can also feel an incongruous emotion. So certainly in the case of depression, you can be depressed and being a depressed mood, but still laugh and experience an emotion of happiness or of sadness or anger or some other emotion that's not itself the same as depression. Likewise for other types of moods. So they're typically longer-lasting, more kind of diffuse in the sense that they have a less clear contextual stimulus. And that's one key differentiation between a mood and an emotion. Emotions nearly always have specific and usually identifiable stimuli, whether that's an external stimulus, something that

happens in the world, or an internal mental representation, like a memory or some kind of internal state. Not always. Of course, you can't always identify what that specific stimulus is, but typically emotions do have that because they represent a cognitive physiological response to that stimulus. Whereas moods aren't like that. Moods often kind of slowly develop over time and you kind of realize, oh yeah, I'm in a bad mood today, or I'm in a good mood today, or I'm in a mischievous mood today, or whatever it is. Whereas emotions, particularly things like fear and anger, you can see how those are often elicited by very particular things that happen, and they sort of come on, often, fairly suddenly, and then abate often fairly rapidly as well. Again, this is speaking in general terms,

not that there's a precise demarcation, but that at least we can identify that there are differences between emotions, which are relatively sudden, relatively short onset, relatively intense, and typically triggered by specific stimuli, whereas moods are relatively longer lasting, relatively slow in onset, and less clearly caused by any particular external stimulus. So the way that we've unpacked this, both emotions and moods have associated feelings with them, so there's a subjective experience to them, and there are other types of feelings as well, like the feeling of knowing, feeling of hunger, etc. And so a feeling is not the same as an emotion, rather it's a component of an emotion. Okay, so we've talked about some of the components of emotions and

basic definitions of emotions, and then we've distinguished emotions from related concepts like feelings and moods. Let's now talk about different aspects of emotions. Now, I've talked about components of emotions and now I'm talking about aspects of emotion, so this may be slightly confusing. By components of emotions, I mean sort of things that go into the basket of the basket of what makes an emotion and emotion. Maybe basket's not the right word, because really what we're saying is the different threads that are woven together to form the tapestry of emotion. Like pieces in a computer or something like that. They all need to fit together to form the overall thing that is and emotion. Aspects of emotions, by this, what I mean is kind of more like parameters or things that can vary. So the idea is, Emotions always have essentially these five aspects, the cognitive appraisal, the bodily symptoms, action tendencies, facial and vocal expressions, and subjective feeling. Some may be more pronounced than others, and you can suppress the motivational tendencies and so forth, but they're all there to some extent is the idea. Aspects of emotions are more different parameters that you can kind of vary, or that are varied

in response to different circumstances. So if I go through them, it might be a little bit more clear what this means here. So one is valence. We've already discussed this. So emotions are typically, although not universally held to be valenced, that means that they're characterized as positive or negative, or good or bad, or repetitive or aversive, different ways you can characterize that. But basically, that they're sort of good or bad.

That's why we would typically not say that, say, curiosity is an emotion, because curiosity is not really valenced. It's not really good or bad. I mean, you may subjectively think, well, when I'm curious, I'm usually in a better mood, or maybe you're in a bad mood when you're curious, I don't know. but in general terms it's less clear that that is relates to any kind of appetitive or aversive behavior. I'll talk more about what those are in a moment, but it's not, it's less clear that that's sort of a good or a bad state in a way that, say, anger and fear are clearly

negative states and happiness or joy is a positive state. So emotions are valanced and then they can vary in terms of their valence. Another is intensity. So emotions occur in a graded way. They can be weak or can they can be strong. So you can be a little bit angry or you can be very angry. You can be a little bit happy, you can be very happy. A little bit afraid. You can be very afraid. And that's true for many other physiological and mental phenomena as well. So you can be a little bit hungry or you can be very hungry. You can be a little bit thirsty. You can be very thirsty. You can have a small itch or you can have a very large and irritating itch. And so emotions aren't unique there, but that is a distinctive aspect of emotion. So not all psychophysiological states are

like that. So arguably memory isn't quite like that. You normally kind of remember something or you don't. you may be more or less confident in your memory, but typically kind of the memory comes or it sort of doesn't. Often, I mean, sometimes you kind of get bits of it and not others, but it's less clear that there's an intensity of a memory. We don't normally talk about the intensity of a memory. Maybe you talk about the intensity of the emotional experience that comes with the memory, or how easy it is to recall, but those are somewhat different matters. Anyway, there's some issues here, but let's move on to the other aspects of emotions. Another is priority. So it's typically thought that emotions have priority, over other ongoing processes, such as volitional behaviors or habitual behaviors.

So this is a little bit of a vague point here, but the basic idea is when we feel an emotion, especially highly intense emotion, often that kind of out-competes other things that we're thinking about or doing at the moment and becomes extremely salient to us. Think about when you get suddenly angry or afraid of something or really, really happy. That kind of assumes a high priority. And of course, there's variation in that as well. have a higher or a lower priority depending on, you know, the context there. Another is persistence. So emotional states typically outlast the initial trigger stimulus.

Now, we did say before that emotional states are typically relatively short-lived, and that's true compared to moods or other types of cognitive or physiological states, relatively short-lived, maybe on the order of minutes, you know, perhaps an hour or something, but not really days or weeks. However, emotional states do typically outlast whatever the trigger stimulus was. The trigger stimulus may only occur for a fraction of a second, but the emotion lasts for longer than that. And so there's a persistence to emotions. It's also important. So these are some aspects to emotions, valence, intensity, priority, and persistence, which are all sort of important to bear in mind and can vary across a scale.

So that concludes the introductory section where I'm sort of talking about what we mean by emotion. We talked about a basic definition, the components of emotions, the five key elements, related but distinct concepts. We talk about feelings and moods, and then some of the aspects of emotions like valence and intensity and priority and so forth. So hopefully you've got a reasonable idea about what we are talking about and some of the conceptual tools that particularly psychologists use to think about emotions. Now let's move on and start talking about classification of emotions, so how we think about different types of emotions and what are the emotions. And this is a very highly contested area. There are two main approaches to this,

discrete theories and dimensional theories. So I'll discuss both of these. Discrete theories of emotion postulate that all humans have an innate set of basic emotions that are cross-culturally recognizable. They're called discrete because there's a fixed number of them and they're separated from each other and it's believed that they are distinguishable by facial expression and innate biological processes. And it's thought that these exist cross-culturally. So the same across all cultures. They may be expressed in slightly different ways, of course, but the underlying biological component is sort of the same across all cultures. So a classic expression of this are Paul Ekman's cross-cultural study, which looked at many

different cultures across the world, and concluded that there are six basic emotions, namely anger, disgust, fear, happiness, sadness, and surprise. Now, there's some interesting things to note about this. Firstly, most of these emotions are negatively valenced. anger, disgust, fear, and sadness are all negatively valenced. Only one of them, happiness, is positively valenced. The other thing to note is that surprise is not really valenced either way. I mean, a surprise can be good or it can be bad. It's not distinctively valenced. Or surprises can just be neutral as well. It can just be, oh, that was surprising, but, you know,

doesn't really make me feel anything in particular. So many researchers have questioned whether surprise is even an emotion at all, because it's not really valenced in the way that other emotions are. we typically think that that's a sort of a core component of an emotion. Of course, you could just define an emotion to be something that surprise counts in as. You could just say, well, it doesn't have to be valence, but of course that raises this question about what counts in emotion. From my own point of view, I would say that I think it makes sense to regard emotions as essentially valenced. I think that forms a sort of a meaningful distinction from other types of states that are not valensed, like being familiar with something or remembering something or

understanding something, for example, which are more cognitive states that aren't necessarily valenced. I would put surprise alongside those things and not really call it an emotion, but researchers vary on that point. So this sort of six-way classification of basic emotions is one of them that's very prominent, but it's certainly not the only one. There have been many, many studies over the years that have put forward different classifications of discrete emotions, and these studies use different research methods. So some of them use cross-cultural research, looking at facial expressions. What they'll do is they'll show pictures of people making certain facial expressions and show them to people from different cultures and ask what facial expression is this

and see how accurately they can classify them. And you know, you find that you get quite a lot of accuracy, at least for these basic emotions, especially for things like anger and fear and disgust, I think get very high cross-cultural accuracies. So even people from very different cultures can identify what facial expression that corresponds to. So that's one research. approach. Another is to try to identify underlying physiological systems. So like we talked about sympathetic and parasympathetic nervous system or other behavioral components, behavioral tendencies that are associated with particular emotions. So that's another approach. A third approach is to look at it more linguistically and try to cluster the language that we use and try to find

associations in text or in other treatments with the types of words that we use to describe emotion, so that's another research approach. You can also use brain imaging and try to find which regions of the brain sort of cluster with particular types of experiences, and then based on this say, well, we've got like four distinct states and these corresponds to anger, disgust and whatever. So there's many different research approaches that can be taken to this, which explains why there are so many different theories out there. I think that the six basic emotions is a good starting point in terms of thinking about what are some of the most core, common and fundamental emotions that are probably common across most humans, although, again, as I said,

I don't personally like classifying surprises in emotion. But to give you a sense, nearly everyone seems to agree that anger, disgust, fear, and sadness should count as basic emotions. So those are all the negatively valenced basic emotions that I just mentioned. Pretty much everyone seems to put either those or something basically synonymous with those into their bucket of basic emotions. That is people who go along with his idea of discrete basic emotions. Many people also put surprise in, but not everyone. That one's more controversial. Another one that's a little bit more controversial is happiness. Pretty much everyone will put some kind of positively valenceed emotion in there, but sometimes they call it happiness. Sometimes it's called joy, and sometimes it's sort of classified

a little bit differently. Some of the other discrete emotions that have been postulated by some researchers include guilt, trust, anticipation, acceptance, as well as, Positive surprise and negative surprise has broken up into two separately valenced emotions. But anyway, this hopefully illustrates that there's no one accepted list of basic emotions. There are some that are pretty universally accepted. I'd say the four big negatively valenced ones, anger discussed fear and sadness, are pretty universally agreed to be cross-culturally more or less the same, and to be associated with similar facial expressions, similar felt experience,

and similar kind of arousal and behavioral tendencies and so forth. There are many others that have also been postulated, and there's also dispute as to whether this discrete framework is even the best way to approach things. So the alternative to a discrete theory or a discrete model of classifying emotions is the dimensional theories. So a dimensional theory of emotion ditches this idea that there are sort of these separate discrete, you know, countable number of emotions, and instead says that human emotions can be clustered or characterized based on where they lie on a small number of underlying. dimensions. And each of these dimensions represent some kind of very fundamental underlying psychological slash physiological state or a process that can vary. Different dimensional models postulate a different set of basic dimensions and also different numbers of dimensions.

Typically they postulate two or three, although some have postulated more. And personally, I think that the two dimensional ones are too simplistic, but they're useful as a starting point. And just as for the discrete theories, there are many, many different dimensional theories. So there's not one agreed way of representing emotions in terms of dimensions. But let me just explain how it works. So Robert Plutchik, or Plutchik, I'm not sure how to pronounce his name, but he's offered a influential model, which is sort of a hybrid of discrete and dimensional theories. But this model arranges emotions in concentric circles.

So at the inner you have more basic emotions, and then as you move outwards, you have more complex emotions. And the idea is that the outer circles also form by blending or mixing inner circle emotions. So imagine a circle and around kind of dividing up a pie in the innermost circle. You have the more basic emotions. So rage, loathing, grief, amazement, terror, admiration, ecstasy and vigilance are the ones that he proposed. Now, I don't think any of those words are the same words that we've been using. But the idea is that they are more basic and the most intense forms of some of the emotion.

that we've been talking about. So the argument is, rage is the most fundamental and intense form of anger, loathing of disgust, grief of sadness, amazement of surprise, terror of fear, and ecstasy of joy. So all of those correspond to basic emotions that we've talked about before. Then vigilance is anticipation and admiration is the most intense and basic form of trust. Again, I'm not personally sure I would say trust is an emotion, but again, that's a topic for further discussion there. So the idea is actually move kind of outwards further away from the center of the circle, you get a less intense, but also potentially a more mixed or nuanced hybrid emotion. A different model is called the circumplex model. This is a model of emotion proposed by James

Russell, and it is a more explicitly two-dimensional model of emotions, and the two dimensions here are arousal and valence. And this is sort of paradigmatic of many-dimensional approaches, that they'll postulate two basic dimensions of sort of a fundamental cognitive-physiological variable, and then they'll place different emotions somewhere on this, in this dimensional space. So here we've got these two dimensions, arousal and valence. Valence refers to the goodness and badness of the underlying state, and arousal refers to the extent of physiological arousal, but also, I guess, cognitive arousal or motivation, something like that. It's not precisely defined exactly what these things are, but that gives you the sense of it. And so to see how

things fit on this sort of two-dimensional space here. Let's take the negatively valenced emotions first. So anger is negatively valenced, but it's high arousal. So when you feel angry, you are highly aroused. But when you feel sad, that's also negatively valence. So it's at the same negative direction. But you don't feel highly aroused typically when you're sad, at least not unless that's mixed with something else, right? You feel low arousal. You want to kind of withdraw and sort of draw inwards and you don't feel, you know, active like you're motivated to do things. So, according to this model, the difference between anger and sadness is, although both are negatively valenced, anger is associated with high arousal, whereas sadness is associated with

low arousal. And then, of course, you've got your positively valence demotions, which are on the other side of that axis. So excitement would be a form of positive valence and high arousal, whereas calmness or contentment would be positive valence, but low arousal. So this gives you an idea of how the dimensional approach can work. It tries to kind of reduce the complexity of the space of emotions by explaining how they can be formed by these underlying cognitive and physiological dimensions. However, it's generally recognized, or at least many researchers have argued, that two dimensions is insufficient to account for even fairly basic emotions. And I think a good case study here is the difference between fear and anger, which I think is quite interesting

when you think about it. And I think that this is something that's kind of left out of the discrete models in that they don't place any real structure on the different emotions. They just sort of list them. The dimensional models allow you to see similarities and differences. So they allow you to sort of recognize that anger and fear are both negatively valenceed emotions, as is sadness and as is discussed, right? So they have something in common. But anger and sadness differ in that one is high arousal, whereas the other is low arousal. So we can identify a similarity and a difference there. But that raises a question. What about anger and fear. Anger and fear are both negatively valenced, and they're also both high arousal.

So they're both high, you know, you think of fight or flight, right? Those are kind of the two options. The flight would be more fear and the fight would be more anger, right? Not that that's an essential behavioral response, but those are the kind of matching behavioral responses that might be kind of activated or potentiated by the corresponding emotional state, right? So how do we differentiate anger and fear? They both seem to fit in the same dimensional space. They're both high arousal and they're both negative. So what's the difference between them? Certainly they feel very different, kind of internally, and they are associated with different facial expressions, different behaviours. So what's the difference between them? How can we represent that in a dimensional

model? And so the proposal here is to introduce a third dimension. So in addition to valence and arousal, there's a third dimension. One problem is that different people call this third dimension something different. So one model that I've referring to here is called the pad emotional state model developed by James Russell and another psychologist whose name I won't try to pronounce. The pad model uses three dimensions, so corresponding to pleasure, which is basically valence, arousal and what they call dominance. I don't know about this name dominance. I don't think that that conveys what it is very well. Another way to describe this is called approach avoidance. And I think that this is a better way to say it. So it's approach avoidance as the two extremes.

But you can think of it as like how dominant you are in an encounter or an interaction. And this really does help you to distinguish anger from fear, right? Because when you're feeling anger, you're feeling dominant in the social interaction. It doesn't necessarily mean you are actually dominant, right? But it means that you are exerting or at least wanting to exert control of the situation. You're wanting to act. You're wanting to submit someone to whatever you want to do. Parodomatically, you want to hit them, right?

Whereas in fear, it's the opposite. You want to withdraw. You're being submissive. You don't want to be dominant in the situation. You want to avoid instead of approach, which is what you want to do with anger. Again, you think of a paradigmatic case. If someone has angered you, you approach them and you threaten them, whereas if you're afraid of someone, you withdraw and you try to hide.

That's the key difference here. So there's this dominance or approach avoidance dimension in addition to the valence and arousal. So we can understand the difference between anger and fear in that both are negatively valence and high arousal, but anger is high dominance, whereas fear is low dominance. And this three-dimensional space then allows us more flexibility in classifying different emotions. And I think this is quite helpful in kind of understanding both similarities and differences and the relationships between these different emotional states. And also, what I think this highlights is that there's not really any essential conflict

between discrete and dimensional theories of emotions. Really, we can think of discrete theories as just identifying clusters or commonalities within an underlying dimensional space. So sometimes it might be helpful to talk about those dimensions and theorize about them. Other times it may not be so helpful and we can just talk about the typical discrete clusters or common occurrences within that space. So I think increasingly there's realization within this literature, at least my sense of it is that there's no real conflict between discrete and dimensional theories.

It's kind of what the research question is and what question you're trying to answer. Now, one other point that I wanted to comment on before we move on to psychological theories of emotion is that underpinning the belief that emotions are fundamentally cognitive and physiological states is the idea that they serve a function. So emotions don't just kind of exist. They're not just kind of there. They do something, right? They exist for a purpose. And by that I don't necessarily mean that they've been finally honed by evolution to like do the exact right thing that we would want. That's a common misconception that evolution is an optimizer. It isn't. Evolution is a satisfacer, which means it finds a solution that's accessible and kind of is good enough.

It sort of gets the job done, right? So we should not think that emotions are like perfectly adaptive or anything like that, but they do have some purpose, which is why they exist. And the basic emotions are thought to be widely experienced, at least by other mammals. It's more contested as to whether like reptiles or even insects feel emotions. But certainly many other mammals appear to have at least the same basic emotions that humans do, like fear and anger and joy and so forth. that raises the question, well, what are their functions? Like, what do they do? And I think a useful

way to think about, not the only way, but a useful way to think about the functions of emotions, or why they've evolved, or what purpose they serve, is to think about emotions as representational states. So by representational state, we mean that there's some kind of reality that exists in the world that we then form an internal cognitive slash physiological representation of. So representation is kind of hard to define term, but the idea is that it's a way to store information about the way something else is. So, for example, a map is a representation of the territory that is described by the map. So we have a bunch of beliefs that represent whatever the belief is about, the beliefs about our childhood, or about the best way to earn money, or the best degree to take,

or the best science podcastist or whatever else, right? Those beliefs will be instantiated by some type of cognitive representation in the brain somewhere, right? So that's all we mean by representation. And emotions are a kind of representation, although they exist kind of in the brain and elsewhere in the body as well, because they relate to the activity of like the peripheral nervous system and so forth. So they're a bit more distributed. But the other thing is that they represent particular states. And the type of state they represent is important because it's directly connected to motivation and other basic survival instincts. So it's not always easy to understand what every emotion correspond to in terms of a represented state. But I think the basic ones you kind of can,

right? So fear, for example, is fairly clear. Fear is an emotion that represents the perception or belief of an acute threat. So some sort of immediate, fairly short-term threat. If it's longer lasting, we'd probably call it anxiety and it's a little bit different to fear, right? But fear is a, you can think of it as a cognitive slash physiological representation of an acute threat. Now, representations don't always have to be accurate, right? They just have to, a sense serve the purpose or attempt to represent something accurately. Disgust represents perceptions of a disease state or also extrapolated to some kind of social and moral transgression. So something that's yucky. It's a little bit different from fear, right? Because although you

could have both, of course, but disgust is more associated with, if you think about the actual facial expression of disgust, it's very similar to ejecting something out of your mouth, which is what's generally thought to be evolved from the idea of, well, you taste something often like bitter or sour or that disagrees with you in some way and you spit it out because it may be poisonous or dangerous in some way. That's different from fear. You may then feel fear that you've poisoned yourself, but that's different from the initial disgust, right? And the idea is that that sense of contamination is then translated evolutionarily and kind of cognitively over to other types of situations that we feel should be rejected or ejected like social or moral transgressions,

people doing things that we don't approve of. So that's what disgust represents. It represents a a transgression of some sort or some kind of disease or yucky state. Joy represents the attainment of goals or satisfaction of some sort of appetitive drive. Sadness represents a failure to attain a goal or an expected reward. Often when there is little ability to overcome whatever obstruction has been put in the way. And that is what differentiates it from anger. So anger and sadness have a lot in common because they're both kind of representing obstruction of a goal or failure to attain a reward that we expect.

But the difference appears to be, at least some researchers have argued, that the difference is in our cognitive associations or beliefs, that that can be implicit, like we don't necessarily have to be aware of that, but our beliefs associated with why we think the reward or goal was not attained. So if we associate that with something that's unexpected or sudden or that we don't understand very well, perhaps, we may be liable to feel angry, but especially if it's of a social origin. So if someone does something to us that means we are deprived of our goal or reward, we're more likely to feel angry.

Whereas if our reward or goal is deprived because of some kind of environmental or external happening that we don't have any ability to overcome, and particularly perhaps we're maybe sort of saw it coming or sort of expected it, but hoped it wouldn't happen, then that was more likely to lead to sadness. So the difference here is anger and sadness, both reference. present failure to attain a reward or a goal, but there's different cognitive beliefs associated with them. And that's why one is associated with approach and the other is associated with withdrawal. But of course, you can see that situations which may lead one person to become angry may lead another person to become sad. So it's going to depend on individual differences there.

Anyway, the point there is that although those are fairly simple explanations, hopefully you can see how we can identify a particular type of representation that's instantiated by or that is the function of at least the most basic emotional states. So emotions exist in order to represent some sort of state, or emotions are our internal representations of some kind of state, often relating to achievement of goals or failure to achieve those goals, and often, but not always in social settings. A final word before we move on to psychological theories is, I've already mentioned complex emotions, but I'll just say a little bit more about them.

The idea is that whether you're working with a discrete theory or a dimensional theory of emotions, often you'll sort of start with the more basic fundamental emotions, which are more common across cultures, and they're a bit easier to describe in terms of function and arousal and so forth. And then you might move to more complex emotions. And one way to represent complex emotions as kind of mixtures of basic emotions. It's maybe a little vague in terms of what we mean by a mixture. Perhaps they're both activated at the same time, or they interact cognitively or physiologically or something. I don't have a precise explanation as to how you mix emotions, but the idea is that in some sense, complex emotions are formed from mixtures of simple ones.

Bluchick proposed that there are different types of combinations of two emotions that he called diads. Some of these involve emotions that are related or perhaps just distinct from each other. And then some of them actually involve combinations of opposite emotions, which form sort of interesting types of complex emotions. So anticipation plus joy is optimism, according to Plutjik. Anticipation plus fear gives rise to anxiety, whereas anticipation plus trust gives rise to hope. Fear and surprise, I think I mentioned before, gives rise to awe, whereas fear and sadness gives rise to despair.

Fear and disgust gives rise to shame. I think that one in particular makes sense to me because the idea of shame is that you are disgusted with yourself and also afraid that other people will find out about it. So some of these, I think make a bit more sense than others. But then in terms of these opposite diads are particularly interesting. So according to him, envy is a combination of sadness and anguish. I think the idea there would be that you are both sad and angry, particularly in sort of directed towards another person having something that you don't or think that you should have. And we can kind of see that, right? Because both anger and sadness relate to representing obstruction of a goal or expected reward.

And you can imagine having some sort of combination of those at the same time if it's directed towards another person or maybe another group of people, then that could be the basis of envy. sadness plus disgust, he argued, is remorse. So the idea would be you think backwards on something and you feel sad that it went a certain way, but you're also disgusted, probably at yourself for acting in a certain way, when you think, oh, I wish I'd done this, and that gives rise to remorse. Surprise plus anger gives rise to outrage. So I think you can understand that, right, where it's, you're angry, but also surprise, so it's a strong sort of unexpected sense of anger or mode of anger, and that's outrage.

So the point is that there's different, many, many different proposals for exactly how to produce complex emotions from the basic ones. I think the broad idea that combining together simple emotions in different ways, and then maybe adding on additional constraints, like, for example, envy is kind of like sadness plus anger, but it has to be directed towards comparing yourself to someone else, for example. There's that extra cognitive component there. Or remorse is kind of sadness plus disgust at yourself, but it has to be directed towards something that happened in the past, so extra sort of constraints on them. I think that you can get a long way towards understanding more complex emotions. Although, that being said, it's unclear whether all of

these things that are discussed as complex emotions really should be thought of as emotions, or perhaps should be something else entirely. But, all right, so that concludes a section on classification of emotions, covering the discrete and the dimensional theories. Now I'm going to talk a little bit about psychological theories of emotion. So you might be wondering, well, haven't we already been talking about psychological theories of emotion? In some sense, Yes, but this is a little bit more specific. So when people or like books will talk about psychological theories of emotion, there's a sort of a particular set of ideas that they have in mind. And this is different from just defining or classifying emotions, which is really all we've

been doing so far, explaining what an emotion is and then trying to classify them. And we've talked a bit about like what they do, their function and so forth. But psychological theories of emotions, what they attempt to do specifically is explain the relationship between the different components of emotions. Remember how we talked about there are different components of emotions, so physiological response, behavioral response, cognitive component, an evaluation, cognitive appraisal, and feelings. A psychological theory of emotion attempts to explain the relationship between these different components. And particularly, at least historically, the focus has been on identifying the temporal relationship between these different components, so how they relate to each other in time,

the causal relationship between them, so which gives rise to what. And some psychological theories also attempt to relate different components of emotions to different brain regions or different physiological, like specific physiological states, although they don't all attempt to do that. So you can think of psychological theories of emotion as sort of taking these components of emotion and trying to explain a bit more detail how they relate to each other. And that will become a little bit clearer as we go through some of the major examples. There are, I mean, dozens and dozens of psychological theories of emotion, often named after the researchers who have come up with them. them. I am only going to talk about a couple of the ones here that I think are most relevant. Many of them are kind of outdated these days. They seem to still be discussed in a lot of of psychology books, just because we don't have a lot else to say about emotions necessarily,

but at any rate, let's start with folk psychology. So folk psychology, I said, is the kind of untrained, intuitive beliefs that we have about, well, in this case, psychology and, you know, emotions and cognition and belief and intelligence and all these sorts of other things, right? But here we're particularly talking about folk psychology and emotions. Now, it's difficult to specify exactly what folk psychology is, of course, because as soon as you start talking about it, you've kind of already moved beyond folk psychology because the whole idea is that folk psychology is a kind of unreflective and uneducated view. So if you're speculating about what it is, you're probably already transcended it, right?

But at least the suggestion is that folk psychology says that we start with a stimulus. So let's take a specific example. A bear jumps out, right, where you're walking in the woods. So that's the stimulus. And then there's a subjective experience. So the stimulus causes a subjective experience. So in this case, it's going to be fear, right? That subjective experience then gives rise to a cognitive appraisal, could be conscious or subconscious. So like, oh dear, I guess would be the appraisal in this case, which then leads to a bodily response. So in this case, you become physiological aroused and you might start to run away. That would be the behavioral aspect. And then there might be a report of that response. Like, oh, my heart was pounding and I was terrified and I started running. But the report obviously. comes afterwards. So folk psychology would say stimulus gives rise to subjective experience, gives rise to cognition, which then gives rise to the bodily response. You could perhaps reverse those last two, but I think in many cases it would be feeling, then cognition, and then bodily

response. Now famously, two psychologists developed what's called the James Lang theory of emotion. So this was from some time ago, and it's still discussed in literature, although I don't think it's widely accepted these days, at least not in its original form, but it's still influential this idea. The basic premise of the James Lang theory is to reverse these key elements of the folk psychological belief. So remember, folk psychology, at least according to this idea, says that the subjective experience is the thing that comes first. The subjective experience then causes the cognitive appraisal and the physiological arousal. So you would say something like, oh, my heart was pounding because I was afraid. The point is that you explain, according to

folk psychology, we explain our arousal and also we explain our sort of thoughts in terms of the subjective experience. Our thoughts and bodily reactions are caused by the subjective experience, the feeling. The feeling causes the behavior. James Lang's think, no, no, no, it's completely the other way around. First, there's a stimulus, and then what happens is that there's a physiological arousal. So, you know, adrenaline is released to the heart rate increases, respiration increases, sweating and so forth. So flight and flight response is activated. So bear jumps out, That is obviously perceived, like you're going to have to perceive that. But the first thing that happens after perception is the physiological response and then the behavioral response. Then comes the

cognition. We sort of realize what's happening. We interpret that in terms of, oh, my heart's beating, I'm running, I must be afraid. Of course, that's non-conscious, right? James Lang didn't think that anyone consciously thought that to themselves, but the idea is that implicitly, like subconsciously, our cognition interprets our physiological response to interpret what our body is doing. then constructs the idea that, oh, we're afraid. And then the idea is the subjective feeling comes. The actual feeling of fear comes last of all. So folk psychology says it's the feeling, and then the cognition, and then the bodily response.

But James and Lang said that it's the exact opposite of that. It all goes in reverse. It's the physiological response, and then the cognition, and then the subjective sensation. And critically, it's not just the timing of it that they emphasize. It's actually the causal chance. chain. They said, folk psychology is wrong. Subjective experiences like our feelings don't cause cognitions, which then cause our arousal and bodily responses. Instead, our physiological responses cause our cognitions, which then cause the feelings. We feel afraid because that's the way we've

interpreted our physiological response. So hopefully this makes sense that James Lang was and still is very controversial because it inverts this sort of, at least what many people think as an intuitive of ordering that your heart pounds because you are afraid, whereas James Lang says the opposite. He says, no, no, no, you're afraid because your heart is pounding, or slightly more accurate would be, you're afraid because that's the way you've subconsciously interpreted your heart pounding. Just to emphasize how radical the theory this is, it contrasts very distinctively with the way we typically describe the relationship between actions and motivations and emotions. So you might say, oh, I hit this person because I was angry. Everyone would kind of understand what

saying there. We'd understand what they're saying. We would understand the connection between feeling angry and hitting someone. But what James Lang would say is, well, that's what you think, but in fact, you were angry because you hit someone. Again, perhaps a little bit more carefully, you were angry because of your arousal, which you were then interpreted as anger, they might say your arousal and sort of gesturing towards hitting someone, was then interpreted by you as anger, which is why you hit someone. You can vary as to exactly how much of the body response comes before or after the subjective sensation, whether it's just sort of the initial preparation to hit someone that comes first, and then the actual hitting comes after the subjective sensation, or whether the whole thing

comes first and the subjective sensation is only after the fact. You can vary that, but the basic point is that they're going to reverse the order of explanation. You didn't hit someone because you're angry. You interpreted your arousal as anger, and therefore the arousal itself is what caused you to hit someone. It's the arousal and the kind of process of hitting, or at least preparing to hit, is what caused you to be angry. So it's the exact opposite of that. Another example would be, I'm crying because I'm sad. James Lang would say, no, no, no, you became aroused in a certain way, which led to the crying, and you sort of interpreted that as you being sad.

So you're sad because you're crying. You're not crying because you're sad. So in all these cases, they would flip the order. Hopefully it gets you to understand why this is so radical, because it reverses the order of explanation of many of the attributions you make in folk psychology. This was influential for a while, and still is in some circles, but many people were sort of unhappy with this. One problem with the James Lang theory of emotion is that it doesn't really explain how we

go from the physiological response to the, to the interpretation. Like, why is it that the same physiological response can lead to different emotions? So, as we've just been discussing, the physiological aspect of, say, fear and anger is very similar. They're both negative valence, high arousal, sympathetic, like parasympathetic activity is similar in both cases, flight-to-flight response. It's actually hard to differentiate those states in a pure sort of physiological sense. So why is it that one of them is associated with fear? and the other associated with anger. Like how do you differentiate those? Or what is it about the cognitive process that leads those to be differentiated? And it doesn't seem like James Lang has a lot

to say about this. Another problem with the James Lang theory of emotion is that some emotions have low arousal, like sadness. And it doesn't really seem to make as much sense to say that we feel sad because of low arousal. Like the James Lang theory seems to be mostly tailored towards high arousal emotions. Low arousal ones make a bit less sense. I mean, I just referenced it in terms of the crying, but there's much less of a physiological arousal that seems to correlate with that. So it's a little bit less clear how to make sense of that in the James Lang theory there. It's not clear what the interpretation actually is of, if you're not highly aroused. An alternate theory was developed, and this is called the Canon Bard theory.

This says that the cognition and the physiological activation both occur essentially at the same time, or around about the same time, and they're independent and separate processes. So arousal doesn't cause the emotion. arousal kind of happens along with the emotion. So the idea is that you have your stimulus, so your bear jumps out and you perceive that. The cortex processes that stimulus and produces the emotional feeling of being scared. So that's the cognitive and the subjective component. So while the cortex, the kind of higher part of your brain is processing that stimulus

and kind of producing the subjective sensation, the lower parts of your brain, like the hypothalamus, proteratory gland and peripheral nervous system is activated. that triggers the physiological response, like the racing heart and so forth, and the behavioral response. So it's more of a dual process, a parallel process of cognition plus feeling generated by the cortex, and then the physiological activation and the behavioral response, which is sort of triggered by the hypothalamus and the pituitary system, which activates the sympathetic nervous system. Cannon and Bard also focused on the thalamus as being like the relay center of the brain, so to speak, which then processes the stimuli and then

passes it off to the cortex and the hypothalam. So we won't worry too much about that here. It's not super important for us. So this theory attempts to make a more explicit relationship between the different aspects of emotion or components of emotion and particular components of the nervous system. But we're less interested in that here.

I think the Canon Bard theory is an improvement over the James Lang theory because it allows us to kind of understand how different stimuli give rise to different emotions because we've got the stimulus to work with. See, James Lang theory, says that the stimulus is really irrelevant to the emotion. It's all about the interpretation of the physiological response. The problem is the physiological response just doesn't vary,

very much. I mean, it varies in intensity, right? But it's kind of the same for most emotions. It only sort of depends on the arousal level. So it's not fine-grained enough and doesn't explain low arousal emotions very well. Whereas the canon barbred theory allows the feeling and the cognitive aspect to depend on the stimulus in a more direct way. And so it allows for more variation and to distinguish different types of emotions. So I think that's an improvement. But one problem is that the theory focuses pretty much exclusively on the operation of the autonomic nervous system. And it doesn't really say much about the role of the central nervous system in eliciting physiological changes and behavioral responses. There have been many other theories

that have been proposed over the years. The final one that I want to focus on here is a variation of what's called central or core emotion theories. This one is developed by Anderson and Adolfs, but the precise formulation I'm not too interested in. What these central or core emotion theories have in common is basically they postulate this idea of a central state or a core emotion state, which is activated in response to a stimulus. And that core emotion state then has these multiple components. So, I mean, I've kind of already been leading up to this by talking about them as components, right? Because James Lang, for example, I don't think would have thought of them that way.

But this sort of central or core emotion theory says that there's a core emotion state which will be activated, by a particular stimulus, and that core emotion state has these different components, which basically operate in parallel. They can interact with each other, but it's not like one causes the other in some kind of linear chain, like James Lang postulate. They kind of all go along together, but are caused somewhat separately and have their own sort of separate neural substrate, and they're activated largely simultaneously. According to these theories, basically, you see the bear, and that activates a central emotional

state, which simultaneously triggers a behavior, a physiological response, a feeling, of being scared and a cognition. So, you know, thinking about, oh, there's a bear or something like that, right? So all of those things are kind of activated in parallel. And they can interact with each other, but one doesn't directly cause the other. Because they're all basically components of the central emotional state. And arguing that one causes the other doesn't really make sense. And personally, I think that this is a much better way to think about emotions.

Because, for example, if you think about the cognition as separate from the feeling, which in turn is separate from like the state of arousal, it's kind of hard to understand how these things relate to each other. Like, well, where does the feeling come from? Why don't we just have the cognition? Or, like, what does the cognition have to do with the physiology? Why would one cause the other? Like, why do we need a cognition at all? Whereas I think if you see them as different components of emotion, you see them as more integrated together. And they're just kind of different sides of the same coin, so to speak. Not precisely. I mean, there is a difference between arousal of the sympathetic and parismpathetic nervous system and, you know, cognitions and interpretations and behaviors, right? So they're not precisely the same. But they're all different, I would say different components of an underlying representation, which is the central state, the central emotional state, that represents a particular stimulus and our inclinations in terms of how to respond to it. So personally, I think these sort of central core emotion theories are a better way to think about emotions. So it's not that your heart is pounding because you are afraid, as folk psychology says, nor is it that you're afraid because your heart is pounding, which is more what James Lang would have

said. Rather, the fear and the heart pounding plus your interpretation of the stimulus and other cognitive aspects. All of those together are just different aspects or components which together form the emotion. And to think about emotions as functional states that represent something in our environment and also our sort of behavioral dispositions in response to that. All right, so that concludes the section on psychological theories of emotion. And now let's move to the final section in which we'll discuss the neurobiology of emotion, which is a particularly difficult area, because there's not a lot of agreement, although that's true for the previous series as well. So the way we'll structure this section is essentially to talk about different regions of the brain

that have been particularly associated with processing of emotions. So to begin, I think one of the most important things to understand is that there is no single region of the brain that is uniquely and specifically associated with or responsible for generating emotions or generating feelings or anything like that. All significant emotions are processed and instantiated by a complex interconnected network of brain regions. So we should avoid thinking about emotions as if they are produced by only a single specific part of the brain, or as if there's like different brain regions, one for each emotion or something like that. Very few aspects of brain function are so well localized like that, and emotions certainly aren't one of them.

That being said, there are certain brain regions. are more responsible for and more associated with emotional processing than others, and we'll talk about a few of those here. Broadly speaking, we can think of the emotionally salient regions of the brain in terms of those responsible for processing emotional stimuli, as concentrated around kind of the central regions of the brain as well as the frontal parts of the brain that are closest to those central regions of the brain. So some people may be familiar with triune brain theory, reptilian brain, mammalian brain, and primate brain. The primate brain corresponding to essentially the cortex, which is the wrinkled outermost part of the brain, the reptilian brain corresponding to the oldest part of the brain,

the brain stem, and then the mammalian brain kind of being the subcortical structures that lie between the cortex and the brainstem. So those subcortical regions of the brain, such as the hippocampus and the amygdala, thalamus, and so forth, those are sometimes described as being part of what's called the limbic system, which is thought to be associated with emotional processing. Now, I'm not going to talk about that in detail, because this idea of a limbic system is largely discarded in contemporary neuroscience, because it's not really a single system, and it's involved in many things other than emotional processing, so it's not really considered a very helpful concept. I'm just mentioning it here, because it's something you may have heard of.

It's still discussed occasionally, especially in older texts. But just broadly to describe the location of these regions that we're going to talk about, you can think of them as being located kind of at the top of the brain stem in the central area of the brain. That's where the, kind of where the amygdala is. It's a bit more to the front than that. And then also parts of the cortex that are located kind of around there. So we'll talk about the orbiter frontal and the ventromedio prefrontal cortex, for example, which are kind of parts of the cortex near the front of the brain.

And we'll talk about the singular cortex, which is the part of the cortex that's in between the two cortical hemispheres, kind of down the middle of the brain. But our concern is not too much about precisely where these regions are, because it's a bit hard to explain anyway without a diagram. But instead, we're just going to focus on some of the different regions and what they are known to be responsible for. So let's start with the orbiter frontal cortex, which is the part of the cortex that's just right near the front of the brain, near where the orbits of the eyes are, hence the name. So this region is thought to be involved in emotional regulation and cognitive control, so executive function. It's closely interconnected and highly connected with the amygdala, which we'll get to in a moment. That's a subcortical structure.

And it's thought that this connectivity is important for encoding and processing information about the valuation of different states. Now, one interesting phenomena that is associated with the orbiter frontal cortex is something called decorticate rage or sham rage. This is a phenomenon that's been observed in many different animals. and it's associated with behavior, aggressive behavior, like biting, cloring, hissing, arching the back and so forth that's produced in animals during experiments where the cerebral cortex, including the orbital frontal cortex, is removed. So you remove the cortex, the animal is able to survive that because basic bodily functions like breathing, maintenance of heartbeat and so forth, those are regulated by the brainstem,

so you don't need the cortex for that. So you remove the cortex and it's observed that there appear to be these highly aggressive behaviors, but at least it was argued that there's an absence of any sort of inner experience of rage. So hence it was called sham rage. Small lesions of the hypothalamus, however, actually reversed this sham rage behavior. One explanation for this phenomenon is that it was thought that removal of the neocortex caused a loss of inhibition of areas that were involved in the rage reaction, causing those areas to become hyperactive. Effectively, the idea is that subcortical areas, such as the hypothalamus, which we know is involved

in mediating the, or effectively controlling the activity of the endocrine system, is critical for generating the experience associated with rage and anger in various animals, including humans. And so it's thought that the frontal cortex, including the orbiter frontal cortex in particular, provides inhibitory signals to the hypothalamus, which then prevents or sort of inhibits the experience of rage, whereas if you remove those inhibitory signals, then you get this sort of sham rage experience. Now, it must be said that some researchers have objected to this notion of sham rage because they argue that, well, deconticate animals have the same feelings associated with the behaviours of the biting and chlorine and so forth as any other examples of rage being

experienced. So that's sort of an open question as to whether the experiential component of the emotional display is the same. Personally, I suspect that it is similar, if not exactly the same. The point, however, here is simply to indicate that it appears that the prefrontal cortex, particularly the orbital frontal cortex, is important in executive control and inhibition of behaviors such as aggression that are more directly mediated by subcortical structures like the hypothalamus. And moving on to another part of the prefrontal cortex called the ventromedial prefrontal cortex. This is close to the orbiter frontal cortex, but a little bit to the side, shall we say. I won't try to describe exactly where, but they're sort of near each other.

Now, the ventral medial prefrontal cortex is important for quite a number of aspects of executive function, but also emotional regulation. So particularly the ventral medial prefrontal cortex helps to inhibit our response to emotion, so it's sort of similar to the orbital cortex, but there are some sort of differences in exactly what's been observed. But one of the very interesting findings about the ventral medial prefrontal cortex is that damage to this region impairs behavioral control and decision-making. So patients with lesions in this area show defects in emotional regulation and emotional responses. They show abnormal emotional responses.

Diminished emotional responses, particularly to social stimuli, such as they show reduce compassion, shame, and guilt. They're poor at regulating their behavior or frustration and tolerance to difficult circumstances. A very famous example of a patient with ventrometrial prefrontal cortex damage, was Phineas Gage. I'm sure many of you have heard of him. He was a construction worker in the mid-19th century who had, in an accident, an enormous iron rod passed through his, well, his head, and he was lucky enough to survive, but with damage to his ventral medial prefrontal cortex. Before the accident, he was described as being a very serious, industrious, and energetic man. Afterwards, many people who knew him noticed personality changes, and he became irresponsible,

thoughtless, and childish. There's some dispute as to precisely how accurate those descriptions. are, but there doesn't seem to be any dispute that there was a noticeable change in his personality and that he became worse in regulating his behaviours and emotional responses. There are other cases like this as well. It's not all just based on that particular incident, but it is a very well-known example. The point is that, similar to the orbiter frontal cortex, it appears that the ventrometrial prefrontal cortex is also involved in regulating and inhibiting emotional responses, particularly things like aggression or antisocial behavior. And if that is damaged, then you see a reduction in those sort of pro-social behaviors or regulation of those sort of negative

emotional states in particular. The ventrometer prefrontal cortex is also involved in valuation and reward processing. So it helps to determine and encode the value of different options in choices and decision making, which is associated with processing like rewards and punishments and things like that. So that's also directly related to like the valence of different emotional behaviors. so happiness in experiencing positive reinforcement or in achieving goals or anger or sadness at having one's goals being prevented from achieving one's goals or failing to achieve one's goals. So the ventral media prefrontal cortex is also critical for encoding valuation of different states, which is linked to the corresponding emotions. Damage to that region can disrupt the ability

to appropriately assess the value of different options and also to predict the outcomes of different situations. I mentioned as well that the Venturemedial prefronted cortex is involved in social emotions, but it's also involved in interpreting social cues, like facial expressions, tone of voice, body language, and kind of inferring other people's emotions and in kind of reading the right signals from that. So damage to that region can impair decisions that are made based on social context and other people's perspectives. So there's sort of a few different things going on here, but it seems the Ventura Media prefrontal cortex is involved in emotional regulation, it's involved in social cognition, so understanding other people, it's involved in reward processing and valuation of

different states. So you can see how all of these things are related to emotions, because emotions obviously are about valuation of states. They're about social cognition and recognition, because emotions are highly social. We exhibit them through facial expressions, and we need to recognize them in others. And also emotions need to be regulated. There's a cognitive component to emotions and a regulatory component to how we express them and so forth and how they relate to other cognitions and goals and things. So there's clearly a lot going on there, even if we can't give a precise account as to exactly what the ventral media prefrontal cortex is doing, but it's certainly very important for emotion. Let's now talk about the amygdala. Now the amygdala

is a subcortical structure. It's kind of a little bulbous shape. It's located near the prefrontal cortex, but a little bit below it and sort of behind closer to the middle of the brain. again, I won't try to describe the anatomy precisely. Now, it has been widely studied because of its association with fear and anxiety, emotions and related behaviors, both in animals and in humans. Human patients with bilateral lesions to the amygdala, bilateral meaning because effectively there's an amygdala structure on either side of the brain, so we have to ensure that you're looking at patients who have similar damage to both sides of the brain.

Such human patients do not show normal fear responses or report fear. experiences from external stimuli, but interestingly, they do when they're exposed to internal stimuli that elicit fear responses, such as induced suffocation. So you can increase the CO2 concentration of the air that people are breathing, and that induces a feeling of suffocation, which produces a very extreme fear reaction in many people, understandably, right? So the interesting thing is that bilateral allegiance to the amygdala do not remove that response. So people who have that damage, still feel that, well, they report feeling that kind of fear and exhibiting the relevant behavioral and physiological responses. So they still exhibit fear. It's not like the amygdala

processes, all types of fear. What it appears to do is integrate and process information relating to the emotional responses, particularly the fear response, to external stimuli, stimuli coming from outside of the body like sensory perception as opposed to internal stimuli like detectors of the pH of the blood, which is how we know about CO2 concentration. The amygdala is highly interconnected with the prefrontal cortex and also other structures such as the hippocampus. So it's not like all of this processing happens in just one location in the brain. There's a complex network that happens here. But it's thought that the amygdala alongside these other structures is involved in the evaluation of the press,

or absence of threats and the emotional salience of those threats. It's known to be involved in classical conditioning and animals, so associating unconditioned stimuli with conditioned stimuli. So we've talked about that in previous episodes on classical conditioning, but the basic idea is that an unconditioned stimulus is something that produces a behavioral response innately. So an example would be, you know, food. The animal smells the food and begins salivating. So that's an unconditioned stimulus because it's something that just naturally innately produces a response without having to be learnt. Whereas a condition stimulus is one that is learned, a learned association. That type of learning seems to require, at least for fear stimuli,

it seems to require the functioning of the amygdala, because when the amygdala is damaged, that type of association is not able to be learnt in the same way. So this is further evidence that the amygdala is involved in connecting effectively the external stimuli with the presence or absence of a threat and the kind of valence and salience of that threat. The amygdala also is involved in aiding direction of attention to fearful stimuli. So there's experiments where humans with bilateral amygdala lesions show abnormal patterns of gaze when they're looking at fearful faces. Most people, when you show them a fearful face, they'll focus on the eyes and a little bit on the mouth because that's where you mostly see fear. But if you show the same pictures to people with bilateral

lesions to the amygdala, they kind of just look all over the place and it's a bit chaotic. they don't seem to focus on the relevant aspects of the faces. So they have an impaired ability to correctly identify fear in these photos. So again, there seems to be a connection between the processing of the stimuli internally as well as its detection in other people. We saw that in the ventral medial prefrontal cortex as well. So the amygdalae is not only involved in fear processing, it is involved in other emotions as well,

but it seems to have a particularly pronounced an important role in the processing of fear stimuli, particularly the learning of these associations, threat stimuli, and the negative valence of those. The singular cortex is the kind of bit of the cortex that's in between the two cortical hemispheres. It's kind of folded up in the middle there. It's involved in a wide range of functions, including emotional formation and processing as well as learning and memory. And one of the things that it's known to be involved in is linking motivational outcomes to behavior. So positive reward responses and learning based on those, for example.

and as a result it's important in disorders like depression and schizophrenia, which are highly related to basically dysfunctional reward responses and reward learning. The final region that we'll just talk about briefly is the insular cortex. So the insular cortex is essentially the part of the cortex that's tucked behind and between the frontal and temporal lobes. So it's kind of like the singular cortex, it's kind of buried, but it's buried in a different location. The insular cortex is also associated with emotional processing, and it appears to play an important role in integrating input from different representations of the state of the body, so visceral, somatic input, and so forth. Disgust has also been particularly associated with activity in the

insular, which is, to be unsurprising, because the insular has a role in integrating different bodily states, and obviously, gustation is going to be one of those, so it sort of makes sense that it would have a particular role in disgust, which is, as I said, associated strongly with a sort of bitter and sour taste and a feeling of sort of being sick or a kind of a yucky sensation. There are many other parts of the brain that have been associated with emotional processing as well. We've just talked about a few of them. The thalamus is also, which is sort of a relay center at the kind of at the center of the brain, the thalamus is also highly associated with emotional processing and many other smaller structures kind of surrounding it. But we're not going to go through

all those details here. To summarize, there is no one region of the brain that is responsible for emotional processing generally, nor is there even a single region of the brain that is responsible for any particular emotion. Probably the closest that we are aware of of such a region would be the amygdala, which is known to be very closely associated with fear processing and learning to associate fearful stimuli with behavioral and emotional responses. But even that is not a clear-cut case because humans with bilateral lesions to the amygdala can still show fearful behaviors and report fearful experiences. It's just that the types of stimuli that elicit those are more restricted. It's only internal as opposed to external stimuli that elicits those.

So it's clear that the amygdala isn't solely responsible for the feeling of fear. It's not like there's one little bit of the brain that when it activates, it triggers the feeling of fear. It's much more complicated than that. And as I discussed before, for fear, as well as anger and other emotions, it's much better to think about emotions as complicated, multifaceted, cognitive and bodily states. And according to the central core emotion theory, there's a sort of a central emotional state with different components, the physiological components, the feeling, like the experiential components, behavioral tendency, motivational components, cognitive, evaluative component, as well as facial expression and sort of vocal components,

which is the expression components of emotion. And those are going to be, processed and exemplified in different parts of the brain slash body. And so there's not going to be any one sight of the generation of the emotion. Emotions serve to represent some kind of state, typically an interaction between a motivational state and the realization or failure to realize that motivational state. So fear represents acute threats, anger, obstruction of goals, disgust, perception of disease, joy, attainment of goals, and so forth. And those are represented in a multifaceted way, encompassing the different components that I just discussed. And because of that, it's not really surprising that there are going to be multiple distributed

networks and regions of the brain that are responsible for processing these signals and this information, and thereby sort of generating the sensation or experience of emotion. So I think we'll leave it there. Hopefully you found that interesting and somewhat informative, even if we weren't able to give very definitive answers to the questions about what emotions are or how to classify them. But nevertheless, hope you learned something. If you enjoyed the show, consider supporting the podcast by leaving a favorable review on iTunes or Spotify or the aggregator of your choice. If you have questions, suggestions or other feedback, feel free to send me an email. My address is Fodst12.g.com. That's FODS-12 at gmail.com. You can also support the podcast financially.

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