Are humans on autopilot, relying on habits to navigate the world, or are we fully in control of our lives, actively deciding who we are and who we want to be? Relying on her personal research and advances in the field of neuroscience, Professor Victoria Templer Rotkow examines human and nonhuman animal behavior to investigate the power of habit, how much agency we have in our lives, and our capacity to change.
(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. Victoria Templer Rotkow is Associate Professor of Psychology at Providence College, where she is Principal Investigator at The Neuroscience, Animal & Cognition Lab (“NAC Lab”). She is also a member of Temple Emanu-El in Providence, RI).Read Transcript
Michael Fel: My name is Michael Fel, and I’m the Senior Rabbi here at Temple Emanu-El. And it’s my pleasure to welcome all of you this morning to the first of what will be a series of “Brunch and Learns,” an opportunity not only to enjoy delicious food, but also have a chance to ask me questions, specifically: “What makes us human?” Trying to understand what makes us different from the animal world, what makes us uniquely a different type of creation in the world.
And so we’re joined online by our friends on Zoom, as well as nearly 100 folks who RSVP’ed and wanted to learn about this interesting topic. It really comes from the pandemic going on and seeing how the pandemic changed all of our lives, but specifically realizing that so many of us were struggling with either depression or anxiety or stress during the pandemic, led me to rethink what it means to be fully in control of our lives, right as much as we want to be positive. We want to be optimistic we know we’re going to get through this. It was often really difficult to find the koach, the courage, the strength, to have that attitude. And given what we’ve learned about neurodiversity, given what we’ve learned about neuroscience, what we’ve learned about the chemistry of what makes us who we are, I began exploring this question of “what makes us who we are?”.
And so I went on a walk with Peter Saulson, a fellow congregant here at Emanu-El. And I asked him, and unbeknownst to me, he didn’t have the answer. (laughter) But he said, “I was part of this amazing fellowship with Sinai and Synapses, and maybe we can use that to further explore this question.” And going through that process, we put together a working committee, not only with Peter Saulson, Dennis Gilbride and also Vicky Rotkow, setting up a series of lectures answering the question, “What makes us human?” through the lens of neuroscience, astrophysics and psychology. And of course, I’ll bring in the Rabbinic perspective as well, because that’s my job, right. But trying to answer those big questions in the sense of not to see who’s right, science versus religion, but to see what each can share and what voice they can lend to this conversation.
I want to recognize that we are joined on Zoom by the Director of Sinai and Synapses, Geoff Mitelman. So we wave to you, and I’m going to do this so everyone can see you as well. You can see Geoff, let’s all wave, let’s say hello. He’s much bigger in real life, I promise.
On Tuesday nights, it’s not required to be part of this class, but about 20 individuals have been learning about free will and determinism, studying the texts of Rambam – Moses Maimonides – and Rabbi Hasdai Crescas, looking at two different perspectives on free will. So folks, for doing that, we have these three lectures coming in every other week, every other Sunday. And then sometime in March, we have a presentation [with] Rabbi Jason Rubenstein, who will be our keynote speaker, addressing these issues from the perspective and being in conversation with everything that we’ve learned.
The format for this morning, as we’re going to, in just a moment, introduce Viktoria Templer Rotkow, our presenter, and she’s going to speak for a little bit, she has some exercises for us to think about and work through, and share some of her research. And then I’m going to have a rebuttal and say why Judaism knows everything. (laughter) Just kidding. It’s all adjacent to each other.
So with that, the topic for this morning is: are humans on autopilot, relying on habits to navigate the world, or are we fully in control of our lives, actively deciding who we are and who we want to be? Relying on her personal research and advances in the field of neuroscience, Professor Victoria Templer will examine human and non-human behavior to examine the extent of how much agency we have in our lives, and our capacity to change. Victoria Templer Rotkow holds a PhD in neuroscience and animal behavior from Emory University in 2014, and is an associate professor of psychology and director of neuroscience at Providence College. In her research laboratory, she develops animal models of memory, learning and attention that answer both that answer both behavioral and neurobiological processing questions. The substrates of different memory systems are implicated in human aging, disease and mental health, and inform cognitive evolution in the comparative cognition tradition.
It doesn’t say here in your official bio, but you’re also a member of Temple Emanu-El. And we thank you for that, along with Eric and your kids, Zahava and Jack. I also want to recognize that your parents are watching on Zoom, who I’m sure are incredibly proud of you, and the little Zoom box does not contain the smiles on their faces. So they are watching this morning as well.
Without further ado, it’s my pleasure to welcome our presenter this morning, Victoria Templer Rotkow.
Victoria Templer Rotkow: So thank you all for being here on a Sunday, I’m really excited to be here. I just want to thank Sinai and Synapses, Peter Saulson, Dennis Gilbride and of course Rabbi Fel for putting this together. So I’m hoping that some of you will join me in saying that you’ve had a similar experience to me, where occasionally I will go into a store, I’m waiting for the cashier to finish doing what they’re doing, and I say “Did I already give you my credit card?” So I don’t have to fit the epithet of “absent-minded professor” that my students confirm most of the time. You guys will join me in thinking that things like this happen to us, right. We’re driving home, perhaps, or we need to stop at the store when we’re driving home from work, and all of a sudden we find ourselves! — so this is just an example of how visual experiences really can dominate our lives. And indeed, William James, who was actually the founder of psychology, told us a long time ago that “When we look at living creatures from an outward point of view, one of the first things that strikes us is that there are bundles of habits.”
So he wasn’t actually talking just about animals, he was also talking about humans. And research in psychology and neuroscience actually has told us that approximately 70% of our waking behavior is habitual, right. Reflexes is something different. Reflexes is when we are, say, the eye-blink reflex. If we get, you know, air in our eye, we will blink, right. That’s a reflex. But habits are, actually, I would argue, and many psychologists and neuroscientists would argue, take up most of our waking experience.
And one of the regions of our brain is that deals with habits – and I would kind of call the habit center – is the striatum. So this is an area of the brain, the basal ganglia. And the basal ganglia is a very old evolutionary structure. So your brain really evolves from the inside out, right. So those deeper structures, closer to the spinal cord, those evolved a long time ago. The outer cortex evolved later.
And so the striatum includes an area called the putamen. [They] are deep within our brains, and are really responsible for a lot of the habits that we engage in.
So there are some behaviors that are habitual that are really, really advantageous, like brushing your teeth – so these are very routinized. And we use habits to navigate our worlds.. And this is an example of a really ingrained habit, brushing our teeth. One of the reasons we know it’s so ingrained is that it’s context-independent. So you travel, you’re still going to brush your teeth. It doesn’t matter which environment you’re in. You also are extremely tired, perhaps you didn’t sleep the night before, you’re probably still going to brush your teeth, right.
Unfortunately, things like exercise, other things we probably wish were habitual, we might not do when we’re feeling tired or we’re traveling or we’re on vacation. And so this is one of the main messages I want to make about the brain. If you remember anything from today, it’s this. And this is what I’d say if I were to summarize neuroscience. What we know about the brain, one of the biggest messages, is our brains are really good at being efficient, taking shortcuts, offloading as much as possible to reflexive processes, so that we don’t need awareness. It doesn’t take as much energy expenditure. So that’s what our brains are really, really good at.
But what happens when you’re first learning something? So this is a video of my daughter Zahava. She was just four at the time, learning to ski. And this is a procedural memory. So it’s not the same as a habit, but it is somewhat similar. You don’t really need to hear the audio, but my brother-in-law is encouraging her here, skiing. So this is a procedural memory. She doesn’t quite have the turns down at this point. She’s gotten better since then. She’s just sort of flying down the mountain. But when you’re first learning something, a procedure, it takes actually a lot of effort and engagement, right. And you know what this feels like. It’s actually taking your prefrontal cortex – that focus and attention needs to be there, right, when you’re first learning to do something. My husband will thank me that I didn’t have a video of him trying to ski for the first time. He was over 40. So this is him and Zahava, and he’s never going to try it again. (laughter) But Zahava picked it up pretty quickly. This is her when she was four, learning to bike in the JCC parking lot. This was literally her first time biking.
And so this takes a lot of effort, though. So the circuits that come online, which I’ll show you in a minute, early on, deal with a region of the striatum. And the prefrontal cortex really needs to take a lot of effort when you’re learning something new, right. And then when you have the habit down, you have the procedural memory down, you can be writing a book when you’re biking, right. Or even if it’s been a really long time – I hadn’t gone skiing in 15, almost 20 years – once you get back into it, you can pick it up pretty easily. It’s very imprinted in these neural circuits, primarily in the striatum, when it becomes really, really ingrained.
So this is a procedural skill, like learning how to learning how to bike. I would say that it’s somewhat habitual in that it’s associative, it’s linking a lot of stimuli to responses. So I want to situate this in a common human long-term memory taxonomy that I use in a lot of my research. And I’ll get into my research in a little bit, but one of the things we know about human memory is that there’s long-term memory, and within that there is implicit memory. This is also called declarative or non-declarative memory. So “implicit” is the same as non-declarative memory, if you’ve ever heard that term. And these are memories that are unconscious, right, like riding a bike. These are unconscious. We can’t consciously access them in the way we can access explicit or conscious memories. So these are memories that we can become aware of.
So I’m going to walk you through these examples. We’ll start over here on this explicit side. So these are memories that we can become aware of. So remembering what you did for Rosh Hashanah – okay. So I’m under 40, but it’s still hard for me to remember exactly what I did for Rosh Hashanah unless I think about it really deeply. But you can bring awareness, right, to what you were doing this past Fall. So that’s episodic memory, that’s remembering a personal past event. And these are the things that we can become aware of.
In this other branch of explicit or conscious memories, we have semantic memory. So these are memories of facts, right. We don’t know where we learned it, doesn’t really matter where we learned it, but we just know that the capital of France is Paris. So these we can become aware of. Implicit memories, in contrast, we can’t really become aware of in the same way. A lot of them, especially when we’re talking about habits, which are sort of like conditioning and sort of like procedural or skill learning, are are really memories that you really have to engage with the actual behavior to become aware of. And you can’t really become aware of it in the same way.
So some other examples that we’re not really going to get into, but just so you know, priming – that’s implicit and unconscious. You’ve heard a word, you might be more likely to use it later. And then within conditioning, there’s associative learning. That’s like Pavlovian conditioning, operant conditioning. And then there’s also non-associative learning, and that includes things like habituation and desensitization. Habituating to the shoes on your feet – you’re not aware of them right now, right.
So one interesting thing about this memory – taxonomy, one of the reasons that it exists, is not just that we have these typologies that make sense in our human minds. I think it was actually William James that said that “Typologies are there because the human mind likes to think in typologies, not because they’re what exists in nature.” But indeed, these taxonomies, these different types of human memory, we know are the case because of functional associations we’ve seen in neuroanatomy, and also in behavior.
So, memory: the other main message that I want you to know is that memory doesn’t just function like a video reel, right. So there are different types of memory, okay. So one reason that we know that this memory taxonomy exists is because there was this patient I’m sure many of you know of, named HM, who passed away a couple years ago, Henry Molaison, who had debilitating epilepsy, and had brain surgery to remove his hippocampus. The hippocampus is a region in the medial temporal lobe. And so he had this whole region of his brain taken out. Turns out more than his hippocampus was taken out. It would actually have included his amygdala and other regions in his parahippocampal cortex. But he had this whole part of his brain taken out, which deals with, primarily, explicit memory. So think medial temporal lobe – hippocampus really deals with this explicit memory – so, declarative memories. And interestingly, he was given this task, an implicit task, a mirror-tracing capacity task, that you learn over time. And he could learn this new task.
So these are his errors. I know it’s hard to see and it’s kind of small – on the first day, he had lots of errors, and they decreased. He came back on day two, he got better, he was even better on day three. So, he could learn a new procedural skill, an implicit memory, but if you were to have a conversation with him, he would reintroduce himself a few minutes later. After you’d had an entire conversation with him, he’d introduce himself and he’d say, “Hi, I’m Henry, what’s your name?”. So he could not encode new memories. That is, he had retrograde amnesia. He had deficits in this explicit branch of long-term memory, but he was able to create new implicit memories.
So when you think about striatum, think about these implicit memories. When you think about explicit memories, think about the hippocampus and the medial temporal lobe. So the striatum, I told you, is our habit center, and within the striatum, it really is concerned with three different things. So one of them is the habit of force, and goal-seeking behavior – also, reward circuitry. So, reward circuitry really deals with releases of dopamine in the brain. And what happens over time when you learn a habit is that the habit “takes over.” Remember how the prefrontal cortex was really involved when Zahava is first learning to bike or ski? Over time, so much striatal activity, in the striatum, can actually inhibit the prefrontal cortex. So when the habit forms, the reward doesn’t even matter anymore. It has a life of its own. This is really what happens in habits.
Now, smoking is a great example. Of course, it’s an addiction, and there are other things to say about that, but you could be not even aware that you have a flame in front of your face, that you went through the sequence of actions and steps to get the cigarette out of your purse, right. You have no – it’s a stimulus and a response. There’s absolutely no awareness taking place. Once that habit has been imprinted on your brain, it has a life of its own.
So just to kind of explain how that habit gets imprinted on the brain, I want to tell you about a research study. So this is the most neuroscience you’re going to hear in the next few minutes, so bear with me. I’m going to try to make it make sense. So this was not my study – this was actually by Kyle Smith and Ann Graybiel, who was at MIT at the time. Now, in this study they had rats trained on this T-maze. So they hear a tone, and they go over to the left arm and get chocolate milk, and that’s rewarding. They go to the right arm and get sugar water.
What they do is they over-train this behavior. So they give the rat hundreds of trials. And they learn this really, really well. And they do some experiments called devaluation experiments, where they actually determine that a habit occurred by devaluing one of the stimuli. So they make the chocolate milk actually make the rat nauseous, and he will still go over, reliably, to that reward, even if it makes him nauseous, okay.
So the habit, when it first gets imprinted, when you’re first exploring an environment — you’ll see here, this is actually neural firing patterns in the striatum. So they use a technique called electrophysiology, where they can actually record in real time from the rat’s brain. And so what you see here – this is high activity in red. So when he’s first exploring, there’s more activity in the striatum, and then as the habit starts to form, you see that there’s kind of less activity in the striatum. And when the habit is fully imprinted, the striatum only comes online at the beginning of this sequence of actions, and then at the end.
So it’s as if there are a few kind of “expert” neurons or cells that become active at the very beginning, and then when the rat is actually engaged in the task, there’s not a lot of activity that is necessary. And this is something that is called “task bracketing,” in the neuroscience literature. And it’s been applied, actually, to how we can create new habits, which we’ll talk about in a little bit. But task bracketing really just means that it’s the beginning of the sequence of actions, of steps. It’s sort of “chunked” or “packaged” all together in one sequence, just like getting that cigarette out of your purse and lighting it. Once the action is sort of set in motion, it’s really just in motion, and it’s going to be there.
So that’s task bracketing. There’s a few of these “expert” cells that come online early in the sequence of actions, and then at the end. So this figure is going to look like a lot, but I’m going to tie it back into what we just showed. This appeared in a Scientific American article in 2014. You’re welcome to look it up. And this really explains how habits form. So that study really, really taught us a lot about the neural circuitry in all the phases of creating a new habit.
So the first one that happens is that this new behavior is explored. So this is a prefrontal cortex, a highly evolved outer region of our brain. It comes online when you’re first learning something. So the prefrontal cortex – think back to that video of Zahava, right. The prefrontal cortex – you need a lot of effort and attention when you’re first learning something. It comes online at this point, and is engaged with this part of the striatum. It’s the more anterior, or sort of forward, part of the striatum when the habit is first being learned.
While the habit is forming, this more posterior part of the striatum – you don’t need to worry so much about the details, but another part of the striatum, talks to the sensorimotor cortex, that involves our actions and in our body, and the proprioceptive feedback we get from that. And so this striatum-sensorimotor cortex pathway is engaged when we are learning something.
And then what happens is it recruits dopamine from the hypothalamus. So dopamine – always think that’s in your reward circuitry. So while the habits are getting imprinted in that sort of middle stage, if we go back to this figure, right, this is when the habit is getting imprinted. And this is when dopamine starts to be released. It becomes extremely rewarding. Remember, the rat didn’t even need to be getting the reward anymore. It even made him nauseous, and he’s still going back. The habit creates a life of its own.
And then, even further on, we have the infralimbic cortex. And the infralimbic cortex is an area of the brain that is in the medial prefrontal cortex, and it deals with the maintenance of that habit. So it’s in the cortex. And what it does is, it can kind of toggle a habit on and off. So what these researchers did is they actually turned off an area of the brain called the infralimbic cortex once they had established this habit. So the habit was extremely imprinted, and then they went in and turned off that area of the brain. And what they found is that the good habit, the habit of going to the sugar water, stayed, but they stopped going to the chocolate milk that had made them nauseous. So they actually created a new habit, right, by turning off this infralimbic cortex. And then what they did is that habit gets imprinted. And then again, they go back and turn off this area of the brain again – the infralimbic cortex. Turn it off again, and that habit comes back.
Okay, so why is that important to you? The chocolate comes back, thank you. So both of them came back. The old habit that we got rid of came back. So that means that, right, just like if you haven’t smoked in 20 years, right, once you’re in a certain situation, it can come back online. So don’t worry so much about the infralimbic cortex – I’m not testing you on the neuroanatomy of it. But the point here is that that old habit, once it’s imprinted on the brain – even if we unlearn it, it can come back.
So another example: I was a lifelong nail-biter. I stopped when I got an engagement ring, right, I had to show off my ring. And then I had a particularly stressful semester last semester. And when I’d see a stimulus – it’s really stimulus-response learning – if I see something that I want to fix on my nails, I immediately start biting them again, even though it has been 10, 15 years since I did it. And you can kind of think of the cortex, of part of your cortex, the infralimbic cortex, toggling this habit on or off. Even if it’s been so long since you actually had the habit, it can re emerge.
Okay, so there are multiple brain circuits. Here’s what you need to know about this. There are multiple brain circuits. There are chunks of sort of neural activity. They saw that “chunking” pattern, or that task bracketing, in both the infralimbic cortex and the striatum. They saw that chunking activity, and even though these are very, very automatic, what this actually is telling us is that in our neocortex, right here, we can actually toggle these habits on or off. So we actually do have some control over these habits, even though they do have a life of their own.
Okay, that was most of the deepest neuroscience we’re going to go into. So I hope you’re still with me. So, habits, like I said, take up about 70% of our waking behavior. And a habit is really when our nervous system is learning something, right. That’s really all a habit is, is when our nervous system is learning something. And so I told you, habits, we can see over here in the implicit part of memory. And so if we say that habits are when our nervous system learns something, you might ask, then, what is learning? Okay, so here are a few really important points. So, learning really is neuroplasticity. You’ll hear about neuroplasticity everywhere these days, right – buy a brain training game. It’s all, you know – I should have probably gone into these types of businesses to make money off of this. But really all it is, right, is that the connections between neurons are changing. This is neuroplasticity. And this, you know, has changes in neural circuitry, changes in connections between neurons, which is the synapses between neurons. And how does this happen? How does learning or neuroplasticity happen? It happens because of experience, attention and repetition. Experience, attention and repetition.
Habit formation is an example of this. Unlearning a habit is also an example of this. And like I said, there’s these changes in connections between neurons. And so I could give a whole lecture, which I love talking about the neurobiology of this, of how does this actually happen at a synaptic level, because it’s very, very interesting. There’s physical changes that can happen. Synaptogenesis is connections between synapses forming between neurons. There’s also neurogenesis – actually creating new neurons, things called long-term potentiation. these are all changes that happen at the level of the synapse, the neuron. You can create more receptors for neurotransmitters to attach to. These are all examples of neuroplasticity.
So the nervous system changes in response to experience. The most malleable when our brain is 0-3 [years old], and then, from then on, birth to 25, when the prefrontal cortex stops developing. But you will be happy to know that a lot of studies have been done indicating that even after 25, up until any age, learning new habits, neuroplasticity, is possible, as long as you have enough focus, attention, awareness and intention.
So we used to think our brains were were not so plastic. Now we know they are very plastic. And it actually doesn’t matter as much as you might think it does how old you are, as long as you can engage these parts of your cortex to have these sort of top-down influences on these older parts of our brain, if you have focus, attention, awareness. And what happens is that neurons are marked for change. They’re marked primarily through acetylcholine. And the neurons, the changes that take place in your brain, don’t actually happen until sleep or deep rest. So they are sort of marked. You get neural circuits and neurons that are kind of marked for change, but they don’t actually make those changes until you engage in deep rest or sleep. So sleep is really important. That’s a main message: take your sleep seriously. It can flush the brain with cerebrospinal fluid that can be protective against dementia and Alzheimer’s disease. But neuroplasticity actually takes place during sleep.
Another message about neuroplasticity that is worth making is the Hebbian synapse. So the Hebbian synapse is really just this idea that when we have co-activation of two neurons – neurons are firing together. You’ve probably heard this before: “when neurons fire together, they wire together.” So Donald Hebb was around a long time ago, and before we even knew about the changes that take place on the NMDA receptor – we know now NMDA receptors and all the details of how this actually works metabolically. But before we even knew that, he said he knew he said “If A keeps firing at B, some growth process or metabolic change takes place in one or two cells.” And this is really what happens in neuroplasticity.
So I want to tell you about an interesting study. So it turns out that if I were to tell all of you a health message – so I tell you about how exercise is really, really important for you – it turns out most of you will not start exercising more. It just doesn’t really work, right. But what does work is if I tell you to do something (I’m going to have you do in just a minute, after I tell you this) to think of not just goal-based habits. Goal-based habits are saying, “I want to start walking after dinner.” That’s a goal that I want to do every night.
But identity-based habits – so, identity-based habits are things where we’re invoking our value system, right – what is important to us? What is relevant to us? What are our chief, core values? It turns out that when people are sort of thinking about these, their chief core values – if you ask them to do that, to talk about, their chief core values (which I’m going to have you do in a minute, so you can start thinking about it) – an area of the brain, in their prefrontal cortex, the ventromedial prefrontal cortex, comes online. And what you see is that then you get that health message about why exercise is important. And you’ve activated your ventromedial prefrontal cortex, and you know that this is important to your life and living a long life, and engaging with your family and friends, etc, etc – invoking your chief, core values, your personal values, identity-based habits – that you do see this decrease in sedentary behavior after you get that help.
Okay, so you can guess what I’m going to ask you to do. I’d like you to take four minutes to just write on your phone app – there might be pieces of paper that we passed around – to do the following. So I’d like you to take a few minutes to write what your core values are. What’s most important to you? So you can think about (#1) family, friends, faith, religion, community, creativity, humor, spontaneity, fitness, hard work… and then think about, if you’re done with that, think about (#2) habits that you have that you want to maintain, (#3) habits that you might want to break. #2 and #4 are sort of similar, but really the last ones (#4) are new habits that aren’t really habits for you, what you’d like them to be habits.
I’m asking you to do a lot, I know – just do what you can.[…]
Okay, in the interest of having time to know why this is all important for Judaism, and Rabbi Fel’s insights later, I’m going to move on, but feel free to continue thinking about this or writing.
So I’m going to have you pull this up later, but first, I want to tell you a little bit about my research, and then we’ll sort of go back into these chief, core values. Okay, so I’ve showed you this common human memory taxonomy. And one thing that I’ve always been interested in is if animals have episodic memories. We know this taxonomy exists in humans, but does the same type of functional and structural associations exist in non-human animals? Okay, so episodic memory, that’s remembering your personal past events. I’ve always been interested in whether animals have memories of their own, personal past events.
So episodic memory, just to unpack this a little bit more, is memory for personal past events. So we know humans have it – you can tell me what your vacation was like, you can tell me what you were doing, where you were, when it occurred. These are kind of the three main elements of episodic memory. Endel Tulving was a human researcher that coined the term “episodic memory” [for when we] remember episodes. And one of the hallmarks of episodic memory is that there are sequences of unique events that occur over time, right. So your vacation day, you did all these wonderful things in a particular order, so much so that you could report which came first: you sat on the beach before you went snorkeling, right? You can remember the order of these events. We can contrast this with other types of sequence memory. We’ve been talking about these types of routinized, highly automatic or behaviors that have a lot of automaticity. And automaticity just means that there’s neural circuits that are really automatic, right. So likely you have a morning routine that follows a particular order – this is repeating. It’s highly routinized.
So my question was: how are these two different types of sequences represented, one being unique events and one being more routinized? So always following the same order, you might guess that this one is more episodic – right, that’s sort of the “when” aspect of episodic memory, that includes that “what, where and when” component. So that’s episodic-like, whereas these routinized responses are more habit, like implicit.
And so I was interested, actually – this is back in graduate school – in the evolution of memory system. So how is it that monkeys – how would they represent episodic-like memory sequences of unique events, and how might they represent routinized sequences of responses that are more habit-like or procedural, the sort of “chunking” behavior of doing something in a sequence of actions?
And so, why rhesus monkeys, you might ask? Well my answer is that they are extremely interesting to us because we share a common ancestor with them that existed about 30 million years ago. I will be talking briefly about rats, which my lab now is primarily rats, which we have a common ancestor that existed about 90 million years ago. But rhesus monkeys are an old-world primate, and they share many of the same brain structures to us. Rats actually do a more more than you might think. So those same areas of the brain that I talked to you about – the striatum, the infralimbic cortex, the prefrontal cortex – are actually very very similar. So they have a lot of shared cognitive and neural mechanisms.
So here’s a video of some of my monkey boyfriends back in graduate school doing these tasks. And I spent a lot of time with these guys. So here you’ll see on the left here. This is Neo, I think. It’s been a while since I knew these guys. This is him. You’ll see him on a touch screen where he’s touching images in a particular order. So he touches an image, it’s a unique image, sort of like an event on a vacation. It goes away, he sees another one, and at tests he’s going to be tested on which one came earlier. And then I’ll show you the other video. So this is really what I did in graduate school, was program computer tests like this for monkeys and they get M&M’s and rewards when they get it right. Okay, so you saw that you saw five images and I tested gets to any two from the list and decides which one came earlier. So that – think of unique sequences of events.
And here’s another task of routinized sequences of responses. I just want to make it clear that this is a five-item list. The images can appear in any of the 12 locations on this grid. So it’s not location-based, but it’s action-based. And then I give them something called “pro” tests, where there’s just two items from the list, but just worry about the five-item list for now. And you’ll see what it looks like.
So they get very, very good at this, learning to touch five items in a row. And then they get a reward for doing that whole sequence of actions.
Audience member: You should see him check email.
Victoria Templer Rotkow: I mean, they’ll test all day like this.
Audience member: They never get sugar rushes?
Victoria Templer Rotkow: I mean, we offer them the M&M’s every 10th correct trial, so they get other nutritionally rich pellets.
We, in this lab, only use male monkeys, which is actually an issue in science, I think. The NIH has come out with a lot of statements about this, I’ll talk to you about it later. But there’s good reason to use males in this study. And in science in general, yes, males are used more often than females. Females are more complicated, hormones get involved and it can change cognition throughout their cycle.
And anyway, okay, so this is unique sequences of events that this task that I showed you. That was: seeing the different image, and then seeing five different images in a test, choosing which ones earlier, and then this one is the sequences of routinized responses. So this one is more episodic-like, this one is more habit-like.
So I wanted kind of two different types of tasks that are hopefully modeling an aspect of explicit memory and implicit memory. And the question is: are they accessible to awareness? Remember, that’s what was the hallmark of explicit memory; you can cognitively access and become aware of your memories. And so the way that I did this is I implemented a metacognitive component. Metacognitive just means “thinking about thinking.” So what I did is I gave animals this task. And at tasks, I give them a forced test, which means they just have to click this check mark, and then they choose which one came earlier, and they’re rewarded for which one came earlier. It’s a forced test, as you have to answer it. If they get it correct, they get two pellets; if they get it incorrect, they get no reward.
Let’s contrast this with choice tests. So we intermix choice tests. With choice tests, we give them the option of saying, “Yes, I want to take it,” and if you get it correct you get two pellets, or, “No, I don’t want to take it,” and you get one pellet if you decline the test, which is this button over here. And you get the guaranteed but less-preferred reward.
Okay, so some of you remember the SATs used to be like this. Do you guys remember this? So if you get it correct, you get plus a point, if you get it incorrect, you get minus a quarter of a point. If you leave it blank, you get plus or minus zero, right. So if you know you don’t remember the Pythagorean theorem, it’s advantageous for you to skip that question, right, and not answer it.
So we basically give monkeys these same types of tasks. I’ve had actually done the same thing with rats as well – no time to tell you about that. We contrast these forced tests with the chosen test. And the idea is if monkeys can distinguish between knowing and not knowing, they should perform, this is predicted, significantly better on those chosen tests, where they have the option to decline tests that they would have gotten wrong, had they not had the option to decline tasks that they know they don’t know. So they have a performance advantage on these.
Okay, so I gave monkeys those two types of trials in that task. I also gave them the same sort of paradigm in this other sequence task that was routinized. So if they get it correct or incorrect, that’s two pellets, and then in the forced test. And in the choice test, if they decline, if they get that guaranteed or less-preferred reward, and if they get it correct, they get a higher reward. You want the higher reward, so if you know you know, you want to say “Yes, I want to take it,” and you want to answer it, and you’re more likely to answer it correctly.
Okay, so the question is: what do we see? Well, is this task accessible to awareness? We saw that performance advantage. Performance on chosen tests was significantly higher than [on] forced tests. So I think, yes, it is accessible to awareness. There’s lots of other experiments needed related to this task. This task, the answer is no, there was no significant difference between those chosen tests and the forced tests.
So what can we say about monkey memory awareness? I would say that like humans, monkeys can have awareness of these explicit episodic-like memories. And also like us, they do not have awareness of those implicit or more habitual memories. So performance on both of these tasks – we actually had these monkeys that had hippocampal lesions, where their hippocampus wasn’t working. And that, I don’t have time to talk about those results, but the overall arching theme of – we did dozens of experiments that we thought were explicit. They were still able to do it without their hippocampus. That’s another discussion you can ask me about it later.
But I’ve also done similar tasks in rats where they’re actually digging in cups, and they can opt out of memory tests. And we actually found a similar result, where they do have that performance advantage. So I do think that rats do have some form of awareness, like monkeys. And so the question now becomes: what sets humans apart? So I gave you that rat example. Rats and monkeys, all animals, form habits in a very similar way to the way humans do. We all follow the same laws of nature. I think laws of nature apply to thoughts and behaviors – neurobiology – but I would argue that awareness is different in humans. So what I mean by that is that humans can have intention and awareness, kind of more advanced metacognition – metacognition, again being thinking about thinking. I think that we have this more advanced or concrete aspect of metacognition, where we can think about our own mental states and engage in these monitoring and control processes to have humanistic or psychological growth, right. We can thought-stop, we can engage in cognitive behavioral therapy, we can try to break a habit. We can actually have control of those habits and decide we want to change our habits, um and kind of toggle those habits on or off with that circuit that I talked about, with the infralimbic cortex.
I think humans also have a greater repertoire of mental states. A lot of comparative cognition researchers – I would consider myself one – we talk about a lot of other interesting things, if you’re interested in what’s different with humans besides things that Rabbi Fel will talk about, like the neshama. We do – there are a lot of other interesting areas of research, including things like language, of course, cooperation, tool use, culture, deception, theory of mind – knowledge of others’ mental states. And these topics are studied widely in the animal literature, and I’d love to talk to you about it sometime if you’re interested.
Okay. I want you to think about where – pull up what you wrote for your value-reflection exercise. We’re almost done. Raise your hand if you had anything on there on wanting to create a new habit that related to physical health or exercise. Raise your hand if you have any of those. Okay, what about any related to sociality, for friends? Okay, great. So we’ve known for a long time that exercise is good for our brains, right. So what you can see in brain, if you look at brain morphology, we know that exercise can actually have volumetric differences in the hippocampus and medial temporal lobe. But we also see the enriched environment – so if you house a rat in an enriched environment, lots of things to play with, they have more dendritic branching in the bottom here. So in enriched housing, or exercise is really, really good for creating more connections or dendrites between neurons.
Okay, so we’ve known that exercise does this for a long time. So if you wrote down “exercise,” that’s great, it’s very good for your brain. My question was: does sociality, being social, can that have the same effects in our brains? Can that create synaptogenesis and neurogenesis? And sometimes, often in studies, that’s confounded. You know, the enrichment piece and the sociality piece are kind of not independent of each other. So I wanted to do something where I separated those two. And so I was also motivated by research, primarily epidemiological studies, which indicate that sociality can be protective in our cognitive health. So we know, for example, that being in a healthy marriage is associated with lower rates of dementia, so even though these studies are really interesting, they are correlational. They’re riddled with confounding variables. And so what I wanted to do was use animals, where we control things a lot more, so that we have a model to look at how there’s this dissociation between cognitive function and cognitive dysfunction as an effect of different levels of sociality.
So how did I do that? This is my last sort of experiment that I want to tell you about, is that I had rats that were non-socially housed – so they’re all in highly enriched cages. So these rats over here live alone, but they give all these study structures. There’s one rat here on the bottom, one on the top. Socially housed rats – 10 rats are living together in this huge ferret cage. So some are socially housed, some are non-socially housed. Both have access to exercise and enrichment. And so what I did is I housed them in these conditions throughout childhood, all through adolescence, into old age. So the rat will be two years old, and that’s equivalent to being about 90 years old in a human. So we can age them pretty quickly, and look at what their brains look like, and look at what their behavior looks like.
So this is something called a radial arm maze. And what a radial arm maze is is this maze where the rat is in the center, and it is rewarded for going to these arms that are correct in yellow. So it’s 1, 3, 5 and 8. So if it goes, if it traverses down one of these arms, it gets a pellet. If it traverses down Arm 6, it doesn’t get a pellet. So it comes back day after day, and it learns to go to these arms. Now, they can also experience something called a working memory error. This is equivalent to you going downstairs to a room in your house and saying “why did I just come to this room?”. It happens to me too, right. That’s a working-memory error. And so rats will go down an arm – I’ll start to play it now. And they only go down for the first entry to that arm. So if they – let’s see where our friend goes now. All the doors open – these guillotine doors. And he goes down Arm 3. That’s correct. He gets a pellet. And then he’s going to come back to the center. If he goes down arm two next, he doesn’t get a reward, but if he goes back down arm three, he doesn’t get rewarded. That’s a working-memory error, because it means he doesn’t remember what he just did. Let’s see where he goes now. He’s – you might say, anthropomorphically speaking – he’s thinking about where to go. He goes down arm eight, [and] they get better and better at this.
And so I tested rats on this task at different time points in their life – so, in early adulthood, in middle age, and in old age. Okay, what happens now? I think he ends up failing. But all of these rats – 10 are socially housed, 10 non-socially housed – do this. And he’s deciding where he wants to go. He goes down to arm five – that’s correct. Do we get the idea here? Cute rat videos, I know. It’s more fun to watch monkey videos than rat videos, but the rats are pretty cute too, I promise.
(An audience member asked about whether the rats’ sense of smell might affect their decisions).
You know, there are pellets at all the pellet dispensers at all eight arms, so I don’t think that smell would really be an issue, but that’s a good question. We do in a lot of other tasks where the reward is differential. So it’s only on one side. We’ll crumple a fruit loop or something like that to control for smell, because they are very good at olfaction.
Okay, so what do we find in adulthood? There’s no difference between non-socially housed and socially housed in terms of working-memory errors. So the y-axis is working-memory errors. And what we see in old age is that the non-socially housed rats experience significantly more working-memory errors as compared to the socially housed rats.
So this was really interesting and exciting. As I said, the socially housed rats showed significantly less working-memory errors as compared to the non-socially housed, suggesting that sociality plays a protective role in cognitive decline due to aging.
We also looked at the brains of these rats. I don’t have time to tell you about that, but there were actually differences in the amount of activity in an area of the hippocampus. So there are really interesting age-related differences that you can look at, at a neural level, too.
Okay, so you guys have stuck with me, I’ve talked about a lot of neuroscience. The last slide – so we’re here, so the final conclusion, exercise and sociality are really good for your brain. So this is my health message to you, that hopefully you’re going to be more likely to have changes in the habits you want to take on because you invoked that value-based system, those identity-based goals that are linked to your value system.
And then the question that I started with is: are we on autopilot? And my answer is actually, yes. I do think that mainly we are on autopilot, as I said. One of the main messages about the brain that I think I take away from the brain is that our brains are really good at being efficient and taking shortcut and offloading as much as possible to habitual behavior and more reflexive behavior – more, you know, sort of primed toward automaticity. But I think we can gain control, especially in humans. We can have this top-down influence on our limbic system. These sort of deeper parts of our brain – motivation, emotion – we can have those influences through the neocortex, given we have the right attention, repetition, experience, awareness, right.
So we really can change our behavior. It’s not the same thing as just a growth mindset or changing your thoughts – you really want to change your behavior. Start with your behavior. Don’t start with your thoughts. Start with your behavior. The mood, thoughts, emotions. will follow. And the other main message is animals imprint habits just like we do. And I already made this point, that where our brains are really just designed to be efficient and to offload as much as possible. But you know, through mindfulness, through a lot of the techniques to hear about in mindfulness, we really indeed can become aware. Our human awareness is different. We can become aware of our behaviors. We can change what how we want to spend our time and what behaviors we want to engage in, and what behaviors we do not want to engage in.
Another thing that I think we’ll be hearing about in this lecture series is about free will: how much control do we have? I don’t think I do. My talk wasn’t about this, but there are people that will say that certain neuroscience says that determinism is true, that we don’t have free will. I just, for what it’s worth don’t believe in that. I think if anything, maybe neuroscience proves we do have free will. And again, if you want to have behavioral change, cultivate that intention, that awareness, your core values. Use these mindfulness approaches, and also use things grounded in neuroscience, like task bracketing, right. So that’s sort of that “chunking” of the behavior at the beginning or the end. If you want to go for a walk after dinner, put your shoes by the door, or next to your bed if you want to go in the morning. That’s chunking a behavior onto sort of the beginning or the end.
So thank you so much for your attention.
Michael Fel: Once again, a big round of applause for Professor Rotkow. The question is, who’s more engaging: the mouse – the rats, or me? We’ll wrap up in about 15 minutes or so; I wanted to just share some thoughts and some ideas about Vicky’s research. Our tradition says that when God offered us the Ten Commandments, when we stood at the foot of Mount Sinai and God said “Do you want this?” our ancestors responded with the phrase “Na’aseh v’nishmah,” “We will first do what is told, and then we’ll learn about it. We’ll listen about it.”
And so deeply embedded in our tradition is this idea that practice actually leads to a deeper understanding. In fact, several Jewish texts, when speaking about Jewish education say the first thing you do is you do the practice, and eventually you’ll come to understand why you do it. An example of this might be, for example, wrapping tefillin, right. First you start doing it, and eventually you’ll come to either appreciate the pressure it has on your hand, or go through the mantra and the motions of putting on tefillin. Giving tzedaka could be an example of this, right. How many of us grew up with a parent or a grandparent having a pushke on the counter, so you automatically would be in tzedaka whenever you saw it? It became more of a habit, as opposed to a conscious thought.
So we have, number one, this idea of Na’aseh v’nishmah. The second thing is the idea of chunking, right. There are certain practices that we just do all at once. And so for example, looking at daily minyan, the way minyan works, where there’s a tzedaka box right there at minyan to remove any obstacles to doing tzedaka. You come to minyan, or you come to Shul, and you automatically do that behavior. Perhaps another practice is leaving kippot outside of either the sanctuary or the doors of the synagogue. So as you enter, you know, how do you enter the Shul? You scan your key card, you grab a mask, or you put on a kippah, and then you walk into the building. The idea is to try to make these things a habit.
So much of our tradition is meant to turn good practices into habits. When we eat, we don’t just start diving in and eating our food, but we say barakhot before we do it, right, to sort of give us more awareness of what we’re actually doing.
I want to talk about the idea of keva versus kevanah, awareness of the act that we’re doing versus making it merely a habit. And I would argue that our tradition wants to get us out of the habit of prayer – merely coming to services and singing the songs and reciting the prayers – get us out of the habit of maybe just getting dressed or just eating. And a lot of what Judaism wants us to do is to return an intentionality into what we do. And the way we do that is with the words of blessing, right.
Traditionally, the way our ancestors imagined we woke up, that we went through the motions of waking up. Which, that is a habit, I presume, for all of us right. The rabbis wanted us to recite blessings for putting on a belt, putting on our shoes, having our first sip of water, stretching first thing in the morning. Standing up, taking our first step. So one could argue Judaism is an attempt at bringing awareness to all of the habits that are inherent to what we’re automatically already doing.
Finally, I think, Vicky, one of the issues you raise is the idea of intention-setting. And I want to highlight perhaps what is a thrice-daily opportunity for intention-setting, for what we’re supposed to do as human beings. If we look at the Amidah, which is recited morning, afternoon and evening, three times a day, it follows a certain trajectory. And I just want to highlight some of the themes that are highlighted in the Amidah, and see if any of these things resonate in the values that you wrote down earlier this morning. Some of the barakhot that we recite are for wisdom and knowledge and learning, the ability to do teshuvah, to ask forgiveness of others and develop relationships with others, the ability to ask forgiveness for the mistakes that we’ve made, for hope and optimism for the future, for our physical health, for having our needs met in terms of food and housing and having our physical needs taken care of, national aspirations for being reunited with other people with similar views, praying for a sense of justice in the world, praying for rewards, that our actions matter in this world, and praying that God hears our needs and our wants and our desires in the world.
And so what you see, three times a day, ritualized, but is also meant to be intentional, is actually focusing on all these values, focusing on all of these ideas. And so what we see [is that] prayer is actually really challenging. And one of the things that maybe sets us apart is taking the time to practice, taking the time to reflect on who we want to be, and then setting up patterns and habits to actually make them come to fruition.
Here at Temple Emanu-El, and in Jewish communities all across the world, I think we’re trying to always find a way of bridging, creating a sense of holiness, right. And it’s really hard to say, “Today I’m going to save the world,” “Today I’m going to be holy.” Those are, like, very lofty terms. And so instead, what our tradition does is it blends some of the habits that we already do – getting dressed, being with friends, being with family – and tries to ritualize them and infuse them with a sense of sanctity and a sense of kedushah, a sense of that we’re more than just what’s of this world or more than what’s of just this Earth.
So, things to think about as you go through the rest of your day – setting an intention for the day, try to lump it with some kind of habits, try to lump it with some physical thing to try to make it happen. So how does that resonate with you? What do you think about that? And does it disagree with neuroscience? Now we’re on the same page – all right, my friends, with that, I want to thank all of you for coming this afternoon. Vicky can stay for a few minutes and answer any questions if you have, but I’m sure others might have them as well. You can approach it right over here.
Our next lecture will be in two weeks for our own Peter Saulson will be presenting astrophysics’ view of free will – is that correct? Something along those lines. And with that I want to wish you all a wonderful afternoon. Thank you for being here.