The physiological psychology of curiosity

Introduction

This text is inspired by a brilliant 1976 article entitled «The physiological psychology of hunger». In it, researchers Friedman, Stricker and Edward discuss various known physiological mechanisms that regulate hunger. They argue for a shift from the brain-centered view of hunger to more ecological and systemic view where hunger and subsequent food intake are driven by the multiple signals from energy metabolism. But hunger is still often seen as something mental, an emotion formed in our head and even something to be controlled by conscious will. Friedman, Stricker and Edward give us numerous examples of why that is a faulty picture of hunger in any species by presenting us with experimental data on the effects of changing the availability of metabolizable fuels for specific cells.

My goal in the following is to visit some of the fundamental factors shaping the physiology of curiosity or drive for learning and to see what these tell us about how we can and should teach. Reductionistic perhaps, but revisiting the foundation on which we base our practices can also bring new knowledge or at least remind us of things forgotten. Learning is in many ways comparable to feeding. To live is to learn. We always learn because learning for any species is how we adapt and survive. Feeding is also a basis for survival as it provides the energy needed to fuel a body and nutrients to build our cells. Language illustrates how we equate feeding and learning with phrases such as «hunger for knowledge» or «satiate my curiosity».  

In the same way that we must ask what the drivers of food intake are we must ask what the drivers of learning are. Hunger may at first glance seem a simple phenomenon as a signal from the brain via an empty stomach resulting in feeding, however decades of research has shown us that hunger is deeply complex. In fact, research suggest that the main driver of food intake is not hunger, but the absence of fullness (Cornil, 2017). In addition to the obvious sensory specific satiety, we are satiated by a decline in enjoyment (Cornil, 2017) while eating. Food intake is also driven by other physiologic and cultural ques. We eat because it is time to eat, whether we are hungry or not, we eat because of low blood sugar perhaps caused by stress. Pregnancy can cause large alterations in hunger as well as other conditions resulting in altered hormonal milieu and so on and so on.

So, is it the same with learning? Is our curiosity gradually satiated as learning becomes less satisfying? And if so, how long until a renewed hunger for learning appears? What are the physiological drivers and inhibitors of learning, and what external factors affect learning the most? And most importantly, do we structure our teaching to fit our physiology, or do we attempt to force our physiology to adapt to our preconceived notions of learning, much in the way we try to pass rows of highly palatable foods in the store by sheer willpower?

As a framework for this short exploration of the physiological psychology of curiosity I will use the 2018 publication by The national academies of sciences titled «How People Learn II: Learners, Contexts, and Cultures» (HPL II) (Sparks, 2018). This is a peer reviewed consensus study report documenting the evidence-based consensus on different perspectives on how humans learn. The report covers learning through the life span and is written by The Committee on How People Learn II: The Science and Practice of Learning, created by the National Academies of Sciences, Engineering, and Medicine. According to the report, the committee was charged with: «[…] reviewing and synthesizing research that has emerged across the various disciplines that focus on the study of learning from birth through adulthood in both formal and informal settings.» The report focuses on research and research approaches with greatest potential to influence practice (Sparks, 2018).

The physiological psychology of curiosity and learning

First, a brief definition of learning is in order. However, briefly defining learning is no easy task as there are both multiple definitions and multiple perspectives from which to define. For the following, I will define learning in a «basic» and physiological sense since I will stay close to physiological perspectives throughout.

At the core, learning in any organism is a process that results in a change in knowledge or behavior as a result of experience. The change in knowledge and or behavior comes from a change in the central nervous system. Our brain adapts as we learn, and the adaptation is a continuous shaping and reshaping of neural connections as well as shaping and reshaping in non-neuronal cells and structures such as astrocytes (Koeppen et al., 2018) and myelin (Long & Corfas, 2014).

Because learning is structural anatomical and physiological change in us, learning itself affects future learning. Any parent, or dog owner for that matter, knows how reinforcement, positive or negative shapes behavior. As an example, positive reinforcement is when a behavior is rewarding or the behavior is followed by another stimulus that is rewarding, thus increasing the frequency of that behavior (Schultz, 2015). The reinforcement is at a physiological level controlled by midbrain dopamine receptors (Steinberg et al., 2014).

For the sake of the following, we can also connect two terms of similar meaning, memory and learning. What I have learned is stored. When it is stored, be it knowledge or physical skills, it is memory and can be retrieved. We usually talk about long term memory when we talk about learning and separate it for working memory which can we considered a temporary storage form.  

Learning is the continuous shaping and reshaping of brain structures. This process starts when we are born and ends when we die. Yet we know from experience that we can experience stronger and weaker drives to learn. Some things spark our interest while some do not. When fatigued even the simplest push to think is tiring. The all-encompassing curiosity we can feel exploring something new as a child is clearly a strong drive to learn. In the same manner I suspect many know the experience of being told to learn something when there was not only a lack of passion and inquisitiveness but a feeling of resistance to learn. For some, this is descriptive of their whole school experience. Experiences like these illustrate a qualitative scale of drive to learn. And going back to the hunger analogy, the all-encompassing curiosity experienced by a child deeply emersed in something is a self-perpetuating state just like the aperitif makes us even hungrier and makes us enjoy the meal even more. It feels good to be this emersed in something. This state or learning process is inherently meaningful and is the main goal and driver of our motivation rather than some achievement ahead in time (Gray, 2013).

The positive end of the scale, where the emotional and psychological state is one of strong drive to learn, seems to be characterized by a particular physiology. For example, dopamine afferent neurons in the prefrontal cortex are important for the motivation to learn (Puig et al., 2014). The neurotransmitter dopamine plays a significant role in creating reward or rather the anticipation of reward. A reward when we are learning can be understanding something or solving a task and is thus what is often termed internal motivation. This dopamine system can also be «hijacked» in situations where unhealthy behavior is learned, often with external motivation such as in gambling (Anselme & Robinson, 2013). The release of dopamine also serves to strengthen that which is being learned.

In an article fittingly entitled «The Hunger for Knowledge: Neural Correlates of Curiosity», the authors argue that neurobiological data support an information-gap hypotheses that states that curiosity is linked to anticipation of information, and that information is a secondary reinforcer (Kang et al., 2008). Also, an important finding relating to curiosity and with relevance for teaching is, in the words of the authors; «The fact that curiosity increases with uncertainty (up to a point), suggests that a small amount of knowledge can pique curiosity and prime the hunger for knowledge, much as an olfactory or visual stimulus can prime a hunger for food.»(Kang et al., 2008)

In fact, the giving of answers or showing of solutions can be an effective killer of curiosity, at least of the inquisitive perceptual curiosity. A well-known example of this was given in an experiment from 2011 (Bonawitz et al., 2011). Children (average age of 4,8 years) were presented with new toys and under different experimental conditions the children were allowed to play with the toy after an adult pedagogically demonstrated a function of a toy, after an interrupted pedagogical demonstration, after a naïve adult demonstrated the function, and at baseline. The researchers found that teaching constrained children’s exploration and discovery. The children who were taught functions of a toy performed fewer kinds of actions on the toy and discovered fewer of its other functions, than the children who did not receive a pedagogical demonstration. The article is fittingly named «The double-edged sword of pedagogy: Instruction limits spontaneous exploration and discovery». If this finding represents a true feature of human curiosity, then what are the consequences for learning in adults? And is a physical multifunctional object representative for how an adult explores a theoretical subject? The answer deserves a larger discussion than is the scope of this text, however we should be conscious of the fact that there seem to be a trade-off in any case of such inductive pedagogy and so we should ask what we lose and how much.

There are studies in adult students suggesting that students learn better (even if they themselves do not experience it this way) by active and exploratory learning than passive didactive methods (Deslauriers et al., 2019) and this may be a feature of our curiosity and thus hunger for learning.

Curiosity or a drive to learn and explore seem to be both an inherent feature and our default state. A lack of curiosity is pathological. For example, reduced curiosity is a hallmark of depression. Curiosity is inversely related to depression and positively related to subjective wellbeing (Spielberger & Reheiser, 2009). The technical word for the loss of hunger to learn (i.e., curiosity) is anhedonia and it is the major symptom in depression.

Physiological conditions of strong drive to learn seems also to be recognized by low stress and restedness (Drexler & Wolf, 2017). Stress is broadly speaking any environmental demand that exceeds our natural regulatory capacity and can be both physical and psychological in nature. From an evolutionary perspective acute stress should help us learn. For example, to better remember a dangerous place with dangerous animals that scared you, should give you an evolutionary advantage. Some studies seem to also suggest that this form of acute stress can enhance some memories (Trammell & Clore, 2014). However, recent research suggest that many forms of stress will impair learning and memory consolidation (Trammell & Clore, 2014).

As with feeding, curiosity is shaped by internal and external factors. An example of an external factor is spacing. As a university teacher and course designer I have to make decisions about when students should learn what they should learn and how much they should learn in a certain time. It matters if learning is spaced out over the course of a semester or if it is packed tightly just before the final exam (Carpenter et al., 2012). Research suggest that we often need surprisingly long ting for new information and new knowledge to stick (Carpenter et al., 2012). This is one argument for avoiding too intensive courses and to give students time to let new material sink in. The effect of spacing can be seen both in the space of a day and in the space of weeks where studies has shown increased learning with larger spaces (Carpenter et al., 2012).

One reason for a spacing effect over the long scale is sleep because both sleep quality and quantity greatly affects memory consolidation (Boyce et al., 2017). It is sleep that allows for wakefulness and it is sleep that allows for learning. Lack of sleep and poor sleep is vastly deleterious for all systems of our body (Freeman et al., 2020) and can be easily measured even after a single night of poor sleep (Walker, 2017). Sleep problems increases risk of depression and anhedonia and is a well-known killer of  curiosity (Walker, 2017).

How people learn – Implications

We could imagine that our role as educators should not simply be to make sure students learn curricula, but that we also teach them how to learn. We can even imagine teaching students about the role of sleep in learning, all be it with a risk of creating orthosomnia or an unhealthy obsession with getting good sleep. I find it a valid question if we should, especially if we consider it our role to do our best to make students learn what they should learn in the healthiest way possible.

But an obvious question emerges of where we should draw the line. Should we give nutrition advice or teach stress management skills? Both nutrition and stress can play a large role in how we learn.

But there is definitely something we can do as educators to nurture good learning. For example, since stress plays a seemingly important role in learning we should strive to make any learning situation experienced as safe and make it so that that emotional arousal comes from the excitement of learning, understanding or feelings of exited curiosity.

In fact, perhaps we should treat our students more like plants. Jokingly as it may seem the plant analogy holds water (pun intended). If you want a plant to thrive and be healthy, you make sure to give it just the right amount of water, light, soil properties and so on. Then you lean back and watch it grow strong. Professor in developmental psychology, Alison Gopnic uses a carpenter or gardener analogy to explain differences in parenting and thinks most of us are carpenters when we should be gardeners (Gopnik, 2016). A parent who is a carpenter thinks that his or her child can be molded and that if you just do the right things, get the right skills, read the right books, you’re going to be able to shape your child into a particular kind of adult. The «gardener,» is less concerned about controlling who the child will become and instead provides a protected space to explore. It is a matter of «[…] creating a rich, nurturant but also variable, diverse, dynamic ecosystem.»(Gopnik, 2016)

Biologist Sir Peter Medawar once wrote that «Biologists work very close to the frontier between bewilderment and understanding. Biology is complex, messy and richly various […]» (Medawar, 2009). Learning is a function of our biology and thus also vastly complex, most of all because of the many ways our environment can shape us. HPL II writes:

[…] different individuals would be expected to grow or decline at varying rates, depending on the characteristics of their environments, exposure to pollutants that affect neurophysiological functioning, health and sleep habits, and many other factors. Every individual’s trajectory will be idiosyncratic and depend on his particular experiences with schooling, work, family and community, hobbies, and more. Further, there is not one standard age at which abilities change in a way that affects learning and development. (Sparks, 2018, p. 199)

In my view, this quote is an argument for us as teachers to take the role of a gardener. The best we can do, and what we should do our best to do, is to create a nurturing environment. And perhaps it is also in our interest to teach student how they themselves can optimize their environment through for example healthy habits and study skills. The quote also stresses our individual differences. No students are the same, some need more time some need less. Some prefer talking and some prefer reading. A safe and nurturing learning environment allows for students to learn in the way they learn best and is an environment that allows for different strategies and different needs. This is a logic consequence if our goal is to maximize students’ motivation. The narrower the learning environment and the less it allows for, the more students will have to fight harder to keep up their motivation.

Motivation to learn is in large part synonymous to curiosity and both can be considered emergent phenomena, meaning that they change with changes in physiology, environment and experience. Writes HPL II: «Research suggests, for example, that aspects of the learning environment can both trigger and sustain a student’s curiosity and interest in ways that support motivation and learning.» (Sparks, 2018, p. 130)

Of course, every educator wishes for motivated students. Looking at the complex varieties of factors that affect a person’s motivation, can also be comforting in that it helps us as educators realize that there are only some of the factors we can control and that many are beyond our reach. HPL II recognizes the role of the environment and experience in shaping our drive to learn and writes in Conclusion 6.1:

Motivation to learn is influenced by the multiple goals that individuals construct for themselves as a result of their life and school experiences and the sociocultural context in which learning takes place. Motivation to learn is fostered for learners of all ages when they perceive the school or learning environment is a place where they “belong” and when the environment promotes their sense of agency and purpose. (Sparks, 2018, p. 24)

My personal experience is that it is not enough to simply show your students the wonderfully interesting and exciting subjects you are teaching, because they don’t see them as such yet. It is also possible to work with motivation specifically for example through helping them set goals or encouraging them to focus on learning instead of performance and helping them to develop a learning orientation.  

One of the major and general conclusions of HPL II is the following:

Each learner develops a unique array of knowledge and cognitive resources in the course of life that are molded by the interplay of that learner’s cultural, social, cognitive, and biological contexts. Understanding the developmental, cultural, contextual, and historical diversity of learners is central to understanding how people learn. (Sparks, 2018, p. 22)

As I’ve argued here, learning is the stored knowledge resulting from the interplay between the physiology that constitutes a body and its environment. Curiosity is similarly shaped by the sum of our experiences and curiosity shapes us. It seems that we know a great deal about how we learn at the most basic level and how we best learn i.e., how we learn the fastest or most efficient as well as how we learn in a way that is constructive and healthy. Understanding the developmental, cultural, contextual, and historical diversity of learners as HPL II puts it, means we can work with the homogeneity that are student groups, and work with unique individuals.

Reflecting on these conclusions it is obvious that they can and should play a part in my structuring of university teaching. I should ask if a classic one-way lecture increases motivation and curiosity in as many students as possible or if there are better ways to reach this goal. How I answer questions from students will of course affect their feeling of wellbeing and belonging and wanting to learn more. How long I teach and how long brakes I allow for, how I give feedback, how students give feedback, how I structure final assessments are but a few examples of choices I make that constitute a student’s learning environment. A learning environment that is one of the most important factors that shape curiosity.

I had a cat once. I am not sure if it was curiosity that killed it. I am sure however that it is easier to kill curiosity than to create it.

References

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