#Interview: Dr. Carina de Klerk is a developmental psychologist who studies how infants learn to copy other people. This week we asked Carina what she does in the lab and what her research can tell us about our little one’s development.
Tell us about yourself!
Being fascinated by how infants develop, I did a research Masters in Developmental Psychology at Leiden University in the Netherlands. In the final year, I did an internship at Birkbeck’s Centre for Brain and Cognitive Development and it was then that I decided I wanted to do a PhD at their Baby Lab. My PhD research focused on how infants’ experience with actions influences the way in which they process and predict other people’s actions. It involved some pretty fun experiments, like one in which I put pre-walking babies on a special baby treadmill to allow me to investigate how experience with a novel action (in this case stepping) influenced how the baby’s brain responds to seeing others perform that action (I got very strong arms from holding the babies on the treadmill!).
After my PhD, I did a postdoc project investigating the development of mimicry – the spontaneous tendency to copy others’ actions. Together with the principal investigators Dr. Hamilton (UCL), and Dr. Southgate (University of Copenhagen), and the PhD student on the project, Chiara Bulgarelli, we followed a group of babies from when they were 4 months until they were 3 years to investigate how mimicry develops from infancy to toddlerhood.
This January I started as a lecturer at the University of Essex and joined the Essex Babylab!
What is the one thing you have learned in your studies that no parent should ignore?
The importance of face-to-face interaction. Making eye contact, smiling, and talking to your baby in response to their vocalization and actions will help them develop a sense of turn-taking. Furthermore, by copying your baby’s actions and facial expressions you provide them with a ‘social’ mirror which allows them to learn about their actions and emotions. Together, these earliest forms of communication between the caregiver and the infant are thought to provide the foundation for things like mimicry, language development, and even empathy.
Can you tell us a little bit more about your own research field? What are the hot topics you are dealing with?
My main research interest is the development and modulation of imitative behaviour in infancy and toddlerhood. Using a range of methods (fNIRS, EEG, EMG, behavioural studies), my research aims to answer questions like: How do infants learn to copy others’ actions? What role does sensorimotor experience play in this process? How does infants’ knowledge about their bodies help them imitate others’ actions? What is the role of cognitive control in determining what and who we imitate?
The frequency with which we copy others’ actions seems to suggest it is a very easy thing to do. However, to be able to copy someone else’s actions, we need to solve a complex problem, sometimes known as the ‘correspondence problem’. Specifically, how does our brain translate the observed action into a pattern of motor activation that will make our action match that of the person we are trying to imitate? This process is even more complex for infants who have limited action experience and whose bodies are quite different from those of the adults they are trying to copy. My research investigates how the ability to cross this divide between ‘seeing’ and ‘doing’ actions develops over the first few years of life.
What is your most exciting finding so far?
That babies learn to mimic others’ facial actions by being copied by their caregiver. In this study, we asked parents to interact with their 4-month-old infant like they would at home. We filmed this interaction and carefully looked through the videos to count the number of times the mum copied her baby. We also measured the baby’s tendency to mimic other people’s facial actions by measuring their facial muscle activation while they watched videos of models who were performing facial actions, such as opening their mouth or raising their eyebrows. To measure the infants’ facial muscle activation we used electromyography (or EMG), a method that can measure the faint electrical signals that are generated when our muscles contract. We found that the mothers’ tendency to copy their 4-month-olds’ facial expressions during this play session related to the infants’ facial mimicry as measured by EMG. These results suggest that infants learn to solve the correspondence problem by forming links between ‘seeing’ and ‘doing’ actions, for example when they are being copied by others.
Here is a link to my paper for those who want a little more information: https://onlinelibrary.wiley.com/doi/pdf/10.1111/desc.12771
What is your favourite method? What does it tell us about what goes on in those little heads?
I have used a wide variety of methods in my research and I can’t really say I have a clear 📷favourite! In the past few years, I have mainly used electromyography (EMG) to measure infants’ facial muscle activation while they observed models perform various facial actions. The benefit of EMG is that it can measure even very subtle muscle changes that may not be visible to the naked eye. EMG provides a more objective and sensitive measure of mimicry compared to mimicry measured by researchers watching videos of the child. This is important for studying facial mimicry in infancy, especially because there has been a lot of controversy surrounding the question of whether or not newborn infants can mimic others’ facial actions.
I also really like using electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) to measure infants’ brain activation. EEG measures the electrical activity generated by the firing of neurons. This method can tell us exactly when things are being processed in the brain but it is less good at telling us where in the brain the activation originates. fNIRS measures the increase in oxygenated blood that is the result of a certain brain area being busy responding to something. This method can give us a pretty good idea about which area of the brain is being activated, but it is less good at telling us exactly when things are being processed. Both methods allow us to figure out what is going on inside babies’ heads but come with their own benefits and drawbacks, and in the future, I would potentially like to use both EEG and fNIRS simultaneously to get a better picture of what is going on inside infants’ heads.
Is there a parenting book or website you would recommend?
Not exactly a parenting book but “Experimenting with Babies” by Shaun Gallagher allows you to reproduce some of the classic developmental studies at home. While doing so, you learn more about how your baby is acquiring new skills ranging from recognising faces, voices, and shapes, to understanding new words and learning to walk.
Can you sing the Babybrains song? (no pressure!)
I can’t but would be happy to learn! I often sing to the babies and toddlers that take part in my studies, especially if they seem a bit unsure about me putting one of our EEG or NIRS hats on their head.
Parent Question Time: How to manage toddlers’ frustration and mood swings?
I am not a parent myself so I think it is a bit difficult to comment on this (in Dutch we have a saying ‘the best helmsmen stand on shore’ meaning that the ‘watchers’ often know better than the ‘doers’). However, one thing I learned from running studies with toddlers is that they do not respond well to uncertainty. So I always tried to be very clear about what was going to happen in the experiment. I would often tell my little participants what we were going to do in the lab at least two times while we were still in the playroom, and then I would explain it again once we got to the study room. Similarly, parents may find that their toddler is less likely to get frustrated when they set clear expectations about how a certain activity, such as a trip to the supermarket, is going to go. I also tried to make sure that the toddlers participating in our studies weren’t hungry, thirsty, or tired because these are also factors that are likely to contribute to a more volatile mood (and many of us will know from our own personal experience that this is true for us adults too! If the infant is “hangry” then you can forget about collecting any good quality data).
If toddlers did end up being upset or frustrated, I would often take advantage of the fact that at this age children usually can be relatively easily distracted. At the Babylab we have a range of exciting toys, and often just showing a toddler who is starting to get upset a novel toy (or singing them a song) would help them calm down. However, I realise that in real-life parents cannot always anticipate every possible frustration, and sometimes distraction simply doesn’t work. It may be helpful to remember that being frustrated and unhappy at times is a normal part of development (and life!) and it will take time for your child to learn how to manage their emotions – check out last week’s post on this. Talking about your child’s emotions after they have calmed down may be a particularly good way for them to start understanding emotions in themselves and others.