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Speaker spotlight: Dr Vicky Leong

How much do you think you are in sync with your baby? Looking at behaviour and brain waves, book a session and find out how we think together, how our brains dance. Stanimira Georgieva and Dr Vicky Leong open the Baby Lab in the Department of Psychology for a baby-mum brain connection experience.

CSF caught up with Dr Vicky Leong to find out more.

CSF: When did you first realise you wanted to be a scientist and why?

VL: The realisation dawned when I was teaching children with special needs 15 years ago. These children had bodies that were developing quite normally, but their minds were not. And although all the children had been diagnosed with a ‘severe learning difficulty’, each child was as different from the next as night and day. One child would not speak and was over-sensitive to sounds. He would sit hunched up in a corner of the classroom with his hands clamped tightly over his ears, lost in his own world. Another child would continuously babble to himself and to others, interjecting loudly into others' conversations. We even had a child who would try to eat anything within reach - including pencils and sharp objects! As a teacher, the primary challenge was to manage behaviour and to try to impart some basic life skills. However, having previously trained in medicine, this felt to me like I was only treating the surface symptoms without understanding or addressing the core problem. And the core problem was that at some point - either before or after birth - the normal programme of neural development had been derailed in these children. I became a scientist to find out how and why this could happen, and to investigate what could be done about it.

CSF: What drew you to cognitive science?

VL: Cognitive scientists can come from virtually any discipline (from philosophy to artificial intelligence and neuroscience), but we have one common interest - the human mind. The draw of this field is its people - we are a group of scientists who operate on the premise that there is strength in diversity and strength in partnership across disciplines. And I have found my colleagues, in general, to be open-minded and versatile thinkers. I, for one, am a cognitive scientist precisely because I like to work across more than one discipline. I am a psychologist, a neuroscientist and an (amateur) linguist, but I also have a taste for clever computational methods, and I care about educating children and public policy.

Working at the interface between two or more fields is challenging. There are invariably problems with translation, and this requires patience and a continuous re-thinking of one's assumptions. When done right, however, the rewards are handsome - working in the interdisciplinary zone is exciting, it fosters creativity and it is deeply satisfying to be able to solve an intractable problem in a novel way by merging knowledge from a partner field with your own. For example, during my PhD, I came up with a computational model for extracting language from the speech signal that was based on how neuronal oscillations are hierarchically organised in the human auditory cortex. This artificial-intelligence-style effort won me a generous prize from the Cognitive Science Society, which was not only tremendously kind, but also immensely useful for funding conference trips and cups of tea!

CSF: During your research, what has been the most surprising thing you have discovered?

VL: Well, if I'm honest, I've discovered the most surprising things quite by accident in the course of daily life rather than through any orderly system of scientific inquiry! But I digress; your question is not about the usefulness of the scientific method...  I would say that my most surprising scientific discovery (to date) is that a baby's brain can be just as good - if not better - than an adult brain at some things. We human adults are rather egocentric beings, so we like to assume that we currently have the most fully-formed and functional version of a brain that we will possess in our lifetime. To some extent this is true, cortical maturation does take years, if not decades, to complete. However, it does not then follow that the infant brain is inherently weaker or less functional. Rather, the infant brain is highly adept at, and focussed upon, what the infant must do at this stage in life: and that is to Learn (i.e. figure out who and what matters, and how everything works), Grow (i.e. get bigger, faster, stronger), and Survive (i.e. secure physical and emotional support). So it should not really be surprising that by the age of 11 months, we have found that the infant brain can track rapid fluctuations in the speech signal (which are needed for language learning) with even greater fidelity and accuracy than their own mothers! The paper I’ve written on this is currently under review, and hopefully you'll see it soon.

CSF: How connected are mother and baby brains?

VL: Mothers and infants (and indeed some other types of close human pairs) appear to share a privileged bond. This is an implicit form of communication or empathy that is most clearly evidenced through ‘behavioural synchrony’ - a mirroring of postures, gestures and even mood between mother and infant. Daniel Stern meticulously recorded instances of this synchrony with glorious detail in his book 'The Interpersonal World of the Infant' (1985). Usually, this connection has an adaptive role - it keeps the mother physically and emotionally close to her baby and thereby in-tune with and responsive to his/her needs. However, this bi-directional connection can sometimes have unhappy consequences for the infant. For example, if a mother suffers from post-natal depression, she will tend to speak with a flattened tone that conveys sadness, and she will interact less with her baby. As a consequence, her infant will intuitively also start to vocalise less and express sadder emotional tone. We know from brain research that this goes beyond mimicry - these infants' brain patterns also show a fundamental shift from positive to negative valence (the technical term is frontal alpha power asymmetry), just like their depressed mothers. And if these infants are followed-up, their neural changes can sometimes persist and be associated with higher risk for emotional disturbances in later life. Of course, none of this is set in stone and other psychosocial factors can give infants resilience to ill effects (e.g. support from other family members). However, the point that I am trying to make is that mothers and infants share a close emotional bond that shapes some aspects of early brain development, and disturbances to this early bond can produce long-lasting effects.

CSF: What is the reason for this and how does it work?

VL: That is a very good question, and one that I hope to find the answer to. I head the Baby-LINC (Learning through Interpersonal Neural Communication) Lab at the Department of Psychology, and one of our core interests is studying a phenomenon called ‘brain-to-brain synchrony’. Interpersonal neural synchrony can occur between any pair of humans, even strangers, but we are particularly interested in studying mother-infant neural synchrony, because this is a plausible mechanism that could explain some of the very pronounced forms of cognitive and emotional connection that occur between mother and infant. In purely technical terms, brain-to-brain synchrony is defined as a correlation in the temporal and/or spatial pattern of neural activity between two individuals.

In our lab, we measure this correlation using electroencephalography (EEG), a method that detects minute fluctuations in scalp electrical activity that are generated by the brain when one thinks, sees or hears. We place EEG sensor caps on both mothers and infants, and then simultaneously record their brain activity whilst they are engaged in social interaction. We then assess the degree of similarity between mothers' and infants' EEG signals in different social scenarios. For example, our preliminary findings are revealing that brain synchrony between mothers and infants is reduced when mothers are looking away (as if distracted) as compared to when they are looking directly at their babies. This drop in synchrony is not trivially explained by low-level changes in the physical or sensory environment. It holds true when mothers are told to sing exactly the same songs irrespective of where they are looking, when mothers avert their gaze by only a tiny amount (5 degrees), and when infants' own behaviour and gaze patterns are held constant. Thus, we are finding that this neural connection between mothers and infants is exquisitely sensitive to important social cues such as gaze direction, which has a social function as well as a role in learning (e.g. infants follow their mothers' gaze to learn the names for new objects). We've also started to test whether mother-infant synchrony is higher than stranger-infant synchrony (yes, we think it is!), and whether this has any consequences for language learning. Our work is just beginning, and we have yet to understand exactly how brain-to-brain synchrony is established and maintained, and what (if any) role it has in infants' cognitive and emotional processing.

CSF: Through your research, what are you hoping to accomplish?

VL: This work is so interesting and there are so many avenues to explore - there is not enough time in my day to accomplish all that I would like to. But for the next 18 months at least, we have some concrete targets that we have promised the ESRC (our major funder) that we will meet. We will measure brain-to-brain synchrony in 80 pairs of mothers and infants (aged 9-15 months), and we will assess the relationship between brain synchrony, joint attention and word learning in these participants. If there are any mothers with babies out there who would like to help us with our research, please do get in touch with me at vvec2@cam.ac.uk. We’re a lovely, friendly lab and we’d be very grateful! We also offer copious amounts of tea (or coffee) and biscuits, and your baby will get a free 'Baby Scientist' t-shirt and a polaroid snapshot of their brain waves! Book in to come and see us during our Science Festival open house (14-18 March), or email me to find out more.

In the bigger picture, we are also trying to establish and optimise the behavioural and neuroimaging methods for detecting and measuring mother-infant brain synchrony so that other people can easily catch-on to this line of research. I think that brain synchrony research is a very promising new field. If we get it right, we will be helping to open doors for other people to study many other potential areas of interpersonal synchrony (e.g. leadership, co-operation, etc). The ESRC backed our research because they could see the potential for it to change the way we think about interpersonal communication. I hope that we can deliver this result!

CSF: What do you think will be the big breakthroughs in cognitive research in the next decade?

VL: I think that human minds are naturally predisposed to form social networks with other minds - we are social beings and the brain is our primary social organ for connecting with others. If there is a big breakthrough in my field, it will come from understanding the neural mechanisms that allow our minds to infer and understand others' mental states, to empathise with others, to lead or follow others, and to be part a larger collective. And achieving those big breakthroughs will require a paradigm shift away from studying single brains in isolation (as closed systems), to studying multiple brains concurrently as open interacting systems and networks - within intimate dyads, peer groups, families and classrooms.