This is us: Chi (Zoe) Ngo

Developmental psychologist Zoe Ngo focuses on studying memory development in childhood. In the interview, she explains what makes working with children so unique and how she uses a gamification approach to make her experiments particularly appealing to young children. In our "This is us" format, colleagues share insights into their work and motivation.

One of your research topics at the Center for Lifespan Psychology is how children develop memory skills between the ages of 4 and 8. What fascinates you about this topic? 

Zoe Ngo: The topic of memory development involves a long-standing mystery that we all share, which is that some forms of early memory are long-lasting, while others are not. Early on in life, infants and toddlers are very good at learning the regularities of their environment. They accumulate and retain impressive knowledge about their environment. In contrast, during the same age window, they are not as able to form long-lasting memories of specific events like a family trip to the beach. I am fascinated by the way children develop the necessary building blocks to be able to excel at both: the generality across events, and the specificity within a single event. I am also fascinated by the relationship between brain maturation and the growth of different memory abilities. Memory models have made specific predictions about which sets of brain regions should be involved in which memory processes. However, we do not yet know how their maturation rates relate to memory growth during early development.

Can you elaborate on how children develop the ability to remember specific events from their past and how they build general knowledge from these experiences? 

Zoe Ngo: Memory models suggest that the brain carries out a series of complementary processes that help us achieve both the goals of remembering the specifics and learning the generalities in our environment.  The hippocampus helps us remember entire events from just a small clue (pattern completion) and keeps similar events separate to avoid confusion (pattern separation). The hippocampus, in concert/along with the medial prefrontal cortex, helps -to extract the recurring patterns across our experiences to build a general knowledge that can be applied to new situations.  

These brain regions undergo a prolonged development in childhood.  In early childhood, pattern separation develops very quickly between the ages of 4 and 6.  For example, 4-year-old children often confuse similar events, but this kind of error decreases drastically by age 6. However, children improve their ability to discriminate between similar experiences as they enter late childhood and adolescence.   With age, children become better at remembering which things have occurred together in the past. Generalization develops earlier, as we see that infants and toddlers can already build object categories and accumulate an impressive vocabulary. 

What is special about working with children? 

Zoe Ngo: Conducting research with children is incredibly exciting, but it also presents unique challenges. In the field of cognitive development, it's essential to carefully consider how we define and measure cognitive constructs while tailoring our behavioral assessments to be age-appropriate for our young participants. For instance, when testing children's memory, we need to ensure that the materials are engaging, such as cartoon images or animated videos. In addition, the concepts need to be familiar to them.  

Striking this balance between developing age-appropriate tasks without introducing noise into the measures is critical to obtaining valid and meaningful data from children. In addition, it's crucial to communicate instructions in a language that children can easily understand, which is a specialized skill that developmental psychologists hone through training. I find this challenge to be very rewarding.  

What methods do you use? 

Zoe Ngo: We use a combination of behavioral and neuroimaging techniques. In terms of neuroimaging, we use both MRI to map the structure of children’s brains, and EEG to investigate how sleep physiology plays a role in different memory functions. 

You use the gamification approach to design your experiments. Can you explain this in more detail? 

Zoe Ngo: The core of our gaming approach is to integrate memory tasks into engaging, game-like scenarios using what we call cover stories. These cover stories create an engaging narrative that captures children's interest and keeps them motivated throughout the experiment. 

For example, in our COMIC study, we use a cover story in which the children are on a mission to save mythical creatures that live in a forest. To complete this mission, they must collect gems by participating in various mini missions. Each mini-mission is designed to incorporate a memory task, disguised as a fun challenge.

How do you hope your findings will impact educational practices or parenting strategies in the future? 

Zoe Ngo: We hope that our findings will shed light on how children of the same age can differ from one another in their memory abilities at a given age, as well as the rate at which a certain memory ability grows over time. Understanding inter-individual differences can tell us about the extent to which learning, and memory, can be different for different children of the same age.  

Understanding the complex relationship between different memory abilities, and how this relationship may vary across childhood, will help us leverage a child's strength in supporting other memory abilities that are less robust.  

When did you decide to become a scientist? How did you get into this research field? 

Zoe Ngo: I decided to become a scientist in 2009, when I took the Cognitive Psychology course at Denison University with Dr. Seth Chin-Parker. I found the topic to be fascinating and thus asked Dr. Chin-Parker if I could be a research assistant in his lab. I quickly found my calling in cognitive research and decided to pursue a Master's degree in Experimental Psychology. Having an effective and compassionate mentor like Seth during my undergraduate career was the beginning of my path towards the exciting research program that I work on today. 

You were awarded the Jacobs Research Fellowship, which ends this year: What are your professional plans? 

Zoe Ngo: In 2025, I will lead an independent Emmy Noether group here at our institute. In this 6-year funding period, my lab will continue to focus on the neural bases of memory development in early childhood. There will be two main areas of expansion. First, we will try to understand how developmental changes in memory abilities measured in the lab are mapped onto children’s real-world memory abilities. Second, we will investigate the patterns of brain activation during memory retrieval of recent and remote personal life events in children from age 4 to age 10.  

What do you appreciate about the Max Planck Community?  

Zoe Ngo: What I appreciate most about the Max Planck Community is the remarkable breadth of expertise among scientists here. I also deeply appreciate the collegiality and intellectual humility among the members of our community.