The brain activities in goal-directed learning: Meet Sophia Liang

By Vina Putra

Sophia is a PhD candidate in the School of Psychology, UNSW. Her research looks into how the brain learns to perform specific actions in order to produce certain outcomes, otherwise known as goal-directed behaviour. In particular, she studies the activity of different parts of the brain to understand their role in the action-outcome learning process. Understanding the communication within the brain during this process could be the first step towards improving learning ability and addressing the learning challenges commonly seen in our aging population, especially those with dementia.

Sophia is a PhD candidate in the School of Psychology, where she studies the brain activities in learning

Throughout life, we continuously learn new things that help us achieve our goals or simply to just get things done. For example, learning to drive a car, opening a push/pull door, or operating a machine. These are known as goal-directed behaviour – when we perform action that results in desired outcome, the action-outcome relationship. While much is known about how our brain understands the action-outcome relationship after long periods of time (Matamales et al., 2020), Sophia’s work focuses on the very early stages of this learning and the areas of the brain that receives this action-outcome relationship way before it is retrieved by other regions of the brain. 

Without realising, humans learn action-outcome relationships every day. This learning consists of three main stages: 1) acquisition when we first learn the information, 2) consolidation when we remember that learning, and 3) retrieval, when we retrieve that memory so that we can perform the learned behaviour. In her research, Sophia has shown that early in the acquisition stage, the prelimbic cortex is the region responsible for how we learn that action produces an outcome. Later on, she explores another region called the dorsal hippocampus which is important in acquiring contextual information – that is, the dorsal hippocampus helps us know where it is appropriate to perform or apply those relationships. While the two regions are responsible for similar functions, they are, however, not connected at all directly in the brain. Sophia’s work investigates the possible pathways or how communication occurs between the two regions in mediating learning.

Unfortunately, in the aging population, the ability to learn action-outcome relationships deteriorate. This can become very distressing, especially for people with dementia who begin to lose their ability to learn and retain new learning memories in every aspect of life. “Understanding how the two involved regions talk to each other means that we can then start to figure out what biological components are involved, which could be important targets in the development of therapeutic or pharmaceutical alternatives for dementia patients.”, Sophia shares the excitement for the future possibility of applying her research to clinics. This is how her research becomes the first step to improving learning in aging populations.

Sophia demonstrates how our brain might work during learning in certain situations, such as when we learn to push or pull a door. The cortex is highlighted in blue and the hippocampus is highlighted in green.

Working as an allied health professional to help others heal and improve their health has always been Sophia’s purpose. This led her into pursuing science in high school, although she admitted that she disliked biology and chemistry. For her high school exam, Sophia recalled that chemistry ended up being the subject that she performed the worst at and how it affected her overall score. The surprising twist was that among the range of allied health subjects that she wanted to do after high school such as physiotherapy, speech pathology, and occupational therapy, she also listed psychology without realising that it is a science subject. Soon in her psychology degree, she found herself enjoying the research work in behavioural neuroscience, studying various drugs’ effects on nervous systems, the modulation of pathways and behaviour – being immersed in more biology and chemistry than ever before.

In her second-year undergraduate study, Sophia received the UNSW Summer Science Vacation Scholarship which allowed her to experience research in social psychology early on. Under the mentorship of Professor Lisa Williams, Sophia worked on a collaborative project with the Red Cross Blood Donation Centre where she investigated how emotions shape the experience of first-time blood donors and influence their return rate for future donation (Williams et al., 2018).

Sophia’s journey to her current research started from her fascination with the possibility in manipulating the brain. When she joined Prof. Bernard Balleine’s lab as an honour’s student, Sophia learned the techniques of turning on/off specific regions in the brain. This process typically involves injecting a virus that causes the brain to express certain receptor proteins that can later be activated by a specific drug. When the virus is injected into specific brain regions, the virus makes receptors multiply, and the receptors will only be activated with a certain drug – clozapine (commonly used) – injected at a certain timepoint, resulting in brain regions turning on/off. This then translates to changes in behaviour that can be monitored to support the relevant hypothesis.

Sophia (second from left) and her team working with an animal model in the lab

Going back to her honour’s year, Sophia was looking to turning on the region called the orbitofrontal cortex, hypothesised to be involved in learning some actions that produce no outcome. The increased activity of this region is shown in patients with obsessive-compulsive disorder (OCD) where they compulsively perform actions even though they learn no outcomes would appear (Ursu & Carter, 2009). Sophia used animal models and train them on action-outcome relationships for a period of time before removing the outcome. She then observed whether animals with increased activity in the orbitofrontal cortex would still perform the actions, even if they get no reward. Sophia then continued working as a research assistant in Prof. Bailleine’s lab, working on a project that closely links to her now PhD research. Using the same virus-mediated brain manipulation technique in rats, she turned off the dorsal hippocampus region and trained those rats on action-outcome relationships to study the pathways in goal-directed learning.

Sophia (top row, second from left) enjoys playing OzTag with her team

Sophia enjoys many things that come with being a PhD candidate such as teaching undergraduate psychology courses, mentoring honours students, and seeing new findings emerge from her experiments. Apart from science, Sophia also loves history, and she always finds the chance to visit museums and historical sites wherever she travels, to learn about the different stories and the people of that area. She also enjoys watching movies and playing OzTag – her favourite ways to have a break and have fun.

As a champion, Sophia’s advice to young women who would like to pursue science is, “Don’t doubt yourself! Even if you don’t do well in science in school, it should not stop you from having career goals in science. The important thing is if you are passionate about something, go for it because you will adapt, learn, and grow.”

Follow Sophia on Twitter @SophiaLiang_

Detecting lung diseases through breath analysis: Meet Merryn Baker

By Vina Putra

Merryn is a Scientia PhD candidate in the School of Chemistry, UNSW. Her research focuses on analysing chemicals in the breath for the detection of lung diseases such as lung cancer. This could ultimately present a cheaper, non-invasive way to diagnose or screen lung cancer. Merryn is also passionate about translating her research to the clinics and into a business which led her and her team to win the Peter Farrell Cup in 2021 – UNSW’s prestigious entrepreneurship pitch competition for start-ups.

Merryn is a PhD candidate in the School of Chemistry, UNSW

For Merryn, working on the fundamental science is just as important as research translation and science communication. Often, figuring out the mechanism in basic science can help present a solution, and bringing this solution to market requires a different approach and skillset that many scientists would benefit from learning. Working on a translational PhD project, Merryn finds it enjoyable to learn all the aspects of innovating and promoting not only the science, but also in establishing a business. In 2021, she and her team, Beagle, participated in the Peter Farrell Cup, a UNSW pitch competition for start-up companies, where they were awarded first prize in the higher degree research category. Their pitch brought Merryn and her team’s research on breath analysis a step closer to clinical reality.

Merryn and her team as the winner of Peter Farrel Cup 2021

Merryn’s PhD research focuses on the analysis of breath samples for disease diagnosis. Part of her research aims to identify the specific components in the breath that can be used as markers for diseases. Among the numerous types of chemicals in our breath, she focuses on aldehydes and ketones as they are known to be common biomarkers. Because these chemicals are present in small quantities in the breath (as low as parts per trillion!), Merryn uses Metal Organic Frameworks (MOFs) to enable detection. The MOFs serve as a net that can capture the chemicals in the breath and concentrate them so there is a sufficient amount to analyse.

In a typical week, Merryn would fill her days with teaching, demonstrating, marking, reading literature, analysing data, writing, and most importantly, working in the chemistry lab. Her experiments primarily involve running derivatisation reactions and mass spectrometry, which work hand-in-hand to improve detection. Mass spectrometry is an analytical technique that detects charged chemicals, known as ions, and the derivatisation reaction is used to put a positive charge onto the aldehyde and ketone biomarkers. By selectively placing the charge only on the analytes of interest, the mass spectrometry then detects only those charged chemicals, leaving all the noise and other chemicals aside. The mass readout from this can then tell which type of aldehyde and ketone are present in the sample. Depending on their concentration, some of these could be biomarkers for certain diseases. But sometimes, it is hard to tell because those chemicals may be just highly expressed with no association to any disease – what a challenge!

To really distinguish whether the aldehydes and ketones could serve as disease biomarkers, Merryn quantitatively analyses real breath samples using mass spectrometry and ion mobility spectrometry. She hopes to collaborate with clinicians and patients with lung cancer, as well as coal miners who are likely to develop lung diseases, and ultimately use their breath as references to establish a library of breath profiles between the healthy and the diseased. But the challenge does not end there – sometimes the breath profile of cancer patient does not match the profile of the cancer cells, which can happen as cancer may change the metabolic processes in the body, rather than produce chemicals directly. Merryn’s work contributes to the important task of identifying and characterising the specific chemical markers for lung diseases and testing the feasibility of using breath for diagnosis.

Merryn, her father and grand father (from left to right) share the same passion for science

With the mentorship of her father and grandfather who both received their PhD in chemistry, Merryn always knew that science was an exciting and potential career path. Her journey started when she moved from Canberra to Sydney at the age of 10. In high school, she enjoyed the rigor and curiosity of maths and science, and how they enable a deeper understanding of our world. Her interest grew as she became amazed with spectroscopy – a tool that allows us to understand how atoms or molecules absorb and emit light, giving information about the structure and identity of that atom. It was her love for science that made her want to learn more.

Merryn received her B.S. in chemistry and physics in 2018 from UNSW and went to pursue research as an honours student in the school of chemistry. In her honour’s year, she found herself loving research and communicating research. She also enjoys teaching and demonstrating, and hence knew that she could be involved in all that a PhD program has to offer. Now 3 years into her PhD, she has been enjoying both the research and the opportunity for science communication, including being in the champions program. She is also a teaching fellow in the school of chemistry, and she works with the school’s education group to improve student learning and experience.

Along her journey in science, she has taken mentorship and inspiration not only from her amazing science teachers and supervisors, but also from her peers. Merryn added, “Being surrounded by other PhD fellows and learning from their achievements can be really powerful to figure out our own paths and aspirations – to learn how we can make an impact as scientists”. It is also possible to get inspiration from nature, as Merryn lives by the beach, she would go swimming or surfing in her spare time which helps boost her creativity.

Merryn enjoys her spare time in the water and being inspired by nature

As a champion, Merryn envisions a better future for women in STEM by cultivating an interest in science and maths from an early age, and to act as a mentor for these young women so they see STEM careers as potential pathways for themselves. “Often, young girls are being put off because people around them perpetuate the idea that science and maths are too hard”. Through the champions program Merryn aims to help promote young girls’ interest in science and maths – to change how they view the subjects from being hard to something rewarding and that serves as the key to solving many challenges in the world.

Follow Merryn on Twitter @merryn_baker