My name is Aurora Yuan, and I am from a small town in New Jersey called Cranbury. I am a rising sophomore at the University of Pennsylvania studying Neuroscience and Chemistry. I am interested in the intersection of the environment, health, and neuroscience. Throughout the STEER program, I have had the exciting opportunity to work with Dr. Jianghong Liu of the Nursing School here at Penn, and we were broadly interested this summer in studying air pollution exposure and its effects on human health across the lifespan.
What is your summer research project?
My summer research project primarily focused on a systematic review on the association between air pollution and cognition, as mediated by magnetic resonance imaging (MRI) outcomes. Systematic reviews are robust ways of gathering and synthesizing previous data and literature on a topic to answer questions of interest, and are also important in making recommendations for future work. I conducted an extensive search of previously published literature on this topic using several search engines like PubMed, Cochrane, PsycInfo, etc. We ended up including 11 papers in the review that met the inclusion criteria. Air pollution was identified as the environmental exposure for this systematic review, and within our sources all types of air pollution ranging from PM10 to nitrogen oxides were included. Measurements of exposure of air pollutants varied but often included land use regression models and geocoding of residential addresses.
We stratified our results by children and adolescents, and compared this to adults and seniors who are more prone to cognitive decline and dementia diagnoses. Some papers measured MRI outcomes through volumes of different structures of the brain such as the prefrontal cortex, and others looked at the functional connectivity between different important networks with the brain such as the Default Mode Network (DMN). The third facet of this project focused on cognitive outcomes, which were diverse in the methods of measurement but included tests on cognitive domains like memory, attention, and processing speed. Information from these papers was then dissected and organized, and results were presented in tables and synthesized in the discussion.
What are the implications of your research?
This research has far-reaching implications in several fields of study spanning environmental science, public health, and neuroscience. We chose this topic because it was a novel systematic review as no previous one had looked at cognitive effects from air pollution exposure based on MRI findings.
Air pollution is an important environmental exposure, especially because the incidence of air pollution is increasing in most places around the world. Because of this, it is imperative for us to understand the mechanisms and how air pollutant exposure ranging from childhood to adulthood exposure, can impact different areas and connectivity of the brain. From there, we can also understand how this impacts cognition and how it may have an impact on future medical diagnoses such as dementia and Alzheimer’s. Many people around the world are impacted by air pollution, so it’s incredibly important to synthesize previous literature and understand these relationships, and also provide some direction for future research, public health, clinical, and policy decisions. For example, we might consider for clinical purposes, assessing individuals with known high or medium levels of air pollution exposure with MRI scans of the brain as well as cognitive testing in order to identify and/or prevent future decline.
What new skills have you gained through your research?
I gained a lot of skills throughout my time in the lab working on my project. I learned how to conduct thorough and extensive literature searches for both my systematic review, and also on previous topics that we considered such as lead exposure and behavior, and air pollution and Parkinson’s disease. Another important skill that will be very valuable in the future is understanding how to analyze and synthesize sources, and being able to draw conclusions from this. This is a huge part of writing a systematic review and was a skill I applied a lot when writing my paper. Writing a good systematic review takes critical thinking, creativity, and questioning of scientific ideas as well as developing novel ideas for implications and future research. These were all skills I felt I gained throughout my work this summer in my independent project research as well as my contributions to a few other projects in the lab. I helped a bit with a few other projects that Dr. Liu was contributing to, like editing manuscripts and addressing comments from reviewers on manuscripts. These contributions and mentorship helped me to gain invaluable skills and knowledge about the research process.