Science, in German, is Wissenschaft, which translates to “pursuit of knowledge” in English. I recently finished my neuroscience PhD training and revisited my scientific journey spanning from my teenage years to my PhD thesis. As a teenager, I was busy memorizing knowledge from textbooks. As an undergraduate, I had some experiences where I learned that science is not always as clear-cut as what I was taught in classes. As a PhD student, I have been trained to look at scientific findings with a critical eye and always ask if they are accurate. The more I learn about the brain, the more I am humbled by its complexity. A teenage version of myself thought that I would have a perfect and clear understanding of science once I earned my PhD. However, the opposite is true. I now appreciate the complexity even in the simple scientific facts that I memorized in classes. I ask myself, “How clear-cut of an answer about the brain will I have in the future? How close are we as a field to fully understanding the mechanism of brain disorders and making clinical care more effective?”

When I was a teenager, my grandmother showed me a documentary about higher education systems in different countries. She always preached that I should aim high, be open to different ideas and venture forward. She often said, “There is no end in learning. Never be complacent in learning new ideas and thoughts.” My parents were out of town, and the documentary paired with my favorite food as dinner was her choice to entertain me. Her choice turned out to be an excellent inspiration for me as a teenage student. Seeing how students across the globe think and learn differently in their own language inspired my curiosity and motivation. 

In the documentary, a professor in North America courageously stated in English, “No, we can’t fail. We’ve already made some major discoveries about vision that nobody knew before.” I did not have any clue about what those “major discoveries about vision” were, but I vaguely thought her research projects showing images of “active” brain regions might be interesting. A few weeks before watching this documentary, I had an exam in biology and memorized functions of different parts of the brain. The frontal cortex is for problem solving, and the cerebellum is for balance control. As a middle school student, I had thought that there was a clear-cut division of labor in the brain.

A few years later in college, I went to a neuroscience talk with a graduate student that I was working with. The speaker had recently begun research projects investigating the underlying mechanism of autism using functional Magnetic Resonance Imaging (fMRI) methods: taking pictures of the brain in the MRI scanner while subjects engage in different tasks. I later realized that the speaker, Professor Nancy Kanwisher at MIT, was the scientist whom I had seen on TV as a teenage student. The “major discoveries” in the documentary were about a brain region that has been implicated in face recognition: the fusiform face area (FFA). The speaker described the brain as a Swiss Army knife because different brain regions have specific roles in recognition of faces, scenes and body parts. 

I asked the graduate student about facial recognition after coming back to the lab. “I understand that FFA is important for us to recognize faces, but what is happening in all the other brain regions besides FFA in face recognition? They are not completely silent when we see faces, so they should be doing something as well, right?” 

The graduate student smiled and answered, “Good question. If you’re interested in that, you should read this.” The paper that he suggested was about how the parietal cortex, a region besides FFA, shows different responses to objects. 

My superficial understanding of the parietal cortex from my introductory neuroscience course was that this area is a part of the brain important for spatial cognition but not for recognizing objects. The paper that the graduate student sent me was my first encounter with the parietal cortex that brought me both confusion and delight. I was confused because this finding about parietal cortex was not what I had memorized for exams, but I was also delighted because I could have an answer to my own question aside from lecture slides.

The more I learned about the parietal cortex, the more I was puzzled about its precise role. This brain region is involved in a lot of cognitive processes such as where we direct our attention, how we put things into different categories and how we prepare our movements. In fact, whether or not and how the Lateral Intraparietal area (LIP) in the monkey parietal cortex is important for attending to an object of interest (“attention”) or for moving the eyes (“eye movement intention”) has been one of the central questions in systems neuroscience. Professor Michael Goldberg, a neurologist at Columbia University who is a strong proponent of the idea that LIP is important for attention, once showed an art piece entitled “Attention and Intention Coexist” in a lecture. The neurologist was struck by this work of art, and he reached out to the artist. Surprisingly, the artist, who did not follow any LIP literature, had already grasped the essence of the attention and intention debate in the neuroscience community. The artist said that attention is about our external world, and we make our intention based on what is out there in the world. In other words, visual attention and eye movement intention are hard to dissociate because we usually look at that which captures our attention.

I was inspired by this question of attention vs. intention signals in LIP neurons and aimed to search for an answer as a PhD student. For my PhD thesis project, I studied how LIP and a nearby area involved in arm movements, the Parietal Reach Region (PRR), communicate when monkeys make coordinated eye and arm movements. If LIP is controlling visual attention, LIP will send information to PRR to convey information worthy of attention. If LIP is a part of a circuit for eye movements, there should be mutual exchange of information between LIP and PRR for eye-hand coordination. From my experiments, I learned that reciprocal exchange of information between the two areas is better explained by LIP’s role in eye movement rather than attention. Do I have a perfect answer about LIP after finishing this project? Well, I learned that the brain is indeed complicated with lots of information such as cognitive, visual and motor signals coexisting in it.

A few months ago, I watched the documentary on YouTube again that fascinated me as a middle school student to revisit the scientist’s argument about “the brain as a Swiss Army knife.” From my scientific journey, I came to realize that the brain does not always give us a nice and precise answer. In fact, neurons’ signals are incredibly complicated, and scientists have to come up with clever ways to figure out what neurons are telling us. I also had to put in a lot of time and effort as an undergraduate and graduate student to have a better answer about the role of a small area in the monkey brain. I have been realizing that the artist’s insight on “coexistence” captures the essence of neuroscience. Indeed, “we can’t fail.” We have already made important discoveries about how complicated neuronal signals are, and we are getting closer step by step to having a better answer about how the brain works. For instance, the pattern of information exchange between the two brain areas during eye-hand coordination that I learned as a PhD student lays a strong foundation in developing neural prosthetics for stroke patients suffering from movement difficulties. Whenever we move, talk or think, different parts of the brain communicate to share information between them. Brain areas for vision and movement must exchange information when we make coordinated eye and arm movements. The pattern of information flow between LIP and PRR in eye-hand coordination has broad implications in both basic neuroscience and patient care.

My grandmother, a strong woman who always encouraged me to venture forward, now sadly suffers from Parkinson’s disease. She still has a very good memory, does mental arithmetic without any trouble and sometimes guides my mother’s driving with a solid spatial map in mind. However, she does have difficulties in initiating her movements and needs help when she wants to start walking. Her medications help mitigate her movement difficulties, but they are neither fundamental treatments nor solutions for her. 

She once asked me after I completed my PhD thesis, “Congratulations! So, now that you have finished graduate school, do you have a solution for people like me?” 

I had to answer, “Grandma, I learned that science does not always give me the clear answer I seek. I don’t have a solution for you yet as the brain is indeed complicated, but trust me, we’re getting closer!”

Image credit: Interneurons (CC BY-NC-ND 2.0) by NICHD NIH