Connecting the brain and the mind
Dr. Danlei Chen on her work as a postdoc at the Lewis Lab and her role as Corresponding Secretary of the MIT Postdoc Association
Photo courtesy of Danlei Chen
When you finish reading this sentence, close your eyes and picture a river.
While you might not be around any bodies of water right now, your brain is still able to recreate the image of one. How this works is one of the many questions that fascinates Dr. Danlei Chen, a Postdoctoral Associate in the Lewis Lab. Dr. Chen, who is also the Corresponding Secretary of the MIT Postdoctoral Association (PDA), sat down with The Tech last week to talk about her research and the community she’s found through her work.
It “makes me feel purposeful”
Dr. Chen describes herself as “a neuroscientist, a psychologist, and a bit of a programmer.” The goal of her research is to develop and utilize new tools to investigate the connection between a human’s physical brain and their thoughts and behaviors.
The same prediction abilities that allow your brain to imagine a river also enable your brain to elevate your blood pressure before you stand up so you don’t faint, and how you know where to put your pencil to write letters. Scientists like Dr. Chen think these prediction abilities might play a major role in optimizing energy.
“Your brain's primary mission is to try to regulate your body in the most energy efficient way possible,” Dr. Chen said. At the same time, humans are wired with memories, cognition, and sleep. The reasons our brains do these things are not well understood, or even “well-hypothesized.”
An international student from China, Dr. Chen first came to the United States as an undergraduate student at the University of Rochester, where she initially planned on majoring in finance and took on multiple finance internships. She recalled feeling like she was missing opportunities for growth. After taking some cognitive science classes, she fell in love with the subject and completed a Bachelors in Brain and Cognitive Science.
“Build[ing] code to record the brain makes me feel purposeful,” Dr. Chen stated. It’s “my calling that I can do without feeling like I'm doing work. It's kind of like one of my interests, like knitting or playing tennis.”
Her primary research focus now is sleep. In the quest to understand why people sleep, researchers often look at the motion of cerebrospinal fluid, a watery substance surrounding the brain and pooling in its cavities. In addition to providing a cushion for the brain, cerebrospinal fluid acts like a sewer system for brain cells.
“We think the brain produces large waves of neural [electrical] signals” to drive cerebrospinal fluid flow while you sleep, she said, carrying waste products out of your brain so that you wake up feeling “refreshed.”
This research has the potential to unlock treatments for neurological diseases like Parkinson’s or Alzheimer’s, where deteriorating tissues increase the size of brain cavities. Just like changing riverbanks may cause a river to bend in some spots and pool in others, tissue decay in Alzheimer’s and Parkinson’s patients may cause an irregular cerebrospinal fluid flowing pattern. This could lead to a waste buildup that causes “even worse types of tissue damage,” Dr. Chen said, accelerating the progress of the disease.
Though understanding what healthy fluid flow looks like isn’t necessarily enough to treat these diseases, Dr. Chen stressed that without an understanding of healthy fluid flow, there’s little possibility of “understanding the pathology and even having drugs to help people.” Describing curiosity-driven scientific discovery and scientific problem-solving as “inseparable” forms of research, she remarked, “I think [scientists] as individuals are contributing in both ways, but the percentage of efforts maybe going to one more than the other.”
“They’re my people”
Dr. Chen earned her PhD in Psychology and Neuroscience from Northeastern University in 2023, after six years of work, part of which happened during the COVID-19 pandemic. The uncertainty of conducting scientific research during COVID was particularly hard with her family “all the way in China,” where all they could do was send “thoughts and prayers.”
Despite the challenges, Dr. Chen emphasized, “Things would have been harder if I wasn't doing something that I truly loved.” The experience brought her closer to her friends and colleagues and mentors, who “stepped in and checked in” on her.
“That's when I realized that they are not just people that I work with or people that I share a similar interest with, but they're the people around me and they're my people,” Dr. Chen recalled. “Without that, I don't think I'd be able to have a good enough well-being in general, or be able to survive in a particularly hard time and by myself in another country.”
That sense of community was one of the reasons Dr. Chen ran for Corresponding Secretary of the Postdoc Association (PDA) almost a year ago. As Corresponding Secretary, her job is to foster communication between the PDA officers and the general postdoc population, and also advocate for better salaries, housing opportunities, and postdoc-PI mentorship.
She initially focused on increasing connections between postdocs through fun activities and retreats, but her focus has since shifted. The current budget proposal for the 2026 Fiscal Year on the National Science Foundation (NSF) website features a 91.4% decrease in post doctoral funding, eliminating eight different funding programs.
Their rush to cancel grants and defund scientific projects is especially hard for postdocs, Dr. Chen admitted, “because we see ourselves as future academics.”
“The scientists that these cuts are directly impacting have very little to do [with the decision-making],” Dr. Chen said, “even though we're the producers of the science, and we're the makers of these experiments.”
The situation is particularly hard for international postdocs, who make up 60 to 70 percent of MIT’s postdoc population. Dr. Chen stated, “If we get fired, then there's very little room for us to look for another type of job or in a similar field.” With their jobs tied to their working visas, their housing, and their health insurance, MIT’s over 900 international postdocs are living one funding cut away from losing the lives they’ve built in the US.
“MIT is really great because they created this type of welcoming environment for us, and that is honestly quite unique, even in the top-tier universities in America,” Dr. Chen said. But now, she knows postdocs who have lost their funding and have left the country. They may even leave their fields for good.
“That's really just a loss,” Dr. Chen stated, “not just for the school or for this country, but as an international community with a very similar mission.”
Shouldering the burden
Though her work schedule is relatively “flexible,” in the summer, she comes to the lab often so that she can be a mentor for undergraduate researchers. She also gives reports and runs meetings. She runs experiments and helps with other people’s experiments, including nightly ones from 10 p.m. to 4 a.m. where she can analyze the subjects’ brain waves while they sleep.
For the rest of the time, Dr. Chen writes code to analyze her data and brainstorms new research questions, which “can happen anywhere,” from her home office to her lab to even on airplanes.
The work is hard, but it feels harder when “you're not sure whether funding will continue, or whether you can do your next experiment, or whether your employment is safe or not,” Dr. Chen admitted, describing the uncertainty as a “layer of burden on your shoulder.”
“We do what we can, but we can’t really direct the trend, and that makes me feel, honestly, very helpless from time to time,” she commented.
Meanwhile, she continues her research, motivated both by her intellectual curiosity and by the relationships she’s formed. “This is my community now,” she concluded. “There's very little possibility that I will steer away, not from the science, but from the people.”
The Meet the Minds series focuses on creating holistic profiles of scientists at MIT. If you or someone you know is interested in being interviewed about the role your science plays in your life, please reach out to Science Editor Veronika Moroz at tt-science-editors@mit.edu.