Rahul Gaurav & Naomi L. Gaggi
Looking at the past and future of functional connectivity
Dr. Bharat B. Biswal is a distinguished professor in Biomedical Engineering at the New Jersey Institute of Technology, where he serves as director for the Center for Brain Imaging and leads the Brain Connectivity Lab. He received his doctorate in biophysics from the Medical College of Wisconsin, following a masters from Michigan Technical University and a bachelors of science in electrical engineering from Utkal University in India.
Dr. Biswal is well-known for his seminal work in functional connectivity and continues his research in brain connectivity and signal processing using MRI. He is also a familiar guest on the NeuroSalience Podcast, having been featured in Season 3, Episode 5 in conversation with his former labmate Dr. Peter Bandettini.
In this interview, Rahul Gaurav and Naomi L. Gaggi talked with Dr. Biswal as a keynote speaker for the upcoming 2023 Organization for Human Brain Mapping Conference in Montreal, Canada. They cover his academic journey, his research, and the potential future of resting state functional magnetic resonance imaging.
Rahul Gaurav (RG): Welcome Dr. Biswal, it is an absolute honor to have you here. Thank you very much for your time. Could you please tell us about your early career?
Bharat Biswal (BB): I studied electrical engineering in India. Then I came to the US to complete my master’s in electrical engineering, specifically in signal processing. I was interested in a PhD, so a friend of mine who was there at that time said that I should go and meet this famous physicist Jim Hyde. So, I decided to do a PhD in medical imaging.
RG: How difficult was it in those days to integrate into a foreign lab?
BB: Coming from India, it was a big culture shock in terms of food and so on. However, students are more open-minded. I never felt like a foreigner in the lab. We talked about science and about our struggles. My struggle was what I wanted to cook and eat, especially Indian food. I didn’t have as many options compared to now. I got to know about other cultures quite well. I had friends from France, Switzerland, and many countries. When I first landed at Chicago O'Hare International Airport, there was a lot of snow. Before my flight landed, I saw all of these swimming pools and thought so many people had swimming pools in their houses. The way they interact with snow in Bollywood movies was very different than the way it was when I saw snow. I would say I was very lucky.
RG: What obstacles did you face while developing your career?
BB: When I wrote the resting state paper there was a lot of criticism. Reviewers and others who had initially read the paper made the assumption that I was wrong. They could not pinpoint where I was wrong, but they thought that I was wrong. And that’s a very difficult situation to be in because you have to constantly prove that you’re not wrong. To this day, I still feel that some people think there is a mistake somewhere that I have made. That was the biggest challenge I faced in terms of my research. Other than that, I was in a very good lab and I had very good fellow graduate students. Many of them are now ‘who’s who’ in fMRI. I was very lucky to be in the right place at the right time when fMRI started.
RG: How did the idea of the functional connectivity paper come to you?
BB: I chose signal processing as my topic as a graduate student. I had read that if you do a specific task then the respiration rate changes a little bit. So, I thought maybe that was something I could also look at. Other people were looking at auditory tasks, motor tasks, etc. I thought if I could come up with a method that could help to understand the physiological sources, then this could better characterize the task.
In engineering, the best way to describe a system is to provide a random noise as the input. I thought that random noise could be something like a resting state. I would make the subject do certain tasks and also make them rest for about 7 minutes. Even when I removed the respiration and cardiac signal, I still saw that there was a large signal variation in the low frequency. Then, I wondered what would happen if I took a signal from the motor region and correlated it. During rest, I saw that the sensorimotor region was lighting up after correlation.
My colleagues thought it was very interesting and one of my mentors suggested that I should drop everything else I was doing and focus on this. This was my first experiment as a graduate student and my paper got rejected by 4 journals. It was painful as other students were publishing in high profile journals by doing motor tasks.
RG: Did you have many supportive people around you?
BB: My advisor was Jim Hyde and his other student was Peter Bandettini, who is now really famous. There were also many others who have been very successful. Jim was a physicist by training, so my research was supported by him even when others said it couldn’t be true. He always supported me, and I was very lucky to be his student. He taught me that if you can do an experiment and replicate it, just write how the experiment was done—that is all that is needed.
RG: Do you believe your paper on resting state fMRI was your most important contribution to the field?
BB: Maybe that’s my most important work because it was such a simple idea and so many people have taken it to the next level. There’s also another paper about the functional connectome that is equally important, where we asked everyone who was able to share their data, and we were able to analyze more than 1,000 subjects. We put all of the scripts on a public forum. It helped to push journals to ask for data and scripts to be published to be used by others. Data sharing has now become so common.
RG: If you could roll back the clock, what would you do differently?
BB: I would have tried to write the functional connectivity analysis as a software package and put it online. I would have also tried to resubmit and refine our rejected papers.
RG: Where do you see the future of functional connectivity going?
BB: I would not have imagined the amount of success that functional connectivity has had. It has far exceeded my wildest imagination. It’s hard for me to predict, but I see researchers using multimodal imaging to better understand functional connectivity.
RG: Do you have any advice for early career researchers?
BB: Being a postdoc and a student is the best time. This is the time where you can take a lot of risks. Even if you make a big mistake, you are still learning and no one will fault you. This is a really good time to be in research. Everything is so accessible, but this also makes the field very competitive. After COVID-19 pandemic restrictions, people are starting to again get together and share ideas face-to-face.