"I came to Hopkins because I was interested in medicine and math. I wanted to find a quantitative bridge between the two," says Nikhil Ram Mohan. "Originally, I thought I would find that in bioengineering. But then I attended a seminar by Dr. Carey E. Priebe in which he described the work being done in the Center for Imaging Science — it was absolutely where I wanted to be — the interface between math and medicine.
Nikhil then transferred to the Applied Mathematics and Statistics department and is also being mentored by Professor Carey Priebe in the Whiting School's Center for Imaging Science. At the center, Nikhil joins other mathematicians, engineers, and scientists to study the correlations between certain brain structures and psychological disorders.
"We are looking, in particular, at the shape of the hippocampus as it correlates to depression," Nikhil says. "We are essentially interested in the biological foundations for various psychological disorders."
Comparing control groups to those that are deemed "High Risk" and "MDD: Major Depressive Disorder," and using MRI images to evaluate the shapes of individual hippocampuses, these researchers are searching for biological predictors that could, ultimately, indicate the onset of clinical depression.
"It's actually very difficult to study the shapes of things mathematically. If I ask you what the size of my hand is, you can just give me a number that corresponds to its volume. However, it's quite a different task for you to give me a numerical value for its shape."
To do so, Nikhil and his colleagues embark on a method referred to as "landmark matching," which involves mapping out the shape of the subjects' hippocampuses.
"The first step is to define three dimensional landmarks on the MRI images of all the subjects, including the control group," Nikhil explains. The landmarks of the control group are then used in comparison to the MRI images of the High Risk and MDD groups. Using an optimal diffeomorphism that takes into account landmark mismatch and transformational complexity, researchers can then begin to measure hippocampus shape difference among the three populations in question.
"We collaborate with researchers from Washington University, Massachusetts General Hospital, and other schools within Hopkins," Nikhil says. He is also going to be presenting this project at the National Conference for Undergraduate Research (NCUR) in April. “It’s a fantastic opportunity and I’m really looking forward to it!” says Nikhil. Although he’s an undergraduate, the academic structure that Hopkins embraces allows him to have the experiences that, at many other universities, would not be available even to graduate students.
"Before I came to Hopkins people told me that the university was an incredible 'research' place, but I did not understand what that meant. To me, 'research' was just a word. But now I know that research is about inspiration, encouragement and guidance- I learn something new every day."