Interview: Leon Glass
Leon Glass, Isadore Rosenfeld Chair in Cardiology and Professor of Physiology at McGill University and CAMBAM member, has recently been awarded the Arthur Winfree prize by the Society for Mathematical Biology: “the Arthur T. Winfree Prize […] will honor a theoretician whose research has inspired significant new biology.” [smb.org] On this occasion we (Thomas Quail and Lennart Hilbert) have posed a few questions to Leon. Again, a reminder that Leon is not only a brilliant theorist, but is hardly found short of experiences, insights, and worthwhile pastimes to talk about.
You were friends with Arthur Winfree for many years. How did Winfree’s ideas influence your scientific trajectory?
Art Winfree had an incredible geometric intuition into biological dynamics. One of his early papers described phase resetting of a simple model of a nonlinear oscillator in which the limit cycle had a circular path. Although others, including Poincaré had looked at similar models for oscillations, Art predicted that biological oscillations described by nonlinear equations should display topological differences in the phase resetting curves depending on the amplitude of the stimulus. This was a fascinating approach — going from a simple mathematical idea to generic predictions for experimental findings. The specific model also was a stimulus for thinking about the effects of periodic stimulation of biological oscillators and was one of the important factors that led to the experimental and theoretical work with Michael Guevara and Alvin Shrier on the entrainment of cardiac oscillations. A geometric approach to studying nonlinear dynamics has always seemed the natural way to proceed – Art’s pioneering work has been crucial to my thinking.
How do you choose your topics/problems to work on?
I like to choose problems that seem interesting to me and where there seems to be something basic that I do not understand. There should be the possibility of some mathematical analysis using tools that I understand or feel that I could understand with a bit of work. I also strongly favor problems where there is some local expertise in the biological aspects that would facilitate collaborative work involving both theory and experiments. Since lots of work now is done in a collaborative fashion with students, finding problems that are suitable for a particular student also plays a big role. I once heard Richard Feynman say that he chose problems to work on by optimizing the product: (importance of the problem) X (ability to solve the problem). That might be a bit too calculating for me, but it sounds like good advice to pass on.
When do you know to invest the time to see it through or to cut off a project?
Although I have sometimes, particularly when I was younger, not published work that would have been worth publishing, I rarely cut off projects. I have worked and continue to work in diverse areas – cardiac arrhythmias, genetic networks, visual perception. I am tenacious. I recently went back and worked on a problem related to the wagon wheel illusion – following up on work that had lain dormant for over 35 years but which was still interesting to me and worth pursuing.
You’ve worked closely with experimentalists throughout your career. What are the key ingredients of a successful collaboration?
Most important is having great respect for the knowledge and abilities of your experimental collaborators and finding someone who shares common interests. It also helps to realize that experimental findings will generally trump the theory in terms of the importance and interest. When carrying out research, I like to go into the laboratory when data is being collected and look at data carefully. This helps to focus on dynamics that may be the most interesting mathematically. Finally, experimentalists usually have way overcommitted the funds, so it helps to be willing to cover the costs of students and if possible to share in the costs of the experiments.
How do you ensure depth in research while working with very diverse topics and using various methods?
I do not worry about whether the problems I am studying are “deep”. However, I try to focus on questions in which there are interesting mathematical and physical problems that go beyond a
descriptive model of some phenomenon. I prefer analyses where there appear surprising emergent properties of the mathematics that were not anticipated at the initial formulation of the theoretical model. It helps if we find experimental evidence also for the unexpected dynamics. In some cases the unexpected experimental findings help set the agenda for the mathematical analyses.
We know you are very interested in music, playing an instrument yourself. Any parallels or connections with science or mathematics that you would like to mention?
I just enjoy the sound of the French horn and the challenge of trying to play it better. Although it would be nice if the study of complicated rhythms of the body improved my ability to play the French horn (or even to count in music), as far as I can tell these are occurring in separate regions of my brain and there is no carryover from one to the other. Both science and music are fun – and I have been privileged to have the opportunity to enjoy them both.
How do you feel about receiving the 2013 Arthur T. Winfree Prize?
I am deeply honored to receive this award. Art Winfree
was not only an extraordinary scientist, but he was also a colleague and close friend. His intense scientific curiosity and high personal integrity have been beacons in my own career. Since completing my PhD in Chemistry, I have identified with the Mathematical and Theoretical Biology communities, going back to early Gordon Conferences in the 1970s. I have also had the privilege of having been the President of the Society for Mathematical Biology. Mathematical Biology is still a young field, with only a few prizes – I am truly delighted to have been selected for this award.