As the fall semester gets underway, I’m reminded of a bit of teaching inspiration I read in the letters pages of Science magazine many moons ago. The author was responding to an article about designing effective science classes. Unfortunately, I no longer have his/her letter but the gist of it was that the author thought that the Science magazine article had neglected to mention one of the most important parts of an effective class: pointing out to students intriguing puzzles that remain to be solved.
I think the author is quite correct and looking back on my experiences in the classroom, I think instructors (myself included) often neglect teaching what we don’t know in our rush to cover as much of what we do know as we can. This is a disservice to our students as the beguiling mysteries of neuroscience may be the most effective way to feed the fire of their curiosity and their sense of awe at the amazing machine tucked between their ears.
So what do you think are some of the most exciting open questions in neuroscience that we should be teaching our undergrads about?
For my part, here are two:
1. Superior Autobiographical Memory
A few years ago, James McGaugh’s lab at the University of California, Irvine discovered that some individuals can recall a stunning number of life events. For example, given a random date from 10 or more years ago, the person can tell you something about what happened to them that day. I actually had the fortune to meet one of the individuals in the study (who has extraordinary musical and culinary abilities in addition to her amazing memory) and it is truly mind-blowing to see her memory in action. It’s like seeing someone walk on air; it shouldn’t be physically possible. We generally assume that forgetting must somehow be adaptive, that it makes it easier to learn and remember things that are most important, but this group of extraordinary people shows us how little we understand about the potential of the human brain.
Over the past few years, 60 Minutes has done two excellent episodes on McGaugh’s project, called “Endless Memory,” which you can watch here:
2. The Format of Neural Representation
Neuroscience is sometimes described as “data rich, but theory poor,” in that it has collected lots of complicated, fascinating, empirical phenomena but it rarely has precise, general theoretical principles to explain them. This talk by Ila Fiete from the 2012 Allen Institute for Brain Science Symposium is a fantastic exception to the norm:
In the talk, she describes the computational logic of place and grid cells, two types of neurons in the hippocampus that represent a creature’s location in very different ways. Place cells are computationally inefficient/sensitive to noise but easy to decode, while grid cells are optimally efficient/insensitive to noise but difficult to decode (i.e., they are an “exponentially strong population code”). In addition to explaining why the brain represents space in two different ways, she raises the likely possibility that the brain uses exponentially strong population codes to represent things besides location. If she’s right then there may be whole new types of representational schemes in the brain that have yet to be discovered (note that grid cells themselves were not discovered until 2005, about 30 years after the discovery of place cells).
Dr. Fiete does a remarkably good job of communicating her ideas with both equations and analogies (e.g., the way Amazon organizes its warehouses), such that your undergrads with both strong and weak mathematical backgrounds will be able to understand the gist of her talk and share in her enthusiasm. “The hunt for exponentially strong population codes is on!”