Is the brain optimal? How does it cope with noise?

The brain is a computation machine, capable of encoding, storing and retrieving information. At the same time, the brain is made up of noisy neurons, and this adversely affects its performance. How does the brain cope with noise? How do neurons encode information? How optimal is the neural code from an information theoretic perspective? These are the questions at the heart of Ngoc Tran’s research. Answering them will help us better understand the brain, and potentially uncover new roles for neurons seen in experiments. Currently Ngoc is working on these questions for grid cells. In mammals, grid cells encode the animal’s two-dimensional location with a set of periodic spatial firing pattern of different periods. Dubbed as the brain’s ‘inner GPS’, their discovery led to the 2014 Nobel prize in medicine. However, grid cells’ theoretical performance is extremely sensitive to noise. In a recent work, Ila Fiete and Ngoc Tran have built a biologically plausible grid cell decoder with optimal performance.