How Flies Compute with Vectors

The central complex of the fly brain serves as a navigational computer. Neurons in this area perform all of the vector operations familiar to physicists- addition, subtraction, dot and cross products - using a phaser representation, with many of the operations hard-wired into the anatomy of the fly brain. I will describe neuronal circuits that transform vectors between ego- and allocentric coordinate systems, represent allocentric goals and, from them, compute turning signals, and I will present a model of how flies use vector computations to track odor plumes.