How the Hippocampal Cognitive Map Supports Flexible Navigation.

During navigation to a goal, a portion of the hippocampal place cells exhibit directional preferences, firing more in some directions than in others. These directional preferences create vector fields oriented toward locations scattered around the environment called ConSinks. The population vector field averaged across all of the cells recorded in each animal flows toward an average ConSink located close to the goal, providing a means for navigation in unobstructed environments. Closer examination of the ConSink place cell directional firing reveals a fantail representation in which alternative paths to the goal are evaluated, providing the basis for flexible navigation. Additional assumptions about how obstructions might be represented suggest a solution for navigation in more complicated environments. Implications for the phenomena of directionality on linear tracks and splitter cells are discussed.