The neural correlates of navigation: do head direction and place cells guide spatial behavior?

Head direction (HD) and place cells are thought to represent the neural correlates of processes underlying navigation. At present, however, a large gap exists in our knowledge as to how the firing characteristics of HD and place cells relate to performance in a navigational task. The purpose of this review is to evaluate critically the current evidence that such a relationship exists by examining the studies that have directly addressed this issue. The results of these studies are consistent with the notion that behavior and perceived orientation (as represented in the firing of HD and place cells) can be independently controlled by different cues but, under certain conditions, are controlled by the same cue(s). Much work, however, remains to be done to clarify the role of the HD and place cell systems in the neurobiology of spatial cognition and navigation.