What does the hippocampus do?
Historically, the earliest widely held hypothesis was that the hippocampus is involved in olfaction. This idea was largely motivated by a belief, later shown to be false, that the hippocampus receives direct input from the olfactory bulb. There continues to be some interest in hippocampal olfactory responses, particular the role of the hippocampus in memory for odors, but few people believe today that olfaction is a primary function of the hippocampus. Over the years, three main ideas of hippocampal function have dominated the literature: inhibition, memory, and space. The behavioral inhibition theory (caricatured by O’Keefe and Nadel as “slam on the brakes!”) was very popular up to the 1960s. It derived much of its force from two observations: first, that animals with hippocampal damage tend to be hyperactive; second, that animals with hippocampal damage often have difficulty learning to inhibit responses that they have previously been taught. Jeffrey Gray developed this line of thoug
