[3] The hippocampal formation is thought to play a role in memory, spatial navigation and control of attention.

[5] In 1937, Papez theorized that a circuit (the Papez circuit) including the hippocampal formation constitutes the neural substrate of emotional behavior,[6] and Klüver and Bucy reported that, in monkeys, surgical removal of the hippocampal formation and the amygdaloid complex has a profound effect on emotional responses.

[14] Thanks to these observations and a great deal of subsequent research, it is now broadly accepted that the hippocampal formation plays a role in some aspects of memory.

[12] In 1971, John O'Keefe and his student Jonathan Dostrovsky discovered place cells: neurons in the rat hippocampus whose activity relates to the animal's location within its environment.

As with the memory theory, there is now almost universal agreement that the hippocampal formation plays an important role in spatial coding, but the details are widely debated.