The hippocampus reconsidered: gated informational transfer allows formation of cognitive maps

A hypothesis is offered for the functional role of the mammalian hippocampus in the ontogenetic formation of cognitive maps. It is suggested that the hippocampus functions as a gate for the transfer of sensory information which, when associated with each other, allows the buildup of cognitive maps. The authors (1991) previously reported large parallel changes in the accommodation of CA1 neurons to current injection and the distribution of protein kinase C which occur around the time that the neonate opens its eyes. In the present work, it is argued that (1) such changes reflect the developmentally programmed engagement of the hippocampal mapping system, (2) visual information has a special privileged access to such a system, and (3) the engagement of this system is one of the definitive events of early mammalian development in that it allows the newborn to create cognitive maps of its immediate environs