ABSTRACT
Our hippocampi function as an internal search engine and preferred-term indexing system able to retrieve explicit memories of past experiences, particularly those with emotionally important content, and hold these memories in readiness for rapid reference. They are essential for encoding, storing and indexing memories, including semantic memories (about people, places and the meaning of words or objects) and spatial memories (including large-scale maps of the environment and the location of such things as food sources). The right hippocampus is more specialised for spatial memory storage and the left for semantic memory. Both left and right hippocampi are involved in learning and act as an expandable processing area for new information during the process of memory consolidation, which may take years, during which time memories are transferred to the neocortex. When we want to put a name to a familiar face, the left hippocampus is activated and draws upon information stored in other parts of the brain in order to make the match. Thus, you could think of the hippocampi as a key-word based search engine on the left and rather like Google Maps on the right, providing 3-D street views and mapping information.
