Neuroimaging, memory and the human hippocampus.

The hippocampus has long been implicated in mnemonic function, although its precise role is still keenly debated. Neuroimaging techniques such as positron emission tomography, functional magnetic resonance imaging and structural MRI, provide the means to examine in vivo the dynamic nature of human memory. Here, I briefly discuss how neuroimaging has investigated complex real-world memories of the kind typically reported lost by patients in the clinical context. A role, paralleling that documented in animals, for the right hippocampus in navigation is clearly apparent from functional and structural neuroimaging findings. In contrast, the left hippocampus is more responsive to memories for events that occur in a specific time and place (episodic memory) that characterise one's personal, or autobiographical, memory store from throughout the lifetime. Neuroimaging is well-placed to extend our understanding of the differential contributions the left and right hippocampi make to aspects of memory and how they interface to produce a unitary representation of the past.