The hippocampus: Part of an interactive posterior representational system spanning perceptual and memorial systems

The hippocampus has frequently been viewed as a core long-term memory structure, separate from brain structures mediating other cognitive functions such as working memory and perception. Much the sameis true of other medial temporal lobe (MTL) structures such as the parahippocampal gyrus and the perirhinal cortex. Recent evidence suggests, instead, that these latter structures are also important for certain perceptual functions, leading many to propose a representational account of MTL that defines its functions in terms of what is being represented, rather than how long this representation lasts, or which psychological function is being invoked. We discuss a common framework within which perception and memory are seen as involving many, if not most, of the structures in the ventral representational stream, critically dependent on extensive feedforward and feedback processes. A variety of perceptual and memorial phenomena are discussed within this framework, and it is concluded that the hippocampus is in many ways like its neighbors in the MTL, yet has some distinct properties that account for its unique role in episodic memory.