Invited Address at the Occasion of the Bertelson Award 2005 Impairments in visual discrimination in amnesia: Implications for theories of the role of medial temporal lobe regions in human memory

A prominent and long-standing view of human long-term memory is that structures within the medial temporal lobe (MTL) work together to support the acquisition of memory for facts and events. In contrast to this view, recent studies in rats and non-human primates suggest dissociations in function between regions comprising the MTL. Evidence in support of such specialisation in humans, however, has been inconclusive, leading some researchers to propose that human MTL functions as a unitary system uniquely specialised for the acquisition and storage of long-term memory. This paper reviews some of the key studies from the animal and human literature that support an account of functional differentiation and discusses the different theoretical positions that have emerged from their findings. A series of recent experiments in humans designed to determine whether there is functional homogeneity in MTL regions across species are also reviewed and an alternative account of human memory—in which long-term memory is dependent upon representations distributed throughout the human brain rather than one specialised system—is proposed.