There is considerable evidence that the hippocampal system contributes both to the temporary maintenance of memories and to the processing of a particular type of memory representation. The findings on amnesia suggest that these two distinguishing features of hippocampal memory processing are orthogonal. Together with anatomical and physiological data, the neuropsychological findings support a model of cortico-hippocampal interactions in which the temporal and representational properties of hippocampal memory processing are mediated separately. We propose that neocortical association areas maintain shortterm memories (...) for specific items and events prior to hippocampal processing as well as providing the final repositories of long-term memory. The parahippocampal region supports intermediate-term storage of individual items, and the hippocampal formation itself mediates an organization of memories according to relevant relationships among items. Hippocampal-cortical interactions produce strong and persistent memories for events, including their constituent elements and the relationships among them, and a capacity to express memories flexibly across a wide range of circumstances. (shrink)

Gray's account is remarkable in its depth and scope but too little attention is paid to poor correspondences with the literature on hippocampal/subicular damage, the theta rhythm, and novelty detection. An alternative account, focusing on hippocampal involvement in organizing memories in a way that makes them accessible to conscious recollection but not in access to consciousness per se, avoids each of these limitations.

Continuing commentary raised several issues concerning our proposal that the hippocampus, parahippocampal region, and cortical association areas mediate different aspects of memory function. Recent relevant findings strengthen our argument that neocortical areas and the parahippocampal region maintain persistent encodings of specific single items and that the hippocampus mediates representations of the relations among these items. The reciprocally and closely interconnected structures that compose the hippocampal memory system work interactively to support flexible memory expression that is relevant to the natural behavior (...) of animals and to conscious recollection in humans. (shrink)

Ruchkin et al. ascribe a pivotal role to long-term memory representations and binding within working memory. Here we focus on the interaction of working memory and long-term memory in supporting on-line representations of experience available to guide on-going processing, and we distinguish the role of frontal-lobe systems from what the hippocampus contributes to relational long-term memory binding.

Although O'Regan & Noë (O&N) claim that the world may serve as the viewers' external visual memory, findings from the field of memory research have demonstrated the existence of internal visual representations. These representations are stored in the viewer's brain, contain information regarding visual objects and their relations, guide subsequent exploration of the visual world and promote change detection.