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This chapter outlines a framework that describes how interactions between medial temporal lobe structures, such as the hippocampus and the prefrontal cortex bind and organize information to support episodic memory and relational memory. Within this structure, the medial temporal lobe system passively collects attended perceptual and cognitive information, out of which emerges a network of relationships among experienced items and events. By contrast, prefrontal circuits use this network to abstract broad categorical comparisons to apply behaviorally relevant rules in a task‐dependent manner.

This chapter reviews data on amnesia in humans and other animals. It argues that hippocampal ‘amnesia’ does not result from changes in a particular type of memory and does not depend primarily on effects of delay and context. Relational memory, configural memory, semantic encoding, recognition memory, working memory, temporal buffering, and spatial memory are all shown to fail as an explanation of hippocampal sensitivity of learning and memory. The nature of hippocampal deficits, both in tasks involving memory and those involving innate responses, are more consistent with the view that hippocampal damage removes the capacity to select between strongly competing, conflicting goals by increased avoidance of one of the alternatives — in many memory tasks this adds up to the capacity to eliminate interference of whatever origin.

Studies using non-primates, especially rats, have provided further elucidation of the role of the hippocampus itself in relational memory. These studies have shown that damage to the hippocampus does not result in deficits in non-memory functions, including perceptual, motor, and non-memory cognitive functions. Hippocampal damage does produce profound deficits in some types of spatial learning and memory, particularly when animals must learn multiple or complex routes, i.e., cognitive mapping, to navigate mazes where simple egocentric turn strategies or approach to specific cues are not sufficient for success. In addition, the hippocampus is essential for spatial and non-spatial memory for recent episodes when learning consistent spatial or non-spatial associations is not sufficient. Also, the hippocampus is critical when learned responses involve conditional or contextual associations, or when animals must learn relations among multiple experiences, and when they must use inferential expression to solve novel problems.

This chapter addresses the issue of just which structures should be considered to comprise the “hippocampal memory system”, describes its inputs, explores how the components of the system interact, and considers the distinct contributions made by the separate components of this system. The parahippocampal region receives inputs from virtually every part of association cortex and this information converges onto the hippocampus itself. Outputs of the hippocampus are returned to the parahippocampal region and then to the same cortical areas that provided the main inputs. The parahippocampal region is critical for recognition memory of individual stimuli. Correspondingly, neurons in the parahippocampal region encode and maintain representations of individual stimuli and respond differentially to familiar and novel stimuli. By contrast, the hippocampus is not essential for this capacity, but is required when information from multiple experiences must be related (relational memory) and this information used flexibly for inferential memory expression.

This chapter provides an historical review and analysis of systematic attempts to characterize different forms of memory, and the central observations that support the idea of multiple memory systems. It reviews early ideas of multiple memory systems by the philosopher Maine de Biran, the distinction between habit and memory proposed by William James, the notions of behaviorism by Edward Thorndike, cognitive maps by Edward Tolman, schemas by Fredric Bartlett, and cell assemblies by Donald Hebb, and more. It also introduces insights from amnesia resulting from hippocampal damage in humans and from studies of animals that have suggested the hippocampus is critical to cognitive mapping, conditional and contextual association, and episodic memory, each of which highlights relational memory representation and flexible memory expression. Current research focuses on the mechanisms of relational memory and flexible memory expression, and on non-hippocampal memory systems.

Studies on the amnesic patient H.M. began the modern era of the cognitive neuroscience of memory. These studies, and other case studies, showed that damage limited to the hippocampal region results in an impairment that is selective to memory and spares other perceptual, motor, emotional, or cognitive functions. Furthermore, the amnesic deficit is selective to the permanent establishment of new declarative memories. Thus H.M. and other patients with hippocampal damage have intact short-term and working memory, and can form long-term memories that do not rely on remembering specific past events or on the flexible use of memories to solve new problems. These and other characteristics of amnesia following hippocampal damage indicate that the hippocampal memory system is essential to relational memory, the ability to associate multiple events with one other and with their spatial and temporal context, and the ability to integrate many memories into a network of knowledge.

This chapter updates relational memory theory and outlines an information processing syntax that contributes to a broad range of phenomena in declarative memory, including episodic and semantic memory, flexibility in memory expression, and cognitive mapping. It outlines a set of specific biologically realistic ‘binding’ mechanisms performed within the hippocampus in support of these phenomena in declarative memory processing. It proposes that the hippocampus binds together information about stimuli, actions, and places to compose representations of events; binds these events in the order in which they were experienced to compose representations of unique episodes; and binds together representations of distinct episodes, thereby abstracting common ‘semantic’ information and linking overlapping representations to construct a relational memory network. Relational networks retrieve multiple, related, episodic, and semantic memories and support cortical processing that identifies relationships among those memories. In addition, the same relational processing of memories for journeys through space could support the development and utilization of cognitive maps.

When we remember a past event, we typically remember not only the various components of the event, or item memory (IM), but also the associations among these components, or relational memory (RM). RM is more sensitive than IM to several memory disorders, including those associated with healthy ageing. In fact, the age effects on RM are about twice as large as those on IM. Studies with animals, human patients, and neuroimaging techniques have shown that RM depends prominently on the prefrontal cortex (PFC) and the medial temporal lobes (MTLs). Although age-related RM deficits are most likely due to PFC and/or MTL dysfunction, direct evidence for this causal link is very scarce. This chapter reviews ideas and findings concerning the neural correlates of RM and how they change as a function of ageing. The first section introduces some basic concepts; the second section describes theories and evidence linking RM to PFC and MTL function; the third section considers the effects of ageing on the PFC and MTL substrates of RM. Finally, the fourth section discusses several open issues.

The chapter uses the ethnocidal pedagogy of Canada’s Indian Residential Schools to illustrate how control of memory-sharing activities can impact group identities, and how non-relational conceptions of both selves and memories can obscure the prospects for renewing and transforming relations between diverse groups. It asks how sharing memories of harm and wrongdoing across pasts that are linked by a toxic history can aid reparative projects, and what forms such sharing should take. It argues that respect for the relational dimensions of memory, as described by many indigenous thinkers, may be essential to the work of the Indian Residential Schools Truth and Reconciliation Commission as it engages Aboriginal and non-Aboriginal Canadians in sharing memory.

Campbell argues that the presumed threat to the integrity of the self that is posed by others with whom we share memories assumes an implausibly homogenous and non-relational conception of the self. On the view that she defends, both the individual and her memories are already fully relational, so the study of memory is inevitably concerned with the interrogation of boundaries between the individual and the collective. On Campbell’s account of sharing memories, the influence of others is not intrinsically contaminating but constituting, and our relations to those with whom we share a past, as well as those to whom we relate our past, are deeply implicated in shaping and reshaping our identities. The activities and contexts of sharing memories with others are therefore central among the occasions in which our identities get created.

Originally written for the Canadian Indian Residential Schools Truth and Reconciliation Commission, this chapter provides numerous applications of Campbell’s views about the personal, ethical, and political meanings of remembering. In resonance with rich indigenous traditions of orality, it maintains that how and with whom we share our rememberings, and how others respond to them, are necessary for our sense of who we are and how we should go on in the world. A relational conception of memory is employed to challenge the dominant and skeptical view that the past is best forgotten or put behind us if Aboriginal and non-Aboriginal Canadians are to move toward a better future together. The chapter defends the more hopeful view that by sharing memory and being faithful to the past we can reshape and renew present and future relationships between Aboriginal and non-Aboriginal Canadians.