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This chapter considers a number of prominent theories of hippocampal function that have been developed from work on animals. Two theories have dominated research on hippocampal function over the past quarter century. The first is that it is involved in the formation of memories for everyday facts and events that can be consciously recalled—collectively called declarative memory. The other major theory emerging from observations first made during the recording of single-cell activity in freely moving rodents is the idea that it is involved in spatial memory and, more specifically, the formation of cognitive maps and their use in navigation through space. A range of alternative theories, particularly those built around how memory systems handle ambiguity, associative-relations, and context, are also discussed. The chapter concludes by zeroing in on the idea that neural activity in the hippocampal formation contributes to episodic memory.

It's in the Eye of the Beholder: Spatial Language and Spatial Memory Use the Same Perceptual Reference Frames Lipinski et al.Spatial language provides an effective domain to examine the connection between non‐linguistic and linguistic systems because it is an unambiguous case of linguistic and sensori‐motor systems coming together. In the present work we use a process‐based theory of spatial working memory—the Dynamic Field Theory—to generate and test novel predictions regarding the time‐dependent link between spatial memory and spatial language. Our analysis and empirical findings suggest that focusing on the processes underlying spatial language, rather than representations per se, can produce more constrained theories of the connection between sensorimotor and linguistic systems.

This chapter reviews studies dealing with the relationship between environment, food caching, spatial memory, corticosterone, and the hippocampus in North American chickadees while providing comparisons with similar studies done using Eurasian Parids. In particular, this research compares populations which have a variation in food limitation, and discusses how this influences the propensity for food caching and considerst that this may result from physiological differences in the hippocampus and hormone regulation between these populations. Research on spatial memory in Parids has shown that environmental conditions might affect memory performance in several different ways. The chapter discusses these various different ways.

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.

The evidence on spatial and nonspatial neural firing patterns of hippocampal neurons suggests that the hippocampus encodes a broad range of new information within a “memory space”. Hippocampal place cells demonstrate location specific firing, but these spatial firing patterns do not reflect a straightforward encoding of the global topology of the environment. Rather, spatial firing patterns of hippocampal neurons include substantial information about nonspatial stimuli and ongoing behavior, including ongoing behavioral actions and behavioral demands of an ongoing task. In addition, hippocampal encode nonspatial stimuli and behaviors in situations where distinctive events are distributed around the environment. Both the spatial and nonspatial firing properties of hippocampal neurons emphasize conjunctions or relations among task elements, and include a very broad range of stimuli and behaviors.

This chapter presents a picture of how hippocampal place cells might contribute to spatial memory via a field density model that provides information about direction to goals. A key feature of the model is that it demonstrates a way around the apparent paradox of hippocampal cells representing local features of the environment while at the same time being able to represent a distal goal. The model also circumvents many of the criticisms that have been made of cognitive map-type descriptions of hippocampal spatial function.

This chapter describes the use of virtual reality (VR) in the assessment of spatial memory in patients with epilepsy. VR has been an extremely useful resource for the study of the role of the medial temporal lobes (MTL) in spatial memory and cognitive mapping in patients with epilepsy. While several studies show that the right and left MTLs are specialized in the learning and memory of spatial and verbal information, respectively, recent VR studies in patients with unilateral MTL resections show that, in fact, both the right and left medial temporal lobes are essential. A recent fMRI study conducted with epilepsy patients showed that patients with right-sided MTL lesions have significant activity in the left hippocampus during a virtual navigation task, whereas patients with left-sided lesions have significant activity in the right hippocampus. Studies like these suggest that both the right and left hippocampus contribute to spatial memory and navigation.

This chapter explores spatial navigation in humans, but it goes a step further and argues that a system also forms the basis for the human capacity for episodic memory. It discusses some attempts to establish the biological bases of navigation and spatial memory in humans. It also outlines a few key findings from animal experiments which provide physiological evidence for the location and function of allocentric representations in the mammalian brain. The discussion of the neural basis of human spatial memory starts by looking at its role in small-scale spatial behaviour. It then addresses experiments on human navigation in larger-scale space — which brain regions are involved in finding one's way about a large-scale environment? Next, it deals with the association between spatial and more general episodic memory, considering evidence of functional lateralization and speculating about processes that might be common to topographical and episodic memory and which could thus explain their shared dependence on the hippocampus. The studies of human navigation and memory indicate a surprisingly close relationship between the neural bases of spatial and general mnemonic processes.

This chapter develops a taxonomy of ways to think and talk about levels. Using an example from contemporary neuroscience — the multilevel mechanisms of spatial memory — it argues that ‘levels of mechanisms’ captures the central explanatory sense in which explanations in neuroscience (and elsewhere in the special sciences) span multiple levels. The multilevel structure of neuroscientific explanations is a consequence of the mechanistic structure of neuroscientific explanations. The importance of levels of mechanisms is emphasized by showing how other common notions of levels (such as levels of science, levels of theories, levels of control, levels of entities, levels of aggregativity, and mereological levels) fail to describe the explanatory levels appearing in the explanation for spatial memory.

This chapter reviews alterations observed in the hippocampus during normative ageing in the absence of pathology. Topics include discussions of age-related spatial memory deficits across mammalian species, as well as neuroanatomical, biophysical, and electrophysiological changes observed in the aged hippocampus. Further, the impact that these changes might have on plasticity mechanisms and dynamic processes such as gene expression and epigenetic modifications over the lifespan is discussed. Special emphasis is given to the fact that normative ageing is distinct from neuropathological states such as Alzheimer’s disease. Moreover, this overview highlights how the study of normal ageing in the hippocampus has furthered the understanding of the specificity of pathological processes as well as presented possible avenues for the development of interventions, treatments, or therapeutic strategies for optimizing cognition during the normal life course.

This chapter addresses one possible contributing component to the neglect syndrome that has received relatively little attention to date, namely deficits in spatial working memory. It is proposed that impaired spatial working memory may contribute to recursive examination of ipsilesional locations in many visual tasks. It also considers how possible spatial working memory deficits might impact performance on a standard diagnostic test for neglect, namely cancellation tasks. In doing so, it discusses a new variant of the cancellation task (‘invisible’ cancellation) which provides a clinically applicable method for investigating the role of spatial working memory at the bedside. In general, it is suggested that deficits in spatial working memory may promote visuospatial neglect. Specifically, it indicates a role for a deficit in retaining which locations have already been examined, across saccades during search.

The landmark experiments of Jean Piaget demonstrate that spatial abilities change during childhood. Young children can reproduce the relative spatial relationships of figures — their topology — but not angles and distances. In representing large-scale space, children progress from an egocentric view and the clustering of familiar landmarks, to an accurate representation of local environments, before finally achieving an accurate overall representation. Challenges to this view are found in the demonstration that some young children are able to navigate between locations based on their distances and direction in the absence of vision. Intriguing findings suggest that when children are misoriented in a small environment, they re-orient based on the shape of environment, even in the presence of spatial landmarks. In general, children's knowledge of an environment improves as they have more exposure to it.

The avian food-caching paradigm has greatly contributed to our understanding of a number of cognitive capacities. Although the early work focused on spatial memory, contemporary studies of the cognitive abilities of food-caching birds have a much broader scope. This chapter describes an approach to the comparative cognition of caching which capitalizes on an integrative knowledge of behavioral ecology and comparative psychology. An understanding of behavioral ecology allows one to pose questions about the selective pressures that drive the evolution of cognitive abilities in food-caching birds and how a bird's decisions concerning both caching and cache-recovery are shaped by ecological factors. In comparative psychology, the emphasis is on understanding the general processes of learning, memory, and cognition, and the questions are often inspired by the logical structure of the task. This chapter concludes by asking why an understanding of evolution in general, and of the phylogeny of the studied species in particular, is essential for how we interpret species differences in cognition.

This chapter examines the nature of the spatial reference systems used in perception and memory to locate objects, remember the locations of objects, and guide action in space. Topics discussed include reorientation and environmental shape, location at the categorical and fine-grained levels, and locomotion and spatial updating. Thus, exceptionally clear overviews of four lines of research on the development of spatial memory, locomotion, and orientation are offered. It reveals crucial insights about the spatial reference systems used to locate objects, remember the locations of objects, and guide action in space.

In the wild, several species of birds among the parids (tits and chickadees) and corvids store food in scattered locations and find it again days or months later. The food storers that have been tested use memory to recovery their stores in the laboratory. The importance of memory to a food-storing way of life suggests that these birds possess an adaptive specialization of some aspect or aspects of memory. Recent work has focused on analysing how memory is involved in recovering stored food, discovering how this memory can be tested in tasks that do not involve food storing, and comparing the memory of storing birds with that of their non-storing relatives in a variety of tasks.

This chapter explains the effects of nutritional stress during development, with a focus on the hippocampus and spatial memory. Research work done on spatial memory in birds has provided a clear link between the ecological need to store food, a relatively enhanced spatial memory used to retrieve the cached food, and the relative volume of the hippocampus, the brain region processing spatial memory. With the importance of spatial memory for the survival of certain bird species, the author predicted that hippocampal development, and hence spatial memory, would remain intact even under nutritional stress. The data in the chapter refute that prediction and suggest that constraints during development preclude the insulation of certain brain regions from nutritional stress. Also, favoring animals with better spatial learning might provide an easier path for natural selection to select for better parents to produce high-quality offspring, rather than resolving the potential developmental constraint issue.

In this chapter the author compares two specific computational models of human reasoning with preferred layout models, one based on visual images and the other on abstract spatial representations. This benchmark test concludes that the image-based simulation is likely to have relevance for the occurrence of visual images during premise processing, but the spatial account explains the computational processes underlying human reasoning in a better and comprehensive way. The chapter also discusses the PRISM model (preferred inferences in reasoning with spatial mental models), which simulates all three phases of an inference in a comprehensive way and maps spatial working memory to a symbolic spatial array. The PRISM model is also helpful in predicting which spatial layout model is preferably constructed.

This chapter argues that advances in cognitive neuroscience provide valuable insights into the organization of spatial cognition. It considers a number of current controversies in spatial cognition, particularly, the existence of egocentric and allocentric representations. The chapter also examines distinct neural systems for specific types of spatial information and then describes head-direction cells, patterns of place cell firing, and the dorsal striatum and its location relative to local landmarks. Finally, the chapter investigates the neural bases of landmark and boundary processing in spatial memory.