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Studies of spontaneous behavior to assess memory are widespread, but often the relationships of objects to contexts and spatial locations are poorly defined. We examined whether object-location memory was maintained following global, but not local, changes to the geometric shape of an arena. Rats explored two trial-unique objects in 'a distinctively shaped arena before being exposed to two identical copies of one of these objects in a different shape in a different physical location. Rats preferentially explored objects that were novel in relation to their local geometric context rather than identifying both locations as novel in the global geometric context. [ABSTRACT FROM AUTHOR]

Two experiments investigated whether the spatial reference directions that are used to specify objects' locations in memory can be solely determined by layout geometry. Participants studied a layout of objects from a single viewpoint while their eye movements were recorded. Subsequently, participants used memory to make judgments of relative direction (e.g., "Imagine you are standing at X, facing Y, please point to Z"). When the layout had a symmetric axis that was different from participants' viewing direction, the sequence of eye fixations on objects during learning and the preferred directions in pointing judgments were both determined by the direction of the symmetric axis. These results provide further evidence that interobject spatial relations are represented in memory with intrinsic frames of reference. [ABSTRACT FROM AUTHOR]

An influential view in the field of spatial cognition is that an obligatory geometric module constrains spatial learning and memory. In this issue, P. M. Jones, J. M. Pearce, V. J. Davies, M. A. Good, and A. McGregor (2007) showed that learning based on the geometry, or shape, of the environment requires the hippocampus. To place this work in context, the author of the present article considers the evidence for and against a geometric module for rat spatial learning, outlines the influence of geometry on neurons that encode spatial information, and attempts to relate spatial behavior to neuronal representations of direction and location. [ABSTRACT FROM AUTHOR]

Four experiments investigated the roles of layout geometry in the selection of intrinsic frames of reference in spatial memory. Participants learned the locations of objects in a room from 2 or 3 viewing perspectives. One view corresponded to the axis of bilateral symmetry of the layout, and the other view(s) was (were) nonorthogonal to the axis of bilateral symmetry. Judgments of relative direction using spatial memory were quicker for imagined headings parallel to the symmetric axis than for those parallel to the other viewing perspectives. This advantage disappeared when the symmetric axis was eliminated. Moreover, there was more consistency across participants in the selection of intrinsic axes when the layout contained an axis of bilateral symmetry than when it did not. These results indicate that the layout geometry affects the selection of intrinsic frames of reference supporting the intrinsic model of spatial memory proposed by W. Mou and T. P. McNamara (2002) and by A. L. Shelton and T. P. McNamara (2001). [ABSTRACT FROM AUTHOR]