Search

Whereas maps primarily represent the 2-dimensional layout of the environment, people are also aware of the 3-dimensional layout of their environment. An experiment conducted on a small college campus tested whether the remembered slants of familiar paths were precisely represented. Three measures of slant (verbal, manual, and pictorial) were collected in 2 different between-subject conditions (perception and memory) for 5 familiar paths on the campus of Swarthmore College, ranging in slant from 0.5° to 8.6°. Estimates from memory and from perception did not differ for any of the measures. Moreover, estimates from all measures, though different in mean value, were correlated within participant, suggesting a common underlying representation was consulted in all cases. [ABSTRACT FROM AUTHOR]

Mou, Zhao, and McNamara (2007) proposed the "intrinsic model of human spatial memory," which posits that a viewer's memory of an array of objects will exhibit a preferred direction that is aligned with an intrinsic axis of the array. They defined intrinsic axes as salient axes created in part by the physical (geometric) properties of the array. To date, these geometric characteristics have received little research attention. We begin such an endeavor by evaluating the role of symmetry and orthogonality (i.e., number of right angles in an array of objects) in spatial memory. Participants viewed a layout of objects from a single (Experiment 1) viewpoint or 2 (Experiment 2) viewpoints and then judged relative directions within the layout from memory. Orthogonality and symmetry were associated with decreased reliance on egocentric reference systems but were qualified by a generally greater reliance on egocentric reference frames than is common in the literature. Indeed, for only 1 array--a highly orthogonal and symmetric one--did participants consistently respond nonegocentrically. We suggest that overuse of this array in the literature has led to an overestimation of the importance of allocentricity in spatial memory. [ABSTRACT FROM AUTHOR]

A substantial amount of research has demonstrated the importance of reference frames in organizing memory of object locations in both small and large environments. However, to date, little research has examined how the object locations represented in one reference frame are specified relative to object locations represented in another. In a series of 4 experiments, we demonstrate that multiple microreference frames can be established in memory for sets of objects that are spatially and semantically distinct, and that the spatial relations between these microreference frames are specified in memory by means of a more global, macroreference frame. Additionally, these experiments demonstrate that an established macroreference frame can influence which of several microreference frames will be coded in memory, but that a previously established microreference frame had no appreciable influence on the subsequent formation of a macroreference frame. These results are interpreted as indicating that the same cognitive mechanisms underlie interobject coding across multiple environmental scales. The implications for reference frame theories and theories positing hierarchical memory organization are discussed. [ABSTRACT FROM AUTHOR]

The Barnes maze offers advantages for cognitive aging studies, because of its relatively unstressful design and its modest physical demands. The authors therefore undertook a detailed chronological investigation of performance against age, for female Sprague-Dawley and male and female Dark Agouti rats. The trial duration was 10 days. Rats were tested at 6, 11, 14, 17, 20, and 26 months of age, but individual rats were tested at one age only. At 6 months of age, all rats reached the criterion. Sprague-Dawley rats performed best at this age. Impairment began at 14 months in Dark Agouti rats and continued to increase up to 26 months of age. Impairment was greater in Dark Agouti than Sprague- Dawley rats and was greater in females than males. At 26 months, 70% of Sprague-Dawley females reached criterion; of the Dark Agoutis, only 33% of females and 57% of males reached criterion. This study confirms the utility of the Barnes maze as a robust vehicle in aged rats. It also highlights major performance differences between strains and genders in aging rats. [ABSTRACT FROM AUTHOR]

Effects of a spatial cue on representational momentum were examined. If a cue was present during or after target motion and indicated the location at which the target would vanish or had vanished, forward displacement of that target decreased. The decrease in forward displacement was larger when cues were present after target motion than when cues were present during target motion. If a cue was present during target motion, high-relevant cues (that indicated the final location of the target) led to larger decreases in forward displacement than did low-relevant cues (that indicated only the horizontal coordinate of the final location of the target). If a cue was present after target motion, there was a trend for low-relevant cues to lead to larger decreases in forward displacement than did high-relevant cues. Possible explanations involving displacement of the cue or landmark attraction are considered. Implications for the relationship of attention and representational momentum, and for whether representational momentum reflects an automatic process, are discussed. [ABSTRACT FROM AUTHOR]

How rapidly does boundary extension occur? Across experiments, trials included a 3-scene sequence (325 ms/picture), masked interval, and repetition of 1 scene. The repetition was the same view or differed (more close-up or wide angle). Observers rated the repetition as same as, closer than, or more wide angle than the original view on a 5-point scale. Masked intervals were 100, 250, 625, or 1,000 ms in Experiment 1 and 42, 100, or 250 ms in Experiments 2 and 3. Boundary extension occurred in all cases: Identical views were rated as too "close-up," and distractor views elicited the rating asymmetry typical of boundary extension (wider angle distractors were rated as being more similar to the original than were closer up distractors). Most important, boundary extension was evident when only a 42-ms mask separated the original and test views. Experiments 1 and 3 included conditions eliciting a gaze shift prior to the rating test; this did not eliminate boundary extension. Results show that boundary extension is available soon enough and is robust enough to play an on-line role in view integration, perhaps supporting incorporation of views within a larger spatial framework. [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]

Three experiments investigated the acquisition and retention of structural and object landmarks in virtual indoor environments. The experiments investigated the rate of acquisition and memory retention for hallway structure (structural landmarks) and pictures (object landmarks). The experiments investigated the rate of acquisition, the role of information content, and memory retention of this information when participants were trained and tested in novel virtual indoor environments. The results from these experiments suggest that (a) even initially, participants are biased toward encoding building structure over object landmarks; (b) participants are sensitive to the information content of landmarks and will allocate memory resources to landmarks that are more informative; and (c) information about these landmarks is retained even after a 1-year delay. [ABSTRACT FROM AUTHOR]

To investigate the ability of aged monkeys to plan and the effect of aging on this ability, performance in a food retrieval task was assessed in aged and younger Japanese monkeys (Macaca fuscara). In this task, the monkeys had to retrieve food items by selecting from a set of 9 holes, each of which contained I food item. Results showed that task performance declined significantly with age. All monkeys showed, to a greater or lesser extent, some consistent patterns in their sequence of selecting holes for retrieving the food item. An analysis of these selection patterns indicated that the younger monkeys showed more consistent sequences in selection than the aged monkeys. Furthermore, success in the task performance correlated strongly with higher consistency in the sequence of selecting holes. The authors simulated performance for this task by monkeys without any strategies or plans. The results suggest that the empirical data were far more systematic than the simulated data. Thus, the authors conclude that Japanese monkeys have the ability to plan and that this ability to plan deteriorates with age. [ABSTRACT FROM AUTHOR]

Current theories of environmental cognition typically differentiate between an online, transient, and dynamic system of spatial representation and an offline and enduring system of memory representation. Here the authors present additional evidence for such 2-system theories in the context of the disorientation paradigm introduced by R. F. Wang and E. S. Spelke (2000). Several experiments replicate the finding that disorientation results in a decrease in the precision of people's estimates of relative directions. In contrast to the typical interpretation of this effect as indicating the primacy of a transient spatial system, the present results are generally more consistent with an interpretation of it as indicating a switch from a relatively precise online representation to a relatively coarse enduring one. Further experiments examine the relative precision of transient and enduring representations and show that switching between them does not require disorientation, but can also be produced by self-rotations as small as 135°. [ABSTRACT FROM AUTHOR]