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Dissociable Retrosplenial and Hippocampal Contributions to Successful Formation of Survey Representations
, 2005
"... During everyday navigation, humans encounter complex environments predominantly from a first-person perspective. Behavioral evidence suggests that these perceptual experiences can be used not only to acquire route knowledge but also to directly assemble map-like survey representations. Most studies ..."
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Cited by 32 (3 self)
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During everyday navigation, humans encounter complex environments predominantly from a first-person perspective. Behavioral evidence suggests that these perceptual experiences can be used not only to acquire route knowledge but also to directly assemble map-like survey representations. Most studies of human navigation focus on the retrieval of previously learned environments, and the neural foundations of integrating sequential views into a coherent representation are not yet fully understood. We therefore used our recently introduced virtual-reality paradigm, which provides accuracy and reaction-time measurements precisely indicating the emergence of survey knowledge, and functional magnetic resonance imaging while participants repeatedly encoded a complex environment from a first-person ground-level perspective. Before the experiment, we gave specific instructions to induce survey learning, which, based on the clear evidence for emerging survey knowledge in the behavioral data from 11 participants, proved successful. Neuroimaging data revealed increasing activation across sessions only in bilateral retrosplenial cortices, thus paralleling behavioral measures of map expertise. In contrast, hippocampal activation did not follow absolute performance but rather reflected the amount of knowledge acquired in a given session. In other words, hippocampal activation was most prominent during the initial learning phase and decayed after performance had approached ceiling level. We therefore conclude that, during navigational learning, retrosplenial areas mainly serve to integrate egocentric spatial information with cues about self-motion, whereas the hippocampus is needed to incorporate new information into an emerging memory representation.
D.R.: Global-Scale Location and Distance Estimates: Common Representations and Strategies in Absolute and Relative Judgments
- Journal of Experimental Psychology: Learning, Memory, & Cognition
, 2006
"... The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all p ..."
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Cited by 12 (3 self)
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The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens’s law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.
Comparing decision-making and control for learning a virtual environment: Backseat drivers learn where they are going. Human Factors and Ergonomics Society Annual Meeting Proceedings
, 2008
"... A considerable amount of research has been conducted on the role interactivity, active versus passive navigation, for learning the spatial layout of a virtual environment (VE). However, active navigation is not unitary. It has two distinct components: decision-making and control. In the present work ..."
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Cited by 4 (1 self)
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A considerable amount of research has been conducted on the role interactivity, active versus passive navigation, for learning the spatial layout of a virtual environment (VE). However, active navigation is not unitary. It has two distinct components: decision-making and control. In the present work we investigated which main component of active navigation was critical for acquiring spatial knowledge of a virtual city. We found that spatial knowledge was comparable when the VE was learned with active navigation or decision-making in the absence of control, but was much worse when only control was present. These results suggest decision-making, not control, is the critical component for learning a VE.
The Role of Categories and Spatial Cuing in Global-Scale Location Estimates
"... Seven independent groups estimated the location of North American cities using both spatial and numeric response modes and a variety of perceptual and memory supports. These supports included having location markers for each city color coded by nation and identified by name, giving participants the ..."
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Seven independent groups estimated the location of North American cities using both spatial and numeric response modes and a variety of perceptual and memory supports. These supports included having location markers for each city color coded by nation and identified by name, giving participants the opportunity to see and update all their estimates throughout the task, and allowing them to respond directly on a map. No manipulation mitigated the influence of categories on the judgments, but some manipulations improved within-region ordinal accuracy. The data provide evidence that the city and regional levels are independent, spatial and numeric response modalities affect accuracy differently at the different levels, biases at the regional level have multiple sources, and accurate spatial cues improve estimates primarily by limiting the use of global landmarks to partition the response space. Results support J. Huttenlocher, L. V. Hedges, and S. Duncan’s (1991) theory of spatial location estimates and extend it to the domain of real-world geography.
Iterative fragmentation of cognitive maps in a visual imagery task.” PLoS One 8
"... It remains unclear whether spontaneous eye movements during visual imagery reflect the mental generation of a visual image (i.e. the arrangement of the component parts of a mental representation). To address this specificity, we recorded eye movements in an imagery task and in a phonological fluency ..."
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It remains unclear whether spontaneous eye movements during visual imagery reflect the mental generation of a visual image (i.e. the arrangement of the component parts of a mental representation). To address this specificity, we recorded eye movements in an imagery task and in a phonological fluency (non-imagery) task, both consisting in naming French towns from long-term memory. Only in the condition of visual imagery the spontaneous eye positions reflected the geographic position of the towns evoked by the subjects. This demonstrates that eye positions closely reflect the mapping of mental images. Advanced analysis of gaze positions using the bi-dimensional regression model confirmed the spatial correlation of gaze and towns ’ locations in every single individual in the visual imagery task and in none of the individuals when no imagery accompanied memory retrieval. In addition, the evolution of the bi-dimensional regression’s coefficient of determination revealed, in each individual, a process of generating several iterative series of a limited number of towns mapped with the same spatial distortion, despite different individual order of towns ’ evocation and different individual mappings. Such consistency across subjects revealed by gaze (the mind’s eye) gives empirical support to theories
Pigeons Encode Absolute Distance but Relational Direction From Landmarks and Walls
"... In recent studies, researchers have examined animals ’ use of absolute or relational distances in finding a hidden goal. When trained with an array of landmarks, most animals use the default strategy of searching at an absolute distance from 1 or more landmarks. In contrast, when trained in enclosur ..."
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In recent studies, researchers have examined animals ’ use of absolute or relational distances in finding a hidden goal. When trained with an array of landmarks, most animals use the default strategy of searching at an absolute distance from 1 or more landmarks. In contrast, when trained in enclosures, animals often use the relationship among walls. In the present study, pigeons were trained to find the center of an array of landmarks or a set of short walls that did not block external cues. Expansion tests showed that both groups of pigeons primarily used an absolute distance strategy. However, on rotational tests, pigeons continued to search in the center of the array, suggesting that direction was learned in relation to array.
Bayesian combination of two-dimensional location estimates
, 2012
"... Abstract We extend a Bayesian method for combining estimates of means and variances from independent cues in a spatial cue-combination paradigm. In a typical cue-combination experiment, subjects estimate a value on a single dimension—for example, depth—on the basis of two different cues, such as ret ..."
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Abstract We extend a Bayesian method for combining estimates of means and variances from independent cues in a spatial cue-combination paradigm. In a typical cue-combination experiment, subjects estimate a value on a single dimension—for example, depth—on the basis of two different cues, such as retinal disparity and motion. The mathematics for this one-dimensional case is well established. When the variable to be estimated has two dimensions, such as location (which has both x and y val-ues), then the one-dimensional method may be inappropriate due to possible correlations between x and y and the fact that the dimensions may be inseparable. A cue-combination task for location involves people or animals estimating xy loca-tions under two single-cue conditions and in a condition in which both cues are combined. We present the mathematics for the two-dimensional case in an analogous manner to the one-dimensional case and illustrate them using a numeric example. Our example involves locations on maps, but the method illustrated is relevant for any task for which the estimated variable has two or more dimensions.
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content, accuracy and utility of mental representations
"... Spatial representation and low vision: Two studies on the content, accuracy and utility of mental representations ..."
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Spatial representation and low vision: Two studies on the content, accuracy and utility of mental representations
