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39
Bayesian integration of spatial information
- Psychological Bulletin
, 2007
"... Spatial judgments and actions are often based on multiple cues. The authors review a multitude of phenomena on the integration of spatial cues in diverse species to consider how nearly optimally animals combine the cues. Under the banner of Bayesian perception, cues are sometimes combined and weight ..."
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Cited by 27 (3 self)
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Spatial judgments and actions are often based on multiple cues. The authors review a multitude of phenomena on the integration of spatial cues in diverse species to consider how nearly optimally animals combine the cues. Under the banner of Bayesian perception, cues are sometimes combined and weighted in a near optimal fashion. In other instances when cues are combined, how optimal the integration is might be unclear. Only 1 cue may be relied on, or cues may seem to compete with one another. The authors attempt to bring some order to the diversity by taking into account the subjective discrepancy in the dictates of multiple cues. When cues are too discrepant, it may be best to rely on 1 cue source. When cues are not too discrepant, it may be advantageous to combine cues. Such a dual principle provides an extended Bayesian framework for understanding the functional reasons for the integration of spatial cues.
A Controlled Attractor Network Model of Path Integration in the Rat
"... Cells in several areas of the hippocampal formation show place specific firing patterns, and are thought to form a distributed representation of an animal’s current location in an environment. Experimental results suggest that this representation is continually updated even in complete darkness, ind ..."
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Cited by 17 (4 self)
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Cells in several areas of the hippocampal formation show place specific firing patterns, and are thought to form a distributed representation of an animal’s current location in an environment. Experimental results suggest that this representation is continually updated even in complete darkness, indicating the presence of a path integration mechanism in the rat. Adopting the Neural Engineering Framework (NEF) presented by Eliasmith and Anderson (2003) we derive a novel attractor network model of path integration, using heterogeneous spiking neurons. The network we derive incorporates representation and updating of position into a single layer of neurons, eliminating the need for a large external control population, and without making use of multiplicative synapses. An efficient and biologically plausible control mechanism results directly from applying the principles of the NEF. We simulate the network for a variety of inputs, analyze its performance, and give three testable predictions of our model.
Is there a geometric module for spatial orientation? insights from a rodent navigation model
- Psychological Review
, 2009
"... Modern psychological theories of spatial cognition postulate the existence of a ‘geometric module ’ for reorientation. This concept is derived from experimental data showing that in rectangular arenas with distinct landmarks in the corners, disoriented rats often make diagonal errors, suggesting the ..."
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Cited by 17 (5 self)
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Modern psychological theories of spatial cognition postulate the existence of a ‘geometric module ’ for reorientation. This concept is derived from experimental data showing that in rectangular arenas with distinct landmarks in the corners, disoriented rats often make diagonal errors, suggesting their preference for the geometric (arena shape) over the non-geometric (landmarks) cues. Moreover, experimentally observed sensitivity of hippocampal cell firing to the changes in the environment layout was taken in support of the geometric module hypothesis. Using a computational model of rat navigation, we propose and test the alternative hypothesis that the influence of spatial geometry on both behavioral and neuronal levels can be explained by the properties of visual features that constitute local views of the environment. Our modeling results suggest that the pattern of diagonal errors observed in the reorientation task can be understood by the analysis of sensory information processing that underlies the navigation strategy employed
Reflections on geometry and navigation
- Connection Science
, 2005
"... The geometric arrangement of surfaces in an environment plays an important role in navigation in vertebrate animals. In this line of research, an animal is typically disoriented and then presented the task of relocating a previously encountered goal. Aside from the geometric shape of the enclosure, ..."
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Cited by 14 (3 self)
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The geometric arrangement of surfaces in an environment plays an important role in navigation in vertebrate animals. In this line of research, an animal is typically disoriented and then presented the task of relocating a previously encountered goal. Aside from the geometric shape of the enclosure, other non-geometric (featural) cues are typically available, including colours of walls, objects serving as landmarks, or smells. Animals use both geometric and featural cues, but mammals sometimes rely solely on geometric cues. This has led to views that the processing of geometric information is modular, being the work of a geometric module. Recent work has started to address just what geometric properties are encoded. These current issues are commented on in this paper, and a tentative picture is drawn that both global and local geometry, each in limited ways, are used for navigation. A view of modularity is also presented in which spatial information is stored together (in non-modular fashion), but some computational processes are modular and operate on limited kinds of information.
Unstable CA1 place cell representation in rats with entorhinal cortex lesions
- Eur. J. Neurosci
, 2008
"... Recent studies emphasize the importance of the entorhinal cortex in spatial representation and navigation. Furthermore, evidence is accumulating to show that spatial processing depends on interactions between the entorhinal cortex and the hippocampus. To investigate these interactions, we examined t ..."
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Cited by 8 (2 self)
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Recent studies emphasize the importance of the entorhinal cortex in spatial representation and navigation. Furthermore, evidence is accumulating to show that spatial processing depends on interactions between the entorhinal cortex and the hippocampus. To investigate these interactions, we examined the effects of entorhinal cortex lesions on the activity of hippocampal CA1 place cells. Rats received bilateral radiofrequency lesions of the entorhinal cortex or sham lesions before place cell recording. Place cells were recorded as the rats performed a pellet-chasing task in a cylinder containing three cue-objects. Entorhinal cortex lesions did not abolish place cell spatial firing but reduced noticeably discharge rate and field size. Most importantly, the lesions affected firing field stability when cells were recorded both in constant conditions and following cue manipulations (object rotation, object removal). These findings indicate that the entorhinal cortex is necessary for the stability of hippocampal representations across exposures to a familiar environment. Consistent with the recent discovery of grid cells in the medial entorhinal cortex, our results suggest that the entorhinal cortex contributes to providing a spatial framework that would enable the hippocampus to maintain stable environment-specific representations.
Review Causal inference in perception
"... Until recently, the question of how the brain performs causal inference has been studied primarily in the context of cognitive reasoning. However, this problem is at least equally crucial in perceptual processing. At any given moment, the perceptual system receives multiple sensory signals within an ..."
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Cited by 7 (0 self)
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Until recently, the question of how the brain performs causal inference has been studied primarily in the context of cognitive reasoning. However, this problem is at least equally crucial in perceptual processing. At any given moment, the perceptual system receives multiple sensory signals within and across modalities and, for example, has to determine the source of each of these signals. Recently, a growing number of studies from various fields of cognitive science have started to address this question and have converged to very similar computational models. Therefore, it seems that a common computational strategy, which is highly consistent with a normative model of causal inference, is exploited by the perceptual system in a variety of domains.
Punishment i n o r g a n i z a t i o n s : A rev iew, p r o p o s i t i o n s and r e s e a r c h s u g g e s t i o n s
- Academy of Management Review
, 1980
"... Dissociation, as the editor of this important volume reminds us, "challenges many comfortable assumptions." From a theoretical vantage, it demands great conceptual clar-ity and a knowledge ofmany areas of import in psychology; from a clinical vantage, it has brought about one ofthe most co ..."
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Cited by 6 (0 self)
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Dissociation, as the editor of this important volume reminds us, "challenges many comfortable assumptions." From a theoretical vantage, it demands great conceptual clar-ity and a knowledge ofmany areas of import in psychology; from a clinical vantage, it has brought about one ofthe most contentious debates in recent history, whether or notimpor-tant memories can be "forgotten " only to appear as habits, behaviors, and dreams, or even later as full-fledged remem-brances. But above all, dissociative phenomena challenge the cherished notion that our conscious self is an all-knowing, integrated entity. This volume is the result of a 1991 conference at the Center for Advanced Study in the Behavioral Sciences, sponsored by the MacArthur Foundation. I was fortunate to be present at this truly multidisciplinary meeting.
The Information Content of Panoramic Images II: View-Based Navigation in Nonrectangular Experimental Arenas
"... Two recent studies testing navigation of rats in swimming pools have posed problems for any account of the use of purely geometric properties of space in navigation (M. Graham, M. A. Good, A. McGregor, ..."
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Cited by 6 (0 self)
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Two recent studies testing navigation of rats in swimming pools have posed problems for any account of the use of purely geometric properties of space in navigation (M. Graham, M. A. Good, A. McGregor,
Firing fields of dorsocaudal medial entorhinal cortex as a context-independent spatial map, Robotics Institute
- Context-Independent Spatial Map. Robotics Institute Tech Report, Number
, 2006
"... The firing fields of the ”grid cells ” found in the rat dorsocaudal medial entorhinal cortex (dMEC) present a surprising pattern of context-independent regularity. We use computational means to analyze and validate the geometric and algebraic invariant properties of the firing fields, leading to a c ..."
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Cited by 3 (0 self)
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The firing fields of the ”grid cells ” found in the rat dorsocaudal medial entorhinal cortex (dMEC) present a surprising pattern of context-independent regularity. We use computational means to analyze and validate the geometric and algebraic invariant properties of the firing fields, leading to a context invariant spatial map. Our method computes the specific symmetry group implicitly associated with the spatial map, and quantifies the regularity of the firing fields to achieve a symmetry-based clustering of two different types of “grid cells. ” This quantified regularity makes spatial mapping more computationally efficient and suggests a way to use the dMEC firing patterns to estimate the probabilty of the rat being located at different points in the room. Finally, general properties of context-independent population codes are suggested. Namely, context-independent population codes gain robustness by introducing uncertainty and ambiguity.
Egocentric Path Integration Models and their Application to Desert Arthropods
, 2008
"... Path integration enables desert arthropods to find back to their nest on the shortest track from any position. To perform path integration successfully, speeds and turning angles along the preceding outbound path have to be measured continuously and combined to determine an internal global vector le ..."
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Path integration enables desert arthropods to find back to their nest on the shortest track from any position. To perform path integration successfully, speeds and turning angles along the preceding outbound path have to be measured continuously and combined to determine an internal global vector leading back home at any time. A number of experiments have given an idea how arthropods might use allothetic or idiothetic signals to perceive their orientation and moving speed. We systematically review the four possible model descriptions of mathematically precise path integration, whereby we favour and elaborate the hitherto not used variant of egocentric cartesian coordinates. Its simple and intuitive structure is demonstrated in comparison to the other models. Measuring two speeds, the forward moving speed and the angular turning rate, and implementing them into a linear system of differential equations provides the necessary information during outbound route, reorientation process and return path. In addition, we propose several possible types of systematic errors that can cause deviations from the correct homeward course. Deviations have been observed for several species of desert arthropods in different experiments, but their origin is still under debate. Using our egocentric path integration model we propose simple error indices depending on path geometry that will allow future experiments to rule out or corroborate certain error types.
