Spatial memory and navigation by honeybees on the scale of the foraging range

1996 ◽  
Vol 199 (1) ◽  
pp. 147-154 ◽  
Author(s):  
F Dyer
Keyword(s):  
Spatial Memory ◽  
Recent Progress ◽  
Spatial Information ◽  
Spatial Relationships ◽  
The Sun ◽  
Feeding Sites ◽  
Environmental Features ◽  
Foraging Range

Honeybees and other nesting animals face the problem of finding their way between their nest and distant feeding sites. Many studies have shown that insects can learn foraging routes in reference to both landmarks and celestial cues, but it is a major puzzle how spatial information obtained from these environmental features is encoded in memory. This paper reviews recent progress by my colleagues and me towards understanding three specific aspects of this problem in honeybees: (1) how bees learn the spatial relationships among widely separated locations in a familiar terrain; (2) how bees learn the pattern of movement of the sun over the day; and (3) whether, and if so how, bees learn the relationships between celestial cues and landmarks.

scholarly journals Biases in object location estimation: the role of camera rotations and translation

2021 ◽  
Author(s):  
Vladislava Segen
Keyword(s):  
Older Adults ◽  
Spatial Memory ◽  
Spatial Information ◽  
Location Estimation ◽  
Object Location ◽  
Systematic Bias ◽  
Accurate Representation ◽  
Object Locations ◽  
Age Related

The current study investigated a systematic bias in spatial memory in which people, following a perspective shift from encoding to recall, indicated the location of an object further to the direction of the shit. In Experiment 1, we documented this bias by asking participants to encode the position of an object in a virtual room and then indicate it from memory following a perspective shift induced by camera translation and rotation. In Experiment 2, we decoupled the influence of camera translations and camera rotations and examined also whether adding more information in the scene would reduce the bias. We also investigated the presence of age-related differences in the precision of object location estimates and the tendency to display the bias related to perspective shift. Overall, our results showed that camera translations led to greater systematic bias than camera rotations. Furthermore, the use of additional spatial information improved the precision with which object locations were estimated and reduced the bias associated with camera translation. Finally, we found that although older adults were as precise as younger participants when estimating object locations, they benefited less from additional spatial information and their responses were more biased in the direction of camera translations. We propose that accurate representation of camera translations requires more demanding mental computations than camera rotations, leading to greater uncertainty about the position of an object in memory. This uncertainty causes people to rely on an egocentric anchor thereby giving rise to the systematic bias in the direction of camera translation.

scholarly journals A contemporary view of coronal heating

2012 ◽  
Vol 370 (1970) ◽  
pp. 3217-3240 ◽  
Author(s):  
Clare E. Parnell ◽  
Ineke De Moortel
Keyword(s):  
Magnetic Field ◽  
Recent Progress ◽  
Coupled System ◽  
Coronal Heating ◽  
The Sun ◽  
Key Factors ◽  
Computing Power ◽  
Heating Mechanism ◽  
Outer Atmosphere ◽  
The Magnetic Field

Determining the heating mechanism (or mechanisms) that causes the outer atmosphere of the Sun, and many other stars, to reach temperatures orders of magnitude higher than their surface temperatures has long been a key problem. For decades, the problem has been known as the coronal heating problem, but it is now clear that ‘coronal heating’ cannot be treated or explained in isolation and that the heating of the whole solar atmosphere must be studied as a highly coupled system. The magnetic field of the star is known to play a key role, but, despite significant advancements in solar telescopes, computing power and much greater understanding of theoretical mechanisms, the question of which mechanism or mechanisms are the dominant supplier of energy to the chromosphere and corona is still open. Following substantial recent progress, we consider the most likely contenders and discuss the key factors that have made, and still make, determining the actual (coronal) heating mechanism (or mechanisms) so difficult.

scholarly journals Variations in Solar Radiation and the Cause of Ice Ages

1950 ◽  
Vol 1 (08) ◽  
pp. 453-455 ◽  
Author(s):  
F. Hoyle ◽  
R. A. Lyttleton
Keyword(s):  
Solar Radiation ◽  
Stellar Evolution ◽  
Recent Progress ◽  
Solar Surface ◽  
The Sun ◽  
Total Radiation ◽  
Ice Ages ◽  
Gravitational Action ◽  
Extra Energy ◽  
Possible Cause

Abstract Most astronomical hypotheses on the causes of ice ages are dynamically untenable. Alterations in the amount of solar radiation, however, have long been recognized as a possible cause, but only with recent progress in the theory of stellar evolution has it become clear that such changes must occur. At irregular intervals the sun will pass, and will have passed, with low relative speeds through interstellar hydrogen clouds, and the gravitational action of the sun leads to an increase in the quantity of material falling to the surface with high velocity. The conversion of the kinetic energy of fall of this material results in an increase of emission at the solar surface. Increases of order up to about 10 per cent of the present total radiation could occur, and the process is such that the extra energy would be located mainly in the shorter wavelengths.

scholarly journals Object-in-place Memory Predicted by Anterolateral Entorhinal Cortex and Parahippocampal Cortex Volume in Older Adults

2019 ◽  
Vol 31 (5) ◽  
pp. 711-729 ◽  
Author(s):  
Lok-Kin Yeung ◽  
Rosanna K. Olsen ◽  
Bryan Hong ◽  
Valentina Mihajlovic ◽  
Maria C. D'Angelo ◽  
...  
Keyword(s):  
Older Adults ◽  
Alzheimer Disease ◽  
Entorhinal Cortex ◽  
Spatial Information ◽  
Brain Regions ◽  
Spatial Relationships ◽  
Object Representations ◽  
Functional Connections ◽  
Place Memory ◽  
Parahippocampal Cortex

The lateral portion of the entorhinal cortex is one of the first brain regions affected by tau pathology, an important biomarker for Alzheimer disease. Improving our understanding of this region's cognitive role may help identify better cognitive tests for early detection of Alzheimer disease. Based on its functional connections, we tested the idea that the human anterolateral entorhinal cortex (alERC) may play a role in integrating spatial information into object representations. We recently demonstrated that the volume of the alERC was related to processing the spatial relationships of the features within an object [Yeung, L. K., Olsen, R. K., Bild-Enkin, H. E. P., D'Angelo, M. C., Kacollja, A., McQuiggan, D. A., et al. Anterolateral entorhinal cortex volume predicted by altered intra-item configural processing. Journal of Neuroscience, 37, 5527–5538, 2017]. In this study, we investigated whether the human alERC might also play a role in processing the spatial relationships between an object and its environment using an eye-tracking task that assessed visual fixations to a critical object within a scene. Guided by rodent work, we measured both object-in-place memory, the association of an object with a given context [Wilson, D. I., Langston, R. F., Schlesiger, M. I., Wagner, M., Watanabe, S., & Ainge, J. A. Lateral entorhinal cortex is critical for novel object-context recognition. Hippocampus, 23, 352–366, 2013], and object-trace memory, the memory for the former location of objects [Tsao, A., Moser, M. B., & Moser, E. I. Traces of experience in the lateral entorhinal cortex. Current Biology, 23, 399–405, 2013]. In a group of older adults with varying stages of brain atrophy and cognitive decline, we found that the volume of the alERC and the volume of the parahippocampal cortex selectively predicted object-in-place memory, but not object-trace memory. These results provide support for the notion that the alERC may integrate spatial information into object representations.

scholarly journals Stellar Abundance Analyses in the Light of 3D Hydrodynamical Model Atmospheres

2003 ◽  
Vol 210 ◽  
pp. 273-286 ◽  
Author(s):  
Martin Asplund
Keyword(s):  
Recent Progress ◽  
Hydrodynamical Model ◽  
Observational Constraints ◽  
The Sun ◽  
Mixing Length ◽  
Line Formation ◽  
Late Type ◽  
Line Shapes ◽  
Free Parameters

I describe recent progress in terms of 3D hydrodynamical model atmospheres and 3D line formation and their applications to stellar abundance analyses of late-type stars. Such 3D studies remove the free parameters inherent in classical 1D investigations (mixing length parameters, macro- and microturbulence) yet are highly successful in reproducing a large arsenal of observational constraints such as detailed line shapes and asymmetries. Their potential for abundance analyses is illustrated by discussing the derived oxygen abundances in the Sun and in metal-poor stars, where they seem to resolve long-standing problems as well as significantly alter the inferred conclusions.

scholarly journals Long-Term Loop Closure Detection through Visual-Spatial Information Preserving Multi-Order Graph Matching

2020 ◽  
Vol 34 (06) ◽  
pp. 10369-10376
Author(s):  
Peng Gao ◽  
Hao Zhang
Keyword(s):  
Spatial Information ◽  
Graph Matching ◽  
Fundamental Problem ◽  
Graph Representation ◽  
Spatial Relationships ◽  
Matching Problem ◽  
Loop Closure ◽  
Loop Closure Detection ◽  
Visual Spatial

Loop closure detection is a fundamental problem for simultaneous localization and mapping (SLAM) in robotics. Most of the previous methods only consider one type of information, based on either visual appearances or spatial relationships of landmarks. In this paper, we introduce a novel visual-spatial information preserving multi-order graph matching approach for long-term loop closure detection. Our approach constructs a graph representation of a place from an input image to integrate visual-spatial information, including visual appearances of the landmarks and the background environment, as well as the second and third-order spatial relationships between two and three landmarks, respectively. Furthermore, we introduce a new formulation that formulates loop closure detection as a multi-order graph matching problem to compute a similarity score directly from the graph representations of the query and template images, instead of performing conventional vector-based image matching. We evaluate the proposed multi-order graph matching approach based on two public long-term loop closure detection benchmark datasets, including the St. Lucia and CMU-VL datasets. Experimental results have shown that our approach is effective for long-term loop closure detection and it outperforms the previous state-of-the-art methods.

scholarly journals Ranging behaviour of Cape Vultures Gyps coprotheres from an endangered population in Namibia

2007 ◽  
Vol 17 (4) ◽  
pp. 331-339 ◽  
Author(s):  
Andrew J. Bamford ◽  
Maria Diekmann ◽  
Ara Monadjem ◽  
John Mendelsohn
Keyword(s):  
Breeding Population ◽  
Intensive Management ◽  
Adult Males ◽  
Wild Ungulates ◽  
Feeding Sites ◽  
Foraging Range ◽  
Ranging Behaviour ◽  
Nesting Behaviour ◽  
Endangered Population ◽  
Tracking Devices

AbstractThe Cape Vulture (Gyps coprotheres) is an obligate cliff-nesting vulture endemic to southern Africa. Its range and population size have declined markedly over the last century. Namibia has just one colony, located on the cliffs of the Waterberg Plateau, with a population estimated to be eight adult birds, including two females. The species is regarded as Critically Endangered in Namibia, and establishing a secure breeding population may require intensive management. Data on movements, foraging range and behaviour of Cape Vultures, important in any management programme, have been lacking. Five adult males and one immature were captured near the Waterberg site and fitted with satellite-tracking devices. Only two of the adult vultures still roosted on the cliffs and only one of those exclusively; the other individuals roosted in trees. Three individuals were observed building and attending to nests in trees, and, for one of these, the partner was identified as an African White-backed Vulture (Gyps africanus). The foraging range of the adult birds was large compared with other studies of this species. Most foraging took place on freehold farms. All adults avoided areas of communally owned land where wild ungulates are uncommon, thus further decreasing their potentially available food supply. Two ‘vulture restaurants’, feeding sites specifically for vultures, within the foraging range of the adult birds accounted for a large proportion of their time spent on the ground. The ranging behaviour of adult vultures varied throughout the year, and was apparently related to their nesting behaviour.

scholarly journals Testing the precision of spatial memory representations using a change-detection task: Effects of viewpoint change

2020 ◽  
Author(s):  
Edward Heywood-Everett ◽  
Daniel H Baker ◽  
Tom Hartley
Keyword(s):  
Spatial Memory ◽  
Change Detection ◽  
Spatial Information ◽  
Linear Increase ◽  
Spatial Knowledge ◽  
Task Demands ◽  
Task Effects ◽  
Viewpoint Change ◽  
Memory Representations ◽  
The Brain

There are at least two distinct ways in which the brain encodes spatial information: in egocentric representations locations are encoded relative to the observer, whereas in allocentric representations locations are encoded relative to the environment. Both inform spatial memory, but the extent to which they influence behaviour varies depending on the task. In the present study, two preregistered experiments used a psychophysical approach to measure the precision of spatial memory while varying ego- and allocentric task demands. Participants were asked to detect the changed location of one of four objects when seen from a new viewpoint (rotated by 0°, 5°, 15°, 45° or 135°). Experiment 1 used a Same/Different task and Experiment 2 used a 2AFC task. Psychophysical thresholds were calculated, showing that in both experiments, spatial change detection thresholds showed a monotonic but non-linear increase as viewpoint change increased. This was consistent with a preregistered model including distinct parameters corresponding to egocentric and allocentric contributions that change lawfully as a function of viewpoint shift. Our results provide a clearer understanding of how underlying memory representations interact to inform our spatial knowledge of the environment.

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