scholarly journals Observational Spatial Memory in North Island Robins (Petroica Longpies)

2021 ◽  
Author(s):  
◽  
Nicola Ellen Armstrong
Keyword(s):  
Retention Interval ◽  
Spatial Memory ◽  
Interval Number ◽  
Small Scale ◽  
Food Hoarding ◽  
Scale Factors ◽  
Retention Intervals ◽  
Two Parameters ◽  
Prey Items

<p>Observational spatial memory is employed by members of food-hoarding species to pilfer caches created by other individuals more effectively. North Island robins (Petroica australis) experience high levels of reciprocal cache pilferage within mate pairs. These circumstances were hypothesised to produce conditions under which advanced pilferage strategies such as observational spatial memory may evolve. Here I tested the ability of North Island robins to use observational spatial memory to discriminate between varying prey rewards. Three experiments were conducted which differed in the maximum number of prey items offered as a reward. Additional variables of retention interval, number of cache sites and a variable reward were included to assess how the birds’ memory was affected by small-scale factors. Results showed that North Island robins performed above chance expectations in most treatment combinations, indicating that they were able to utilize observational spatial memory. They were equally able to discriminate between different combinations of prey numbers that were hidden in 2, 3 and 4 caches sites from between 0, 10 and 60 seconds. Overall results indicate that North Island robins can solve complex numerical problems involving more than two parameters and up to one minute long retention intervals without training.</p>

scholarly journals Observational Spatial Memory in North Island Robins (Petroica Longpies)

2021 ◽  
Author(s):  
◽  
Nicola Ellen Armstrong
Keyword(s):  
Retention Interval ◽  
Spatial Memory ◽  
Interval Number ◽  
Small Scale ◽  
Food Hoarding ◽  
Scale Factors ◽  
Retention Intervals ◽  
Two Parameters ◽  
Prey Items

<p>Observational spatial memory is employed by members of food-hoarding species to pilfer caches created by other individuals more effectively. North Island robins (Petroica australis) experience high levels of reciprocal cache pilferage within mate pairs. These circumstances were hypothesised to produce conditions under which advanced pilferage strategies such as observational spatial memory may evolve. Here I tested the ability of North Island robins to use observational spatial memory to discriminate between varying prey rewards. Three experiments were conducted which differed in the maximum number of prey items offered as a reward. Additional variables of retention interval, number of cache sites and a variable reward were included to assess how the birds’ memory was affected by small-scale factors. Results showed that North Island robins performed above chance expectations in most treatment combinations, indicating that they were able to utilize observational spatial memory. They were equally able to discriminate between different combinations of prey numbers that were hidden in 2, 3 and 4 caches sites from between 0, 10 and 60 seconds. Overall results indicate that North Island robins can solve complex numerical problems involving more than two parameters and up to one minute long retention intervals without training.</p>

The effects of sex and retention interval on performance in two novel spatial memory tasks

2010 ◽  
Author(s):  
Alia L. Yasen ◽  
Matthew Herson ◽  
Brian J. Piper ◽  
Jeremy K. Miller
Keyword(s):  
Retention Interval ◽  
Spatial Memory

Long Retention Intervals Impair the Confidence-Accuracy Relationship for Eyewitness Recall

2021 ◽  
Author(s):  
Emily Rebecca Spearing ◽  
Kimberley A. Wade
Keyword(s):  
Retention Interval ◽  
Cued Recall ◽  
Eyewitness Confidence ◽  
Eyewitness Accuracy ◽  
Memory Accuracy ◽  
Retrieval Fluency ◽  
Retention Intervals ◽  
Mock Crime ◽  
Very High ◽  
Accuracy Relationship

A growing body of research suggests that confidence judgements can provide a useful indicator of memory accuracy under some conditions. One factor known to affect eyewitness accuracy, yet rarely examined in the confidence-accuracy literature, is retention interval. Using calibration analyses, we investigated how retention interval affects the confidence-accuracy relationship for eyewitness recall. In total, 611 adults watched a mock crime video and completed a cued-recall test either immediately, after 1 week, or after 1 month. Long (1 month) delays led to lower memory accuracy, lower confidence judgements, and impaired the confidence-accuracy relationship compared to shorter (immediate and 1 week) delays. Long-delay participants who reported very high levels of confidence tended to be over-confident in the accuracy of their memories compared to other participants. Self-rated memory ability, however, did not predict eyewitness confidence or the confidence-accuracy relationship. We discuss the findings in relation to cue-utilization theory and a retrieval-fluency account.

The Role of Constant Curvature in 2-D Contour Shape Representations

Perception ◽  
10.1068/p6970 ◽  
2011 ◽  
Vol 40 (11) ◽  
pp. 1290-1308 ◽  
Author(s):  
Patrick Garrigan ◽  
Philip J Kellman
Keyword(s):  
Retention Interval ◽  
Constant Curvature ◽  
Visual Information ◽  
Recognition Performance ◽  
Shape Representations ◽  
Contour Shape ◽  
Position And Orientation ◽  
Retention Intervals ◽  
Invariant Shape

In early cortex, visual information is encoded by retinotopic orientation-selective units. Higher-level representations of abstract properties, such as shape, require encodings that are invariant to changes in size, position, and orientation. Within the domain of open, 2-D contours, we consider how an economical representation that supports viewpoint-invariant shape comparisons can be derived from early encodings. We explore the idea that 2-D contour shapes are encoded as joined segments of constant curvature. We report three experiments in which participants compared sequentially presented 2-D contour shapes comprised of constant curvature (CC) or non-constant curvature (NCC) segments. We show that, when shapes are compared across viewpoint or for a retention interval of 1000 ms, performance is better for CC shapes. Similar recognition performance is observed for both shape types, however, if they are compared at the same viewpoint and the retention interval is reduced to 500 ms. These findings are consistent with a symbolic encoding of 2-D contour shapes into CC parts when the retention intervals over which shapes must be stored exceed the duration of initial, transient, visual representations.

Memory of prey larders in golden orb-web spiders, Nephila clavipes (Araneae: Nephilidae)

Behaviour ◽  
2013 ◽  
Vol 150 (12) ◽  
pp. 1345-1356 ◽  
Author(s):  
Rafael L. Rodríguez ◽  
Robb C. Kolodziej ◽  
Gerlinde Höbel
Keyword(s):  
Field Experiment ◽  
Total Mass ◽  
Potential Effect ◽  
Continuous Variable ◽  
Adaptive Significance ◽  
Nephila Clavipes ◽  
Food Hoarding ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Prey Items

Nephila clavipes spiders accumulate prey larders on their webs. We conducted a field experiment to ask if the spiders search for larders that have been pilfered (experimentally mimicking the potential effect of kleptoparasites), and to ask if the spiders vary their search efforts according to the size of the larder. All spiders searched for larders removed from their web, and spiders that lost larger larders (i.e., consisting of more prey items) searched for longer intervals. We thus suggest that N. clavipes form memories of the size of the larders they have accumulated, and that they use those memories to regulate recovery efforts when the larders are pilfered. The content of those memories may include discrete prey counts or the accumulation of a continuous variable correlated with counts, such as the total mass of captured prey. We discuss the adaptive significance of this ability in the framework of costs related to kleptoparasites and the ecology of food hoarding.

Resonating Waterfalls

1974 ◽  
Vol 339 (1619) ◽  
pp. 435-449 ◽  
Keyword(s):  
Infinite Number ◽  
Surface Friction ◽  
Ambient Air ◽  
Small Scale ◽  
Two Parameters

A sheet of water falling vertically into a pool can vibrate of its own accord in resonance with air trapped behind it. Measurements of modes and frequencies in small-scale apparatus were made by means of a stroboscope. A theory is put forward which shows that the motion depends upon two parameters. It explains some of the features that were observed, but it does not specify which of an infinite number of modes and frequencies will in fact occur. Further experiments, carried out in a decompression chamber, suggested that surface friction, due to the ambient air and ignored in the theory, has some influence in this respect.

scholarly journals Comparable human spatial memory distortions in physical, desktop virtual and immersive virtual environments

2022 ◽  
Author(s):  
Fiona Zisch ◽  
Coco Newton ◽  
Antoine Coutrot ◽  
Maria Murcia-Lopez ◽  
Anisa Motala ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Path Integration ◽  
Goodness Of Fit ◽  
The Body ◽  
Small Scale ◽  
Spatial Distributions ◽  
Head Mounted Display ◽  
Physical Environments ◽  
Desktop Vr ◽  
The Impact

Boundaries define regions of space and are integral to episodic memories. The impact of boundaries on spatial memory and neural representations of space has been extensively studied in freely-moving rodents. But less is known in humans and many prior studies have employed desktop virtual reality (VR) which lacks the body-based self-motion cues of the physical world, diminishing the potentially strong input from path integration to spatial memory. We replicated a desktop-VR study testing the impact of boundaries on spatial memory (Hartley et al., 2004) in a physical room (2.4m x 2.4m, 2m tall) by having participants (N = 27) learn the location of a circular stool and then after a short delay replace it where they thought they had found it. During the delay, the wall boundaries were either expanded or contracted. We compared performance to groups of participants undergoing the same procedure in a laser-scanned replica in both desktop VR (N = 44) and freely-walking head mounted display (HMD) VR (N = 39) environments. Performance was measured as goodness of fit between the spatial distributions of group responses and seven modelled distributions that prioritised different metrics based on boundary geometry or walking paths to estimate the stool location. The best fitting model was a weighted linear combination of all the geometric spatial models, but an individual model derived from place cell firing in Hartley et al. 2004 also fit well. High levels of disorientation in all three environments prevented detailed analysis on the contribution of path integration. We found identical model fits across the three environments, though desktop VR and HMD-VR appeared more consistent in spatial distributions of group responses than the physical environment and displayed known variations in virtual depth perception. Thus, while human spatial representation appears differentially influenced by environmental boundaries, the influence is similar across virtual and physical environments. Despite differences in body-based cue availability, desktop and HMD-VR allow a good and interchangeable approximation for examining human spatial memory in small-scale physical environments.

scholarly journals Decomposition and stabilization of organic matter in an old-growth tropical riparian forest: effects of soil properties and vegetation structure

2020 ◽  
Author(s):  
Pedro Fernandes ◽  
Andrea Teixeira Souza ◽  
Marcel Tanaka ◽  
Renata Sebastiani
Keyword(s):  
Soil Properties ◽  
Forest Structure ◽  
Riparian Forest ◽  
Chemical Properties ◽  
Clay Content ◽  
Small Scale ◽  
Decomposition Rates ◽  
Old Growth ◽  
Scale Factors ◽  
Stabilization Factor

Abstract Background: Nutrient cycling in tropical forests has a large importance for primary productivity, and decomposition of litterfall is a major process influencing nutrient balance in forest soils. Although large-scale factors strongly influence decomposition patterns, small-scale factors can have major influences, especially in old-growth forests that have high structural complexity and strong plant-soil correlations. Here we evaluated the effects of forest structure and soil properties on decomposition rates and stabilization of soil organic matter using the Tea Bag Index in an old-growth riparian forest in southeastern Brazil. These data sets were described separately using Principal Components Analysis (PCA). The main axes for each analysis, together with soil physical properties (clay content and soil moisture), were used to construct structural equations models that evaluated the different parameters of the TBI, decomposition rates and stabilization factor. The best model was selected using Akaike’s criterion.Results: Forest structure and soil physical and chemical properties presented large variation among plots within the studied forest. Clay content was strongly correlated with soil moisture and the first PCA axis of soil chemical properties, and model selection indicated that clay content was a better predictor than this axis. Decomposition rates presented a large variation among tea bags (0.009 and 0.098 g g-1 day-1) and were positively related with forest structure, as characterized by higher basal area, tree density and larger trees. The stabilization factor varied between 0.211 – 0.426 and was related to forest stratification and soil clay content.Conclusions: The old-growth forest studied presented high heterogeneity in both forest structure and soil properties at small spatial scales, that influenced decomposition processes and probably contributed to small-scale variation in nutrient cycling. Decomposition rates were only influenced by forest structure, whereas the stabilization factor was influenced by both forest structure and soil properties. Heterogeneity in ecological processes can contribute to the resilience of old-growth forests, highlighting the importance of restoration strategies that consider the spatial variation of ecosystem processes.

scholarly journals Spatial organisation of catchments – assessment and usage for impartial sub-basin ascertainment and classification

2016 ◽  
Author(s):  
Henning Oppel ◽  
Andreas Schumann
Keyword(s):  
Small Scale ◽  
Rainfall Runoff ◽  
Spatial Organisation ◽  
Characteristic Structure ◽  
Natural Rainfall ◽  
Flow Length ◽  
Wide Range ◽  
Definition Of ◽  
Two Parameters ◽  
Insight Into

Abstract. A hydrological model should represent the hydrological most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject of a certain spatial organisation. In order to reproduce the natural rainfall-runoff response the reduction of variance of catchment properties as well as the incorporation of the spatial organisation of the catchment is desirable. In this study the method of the characteristic structure is introduced to detect and visualize the spatial organisation of catchments, based on stream flow length rearrangement of any catchment feature of interest. Moreover, the method is implemented in an algorithm for automated sub-basin ascertainment, which includes the definition of zones within the newly defined sub-basins. The algorithm is applied on two parameters characterising topography and soil of four mid-European watersheds. Results indicate a wide range of applicability for the method and the algorithm. As a limitation of the application for the algorithm the presence of small scale soil enclosures that do not follow the geomorphologic structure of the catchment could be identified. Finally, results of subdivisions based on soil and topography were intersected to gain insight into catchment organisation. Based on this analysis four types of physiographical types could be established.

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