Spatial Causality in Bilateral Symmetry Detection

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 181-181
Author(s):  
J Hulleman ◽  
A H J Oomes
Keyword(s):  
Spatial Scale ◽  
Multiple Scales ◽  
Reaction Times ◽  
Bilateral Symmetry ◽  
Scale Space ◽  
Causality Principle ◽  
Circular Aperture ◽  
Fine Scale ◽  
Black And White ◽  
Random Patterns

We studied the influence of spatial scale on the detection of vertical and horizontal bilateral symmetry. The causality principle in scale - space theory states that increasing the spatial scale in a representation can only result in a decrease of structure. Consequently, a pattern can be random on the fine scale and symmetric on the coarse scale, never the reverse. Stimuli were bilaterally symmetric or random patterns, black-and-white on a grey background, with a circular aperture. The minimal scale was systematically varied and stimuli ranged from conventional noise patterns, through Dalmatian texture, to cow-like patterns. Observers had to judge whether a briefly presented pattern was ‘symmetric’ or ‘random’. Symmetric patterns resulted in a high accuracy (95%) with no influence of scale, and reaction times with a small linear decrease for increasing scale. Random patterns yielded an accuracy increasing from 70% at the smallest scale to 95% at the middle scales. Reaction times showed a similar pattern: largest at the smallest scales and decreasing to values equal to the symmetric condition at the middle scales. Results were similar for vertical and horizontal bilateral symmetry, though the effect for small scales in the random condition was more pronounced in the horizontal case. We conclude that bilateral symmetry is processed at multiple scales with coarse structures available slightly earlier than fine ones. The dramatic decrease of performance for fine-scale patterns is due to the causality effect; random patterns are judged as symmetric when the smallest scale information is not (yet) available.

Survival analysis at multiple scales for the modeling of track geometry deterioration

2017 ◽  
Vol 232 (3) ◽  
pp. 842-850 ◽  
Author(s):  
Negin Alemazkoor ◽  
Conrad J Ruppert ◽  
Hadi Meidani
Keyword(s):  
Survival Analysis ◽  
Multiple Scales ◽  
Fine Scale ◽  
Coarse Scale ◽  
Track Geometry ◽  
Time Period ◽  
Scale Models ◽  
Optimal Maintenance ◽  
Maintenance Decisions

Defects in track geometry have a notable impact on the safety of rail transportation. In order to make the optimal maintenance decisions to ensure the safety and efficiency of railroads, it is necessary to analyze the track geometry defects and develop reliable defect deterioration models. In general, standard deterioration models are typically developed for a segment of track. As a result, these coarse-scale deterioration models may fail to predict whether the isolated defects in a segment will exceed the safety limits after a given time period or not. In this paper, survival analysis is used to model the probability of exceeding the safety limits of the isolated defects. These fine-scale models are then used to calculate the probability of whether each segment of the track will require maintenance after a given time period. The model validation results show that the prediction quality of the coarse-scale segment-based models can be improved by exploiting information from the fine-scale defect-based deterioration models.

scholarly journals Tracking native small mammals to measure fine-scale space use in grazed and restored dry woodlands

2020 ◽  
Vol 24 ◽  
pp. e01348
Author(s):  
Florencia Spirito ◽  
Mary Rowland ◽  
Michael Wisdom ◽  
Solana Tabeni
Keyword(s):  
Small Mammals ◽  
Space Use ◽  
Scale Space ◽  
Fine Scale

scholarly journals More Than Just a Spawning Location: Examining Fine Scale Space Use of Two Estuarine Fish Species at a Spawning Aggregation Site

2017 ◽  
Vol 4 ◽  
Author(s):  
Ross E. Boucek ◽  
Erin Leone ◽  
Joel Bickford ◽  
Sarah Walters-Burnsed ◽  
Susan Lowerre-Barbieri
Keyword(s):  
Fish Species ◽  
Space Use ◽  
Scale Space ◽  
Estuarine Fish ◽  
Fine Scale ◽  
Spawning Aggregation ◽  
Aggregation Site

Different Spatial Scales for Different Face Categorisations

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 295-295
Author(s):  
A Oliva ◽  
P G Schyns
Keyword(s):  
Spatial Scale ◽  
Spatial Scales ◽  
Visual Input ◽  
Perceptual Information ◽  
Fine Scale ◽  
Perceptual Cues ◽  
Fine Spatial Scale ◽  
Complex Stimuli ◽  
Face Stimuli ◽  
Opposite Gender

When people categorise complex stimuli such as faces, they might flexibly use the perceptual information available from the visual input. Three experiments were run to test this hypothesis with two different categorisations (gender and expression) of identical face stimuli. Stimuli were hybrids (Schyns and Oliva, 1994 Psychological Science5 195 – 200): they combined either a man or a woman with a particular expression at a coarse spatial scale with a face of the opposite gender with a different expression at the fine spatial scale. In experiment 1 we tested whether a gender vs an expression categorisation task tapped preferentially into a different spatial scale of the hybrids. Results showed that expression was biased to the fine scale, but that gender was not biased. In experiment 2 the same task was replicated, following a learning of the identity of the faces. It was then found that gender also became biased to the fine scale. In experiment 3 the expression task was changed to an identification of each expression to establish whether this could revert the scale biases observed in experiments 1 and 2. Results suggest that different categorisations of identical faces use different perceptual cues. This suggests that the nature of a task changes the representation of a stimulus.

The Differential Effects of Simultaneous and Successive Cueing on the Detection of Bilateral Symmetry in Dot Patterns

2000 ◽  
Vol 53 (1) ◽  
pp. 165-190 ◽  
Author(s):  
Peter Wenderoth
Keyword(s):  
Visual Processing ◽  
Processing Time ◽  
Reaction Times ◽  
Vertical Axis ◽  
Bilateral Symmetry ◽  
Frame Of Reference ◽  
Symmetry Detection ◽  
Axis Orientation ◽  
Differential Effects ◽  
Orientation Ordering

Corballis and Roldan (1975) obtained speeded judgements of whether dot patterns were bilaterally symmetrical about, or translated across, a line. Reaction times (RTs) were ordered V (vertical) > D (diagonal) > H (horizontal) where “>” means faster than. Similar results occurred with blocked axis orientations, suggesting subjects cannot prepare by rotating a mental frame of reference. Blocking trials may have been ineffective because blocking cannot provide incremental benefits over those already provided by axis lines. Four experiments show that the usual axis orientation ordering of V > H > D is markedly attentuated by simultaneous but not successive axis lines. Also, axis cue lines and axis blocking are not equivalent treatments. Instead, unblocked line cues require finite processing time whereas, under blocking, subjects can prepare for the expected orientation. There was no suggestion anywhere of the V > D > H axis ordering that Corballis and Roldan reported. Successive axis line cues may only direct attention to the orientation being cued, but simultaneous line cues may change the stimulus itself, thus providing an additional means of visual processing that facilitates symmetry detection at non-vertical axis orientations.

Effect of Color on Developmental Picture-Vocabulary Naming of 4-, 6-, and 8-Year-Old Children

2000 ◽  
Vol 9 (4) ◽  
pp. 310-318 ◽  
Author(s):  
Irene M. Barrow ◽  
Donald Holbert ◽  
Michael P. Rastatter
Keyword(s):  
Statistical Analysis ◽  
Reaction Times ◽  
Reaction Time Data ◽  
Time Data ◽  
White Line ◽  
Line Drawings ◽  
Black And White ◽  
Developmental Age ◽  
Accuracy Rates ◽  
Accuracy Data

This study examined the effect of color on the naming process in children for pictures of increasing vocabulary difficulty levels. Picture-naming reaction times and accuracy rates were measured for both black and white line drawings and color drawings in 30 normally developing children, ages 4, 6, and 8 years, via a tachistoscopic viewing paradigm. Statistical analysis of reaction time data revealed that color affected speed of naming only when the vocabulary level of the picture was within the developmental range of the child. That is, for vocabulary within an emerging period for the child, colored drawings were named significantly faster than black and white line drawings. However, color did not significantly influence speed of naming for pictures either for vocabulary well established in the child’s lexicon or for vocabulary above the child’s developmental age. Statistical analysis of accuracy data revealed significant color by vocabulary interactions. Specifically, when the vocabulary level of the pictures exceeded chronological age level, children named color drawings with significantly higher accuracy rates than black and white line drawings.

scholarly journals MSICA: multi-scale signal decomposition based on independent component analysis with application to denoising and reliable multi-channel

2020 ◽  
Vol 1 (1) ◽  
pp. 25-35
Author(s):  
Abolfazl Hajisami ◽  
Dario Pompili
Keyword(s):  
Independent Component Analysis ◽  
Multiple Scales ◽  
Digital Signal ◽  
Component Analysis ◽  
Scale Space ◽  
Independent Component ◽  
Signal Denoising ◽  
Multi Scale ◽  
Information Preservation ◽  
Bank Structure

Multi-scale decomposition is a signal description method in which the signal is decomposed into multiple scales, which has been shown to be a valuable method in information preservation. Much focus on multi-scale decomposition has been based on scale-space theory and wavelet transform. In this article, a new powerful method to perform multi-scale decomposition exploiting Independent Component Analysis (ICA), called MSICA, is proposed to translate an original signal into multiple statistically independent scales. It is proven that extracting the independent components of the even and odd samples of a digital signal results in the decomposition of the same into approximation and detail. It is also proven that the whitening procedure in ICA is equivalent to a filter bank structure. Performance results of MSICA in signal denoising are presented; also, the statistical independency of the approximation and detail is exploited to propose a novel signal-denoising strategy for multi-channel noisy transmissions aimed at improving communication reliability by exploiting channel diversity.

scholarly journals Deriving fine-scale models of human mobility from aggregated origin-destination flow data

2021 ◽  
Vol 17 (2) ◽  
pp. e1008588
Author(s):  
Constanze Ciavarella ◽  
Neil M. Ferguson
Keyword(s):  
Spatial Scale ◽  
Gravity Model ◽  
Spatial Resolution ◽  
Human Mobility ◽  
Parameter Estimates ◽  
Mobility Models ◽  
Fine Scale ◽  
Flow Data ◽  
Mobility Data ◽  
Movement Data

The spatial dynamics of epidemics are fundamentally affected by patterns of human mobility. Mobile phone call detail records (CDRs) are a rich source of mobility data, and allow semi-mechanistic models of movement to be parameterised even for resource-poor settings. While the gravity model typically reproduces human movement reasonably well at the administrative level spatial scale, past studies suggest that parameter estimates vary with the level of spatial discretisation at which models are fitted. Given that privacy concerns usually preclude public release of very fine-scale movement data, such variation would be problematic for individual-based simulations of epidemic spread parametrised at a fine spatial scale. We therefore present new methods to fit fine-scale mathematical mobility models (here we implement variants of the gravity and radiation models) to spatially aggregated movement data and investigate how model parameter estimates vary with spatial resolution. We use gridded population data at 1km resolution to derive population counts at different spatial scales (down to ∼ 5km grids) and implement mobility models at each scale. Parameters are estimated from administrative-level flow data between overnight locations in Kenya and Namibia derived from CDRs: where the model spatial resolution exceeds that of the mobility data, we compare the flow data between a particular origin and destination with the sum of all model flows between cells that lie within those particular origin and destination administrative units. Clear evidence of over-dispersion supports the use of negative binomial instead of Poisson likelihood for count data with high values. Radiation models use fewer parameters than the gravity model and better predict trips between overnight locations for both considered countries. Results show that estimates for some parameters change between countries and with spatial resolution and highlight how imperfect flow data and spatial population distribution can influence model fit.

scholarly journals Effects of Scale on Multimodal Deixis: Evidence From Quiahije Chatino

2021 ◽  
Vol 11 ◽  
Author(s):  
Kate Mesh ◽  
Emiliana Cruz ◽  
Joost van de Weijer ◽  
Niclas Burenhult ◽  
Marianne Gullberg
Keyword(s):  
Large Scale ◽  
Multiple Scales ◽  
Search Space ◽  
Scale Space ◽  
Hand Movements ◽  
Indigenous Language ◽  
San Juan ◽  
Dynamic Nature ◽  
Local Activity ◽  
The World

As humans interact in the world, they often orient one another's attention to objects through the use of spoken demonstrative expressions and head and/or hand movements to point to the objects. Although indicating behaviors have frequently been studied in lab settings, we know surprisingly little about how demonstratives and pointing are used to coordinate attention in large-scale space and in natural contexts. This study investigates how speakers of Quiahije Chatino, an indigenous language of Mexico, use demonstratives and pointing to give directions to named places in large-scale space across multiple scales (local activity, district, state). The results show that the use and coordination of demonstratives and pointing change as the scale of search space for the target grows. At larger scales, demonstratives and pointing are more likely to occur together, and the two signals appear to manage different aspects of the search for the target: demonstratives orient attention primarily to the gesturing body, while pointing provides cues for narrowing the search space. These findings underscore the distinct contributions of speech and gesture to the linguistic composite, while illustrating the dynamic nature of their interplay.Abstracts in Spanish and Quiahije Chatino are provided as appendices.Se incluyen como apéndices resúmenes en español y en el chatino de San Juan Quiahije. SonG ktyiC reC inH, ngyaqC skaE ktyiC noE ndaH sonB naF ngaJ noI ngyaqC loE ktyiC reC, ngyaqC ranF chaqE xlyaK qoE chaqF jnyaJ noA ndywiqA renqA KchinA KyqyaC.

scholarly journals Subjective wellbeing at different spatial scales for individuals satisfied and dissatisfied with life

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6502 ◽  
Author(s):  
Ida Kubiszewski ◽  
Nabeeh Zakariyya ◽  
Diane Jarvis
Keyword(s):  
Life Satisfaction ◽  
Regression Analysis ◽  
Spatial Scale ◽  
Subjective Wellbeing ◽  
Multiple Scales ◽  
Spatial Scales ◽  
National Level ◽  
International Comparisons ◽  
Multiple Spatial Scales ◽  
The World

Indicators that attempt to gauge wellbeing have been created and used at multiple spatial scales around the world. The most commonly used indicators are at the national level to enable international comparisons. When analyzing subjective life satisfaction (LS), an aspect of wellbeing, at multiple spatial scales in Australia, variables (drawn from environmental, social, and economic domains) that are significantly correlated to LS at smaller scales become less significant at larger sub-national scales. The reverse is seen for other variables, which become more significant at larger scales. Regression analysis over multiple scales on three groups (1) all individuals within the sample, (2) individuals with self-reported LS as dissatisfied (LS ≤ 5), and (3) individuals self-reporting LS as satisfied (LS > 5), show that variables critical for LS differ between subgroups of the sample as well as by spatial scale. Wellbeing measures need to be created at multiple scales appropriate to the purpose of the indicator. Concurrently, policies need to address the factors that are important to wellbeing at those respective scales, segments, and values of the population.

Sign in / Sign up

Export Citation Format

Share Document