Extracting Distributed Orientations in Different Contexts

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 17-17
Author(s):  
C Bonnet ◽  
A Dufour

It has been shown that discriminating the orientations of a target is influenced by the spatial distribution of the orientations of similar elements in the background. However, this effect appears to be essentially decisional (Dufour and Bonnet, 1995 Spatial Vision9 307 – 324). In the present experiment, we explored the accuracy with which subjects can discriminate relative proportions of orientations distributed over a surface (background). Stimuli were textures made of 100 segments with regular spacing. Each of the segments had one of four possible orientations. For each display, one of the orientations was overrepresented (31%, 37%, 43% and 49%). The task of the subject was to discriminate, in a reaction-time paradigm, which of the four orientations was more frequent within a given display. Three spatial conditions were used. In condition 1, the different orientations were randomly distributed over the surface. In the two other conditions, nine elements of the same orientation formed a group within one region of the texture. In condition 2, these grouped elements had the over-represented orientation. In condition 3, they had one of the three under-represented orientations. Grouping of the oriented elements has a facilitating effect when it contains the over-represented orientation, and a negative effect when it contains one of the under-represented orientations. There are good reasons to think that these interferences are decisional rather than sensorial.

2020 ◽  
Vol 75 (1) ◽  
pp. 1-27
Author(s):  
Alex Bliss

The advent of the Portable Antiquities Scheme (PAS) has added a great deal to our understanding of prehistoric metal artefacts in England and Wales, namely in expanding enormously the corpuses of objects previously thought to be quite scarce. One such artefact type is the miniature socketed 'votive' axe, most of which are found in Wiltshire and Hampshire. As a direct result of developing such recording initiatives, reporting of these artefacts as detector finds from the early 2000s onwards has virtually trebled the number originally published by Paul Robinson in his 1995 analysis. Through extensive data-collection, synthesising examples recorded via the PAS with those from published excavations, the broad aims of this paper (in brief) are as follows: firstly, produce a solid typology for these artefacts; secondly, investigate their spatial distribution across England and Wales. As a more indirect third aim, this paper also seeks to redress the imbalance of focus and academic study specifically applying to Hampshire finds of this object type, which despite producing a significant proportion of the currently known corpus have never been the subject of detailed analysis.


1975 ◽  
Vol 41 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Paul D. Jones ◽  
Hilde Wilkinson

Two studies were done in order to assess the effects of wavelength on visual perceptual latency as measured in a disjunctive RT paradigm. The results of the first study, though not statistically significant, suggested a trend toward shorter RT to longer wavelength stimuli. In the second study, using well-practiced subjects, significant differences were found between disjunctive RT to red and green stimuli. The results suggest that latency differences as a function of wavelength are demonstrable in an experimental situation in which the subject must react to chromatic information, as differentiated from brightness information.


2021 ◽  
Author(s):  
Gordon Ingram ◽  
Erick Gustavo Chuquichambi ◽  
William Jimenez-Leal ◽  
Antonio Olivera-LaRosa

The COVID-19 pandemic has caused controversy over new norms of mask-wearing in public places. An online experiment previously showed that people from several Spanish-speaking countries perceived faces wearing medical-style masks as more trustworthy, socially desirable, and likely to be ill, compared to control faces without a mask. We replicated and extended these methods with 1241 English-speaking participants from the UK and USA, adding questions on political orientation and voting intention, and including the online-VAAST task to test the effects of masks on an implicit reaction-time measure. The positive effects of masks on trustworthiness and social desirability were replicated, but the negative effect of masks on perceptions of healthiness was reversed. Participants were also quicker to approach masked faces. Conservative voters’ explicit and implicit reactions to masked faces were less favorable than those of liberals, demonstrating that masks are viewed positively by many but continue to be politically controversial.


Author(s):  
Elvira Vitaljevna Burtseva ◽  
Olga Chepak ◽  
Olga Kulikova

The subject of this research is the implementation of digital technologies in educational process of a university. The goal consists in studying the impact of digital technologies upon the students’ learning activities. The article presents the results of questionnaire-based survey among students by the three question pools. In the course of research, the author examines such aspects of the problem, as the positive and negative impact of technologies upon learning activities of the students of digital generation. Particular attention is given to consideration of students’ attitude on digitalization of higher education. The opinions of pedagogues on the results of conducted research are presented. The scientific novelty lies in mainstreaming the question on the negative impact of digital technologies upon learning activities of the modern generation of students that deserves special attention. On the background of common passion of the scholars of researchers and pedagogues for the ideas of digitalization of education, when digital technologies are viewed as virtually the key factor for modernization of educational process; second come the problems of growing pathological dependence of youth on digital technologies, undesired to switch to digitalized educational process to the disadvantage of communication in social networks and pleasant pastime online. The problem of the negative effect of digital technologies on learning activities must be recognized in order to find the ways for its solution.


2011 ◽  
Vol 26 (2) ◽  
pp. 236-242 ◽  
Author(s):  
A. F. Stein ◽  
Y. Wang ◽  
J. D. de la Rosa ◽  
A. M. Sanchez de la Campa ◽  
Nuria Castell ◽  
...  

Abstract The Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) model has been applied to calculate the spatial and temporal distributions of dust originating from North Africa. The model has been configured to forecast hourly particulate matter ≤10 μm (PM10) dust concentrations focusing on the impacts over the southern Iberian Peninsula. Two full years (2008 and 2009) have been simulated and compared against surface background measurement sites. A statistical analysis using discrete and categorical evaluations is presented. The model is capable of simulating the occurrence of Saharan dust episodes as observed at the measurement stations and captures the generally higher levels observed in eastern Andalusia, Spain, with respect to the western Andalusia station. But the simulation tends to underpredict the magnitude of the dust concentration peaks. The model has also been qualitatively compared with satellite data, showing generally good agreement in the spatial distribution of the dust column.


Perception ◽  
1993 ◽  
Vol 22 (8) ◽  
pp. 963-970 ◽  
Author(s):  
Piotr Jaśkowski

Point of subjective simultaneity and simple reaction time were compared for stimuli with different rise times. It was found that these measures behave differently. To explain the result it is suggested that in the case of temporal-order judgment the subject takes into account not only the stimulus onset but also other events connected with stimulus presentation.


Author(s):  
Ioannis N. Kouris

Research in association rules mining has initially concentrated in solving the obvious problem of finding positive association rules; that is rules among items that exist in the stored transactions. It was only several years after that the possibility of finding also negative association rules became especially appealing and was investigated. Nevertheless researchers based their assumptions regarding negative association rules on the absence of items from transactions. This assumption though besides being dubious, since it equated the absence of an item with a conflict or negative effect on the rest items, it also brought out a series of computational problems with the amount of possible patterns that had to be examined and analyzed. In this work we give an overview of the works having engaged with the subject until now and present a novel view for the definition of negative influence among items.


2019 ◽  
Vol 29 (3) ◽  
pp. 729-745 ◽  
Author(s):  
Blanka Gál ◽  
András Weiperth ◽  
János Farkas ◽  
Dénes Schmera

AbstractAlthough it is well known that the increasing size of the human population has a negative effect on freshwater biodiversity, the subject of whether or how the intersection of roads and streams (hereafter road crossings) influence the diversity of stream macro-invertebrates is under-researched. To fill this gap in our knowledge, we collected stream macro-invertebrates from road crossings (bridges and culverts) and compared their diversity with upstream and downstream sections. We found that road crossings had negative effects on the richness and abundance of native macro-invertebrates, as well as on the number of protected taxa. Our results showed also that alien individuals were more abundant at road crossings. These findings support the assumption that road crossings contribute to the spread of alien species. The assessment of environmental variables indicated that road crossings caused habitat modifications, and based on these it can be assumed that habitat modifications and associated phenomena (e.g. pollutants and storm events) were the major drivers of the observed patterns in biodiversity. Our results fill a knowledge gap and contribute to the deeper understanding of the effect of road crossings on freshwater biodiversity.


2019 ◽  
Vol 35 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Marlous LMI Verheul ◽  
Michel LA Dückers

AbstractIntroduction:Societies invest substantial amounts of resources on disaster preparedness of hospitals. However, the concept is not clearly defined nor operationalized in the international literature.Aim:This review aims to systematically assess definitions and operationalizations of disaster preparedness in hospitals, and to develop an all-encompassing model, incorporating different perspectives on the subject.Methods:A systematic search was conducted in five databases: Scopus, PubMed, Web of Science, Disaster Information Management Research Centre, and SafetyLit. Peer-reviewed articles containing definitions and operationalizations of disaster preparedness in hospitals were included. Articles published in languages other than English, or without available full-text, were excluded, as were articles on prehospital care. The findings from literature were used to build a model for hospital disaster preparedness.Results:In the included publications, 13 unique definitions of disaster preparedness in hospitals and 22 different operationalizations of the concept were found. Although the definitions differed in emphasis and width, they also reflected similar elements. Based on an analysis of the operationalizations, nine different components could be identified that generally were not studied in relation to each other. Moreover, publications primarily focused on structure and process aspects of disaster preparedness. The aim of preparedness was described in seven articles.Discussion/Conclusion:This review points at an absence of consensus on the definition and operationalization of disaster preparedness in hospitals. By combining elements of definitions and components operationalized, disaster preparedness could be conceptualized in a more comprehensive and complete way than before. The model presented can guide future disaster preparedness activities and research.


Sign in / Sign up

Export Citation Format

Share Document