918 resultados para Perceptual confusion


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Remotely sensed land cover maps are increasingly used as inputs into environmental simulation models whose outputs inform decisions and policy-making. Risks associated with these decisions are dependent on model output uncertainty, which is in turn affected by the uncertainty of land cover inputs. This article presents a method of quantifying the uncertainty that results from potential mis-classification in remotely sensed land cover maps. In addition to quantifying uncertainty in the classification of individual pixels in the map, we also address the important case where land cover maps have been upscaled to a coarser grid to suit the users’ needs and are reported as proportions of land cover type. The approach is Bayesian and incorporates several layers of modelling but is straightforward to implement. First, we incorporate data in the confusion matrix derived from an independent field survey, and discuss the appropriate way to model such data. Second, we account for spatial correlation in the true land cover map, using the remotely sensed map as a prior. Third, spatial correlation in the mis-classification characteristics is induced by modelling their variance. The result is that we are able to simulate posterior means and variances for individual sites and the entire map using a simple Monte Carlo algorithm. The method is applied to the Land Cover Map 2000 for the region of England and Wales, a map used as an input into a current dynamic carbon flux model.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This chapter explores the nature of disengagement and the role played by emotions and in doing so will disentangle the overlapping theories and definitions of both engagement and disengagement. The research that forms the basis for the chapter comes from two related studies exploring engagement and disengagement in 10 large UK public and private sector organisations. Both studies used an interpretive approach involving 75 managers and employees. The chapter suggests the that emotions play a mediating role in the process of disengagement and the emotional reaction involved provides a distinction to being ‘not engaged’. It highlights the confusion that different approaches bring to distinguishing engagement and disengagement from other job attitudes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Spatial memory is important for locating objects in hierarchical data structures, such as desktop folders. There are, however, some contradictions in literature concerning the effectiveness of 3D user interfaces when compared to their 2D counterparts. This paper uses a task-based approach in order to investigate the effectiveness of adding a third dimension to specific user tasks, i.e. the impact of depth on navigation in a 3D file manager. Results highlight issues and benefits of using 3D interfaces for visual and verbal tasks, and introduces the possible existence of a correlation between aptitude scores achieved on the Guilford- Zimmerman Orientation Survey and Electroencephalography- measured brainwave activity as participants search for targets of variable perceptual salience in 2D and 3D environments.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Runoff generation processes and pathways vary widely between catchments. Credible simulations of solute and pollutant transport in surface waters are dependent on models which facilitate appropriate, catchment-specific representations of perceptual models of the runoff generation process. Here, we present a flexible, semi-distributed landscape-scale rainfall-runoff modelling toolkit suitable for simulating a broad range of user-specified perceptual models of runoff generation and stream flow occurring in different climatic regions and landscape types. PERSiST (the Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport) is designed for simulating present-day hydrology; projecting possible future effects of climate or land use change on runoff and catchment water storage; and generating hydrologic inputs for the Integrated Catchments (INCA) family of models. PERSiST has limited data requirements and is calibrated using observed time series of precipitation, air temperature and runoff at one or more points in a river network. Here, we apply PERSiST to the river Thames in the UK and describe a Monte Carlo tool for model calibration, sensitivity and uncertainty analysis

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The arousal-biased competition model predicts that arousal increases the gain on neural competition between stimuli representations. Thus, the model predicts that arousal simultaneously enhances processing of salient stimuli and impairs processing of relatively less-salient stimuli. We tested this model with a simple dot-probe task. On each trial, participants were simultaneously exposed to one face image as a salient cue stimulus and one place image as a non-salient stimulus. A border around the face cue location further increased its bottom-up saliency. Before these visual stimuli were shown, one of two tones played: one that predicted a shock (increasing arousal) or one that did not. An arousal-by-saliency interaction in category-specific brain regions (fusiform face area for salient faces and parahippocampal place area for non-salient places) indicated that brain activation associated with processing the salient stimulus was enhanced under arousal whereas activation associated with processing the non-salient stimulus was suppressed under arousal. This is the first functional magnetic resonance imaging study to demonstrate that arousal can enhance information processing for prioritized stimuli while simultaneously impairing processing of non-prioritized stimuli. Thus, it goes beyond previous research to show that arousal does not uniformly enhance perceptual processing, but instead does so selectively in ways that optimizes attention to highly salient stimuli.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose – Today marketers operate in globalised markets, planning new ways to engage with domestic and foreign customers alike. While there is a greater need to understand these two customer groups, few studies examine the impact of customer engagement tactics on the two customer groups, focusing on their perceptual differences. Even less attention is given to customer engagement tactics in a cross-cultural framework. In this research, the authors investigate customers in China and UK, aiming to compare their perceptual differences on the impact of multiple customer engagement tactics. Design/methodology/approach – Using a quantitative approach with 286 usable responses from China and the UK obtained through a combination of person-administered survey and computer-based survey screening process, the authors test a series of hypotheses to distinguish across-cultural differences. Findings – Findings show that the collectivists (Chinese customers) perceive customer engagement tactics differently than the individualists (UK customers). The Chinese customers are more sensitive to price and reputation, whereas the UK customers respond more strongly to service, communication and customisation. Chinese customers’ concerns with extensive price and reputation comparisons may be explained by their awareness towards face (status), increased self-expression and equality. Practical implications – The findings challenge the conventional practice of using similar customer engagement tactics for a specific market place with little concern for multiple cultural backgrounds. The paper proposes strategies for marketers facing challenges in this globalised context. Originality/value – Several contributions have been made to the literatures. First, the study showed the effects of culture on the customers’ perceptual differences. Second, the study provided more information to clarify customers’ different reactions towards customer engagement tactics, highlighted by concerns towards face and status. Third, the study provided empirical evidence to support the use of multiple customer engagement tactics to the across cultural studies.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Synesthesia entails a special kind of sensory perception, where stimulation in one sensory modality leads to an internally generated perceptual experience of another, not stimulated sensory modality. This phenomenon can be viewed as an abnormal multisensory integration process as here the synesthetic percept is aberrantly fused with the stimulated modality. Indeed, recent synesthesia research has focused on multimodal processing even outside of the specific synesthesia-inducing context and has revealed changed multimodal integration, thus suggesting perceptual alterations at a global level. Here, we focused on audio-visual processing in synesthesia using a semantic classification task in combination with visually or auditory-visually presented animated and in animated objects in an audio-visual congruent and incongruent manner. Fourteen subjects with auditory-visual and/or grapheme-color synesthesia and 14 control subjects participated in the experiment. During presentation of the stimuli, event-related potentials were recorded from 32 electrodes. The analysis of reaction times and error rates revealed no group differences with best performance for audio-visually congruent stimulation indicating the well-known multimodal facilitation effect. We found enhanced amplitude of the N1 component over occipital electrode sites for synesthetes compared to controls. The differences occurred irrespective of the experimental condition and therefore suggest a global influence on early sensory processing in synesthetes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In 1972, episodic and semantic memories were considered to reflect different types of knowledge (Tulving, 1972). However, these early definitions encountered many difficulties. Now, Episodic and semantic memories are discussed in terms of awareness associated with retrieval (Wheeler, Stuss, & Tulving, 1997): Autonoetic consciousness (i.e., feeling of remembering) is considered associated with retrieval from the episodic memory system, while noetic consciousness (i.e., feeling of knowing) is considered characterized by retrieval from the semantic memory system. The present article investigated determinants of autonoetic consciousness in order to clarify characteristics of perceptual knowledge that is being recalled, the more strongly the individual feels autonoetic consciousness during retrieval, and that autonoetic consciousness is based on rich sensory-perceptual knowledge. Furthermore, we suggested that the parietal and frontal lobes mediate the process of generating autonoetic consciousness. This suggested that sensory-perceptual knowledge, the parietal lobe and the frontal lobe are important factors for discriminating episodic memory afrom semantic memory.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

There has been an increased emphasis upon the application of science for humanitarian and development planning, decision-making and practice; particularly in the context of understanding, assessing and anticipating risk (e.g. HERR, 2011). However, there remains very little guidance for practitioners on how to integrate sciences they may have had little contact with in the past (e.g. climate). This has led to confusion as to which ‘science’ might be of use and how it would be best utilised. Furthermore, since this integration has stemmed from a need to be more predictive, agencies are struggling with the problems associated with uncertainty and probability. Whilst a range of expertise is required to build resilience, these guidelines focus solely upon the relevant data, information, knowledge, methods, principles and perspective which scientists can provide, that typically lie outside of current humanitarian and development approaches. Using checklists, real-life case studies and scenarios the full guidelines take practitioners through a five step approach to finding, understanding and applying science. This document provides a short summary of the five steps and some key lessons for integrating science.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This article examines how political discourse, language ideologies, recent Chinese curriculum reforms, and their representations in the media are inextricably related. Using the Speak Mandarin Campaign as background for the inquiry, I focus on textual features of the various media sources, TV advertisements, campaign slogans, official speeches, and newspaper excerpts to illuminate the status and changing role of the Chinese language in Singapore’s sociocultural, economic, and political development. Using critical discourse analysis as an analytical framework, I examine the contradictory ideologies that underpin the government’s language policies and planning activities. On the one hand, the government emphasizes the cultural and economic values of the Chinese language; on the other hand, government schools teach Chinese as a subject. In particular, the recent reforms in Chinese language curriculum have arguably further diluted the content of teaching. In addition I point out how conflicting ideologies behind language policies can lead to cultural confusion and educational uncertainty. These mixed messages make it difficult for schools to offer a consistent language education curriculum that will help students appreciate the value, be it economic, cultural or educational, of the Chinese language.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper will present and discuss the results of an empirical study on perception of quality in interpretation carried out on a sample of 286 interpreters across five continents. Since the 1980’s the field of Interpreting Studies has been witnessing an ever growing interest in the issue of quality in interpretation both in academia and in professional circles, but research undertaken so far is surprisingly lacking in methodological rigour. This survey is an attempt to revise previous studies on interpreters’ perception of quality through the implementation of new Information Technology which allowed us to administer a traditional research tool such as a questionnaire, in a highly innovative way; i.e., through the World Wide Web. Using multidimensional scaling, a perceptual map based upon the results of the manner in which interpreters ranked a list of linguistic and nonlinguistic criteria according to their perception of importance in the interpretative process,was devised.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Atypical self-processing is an emerging theme in autism research, suggested by lower self-reference effect in memory, and atypical neural responses to visual self-representations. Most research on physical self-processing in autism uses visual stimuli. However, the self is a multimodal construct, and therefore, it is essential to test self-recognition in other sensory modalities as well. Self-recognition in the auditory modality remains relatively unexplored and has not been tested in relation to autism and related traits. This study investigates self-recognition in auditory and visual domain in the general population and tests if it is associated with autistic traits. Methods Thirty-nine neurotypical adults participated in a two-part study. In the first session, individual participant’s voice was recorded and face was photographed and morphed respectively with voices and faces from unfamiliar identities. In the second session, participants performed a ‘self-identification’ task, classifying each morph as ‘self’ voice (or face) or an ‘other’ voice (or face). All participants also completed the Autism Spectrum Quotient (AQ). For each sensory modality, slope of the self-recognition curve was used as individual self-recognition metric. These two self-recognition metrics were tested for association between each other, and with autistic traits. Results Fifty percent ‘self’ response was reached for a higher percentage of self in the auditory domain compared to the visual domain (t = 3.142; P < 0.01). No significant correlation was noted between self-recognition bias across sensory modalities (τ = −0.165, P = 0.204). Higher recognition bias for self-voice was observed in individuals higher in autistic traits (τ AQ = 0.301, P = 0.008). No such correlation was observed between recognition bias for self-face and autistic traits (τ AQ = −0.020, P = 0.438). Conclusions Our data shows that recognition bias for physical self-representation is not related across sensory modalities. Further, individuals with higher autistic traits were better able to discriminate self from other voices, but this relation was not observed with self-face. A narrow self-other overlap in the auditory domain seen in individuals with high autistic traits could arise due to enhanced perceptual processing of auditory stimuli often observed in individuals with autism.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Possible impairments of memory in end-stage renal disease (ESRD) were investigated in two experiments. In Experiment 1, in which stimulus words were presented visually, participants were tested on conceptual or perceptual memory tasks, with retrieval being either explicit or implicit. Compared with healthy controls, ESRD patients were impaired when memory required conceptual but not when it required perceptual processing, regardless of whether retrieval was explicit or implicit. An impairment of conceptual implicit memory (priming) in the ESRD group represented a previously unreported deficit compared to healthy aging. There were no significant differences between pre- and immediate post-dialysis memory performance in ESRD patients on any of the tasks. In Experiment 2, in which presentation was auditory, patients again performed worse than controls on an explicit conceptual memory task. We conclude that the type of processing required by the task (conceptual vs. perceptual) is more important than the type of retrieval (explicit vs. implicit) in memory failures in ESRD patients, perhaps because temporal brain regions are more susceptible to the effects of the illness than are posterior regions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Resistive respiratory loading is an established stimulus for the induction of experimental dyspnoea. In comparison to unloaded breathing, resistive loaded breathing alters end-tidal CO2 (PETCO2), which has independent physiological effects (e.g. upon cerebral blood flow). We investigated the subjective effects of resistive loaded breathing with stabilized PETCO2 (isocapnia) during manual control of inspired gases on varying baseline levels of mild hypercapnia increased PETCO2). Furthermore, to investigate whether perceptual habituation to dyspnoea stimuli occurs, the study was repeated over four experimental sessions. Isocapnic hypercapnia did not affect dyspnoea unpleasantness during resistive loading. A post hoc analysis revealed a small increase of respiratory unpleasantness during unloaded breathing at +0.6 kPa, the level that reliably induced isocapnia. We didnot observe perceptual habituation over the four sessions. We conclude that isocapnic respiratory loading allows stable induction of respiratory unpleasantness, making it a good stimulus for multi-session studies of dyspnoea.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In recent decades, intuitions' role in philosophy has been hotly debated. Many claim intuitions play an important role. Others, some armed with data, challenge the use of intuitions. This thesis reflects on this debate and advances the debate in two main ways. Having a clear understanding of the challenge which intuition-use in philosophy faces is important. Part I focuses on this. Chapters 1-2 introduce the topic of intuitions, motivate the methodological study of intuitions, and present the historical background to recent empirical challenges to intuition-use. Chapters 3-5 concern the contemporary challenge. I present the empirical evidence the challenge uses, present what I argue to be the strongest version of the challenge, and defend that challenge against some objections. How one characterises intuitions is incredibly important in philosophical methodology. If we are to properly evaluate philosophical methods vis-a-vis their use of something called intuitions { if we are to assess the empirical challenge { it is important to be clear exactly what we mean by `intuitions'. Part II focuses on this. Chapter 6 argues there is little consensus among philosophers as to what intuitions are and their role in philosophy. Chapter 7 questions whether philosophers have developed an idiolect in which `intuition' has distinctive meaning | as frequently supposed. Chapter 8 points out a common misunderstanding about intuitions in philosophy; using quantitative tools to challenge the idea that an increased use of `intuition' in philosophy is the result of an increased use of intuition. So, the developing picture is one of confusion, without a clear idea of what sense of `intuition' is important. Fortunately, Chapter 9 sets us back on the right track. It sets out a positive programme for evaluative methodology: methodologists should adopt a permissive conception of intuitions and make fine distinctions between different intuitions, so long as we can track those distinctions while philosophising.