3,641 research outputs found

    Word contexts enhance the neural representation of individual letters in early visual cortex

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    Visual context facilitates perception, but how this is neurally implemented remains unclear. One example of contextual facilitation is found in reading, where letters are more easily identified when embedded in a word. Bottom-up models explain this word advantage as a post-perceptual decision bias, while top-down models propose that word contexts enhance perception itself. Here, we arbitrate between these accounts by presenting words and nonwords and probing the representational fidelity of individual letters using functional magnetic resonance imaging. In line with top-down models, we find that word contexts enhance letter representations in early visual cortex. Moreover, we observe increased coupling between letter information in visual cortex and brain activity in key areas of the reading network, suggesting these areas may be the source of the enhancement. Our results provide evidence for top-down representational enhancement in word recognition, demonstrating that word contexts can modulate perceptual processing already at the earliest visual regions

    Deception and self-awareness

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    This paper presents a study conducted for the Shades of Grey EPSRC research project (EP/H02302X/1), which aims to develop a suite of interventions for identifying terrorist activities. The study investigated the body movements demonstrated by participants while waiting to be interviewed, in one of two conditions: preparing to lie or preparing to tell the truth. The effect of self-awareness was also investigated, with half of the participants sitting in front of a full length mirror during the waiting period. The other half faced a blank wall. A significant interaction was found for the duration of hand/arm movements between the deception and self-awareness conditions (F=4.335, df=1;76, p<0.05). Without a mirror, participants expecting to lie spent less time moving their hands than those expecting to tell the truth; the opposite was seen in the presence of a mirror. This finding indicates a new research area worth further investigation

    STEPS - an approach for human mobility modeling

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    In this paper we introduce Spatio-TEmporal Parametric Stepping (STEPS) - a simple parametric mobility model which can cover a large spectrum of human mobility patterns. STEPS makes abstraction of spatio-temporal preferences in human mobility by using a power law to rule the nodes movement. Nodes in STEPS have preferential attachment to favorite locations where they spend most of their time. Via simulations, we show that STEPS is able, not only to express the peer to peer properties such as inter-ontact/contact time and to reflect accurately realistic routing performance, but also to express the structural properties of the underlying interaction graph such as small-world phenomenon. Moreover, STEPS is easy to implement, exible to configure and also theoretically tractable

    Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

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    Background: Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery. Purpose, and Research design: Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery. Study sample and data collection: Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed. Conclusions: It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future

    Osteochondrosis in the central and third tarsal bones of young horses

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    Recently, the central and third tarsal bones of 23 equine fetuses and foals were examined using micro-computed tomography. Radiological changes, including incomplete ossification and focal ossification defects interpreted as osteochondrosis, were detected in 16 of 23 cases. The geometry of the osteochondrosis defects suggested they were the result of vascular failure, but this requires histological confirmation. The study aim was to examine central and third tarsal bones from the 16 cases and to describe the tissues present, cartilage canals, and lesions, including suspected osteochondrosis lesions. Cases included 9 males and 7 females from 0 to 150 days of age, comprising 11 Icelandic horses, 2 standardbred horses, 2 warmblood riding horses, and 1 coldblooded trotting horse. Until 4 days of age, all aspects of the bones were covered by growth cartilage, but from 105 days, the dorsal and plantar aspects were covered by fibrous tissue undergoing intramembranous ossification. Cartilage canal vessels gradually decreased but were present in most cases up to 122 days and were absent in the next available case at 150 days. Radiological osteochondrosis defects were confirmed in histological sections from 3 cases and consisted of necrotic vessels surrounded by ischemic chondronecrosis (articular osteochondrosis) and areas of retained, morphologically viable hypertrophic chondrocytes (physeal osteochondrosis). The central and third tarsal bones formed by both endochondral and intramembranous ossification. The blood supply to the growth cartilage of the central and third tarsal bones regressed between 122 and 150 days of age. Radiological osteochondrosis defects represented vascular failure, with chondrocyte necrosis and retention, or a combination of articular and physeal osteochondrosis

    Individual differences in gelotophobia predict responses to joy and contempt

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    In a paradigm facilitating smile misattribution, facial responses and ratings to contempt and joy were investigated in individuals with or without gelotophobia (fear of being laughed at). Participants from two independent samples (N1 = 83, N2 = 50) rated the intensity of eight emotions in 16 photos depicting joy, contempt, and different smiles. Facial responses were coded by the Facial Action Coding System in the second study. Compared with non-fearful individuals, gelotophobes rated joy smiles as less joyful and more contemptuous. Moreover, gelotophobes showed less facial joy and more contempt markers. The contempt ratings were comparable between the two groups. Looking at the photos of smiles lifted the positive mood of non-gelotophobes, whereas gelotophobes did not experience an increase. We hypothesize that the interpretation bias of “joyful faces hiding evil minds” (i.e., being also contemptuous) and exhibiting less joy facially may complicate social interactions for gelotophobes and serve as a maintaining factor of gelotophobia.The research leading to these results has received funding from a research grant from the Swiss National Science Foundation (SNSF; 100014_126967-1

    Emotion-corpus guided lexicons for sentiment analysis on Twitter.

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    Research in Psychology have proposed frameworks that map emotion concepts with sentiment concepts. In this paper we study this mapping from a computational modelling perspective with a view to establish the role of an emotion-rich corpus for lexicon-based sentiment analysis. We propose two different methods which harness an emotion-labelled corpus of tweets to learn world-level numerical quantification of sentiment strengths over a positive to negative spectrum. The proposed methods model the emotion corpus using a generative unigram mixture model (UMM), combined with the emotion-sentiment mapping proposed in Psychology [6] for automated generation of sentiment lexicons. Sentiment analsysis experiments on benchmark Twitter data sets confirm the equality of our proposed lexicons. Further a comparative analysis with standard sentiment lexicons suggest that the proposed lexicons lead to a significantly better performance in both sentimentclassification and sentiment intensity prediction tasks

    Efficient computation of partial elements in the full-wave surface-peec method

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    The partial element equivalent circuit (PEEC) method provides an electromagnetic model of interconnections and packaging structures in terms of standard circuit elements. The surface-based PEEC (S-PEEC) formulation can reduce the number of unknowns compared to the standard volume-based PEEC (V-PEEC) method. This reduction is of particular use in the case of high-speed circuits and high-switching power electronics, where the bandwidth extends from low frequencies to the GHz range. In this article, the S-PEEC formulation is revised and cast in a matrix form. The main novelty is that the interaction integrals involving the curl of the magnetic and electric vector potentials are computed through the Taylor series expansion of the full-wave Green’s function, leading to analytical forms that are rigorously derived. Therefore, the numerical integration is avoided, with a consequent reduction of the computation time. The proposed formulas are studied in terms of the frequency, size of the mesh, and distance between the basis function domains. Three examples are presented, confirming the accuracy of the proposed method compared to the V-PEEC method and surface-based numerical methods from literature

    High-stakes lies: Verbal and nonverbal cues to deception in public appeals for help with missing or murdered relatives

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Psychiatry, Psychology and Law on 23/9/2013 available online: http://wwww.tandfonline.com/10.1080/13218719.2013.839931Low ecological validity is a common limitation in deception studies. The present study investigated the real life, high stake context of public appeals for help with missing or murdered relatives. Behaviours which discriminated between honest and deceptive appeals included some previously identified in research on high stakes lies (deceptive appeals contained more equivocal language, gaze aversion, head shaking, and speech errors), and a number of previously unidentified behaviours (honest appeals contained more references to norms of emotion/behaviour, more expressions of hope of finding the missing relative alive, more expressions of positive emotion towards the relative, more expressions of concern/pain, and an avoidance of brutal language). Case by case analyses yielded 78% correct classifications. Implications are discussed with reference to the importance of using ecologically valid data in deception studies, the context specific nature of some deceptive behaviours, and social interactionist, and individual behavioural profile, accounts of cues to deception.ESRC grant number [ES/I90316X/1
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