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Sample records for brain ambiguous representations

  1. Representation and productive ambiguity in mathematics and the sciences

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    Grosholz, Emily R

    2007-01-01

    Emily Grosholz offers an original investigation of demonstration in mathematics and science, examining how it works and why it is persuasive. Focusing on geometrical demonstration, she shows the roles that representation and ambiguity play in mathematical discovery. She presents a wide range of case studies in mechanics, topology, algebra, logic, and chemistry, from ancient Greece to the present day, but focusing particularly on the seventeenth and twentieth centuries. Anyone interested in how mathematics works will find this a stimulating read.

  2. Disambiguation of ambiguous figures in the brain

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    Ishizu, Tomohiro

    2013-01-01

    Disambiguation refers to the ability to interpret ambiguous information in a sensible way, which is important in an ever-changing external environment. Disambiguation occurs when prior knowledge is given before an ambiguous stimulus is presented. For example, labeling a series of meaningless blobs as a “human body” can change the observer's perception. The aim of this experiment was to study the neural circuitry underlying disambiguation caused by prior knowledge. We presented to participants a series of meaningless blobs with different contextual information. As participants performed this task, we used magnetoencephalography to map the brain areas that were activated when participants perceived blobs as a human body. The participants were presented identical sets of blob stimuli, and were instructed that a human body would appear more frequently in the “high body” condition than in the “low body” condition. We found the blob stimuli were more frequently perceived as the human body when they were presented in the “high body” condition. Such contextual modulation correlated with activity in the extrastriate body area (EBA) and the inferior frontal gyrus (IFG). Furthermore, we observed that IFG activation preceded EBA activation. These findings suggest that top-down processing in the IFG plays a role in disambiguating ambiguous information and modifying an individual's perceptions. PMID:24009570

  3. Disambiguation of ambiguous figures in the brain

    Directory of Open Access Journals (Sweden)

    Tomohiro eIshizu

    2013-08-01

    Full Text Available Disambiguation refers to the ability to interpret ambiguous information in a sensible way, which is important in an ever-changing external environment. Disambiguation occurs when prior knowledge is given before an ambiguous stimulus is presented. For example, labeling a series of meaningless blobs as the human body can change the observer’s perception. The aim of this experiment was to study the neural circuitry underlying disambiguation caused by prior knowledge. We presented to participants a series of meaningless blobs with different contextual information. As participants performed this task, we used magnetoencephalography to map the brain areas that were activated when participants perceived blobs as a human body. The participants were presented identical sets of blob stimuli, and were instructed that a human body would appear more frequently in the high body condition than in the low body condition. We found the blob stimuli were more frequently perceived as the human body when they were presented in the high body condition. Such contextual modulation correlated with activity in the extrastriate body area (EBA and the inferior frontal gyrus (IFG. Furthermore, we observed that IFG activation preceded EBA activation. These findings suggest that top-down processing in the IFG plays a role in disambiguating ambiguous information and modifying an individual’s perceptions.

  4. Temperature representation in the Drosophila brain.

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    Frank, Dominic D; Jouandet, Genevieve C; Kearney, Patrick J; Macpherson, Lindsey J; Gallio, Marco

    2015-03-19

    In Drosophila, rapid temperature changes are detected at the periphery by dedicated receptors forming a simple sensory map for hot and cold in the brain. However, flies show a host of complex innate and learned responses to temperature, indicating that they are able to extract a range of information from this simple input. Here we define the anatomical and physiological repertoire for temperature representation in the Drosophila brain. First, we use a photolabelling strategy to trace the connections that relay peripheral thermosensory information to higher brain centres, and show that they largely converge onto three target regions: the mushroom body, the lateral horn (both of which are well known centres for sensory processing) and the posterior lateral protocerebrum, a region we now define as a major site of thermosensory representation. Next, using in vivo calcium imaging, we describe the thermosensory projection neurons selectively activated by hot or cold stimuli. Fast-adapting neurons display transient ON and OFF responses and track rapid temperature shifts remarkably well, while slow-adapting cell responses better reflect the magnitude of simple thermal changes. Unexpectedly, we also find a population of broadly tuned cells that respond to both heating and cooling, and show that they are required for normal behavioural avoidance of both hot and cold in a simple two-choice temperature preference assay. Taken together, our results uncover a coordinated ensemble of neural responses to temperature in the Drosophila brain, demonstrate that a broadly tuned thermal line contributes to rapid avoidance behaviour, and illustrate how stimulus quality, temporal structure, and intensity can be extracted from a simple glomerular map at a single synaptic station.

  5. The representation of space in the brain.

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    Grieves, Roddy M; Jeffery, Kate J

    2017-02-01

    Animals can navigate vast distances and often display behaviours or activities that indicate a detailed, internal spatial representation of their surrounding environment or a 'cognitive map'. Over a century of behavioural research on spatial navigation in humans and animals has greatly increased our understanding of how this highly complex feat is achieved. In turn this has inspired half a century of electrophysiological spatial navigation and memory research which has further advanced our understanding of the brain. In particular, three functional cell types have been suggested to underlie cognitive mapping processes; place cells, head direction cells and grid cells. However, there are numerous other spatially modulated neurons in the brain. For a more complete understanding of the electrophysiological systems and behavioural processes underlying spatial navigation we must also examine these lesser understood neurons. In this review we will briefly summarise the literature surrounding place cells, head direction cells, grid cells and the evidence that these cells collectively form the neural basis of a cognitive map. We will then review literature covering many other spatially modulated neurons in the brain that perhaps further augment this cognitive map. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Absence, ambiguity, and the representation of creativity in Vermeer's The Art of Painting.

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    Baudry, Francis

    2007-04-01

    This paper examines The Art of Painting, by Johannes Vermeer, to demonstrate how a great artist portrays the realm of imagination and creativity. The crucial points of entry for psychoanalysis reside in two sets of details in the painting that have generally been neglected by art historians: first, the contrast between the realistic rendering of certain parts of the work and the fuzzy, ambiguous nature of other elements; and second, the pervasiveness of the theme of absence in the manifest content. The author refers to some of Winnicott's and Lacan's concepts, particularly the connection between absence and desire as a spur to creativity.

  7. Processing and Representation of Ambiguous Words in Chinese Reading: Evidence from Eye Movements.

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    Shen, Wei; Li, Xingshan

    2016-01-01

    In the current study, we used eye tracking to investigate whether senses of polysemous words and meanings of homonymous words are represented and processed similarly or differently in Chinese reading. Readers read sentences containing target words which was either homonymous words or polysemous words. The contexts of text preceding the target words were manipulated to bias the participants toward reading the ambiguous words according to their dominant, subordinate, or neutral meanings. Similarly, disambiguating regions following the target words were also manipulated to favor either the dominant or subordinate meanings of ambiguous words. The results showed that there were similar eye movement patterns when Chinese participants read sentences containing homonymous and polysemous words. The study also found that participants took longer to read the target word and the disambiguating text following it when the prior context and disambiguating regions favored divergent meanings rather than the same meaning. These results suggested that homonymy and polysemy are represented similarly in the mental lexicon when a particular meaning (sense) is fully specified by disambiguating information. Furthermore, multiple meanings (senses) are represented as separate entries in the mental lexicon.

  8. Processing and representation of ambiguous words in Chinese reading: Evidence from eye movements

    Directory of Open Access Journals (Sweden)

    Wei Shen

    2016-11-01

    Full Text Available In the current study, we used eye tracking to investigate whether senses of polysemous words and meanings of homonymous words are represented and processed similarly or differently in Chinese reading. Readers read sentences containing target words which was either homonymous words or polysemous words. The contexts of text preceding the target words were manipulated to bias the participants toward reading the ambiguous words according to their dominant, subordinate, or neutral meanings. Similarly, disambiguating regions following the target words were also manipulated to favor either the dominant or subordinate meanings of ambiguous words. The results showed that there were similar eye movement patterns when Chinese participants read sentences containing homonymous and polysemous words. The study also found that participants took longer to read the target word and the disambiguating text following it when the prior context and disambiguating regions favored divergent meanings rather than the same meaning. These results suggested that homonymy and polysemy are represented similarly in the mental lexicon when a particular meaning (sense is fully specified by disambiguating information. Furthermore, multiple meanings (senses are represented as separate entries in the mental lexicon.

  9. Intermittent behavior in the brain neuronal network in the perception of ambiguous images

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    Hramov, Alexander E.; Kurovskaya, Maria K.; Runnova, Anastasiya E.; Zhuravlev, Maxim O.; Grubov, Vadim V.; Koronovskii, Alexey A.; Pavlov, Alexey N.; Pisarchik, Alexander N.

    2017-03-01

    Characteristics of intermittency during the perception of ambiguous images have been studied in the case the Necker cube image has been used as a bistable object for demonstration in the experiments, with EEG being simultaneously measured. Distributions of time interval lengths corresponding to the left-oriented and right-oriented Necker cube perception have been obtain. EEG data have been analyzed using continuous wavelet transform which was shown that the destruction of alpha rhythm with accompanying generation of high frequency oscillations can serve as a electroencephalographical marker of Necker cube recognition process in human brain.

  10. Body representation in patients after vascular brain injuries

    OpenAIRE

    Razmus, Magdalena

    2017-01-01

    Neuropsychological literature suggests that body representation is a multidimensional concept consisting of various types of representations. Previous studies have demonstrated dissociations between three types of body representation specified by the kind of data and processes, i.e. body schema, body structural description, and body semantics. The aim of the study was to describe the state of body representation in patients after vascular brain injuries and to provide evidence for the differe...

  11. Body representation in patients after vascular brain injuries.

    Science.gov (United States)

    Razmus, Magdalena

    2017-11-01

    Neuropsychological literature suggests that body representation is a multidimensional concept consisting of various types of representations. Previous studies have demonstrated dissociations between three types of body representation specified by the kind of data and processes, i.e. body schema, body structural description, and body semantics. The aim of the study was to describe the state of body representation in patients after vascular brain injuries and to provide evidence for the different types of body representation. The question about correlations between body representation deficits and neuropsychological dysfunctions was also investigated. Fifty patients after strokes and 50 control individuals participated in the study. They were examined with tasks referring to dynamic representation of body parts positions, topological body map, and lexical and semantic knowledge about the body. Data analysis showed that vascular brain injuries result in deficits of body representation, which may co-occur with cognitive dysfunctions, but the latter are a possible risk factor for body representation deficits rather than sufficient or imperative requisites for them. The study suggests that types of body representation may be separated on the basis not only of their content, but also of their relation with self. Principal component analysis revealed three factors, which explained over 66% of results variance. The factors, which may be interpreted as types or dimensions of mental model of a body, represent different degrees of connection with self. The results indicate another possibility of body representation types classification, which should be verified in future research.

  12. Brain extraction based on locally linear representation-based classification.

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    Huang, Meiyan; Yang, Wei; Jiang, Jun; Wu, Yao; Zhang, Yu; Chen, Wufan; Feng, Qianjin

    2014-05-15

    Brain extraction is an important procedure in brain image analysis. Although numerous brain extraction methods have been presented, enhancing brain extraction methods remains challenging because brain MRI images exhibit complex characteristics, such as anatomical variability and intensity differences across different sequences and scanners. To address this problem, we present a Locally Linear Representation-based Classification (LLRC) method for brain extraction. A novel classification framework is derived by introducing the locally linear representation to the classical classification model. Under this classification framework, a common label fusion approach can be considered as a special case and thoroughly interpreted. Locality is important to calculate fusion weights for LLRC; this factor is also considered to determine that Local Anchor Embedding is more applicable in solving locally linear coefficients compared with other linear representation approaches. Moreover, LLRC supplies a way to learn the optimal classification scores of the training samples in the dictionary to obtain accurate classification. The International Consortium for Brain Mapping and the Alzheimer's Disease Neuroimaging Initiative databases were used to build a training dataset containing 70 scans. To evaluate the proposed method, we used four publicly available datasets (IBSR1, IBSR2, LPBA40, and ADNI3T, with a total of 241 scans). Experimental results demonstrate that the proposed method outperforms the four common brain extraction methods (BET, BSE, GCUT, and ROBEX), and is comparable to the performance of BEaST, while being more accurate on some datasets compared with BEaST. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Toward a brain-based componential semantic representation.

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    Binder, Jeffrey R; Conant, Lisa L; Humphries, Colin J; Fernandino, Leonardo; Simons, Stephen B; Aguilar, Mario; Desai, Rutvik H

    2016-01-01

    Componential theories of lexical semantics assume that concepts can be represented by sets of features or attributes that are in some sense primitive or basic components of meaning. The binary features used in classical category and prototype theories are problematic in that these features are themselves complex concepts, leaving open the question of what constitutes a primitive feature. The present availability of brain imaging tools has enhanced interest in how concepts are represented in brains, and accumulating evidence supports the claim that these representations are at least partly "embodied" in the perception, action, and other modal neural systems through which concepts are experienced. In this study we explore the possibility of devising a componential model of semantic representation based entirely on such functional divisions in the human brain. We propose a basic set of approximately 65 experiential attributes based on neurobiological considerations, comprising sensory, motor, spatial, temporal, affective, social, and cognitive experiences. We provide normative data on the salience of each attribute for a large set of English nouns, verbs, and adjectives, and show how these attribute vectors distinguish a priori conceptual categories and capture semantic similarity. Robust quantitative differences between concrete object categories were observed across a large number of attribute dimensions. A within- versus between-category similarity metric showed much greater separation between categories than representations derived from distributional (latent semantic) analysis of text. Cluster analyses were used to explore the similarity structure in the data independent of a priori labels, revealing several novel category distinctions. We discuss how such a representation might deal with various longstanding problems in semantic theory, such as feature selection and weighting, representation of abstract concepts, effects of context on semantic retrieval, and

  14. Meta-analysis on brain representation of experimental dental pain.

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    Lin, C-S; Niddam, D M; Hsu, M-L

    2014-02-01

    Functional magnetic resonance imaging (fMRI) has been widely used for investigating the brain representation associated with dental pain evoked by pulpal electrical stimulation. However, because of the heterogeneity of experimental designs and the small sample size of individual studies, the common brain representation regarding dental pain has remained elusive. We used imaging meta-analysis to investigate six dental pain-related fMRI studies (n = 87) and tested 3 hypotheses: (1) Dental pain is associated with the 'core' pain-related network; (2) pain-related brain activation is somatotopically organized in the somatosensory cortex; and (3) dental pain is associated with the cognitive-affective network related to pain. Qualitative and quantitative meta-analyses revealed: (1) common activation of the core pain-related network, including the somatosensory cortex, the insula, and the cingulate cortex; (2) inconsistency in somatotopically organized activation of the primary somatosensory cortex; and (3) common activation in the dorsolateral prefrontal cortex, suggesting a role of re-appraisal and coping in the experience of dental pain. In conclusion, fMRI combined with pulpal stimulation can effectively evoke activity in the pain-related network. The dental pain-related brain representation disclosed the mechanisms of how sensory and cognitive-affective factors shape dental pain, which will help in the development of more effective customized methods for central pain control.

  15. Functional Brain Network Classification With Compact Representation of SICE Matrices.

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    Zhang, Jianjia; Zhou, Luping; Wang, Lei; Li, Wanqing

    2015-06-01

    Recently, a sparse inverse covariance estimation (SICE) technique has been employed to model functional brain connectivity. The inverse covariance matrix (SICE matrix in short) estimated for each subject is used as a representation of brain connectivity to discriminate Alzheimers disease from normal controls. However, we observed that direct use of the SICE matrix does not necessarily give satisfying discrimination, due to its high dimensionality and the scarcity of training subjects. Looking into this problem, we argue that the intrinsic dimensionality of these SICE matrices shall be much lower, considering 1) an SICE matrix resides on a Riemannian manifold of symmetric positive definiteness matrices, and 2) human brains share common patterns of connectivity across subjects. Therefore, we propose to employ manifold-based similarity measures and kernel-based PCA to extract principal connectivity components as a compact representation of brain network. Moreover, to cater for the requirement of both discrimination and interpretation in neuroimage analysis, we develop a novel preimage estimation algorithm to make the obtained connectivity components anatomically interpretable. To verify the efficacy of our method and gain insights into SICE-based brain networks, we conduct extensive experimental study on synthetic data and real rs-fMRI data from the ADNI dataset. Our method outperforms the comparable methods and improves the classification accuracy significantly.

  16. Language representation in the human brain: evidence from cortical mapping.

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    Bhatnagar, S C; Mandybur, G T; Buckingham, H W; Andy, O J

    2000-09-01

    The manner in which the human brain processes grammatical-syntactic and lexical-semantic functions has been extensively debated in neurolinguistics. The discreteness and selectivity of the representation of syntactic-morphological properties in the dominant frontal cortex and the representation of the lexical-semantics in the temporo-parietal cortex have been questioned. Three right-handed adult male neurosurgical patients undergoing left craniotomy for intractable seizures were evaluated using various grammatical and semantic tasks during cortical mapping. The sampling of language tasks consisted of trials with stimulation (experimental) and without stimulation (control) from sites in the dominant fronto-temporo-parietal cortex The sampling of language implicated a larger cortical area devoted to language (syntactic-morphological and lexical-semantic) tasks. Further, a large part of the fronto-parieto-temporal cortex was involved with syntactic-morphological functions. However, only the parieto-temporal sites were implicated with the ordering of lexicon in sentence construction. These observations suggest that the representation of language in the human brain may be columnar or multilayered. Copyright 2000 Academic Press.

  17. The representation of biological classes in the human brain.

    Science.gov (United States)

    Connolly, Andrew C; Guntupalli, J Swaroop; Gors, Jason; Hanke, Michael; Halchenko, Yaroslav O; Wu, Yu-Chien; Abdi, Hervé; Haxby, James V

    2012-02-22

    Evidence of category specificity from neuroimaging in the human visual system is generally limited to a few relatively coarse categorical distinctions-e.g., faces versus bodies, or animals versus artifacts-leaving unknown the neural underpinnings of fine-grained category structure within these large domains. Here we use fMRI to explore brain activity for a set of categories within the animate domain, including six animal species-two each from three very different biological classes: primates, birds, and insects. Patterns of activity throughout ventral object vision cortex reflected the biological classes of the stimuli. Specifically, the abstract representational space-measured as dissimilarity matrices defined between species-specific multivariate patterns of brain activity-correlated strongly with behavioral judgments of biological similarity of the same stimuli. This biological class structure was uncorrelated with structure measured in retinotopic visual cortex, which correlated instead with a dissimilarity matrix defined by a model of V1 cortex for the same stimuli. Additionally, analysis of the shape of the similarity space in ventral regions provides evidence for a continuum in the abstract representational space-with primates at one end and insects at the other. Further investigation into the cortical topography of activity that contributes to this category structure reveals the partial engagement of brain systems active normally for inanimate objects in addition to animate regions.

  18. Crossed-Brain Representation of Verbal and Nonverbal Functions

    Directory of Open Access Journals (Sweden)

    Esmeralda Matute

    2015-01-01

    Full Text Available A 74-year-old, left-handed man presented with a rapidly evolving loss of strength in his right leg associated with difficulty in walking. MR images disclosed an extensive left hemisphere tumor. A neuropsychological examination revealed that language was broadly normal but that the patient presented with severe nonlinguistic abnormalities, including hemineglect (both somatic and spatial, constructional defects, and general spatial disturbances; symptoms were usually associated with right hemisphere pathologies. No ideomotor apraxia was found. The implications of crossed-brain representations of verbal and nonverbal functions are analyzed.

  19. Event-related brain potentials and case information in syntactic ambiguities.

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    Hopf, J M; Bayer, J; Bader, M; Meng, M

    1998-03-01

    In an ERP study, German sentences were investigated that contain a case-ambiguous NP that may be assigned accusative or dative case. Sentences were disambiguated by the verb in final position of the sentence. As our data show, sentences ending in a verb that assigns dative case to the ambiguous NP elicit a clear garden-path effect. The garden-path effect was indicated by a broad centro-posterior negative shift that occurred between 300 and 900 msec after the dative-assigning verb was presented. No enhanced P600 following the misanalysis was observed. Noun phrases whose case ambiguity was resolved in favor of accusative case and unambiguously dative-marked NPs did not trigger significant ERP differences. We will discuss the implications of our results for parsing and its neuropsychological correlates. The results of this study support a parser design according to which the so-called structural case (nominative or accusative) is assigned without any delay in the absence of morpho-lexical counterevidence. It is argued that the enhancement of a negative ERP component with a "classical" N400 topography reflects the difficulty of reanalysis due to reaccessing morpho-lexical information that lies outside the domain of the parsing module. Consequently, ERP responses to garden-path effects are not confined to a late positivity but vary depending on the level of processing involved in reanalysis. The fact that garden-path effects may also elicit an N400 can be linked to the nonhomogeneous linguistic properties of the constructions from which they arise.

  20. Intermittency in electric brain activity in the perception of ambiguous images

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    Kurovskaya, Maria K.; Runnova, Anastasiya E.; Zhuravlev, Maxim O.; Grubov, Vadim V.; Koronovskii, Alexey A.; Pavlov, Alexey N.; Pisarchik, Alexander N.

    2017-04-01

    Present paper is devoted to the study of intermittency during the perception of bistable Necker cube image being a good example of an ambiguous object, with simultaneous measurement of EEG. Distributions of time interval lengths corresponding to the left-oriented and right-oriented cube perception have been obtain. EEG data have been analyzed using continuous wavelet transform and it was shown that the destruction of alpha rhythm with accompanying generation of high frequency oscillations can serve as a marker of Necker cube recognition process.

  1. Heterogeneity of the left temporal lobe in semantic representation and control: priming multiple versus single meanings of ambiguous words.

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    Whitney, Carin; Jefferies, Elizabeth; Kircher, Tilo

    2011-04-01

    Semantic judgments involve both representations of meaning plus executive mechanisms that guide knowledge retrieval in a task-appropriate way. These 2 components of semantic cognition-representation and control-are commonly linked to left temporal and prefrontal cortex, respectively. This simple proposal, however, remains contentious because in most functional neuroimaging studies to date, the number of concepts being activated and the involvement of executive processes during retrieval are confounded. Using functional magnetic resonance imaging, we examined a task in which semantic representation and control demands were dissociable. Words with multiple meanings like "bank" served as targets in a double-prime paradigm, in which multiple meaning activation and maximal executive demands loaded onto different priming conditions. Anterior inferior temporal gyrus (ITG) was sensitive to the number of meanings that were retrieved, suggesting a role for this region in semantic representation, while posterior middle temporal gyrus (pMTG) and inferior frontal cortex showed greater activation in conditions that maximized executive demands. These results support a functional dissociation between left ITG and pMTG, consistent with a revised neural organization in which left prefrontal and posterior temporal areas work together to underpin aspects of semantic control.

  2. Supramodal representations of perceived emotions in the human brain.

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    Peelen, Marius V; Atkinson, Anthony P; Vuilleumier, Patrik

    2010-07-28

    Basic emotional states (such as anger, fear, and joy) can be similarly conveyed by the face, the body, and the voice. Are there human brain regions that represent these emotional mental states regardless of the sensory cues from which they are perceived? To address this question, in the present study participants evaluated the intensity of emotions perceived from face movements, body movements, or vocal intonations, while their brain activity was measured with functional magnetic resonance imaging (fMRI). Using multivoxel pattern analysis, we compared the similarity of response patterns across modalities to test for brain regions in which emotion-specific patterns in one modality (e.g., faces) could predict emotion-specific patterns in another modality (e.g., bodies). A whole-brain searchlight analysis revealed modality-independent but emotion category-specific activity patterns in medial prefrontal cortex (MPFC) and left superior temporal sulcus (STS). Multivoxel patterns in these regions contained information about the category of the perceived emotions (anger, disgust, fear, happiness, sadness) across all modality comparisons (face-body, face-voice, body-voice), and independently of the perceived intensity of the emotions. No systematic emotion-related differences were observed in the overall amplitude of activation in MPFC or STS. These results reveal supramodal representations of emotions in high-level brain areas previously implicated in affective processing, mental state attribution, and theory-of-mind. We suggest that MPFC and STS represent perceived emotions at an abstract, modality-independent level, and thus play a key role in the understanding and categorization of others' emotional mental states.

  3. Segmentation and representation of lesions in MRI brain images

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    Tao, Yi; Grosky, William I.; Zamorano, Lucia J.; Jiang, Zhaowei; Gong, JianXing

    1999-05-01

    In this paper, we address the NSPS (a Neurological Surgery Planning System developed at the Neurological Surgery Department of Wayne State University) approaches for segmenting and representing lesions in MRI brain images. Initially, the 2D segmentation algorithm requires the input of a seed (an individual pixel or a small region) and a threshold to control the formation of a lesion region. The 3D segmentation algorithm requires the input of a seed, along with the threshold computed automatically from the corresponding three sample thresholds of lesion regions in sagittal, coronal, and axial views, to form a lesion volume. Then, a novel method is developed to represent the segmented lesion regions with feature point histograms, obtained by discretizing and counting the angles produced from the resulting Delaunay triangulation of a set of feature points which characterize the shape of the lesion region. The proposed shape representation technique is translation, scale, and rotation independent. Through various experiment results, we demonstrate the efficacy of the NSPS methodologies. Finally, based on the lesion representation scheme, we present a prototype system architecture for neurological surgery training. The implemented system will work in a Web-based environment, allowing neurosurgeons to query and browse various patients-related medical records in an effective and efficient way.

  4. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    of “ambiguous walls” as a more “critical” approach to design [1]. The concept of ambiguous walls refers to the diffuse status a lumious and possibly responsive wall will have. Instead of confining it can open up. Instead of having a static appearance, it becomes a context over time. Instead of being hard...... and flat, “ambiguous walls” combine softness, tectonics and three-dimensionality. The paper considers a selection of luminious surfaces and reflects on the extent of their ambiguous qualities. Initial ideas for new directions for the wall will be essayed through the discussion....

  5. Semantic Ambiguity and Perceived Ambiguity

    OpenAIRE

    Poesio, Massimo

    1995-01-01

    I explore some of the issues that arise when trying to establish a connection between the underspecification hypothesis pursued in the NLP literature and work on ambiguity in semantics and in the psychological literature. A theory of underspecification is developed `from the first principles', i.e., starting from a definition of what it means for a sentence to be semantically ambiguous and from what we know about the way humans deal with ambiguity. An underspecified language is specified as t...

  6. Ambiguous words in sentences: brain indices for native and non-native disambiguation.

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    Elston-Güttler, Kerrie E; Friederici, Angela D

    2007-02-27

    In the present study, we compare how native speakers and second language learners process homonyms (such as bank and jam) in sentence context during a late processing phase that involves selection of the appropriate meaning. With both participant groups, we conducted a combined reaction time (RT)/event-related brain potential (ERP) lexical decision experiment with a long stimulus-onset asynchrony (SOA) of 800 ms. Related primes were homonyms at the end of sentences with a context biasing one of the homonym meanings, and targets reflected the contextually appropriate or inappropriate meaning. Both RT and ERP semantic priming in the N400 component revealed that for both natives and learners, only contextually appropriate meanings were primed, or still active, late in processing. The results indicate that L2 learners show similar, though slower, homonym processing mechanisms to those of native speakers of a language, and that both groups can achieve disambiguation based on semantic context.

  7. A propositional representation model of anatomical and functional brain data.

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    Maturana, Pablo; Batrancourt, Bénédicte

    2011-01-01

    Networks can represent a large number of systems. Recent advances in the domain of networks have been transferred to the field of neuroscience. For example, the graph model has been used in neuroscience research as a methodological tool to examine brain networks organization, topology and complex dynamics, as well as a framework to test the structure-function hypothesis using neuroimaging data. In the current work we propose a graph-theoretical framework to represent anatomical, functional and neuropsychological assessment instruments information. On the one hand, interrelationships between anatomic elements constitute an anatomical graph. On the other hand, a functional graph contains several cognitive functions and their more elementary cognitive processes. Finally, the neuropsychological assessment instruments graph includes several neuropsychological tests and scales linked with their different sub-tests and variables. The two last graphs are connected by relations of type "explore" linking a particular instrument with the cognitive function it explores. We applied this framework to a sample of patients with focal brain damage. Each patient was related to: (i) the cerebral entities injured (assessed with structural neuroimaging data) and (ii) the neusopsychological assessment tests carried out (weight by performance). Our model offers a suitable platform to visualize patients' relevant information, facilitating the representation, standardization and sharing of clinical data. At the same time, the integration of a large number of patients in this framework will make possible to explore relations between anatomy (injured entities) and function (performance in different tests assessing different cognitive functions) and the use of neurocomputational tools for graph analysis may help diagnostic and contribute to the comprehension of neural bases of cognitive functions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. The neural underpinnings of semantic ambiguity and anaphora.

    Science.gov (United States)

    Dwivedi, Veena D; Phillips, Natalie A; Einagel, Stephanie; Baum, Shari R

    2010-01-22

    We used event-related brain potentials (ERPs) in order to investigate how definite NP anaphors are integrated into semantically ambiguous contexts. Although sentences such as Every kid climbed a tree lack any syntactic or lexical ambiguity, these structures exhibit two possible meanings, where either many trees or only one tree was climbed. This semantic ambiguity is the result of quantifier scope ambiguity. Previous behavioural studies have shown that a plural definite NP continuation is preferred (as reflected in a continuation sentence, e.g., The trees were in the park) over singular NPs (e.g., The tree was in the park). This study aimed to identify the neurophysiological pattern associated with the integration of the continuation sentences, as well as the time course of this process. We examined ERPs elicited by the noun and verb in continuation sentences following ambiguous and unambiguous context sentences. A sustained negative shift was most evident at the Verb position in sentences exhibiting scope ambiguity. Furthermore, this waveform did not differentiate itself until 900 ms after the presentation of the Noun, suggesting that the parser waits to assign meaning in contexts exhibiting quantifier scope ambiguity, such that such contexts are left as underspecified representations. Copyright 2009 Elsevier B.V. All rights reserved.

  9. Ambiguous genitalia

    Science.gov (United States)

    ... 20th ed. Philadelphia, PA: Elsevier; 2016:chap 575. White PC. Disorders of sexual development. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 233. Witchel SF, Lee PA. Ambiguous ...

  10. Different Brains Process Numbers Differently: Structural Bases of Individual Differences in Spatial and Nonspatial Number Representations

    NARCIS (Netherlands)

    Krause, F.; Lindemann, O.; Toni, I.; Bekkering, H.

    2014-01-01

    A dominant hypothesis on how the brain processes numerical size proposes a spatial representation of numbers as positions on a "mental number line." An alternative hypothesis considers numbers as elements of a generalized representation of sensorimotor-related magnitude, which is not obligatorily

  11. Brain-to-text: Decoding spoken phrases from phone representations in the brain

    Directory of Open Access Journals (Sweden)

    Christian eHerff

    2015-06-01

    Full Text Available It has long been speculated whether communication between humans and machines based on natural speech related cortical activity is possible. Over the past decade, studies have suggested that it is feasible to recognize isolated aspects of speech from neural signals, such as auditory features, phones or one of a few isolated words. However, until now it remained an unsolved challenge to decode continuously spoken speech from the neural substrate associated with speech and language processing. Here, we show for the first time that continuously spoken speech can be decoded into the expressed words from intracranial electrocorticographic (ECoG recordings. Specifically, we implemented a system, which we call Brain-To-Text that models single phones, employs techniques from automatic speech recognition (ASR, and thereby transforms brain activity while speaking into the corresponding textual representation. Our results demonstrate that our system achieved word error rates as low as 25% and phone error rates below 50%. Additionally, our approach contributes to the current understanding of the neural basis of continuous speech production by identifying those cortical regions that hold substantial information about individual phones. In conclusion, the Brain-To-Text system described in this paper represents an important step towards human-machine communication based on imagined speech.

  12. Brain-to-text: decoding spoken phrases from phone representations in the brain.

    Science.gov (United States)

    Herff, Christian; Heger, Dominic; de Pesters, Adriana; Telaar, Dominic; Brunner, Peter; Schalk, Gerwin; Schultz, Tanja

    2015-01-01

    It has long been speculated whether communication between humans and machines based on natural speech related cortical activity is possible. Over the past decade, studies have suggested that it is feasible to recognize isolated aspects of speech from neural signals, such as auditory features, phones or one of a few isolated words. However, until now it remained an unsolved challenge to decode continuously spoken speech from the neural substrate associated with speech and language processing. Here, we show for the first time that continuously spoken speech can be decoded into the expressed words from intracranial electrocorticographic (ECoG) recordings.Specifically, we implemented a system, which we call Brain-To-Text that models single phones, employs techniques from automatic speech recognition (ASR), and thereby transforms brain activity while speaking into the corresponding textual representation. Our results demonstrate that our system can achieve word error rates as low as 25% and phone error rates below 50%. Additionally, our approach contributes to the current understanding of the neural basis of continuous speech production by identifying those cortical regions that hold substantial information about individual phones. In conclusion, the Brain-To-Text system described in this paper represents an important step toward human-machine communication based on imagined speech.

  13. Ambiguous Genitalia

    Science.gov (United States)

    ... a genetic female. Mutations in certain genes can influence fetal sex development and cause ambiguous genitalia. Chromosomal abnormalities, such as ... excess male hormones if the mother has a disease or condition that causes hormone ... Impaired testicle development . This may be due to genetic abnormalities or ...

  14. Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry.

    Science.gov (United States)

    Leikin, Mark; Waisman, Ilana; Shaul, Shelley; Leikin, Roza

    2014-03-01

    This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity.

  15. Media representations of early human development: protecting, feeding and loving the developing brain.

    OpenAIRE

    O Connor, C.; Joffe, H.

    2013-01-01

    The public profile of neurodevelopmental research has expanded in recent years. This paper applies social representations theory to explore how early brain development was represented in the UK print media in the first decade of the 21st century. A thematic analysis was performed on 505 newspaper articles published between 2000 and 2010 that discussed early brain development. Media coverage centred around concern with ‘protecting’ the prenatal brain (identifying threats to foetal neurodevelop...

  16. Neural representation of expected value in the adolescent brain

    OpenAIRE

    Barkley-Levenson, Emily; Galván, Adriana

    2014-01-01

    The brain undergoes significant maturation during adolescence that influences reward sensitivity and risk-taking behavior. However, it is unknown if the adolescent brain truly values rewards in a way that is unique from the mature brain or if confounding factors contribute to this developmental difference. Here we show that adolescents place greater value on rewards than do adults through exaggerated activation of the ventral striatum and that this valuation increases gambling behavior. This ...

  17. Ambiguous Belongings

    DEFF Research Database (Denmark)

    Pallesen, Cecil Marie

    in Tanzania since the Independence, should be viewed not only as generating anxiety but also potentiality, I suggest that there is a need for new metaphors to think with in the examination of certain kinds of migrant minorities. Ambiguous Belongings denotes a way of being in the world. Throughout the thesis...... of borders and walls in the contemporary world leave no space for people whose life worlds are stretched across nation-states....

  18. Ambiguous Adaptation

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Lyngsie, Jacob

    We investigate why some exchange relationships terminate prematurely. We argue that investments in informal governance structures induce premature termination in relationships already governed by formal contracts. The formalized adaptive behavior of formal governance structures and the flexible...... and reciprocal adaptation of informal governance structure create ambiguity in situations of contingencies, which, subsequently, increases the likelihood of premature relationship termination. Using a large sample of exchange relationships in the global service provider industry, we find support for a hypothesis...

  19. The motor cortical representation of a muscle is not homogeneous in brain connectivity.

    Science.gov (United States)

    Smith, Jo Armour; Albishi, Alaa; Babikian, Sarine; Asavasopon, Skulpan; Fisher, Beth E; Kutch, Jason J

    2017-09-01

    Functional connectivity patterns of the motor cortical representational area of single muscles have not been extensively mapped in humans, particularly for the axial musculature. Functional connectivity may provide a neural substrate for adaptation of muscle activity in axial muscles that have both voluntary and postural functions. The purpose of this study was to combine brain stimulation and neuroimaging to both map the cortical representation of the external oblique (EO) in primary motor cortex (M1) and supplementary motor area (SMA), and to establish the resting-state functional connectivity associated with this representation. Motor-evoked potentials were elicited from the EO muscle in stimulation locations encompassing M1 and SMA. The coordinates of locations with the largest motor-evoked potentials were confirmed with task-based fMRI imaging during EO activation. The M1 and SMA components of the EO representation demonstrated significantly different resting-state functional connectivity with other brain regions: the SMA representation of the EO muscle was significantly more connected to the putamen and cerebellum, and the M1 representation of the EO muscle was significantly more connected to somatosensory cortex and the superior parietal lobule. This study confirms the representation of a human axial muscle in M1 and SMA, and demonstrates for the first time that different parts of the cortical representation of a human axial muscle have resting-state functional connectivity with distinct brain regions. Future studies can use the brain regions of interest we have identified here to test the association between resting-state functional connectivity and control of the axial muscles.

  20. The representation of material categories in the brain

    NARCIS (Netherlands)

    Jacobs, R.H.A.H.; Baumgartner, E.; Gegenfurtner, K.R.

    2014-01-01

    Using textures mapped onto virtual nonsense objects, it has recently been shown that early visual cortex plays an important role in processing material properties. Here, we examined brain activation to photographs of materials, consisting of wood, stone, metal and fabric surfaces. These photographs

  1. A stranger in my brain: Neural representation for unfamiliar persons using fMRI repetition suppression.

    Science.gov (United States)

    Heleven, Elien; Boukhlal, Siham; Van Overwalle, Frank

    2017-08-02

    Prior neuroimaging research demonstrated that the ventromedial prefrontal cortex (vmPFC) houses neural representations for traits and familiar persons that possess these traits. But do such neural representations also exist for people we do not know? We hypothesized that knowledge about unknown persons is encoded in "generic" mentalizing representations as opposed to "specific" representations for well-known individuals. Neural representations for unfamiliar persons were investigated by fMRI repetition suppression, which is a rapid suppression of fMRI responses upon repeated presentation of the same stimulus signaling the neural representation of this stimulus. Participants had to infer an unfamiliar person's traits from brief behavioral descriptions. In each trial, a critical sentence was preceded by another sentence in which we manipulated whether or not the person or trait was repeated. The results revealed suppression for unfamiliar others in the vmPFC extending earlier research, as well as in novel areas including the inferior parietal lobule and dorsal posterior cingulate. We also found trait suppression in the vmPFC. This indicates that the vmPFC houses neural populations of "generic" representations of unknown persons and their traits. We speculate that the other brain areas showing suppression might reflect embodied representations at a somatomotor level.

  2. De Novo Emergence of Odor Category Representations in the Human Brain.

    Science.gov (United States)

    Qu, Lisa P; Kahnt, Thorsten; Cole, Sydni M; Gottfried, Jay A

    2016-01-13

    Categorization allows organisms to efficiently extract relevant information from a diverse environment. Because of the multidimensional nature of odor space, this ability is particularly important for the olfactory system. However, categorization relies on experience, and the processes by which the human brain forms categorical representations about new odor percepts are currently unclear. Here we used olfactory psychophysics and multivariate fMRI techniques, in the context of a paired-associates learning task, to examine the emergence of novel odor category representations in the human brain. We found that learning between novel odors and visual category information induces a perceptual reorganization of those odors, in parallel with the emergence of odor category-specific ensemble patterns in perirhinal, orbitofrontal, piriform, and insular cortices. Critically, the learning-induced pattern effects in orbitofrontal and perirhinal cortex predicted the magnitude of categorical learning and perceptual plasticity. The formation of de novo category-specific representations in olfactory and limbic brain regions suggests that such ensemble patterns subserve the development of perceptual classes of information, and imply that these patterns are instrumental to the brain's capacity for odor categorization. How the human brain assigns novel odors to perceptual classes and categories is poorly understood. We combined an olfactory-visual paired-associates task with multivariate pattern-based fMRI approaches to investigate the de novo formation of odor category representations within the human brain. The identification of emergent odor category codes within the perirhinal, piriform, orbitofrontal, and insular cortices suggests that these regions can integrate multimodal sensory input to shape category-specific olfactory representations for novel odors, and may ultimately play an important role in assembling each individual's semantic knowledge base of the olfactory world

  3. Media representations of early human development: protecting, feeding and loving the developing brain.

    Science.gov (United States)

    O'Connor, Cliodhna; Joffe, Helene

    2013-11-01

    The public profile of neurodevelopmental research has expanded in recent years. This paper applies social representations theory to explore how early brain development was represented in the UK print media in the first decade of the 21st century. A thematic analysis was performed on 505 newspaper articles published between 2000 and 2010 that discussed early brain development. Media coverage centred around concern with 'protecting' the prenatal brain (identifying threats to foetal neurodevelopment), 'feeding' the infant brain (indicating the patterns of nutrition that enhance brain development) and 'loving' the young child's brain (elucidating the developmental significance of emotionally nurturing family environments). The media focused almost exclusively on the role of parental action in promoting optimal neurodevelopment, rarely acknowledging wider structural, cultural or political means of supporting child development. The significance of parental care was intensified by deterministic interpretations of critical periods, which implied that inappropriate parental input would produce profound and enduring neurobiological impairments. Neurodevelopmental research was also used to promulgate normative judgements concerning the acceptability of certain gender roles and family contexts. The paper argues that media representations of neurodevelopment stress parental responsibility for shaping a child's future while relegating the contributions of genetic or wider societal factors, and examines the consequences of these representations for society and family life. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. The representation of material categories in the brain

    Science.gov (United States)

    Jacobs, Richard H. A. H.; Baumgartner, Elisabeth; Gegenfurtner, Karl R.

    2014-01-01

    Using textures mapped onto virtual nonsense objects, it has recently been shown that early visual cortex plays an important role in processing material properties. Here, we examined brain activation to photographs of materials, consisting of wood, stone, metal and fabric surfaces. These photographs were close-ups in the sense that the materials filled the image. In the first experiment, observers categorized the material in each image (i.e., wood, stone, metal, or fabric), while in an fMRI-scanner. We predicted the assigned material category using the obtained voxel patterns using a linear classifier. Region-of-interest and whole-brain analyses demonstrated material coding in the early visual regions, with lower accuracies for more anterior regions. There was little evidence for material coding in other brain regions. In the second experiment, we used an adaptation paradigm to reveal additional brain areas involved in the perception of material categories. Participants viewed images of wood, stone, metal, and fabric, presented in blocks with images of either different material categories (no adaptation) or images of different samples from the same material category (material adaptation). To measure baseline activation, blocks with the same material sample were presented (baseline adaptation). Material adaptation effects were found mainly in the parahippocampal gyrus, in agreement with fMRI-studies of texture perception. Our findings suggest that the parahippocampal gyrus, early visual cortex, and possibly the supramarginal gyrus are involved in the perception of material categories, but in different ways. The different outcomes from the two studies are likely due to inherent differences between the two paradigms. A third experiment suggested, based on anatomical overlap between activations, that spatial frequency information is important for within-category material discrimination. PMID:24659972

  5. Human brain somatic representation: a functional magnetic resonance mapping

    Science.gov (United States)

    Romero-Romo, Juan; Rojas, Rafael; Salgado, Perla; Sánchez-Cortázar, Julián; Vazquez-Vela, Arturo; Barrios, Fernando A.

    2001-10-01

    Central nervous system studies of injury and plasticity for the reorganization in the phantom limb sensation area presented. In particular functional magnetic resonance imaging (fMRI) mapping of the somatic and motor cortex of amputee patients, in the case of referred sensations. Using fMRI we can show the correlation between structure and functional field and study the reorganization due to plasticity in the brain.

  6. The representation of material categories in the brain

    Directory of Open Access Journals (Sweden)

    Richard Henrikus Augustinus Hubertus Jacobs

    2014-03-01

    Full Text Available Using textures mapped onto virtual nonsense objects, it has recently been shown that early visual cortex plays an important role in processing material properties. Here, we examined brain activation to photographs of materials, consisting of wood, stone, metal and fabric surfaces. These photographs were close-ups in the sense that the materials filled the image. In the first experiment, observers categorized the material in each image (i.e., wood, stone, metal, or fabric, while in an fMRI-scanner. We predicted the assigned material category using the obtained voxel patterns using a linear classifier. Region-of-interest and whole-brain analyses demonstrated material coding in the early visual regions, with lower accuracies for more anterior regions. There was little evidence for material coding in other brain regions. In the second experiment, we used an adaptation paradigm to reveal additional brain areas involved in the perception of material categories. Participants viewed images of wood, stone, metal, and fabric, presented in blocks with images of either different material categories (no adaptation or images of different samples from the same material category (material adaptation. To measure baseline activation, blocks with the same material sample were presented (baseline adaptation. Material adaptation effects were found mainly in the parahippocampal gyrus, in agreement with fMRI-studies of texture perception. Our findings suggest that the parahippocampal gyrus, early visual cortex, and possibly the supramarginal gyrus are involved in the perception of material categories, but in different ways. The different outcomes from the two studies are likely due to inherent differences between the two paradigms. A third experiment suggested, based on anatomical overlap between activations, that spatial frequency information is important for within-category material discrimination.

  7. Script-event representation in patients with severe traumatic brain injury

    NARCIS (Netherlands)

    Allain, P.; Fasotti, L.; Roy, A.; Chauvire, V.; Etcharry-Bouyx, F.; Gall, D. le

    2012-01-01

    The aim of the present study was to examine the syntactic and semantic dimensions of script representation in patients with structural damage within the cerebral cortex following a severe traumatic brain injury (TBI). Forty TBI patients and 38 healthy control subjects (HC) were asked to sort cards

  8. Decoding the dynamic representation of musical pitch from human brain activity.

    Science.gov (United States)

    Sankaran, N; Thompson, W F; Carlile, S; Carlson, T A

    2018-01-16

    In music, the perception of pitch is governed largely by its tonal function given the preceding harmonic structure of the music. While behavioral research has advanced our understanding of the perceptual representation of musical pitch, relatively little is known about its representational structure in the brain. Using Magnetoencephalography (MEG), we recorded evoked neural responses to different tones presented within a tonal context. Multivariate Pattern Analysis (MVPA) was applied to "decode" the stimulus that listeners heard based on the underlying neural activity. We then characterized the structure of the brain's representation using decoding accuracy as a proxy for representational distance, and compared this structure to several well established perceptual and acoustic models. The observed neural representation was best accounted for by a model based on the Standard Tonal Hierarchy, whereby differences in the neural encoding of musical pitches correspond to their differences in perceived stability. By confirming that perceptual differences honor those in the underlying neuronal population coding, our results provide a crucial link in understanding the cognitive foundations of musical pitch across psychological and neural domains.

  9. Stimulating the Brain's Language Network: Syntactic Ambiguity Resolution after TMS to the Inferior Frontal Gyrus and Middle Temporal Gyrus

    NARCIS (Netherlands)

    Acheson, D.J.; Hagoort, P.

    2013-01-01

    The posterior middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) are two critical nodes of the brain's language network. Previous neuroimaging evidence has supported a dissociation in language comprehension in which parts of the MTG are involved in the retrieval of lexical syntactic

  10. Robust brain parcellation using sparse representation on resting-state fMRI.

    Science.gov (United States)

    Zhang, Yu; Caspers, Svenja; Fan, Lingzhong; Fan, Yong; Song, Ming; Liu, Cirong; Mo, Yin; Roski, Christian; Eickhoff, Simon; Amunts, Katrin; Jiang, Tianzi

    2015-11-01

    Resting-state fMRI (rs-fMRI) has been widely used to segregate the brain into individual modules based on the presence of distinct connectivity patterns. Many parcellation methods have been proposed for brain parcellation using rs-fMRI, but their results have been somewhat inconsistent, potentially due to various types of noise. In this study, we provide a robust parcellation method for rs-fMRI-based brain parcellation, which constructs a sparse similarity graph based on the sparse representation coefficients of each seed voxel and then uses spectral clustering to identify distinct modules. Both the local time-varying BOLD signals and whole-brain connectivity patterns may be used as features and yield similar parcellation results. The robustness of our method was tested on both simulated and real rs-fMRI datasets. In particular, on simulated rs-fMRI data, sparse representation achieved good performance across different noise levels, including high accuracy of parcellation and high robustness to noise. On real rs-fMRI data, stable parcellation of the medial frontal cortex (MFC) and parietal operculum (OP) were achieved on three different datasets, with high reproducibility within each dataset and high consistency across these results. Besides, the parcellation of MFC was little influenced by the degrees of spatial smoothing. Furthermore, the consistent parcellation of OP was also well corresponding to cytoarchitectonic subdivisions and known somatotopic organizations. Our results demonstrate a new promising approach to robust brain parcellation using resting-state fMRI by sparse representation.

  11. Dynamics of trimming the content of face representations for categorization in the brain.

    Directory of Open Access Journals (Sweden)

    Nicola J van Rijsbergen

    2009-11-01

    Full Text Available To understand visual cognition, it is imperative to determine when, how and with what information the human brain categorizes the visual input. Visual categorization consistently involves at least an early and a late stage: the occipito-temporal N170 event related potential related to stimulus encoding and the parietal P300 involved in perceptual decisions. Here we sought to understand how the brain globally transforms its representations of face categories from their early encoding to the later decision stage over the 400 ms time window encompassing the N170 and P300 brain events. We applied classification image techniques to the behavioral and electroencephalographic data of three observers who categorized seven facial expressions of emotion and report two main findings: (1 over the 400 ms time course, processing of facial features initially spreads bilaterally across the left and right occipito-temporal regions to dynamically converge onto the centro-parietal region; (2 concurrently, information processing gradually shifts from encoding common face features across all spatial scales (e.g., the eyes to representing only the finer scales of the diagnostic features that are richer in useful information for behavior (e.g., the wide opened eyes in 'fear'; the detailed mouth in 'happy'. Our findings suggest that the brain refines its diagnostic representations of visual categories over the first 400 ms of processing by trimming a thorough encoding of features over the N170, to leave only the detailed information important for perceptual decisions over the P300.

  12. Maladaptive change of body representation in the brain after damage to central or peripheral nervous system.

    Science.gov (United States)

    Oouchida, Yutaka; Sudo, Tamami; Inamura, Tetsunari; Tanaka, Naofumi; Ohki, Yukari; Izumi, Shin-ichi

    2016-03-01

    Our brain has great flexibility to cope with various changes in the environment. Use-dependent plasticity, a kind of functional plasticity, plays the most important role in this ability to cope. For example, the functional recovery of paretic limb motor movement during post-stroke rehabilitation depends mainly on how much it is used. Patients with hemiparesis, however, tend to gradually disuse the paretic limb because of its motor impairment. Decreased use of the paretic hand then leads to further functional decline brought by use-dependent plasticity. To break this negative loop, body representation, which is the conscious and unconscious information regarding body state stored in the brain, is key for using the paretic limb because it plays an important role in selecting an effector while a motor program is generated. In an attempt to understand body representation in the brain, we reviewed animal and human literature mainly on the alterations of the sensory maps in the primary somatosensory cortex corresponding to the changes in limb usage caused by peripheral or central nervous system damage. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  13. Image ambiguity and fluency.

    Directory of Open Access Journals (Sweden)

    Martina Jakesch

    Full Text Available Ambiguity is often associated with negative affective responses, and enjoying ambiguity seems restricted to only a few situations, such as experiencing art. Nevertheless, theories of judgment formation, especially the "processing fluency account", suggest that easy-to-process (non-ambiguous stimuli are processed faster and are therefore preferred to (ambiguous stimuli, which are hard to process. In a series of six experiments, we investigated these contrasting approaches by manipulating fluency (presentation duration: 10 ms, 50 ms, 100 ms, 500 ms, 1000 ms and testing effects of ambiguity (ambiguous versus non-ambiguous pictures of paintings on classification performance (Part A; speed and accuracy and aesthetic appreciation (Part B; liking and interest. As indicated by signal detection analyses, classification accuracy increased with presentation duration (Exp. 1a, but we found no effects of ambiguity on classification speed (Exp. 1b. Fifty percent of the participants were able to successfully classify ambiguous content at a presentation duration of 100 ms, and at 500 ms even 75% performed above chance level. Ambiguous artworks were found more interesting (in conditions 50 ms to 1000 ms and were preferred over non-ambiguous stimuli at 500 ms and 1000 ms (Exp. 2a - 2c, 3. Importantly, ambiguous images were nonetheless rated significantly harder to process as non-ambiguous images. These results suggest that ambiguity is an essential ingredient in art appreciation even though or maybe because it is harder to process.

  14. Resolving Anatomical and Functional Structure in Human Brain Organization: Identifying Mesoscale Organization in Weighted Network Representations

    Science.gov (United States)

    Lohse, Christian; Bassett, Danielle S.; Lim, Kelvin O.; Carlson, Jean M.

    2014-01-01

    Human brain anatomy and function display a combination of modular and hierarchical organization, suggesting the importance of both cohesive structures and variable resolutions in the facilitation of healthy cognitive processes. However, tools to simultaneously probe these features of brain architecture require further development. We propose and apply a set of methods to extract cohesive structures in network representations of brain connectivity using multi-resolution techniques. We employ a combination of soft thresholding, windowed thresholding, and resolution in community detection, that enable us to identify and isolate structures associated with different weights. One such mesoscale structure is bipartivity, which quantifies the extent to which the brain is divided into two partitions with high connectivity between partitions and low connectivity within partitions. A second, complementary mesoscale structure is modularity, which quantifies the extent to which the brain is divided into multiple communities with strong connectivity within each community and weak connectivity between communities. Our methods lead to multi-resolution curves of these network diagnostics over a range of spatial, geometric, and structural scales. For statistical comparison, we contrast our results with those obtained for several benchmark null models. Our work demonstrates that multi-resolution diagnostic curves capture complex organizational profiles in weighted graphs. We apply these methods to the identification of resolution-specific characteristics of healthy weighted graph architecture and altered connectivity profiles in psychiatric disease. PMID:25275860

  15. Resolving anatomical and functional structure in human brain organization: identifying mesoscale organization in weighted network representations.

    Directory of Open Access Journals (Sweden)

    Christian Lohse

    2014-10-01

    Full Text Available Human brain anatomy and function display a combination of modular and hierarchical organization, suggesting the importance of both cohesive structures and variable resolutions in the facilitation of healthy cognitive processes. However, tools to simultaneously probe these features of brain architecture require further development. We propose and apply a set of methods to extract cohesive structures in network representations of brain connectivity using multi-resolution techniques. We employ a combination of soft thresholding, windowed thresholding, and resolution in community detection, that enable us to identify and isolate structures associated with different weights. One such mesoscale structure is bipartivity, which quantifies the extent to which the brain is divided into two partitions with high connectivity between partitions and low connectivity within partitions. A second, complementary mesoscale structure is modularity, which quantifies the extent to which the brain is divided into multiple communities with strong connectivity within each community and weak connectivity between communities. Our methods lead to multi-resolution curves of these network diagnostics over a range of spatial, geometric, and structural scales. For statistical comparison, we contrast our results with those obtained for several benchmark null models. Our work demonstrates that multi-resolution diagnostic curves capture complex organizational profiles in weighted graphs. We apply these methods to the identification of resolution-specific characteristics of healthy weighted graph architecture and altered connectivity profiles in psychiatric disease.

  16. Resolving anatomical and functional structure in human brain organization: identifying mesoscale organization in weighted network representations.

    Science.gov (United States)

    Lohse, Christian; Bassett, Danielle S; Lim, Kelvin O; Carlson, Jean M

    2014-10-01

    Human brain anatomy and function display a combination of modular and hierarchical organization, suggesting the importance of both cohesive structures and variable resolutions in the facilitation of healthy cognitive processes. However, tools to simultaneously probe these features of brain architecture require further development. We propose and apply a set of methods to extract cohesive structures in network representations of brain connectivity using multi-resolution techniques. We employ a combination of soft thresholding, windowed thresholding, and resolution in community detection, that enable us to identify and isolate structures associated with different weights. One such mesoscale structure is bipartivity, which quantifies the extent to which the brain is divided into two partitions with high connectivity between partitions and low connectivity within partitions. A second, complementary mesoscale structure is modularity, which quantifies the extent to which the brain is divided into multiple communities with strong connectivity within each community and weak connectivity between communities. Our methods lead to multi-resolution curves of these network diagnostics over a range of spatial, geometric, and structural scales. For statistical comparison, we contrast our results with those obtained for several benchmark null models. Our work demonstrates that multi-resolution diagnostic curves capture complex organizational profiles in weighted graphs. We apply these methods to the identification of resolution-specific characteristics of healthy weighted graph architecture and altered connectivity profiles in psychiatric disease.

  17. Different brain circuits underlie motor and perceptual representations of temporal intervals

    DEFF Research Database (Denmark)

    Bueti, Doemnica; Walsh, Vincent; Frith, Christopher

    2008-01-01

    mechanisms. However, only in the reproduction task was activity observed in a wider cortical network including the right pre- SMA, left middle frontal gyrus, left premotor cortex, with a more reliable activity in the right inferior parietal cortex, left fusiform gyrus, and the right extrastriate visual area...... information when either a motor or a perceptual representation is used. Participants viewed two identical sequences of visual stimuli and used the information differently to perform either a temporal reproduction or a temporal estimation task. By comparing brain activity evoked by these tasks and control...... conditions, we explored commonalities and differences in brain areas involved in reproduction and estimation of temporal intervals. The basal ganglia and the cerebellum were commonly active in both temporal tasks, consistent with suggestions that perception and production of time are subserved by the same...

  18. 'Love builds brains': Representations of attachment and children's brain development in parenting education material.

    Science.gov (United States)

    Wall, Glenda

    2017-12-12

    A focus on early brain development has come to dominate expert child rearing advice over the past two decades. Recent scholars have noted a reinvigoration of the concept of attachment in this advice and changes in the ways that attachment is framed and understood. The extent to which the concept of attachment is drawn on, the way it is framed, and the consequences for mothers, families and parent-child relationships is examined through a discursive analysis of a current Canadian parental education campaign. Findings support the argument that attachment is receiving a great deal of attention in brain-based parenting education programmes as children's emotional development becomes increasingly prioritized. Attachment is presented as needing to be actively and continually built through expert-guided empathetic and responsive parental behaviour, and is framed as crucial for the development of brain pathways that promote emotional strength and self-regulation in children. Attachment-building is also presented as requiring highly intensive parenting that falls overwhelmingly to mothers. The parent-child relationship that is envisioned is one that is instrumental, lacking in affect and conducive to the creation of ideal self-regulating neo-liberal citizens. © 2017 Foundation for the Sociology of Health & Illness.

  19. Noise in attractor networks in the brain produced by graded firing rate representations.

    Directory of Open Access Journals (Sweden)

    Tristan J Webb

    Full Text Available Representations in the cortex are often distributed with graded firing rates in the neuronal populations. The firing rate probability distribution of each neuron to a set of stimuli is often exponential or gamma. In processes in the brain, such as decision-making, that are influenced by the noise produced by the close to random spike timings of each neuron for a given mean rate, the noise with this graded type of representation may be larger than with the binary firing rate distribution that is usually investigated. In integrate-and-fire simulations of an attractor decision-making network, we show that the noise is indeed greater for a given sparseness of the representation for graded, exponential, than for binary firing rate distributions. The greater noise was measured by faster escaping times from the spontaneous firing rate state when the decision cues are applied, and this corresponds to faster decision or reaction times. The greater noise was also evident as less stability of the spontaneous firing state before the decision cues are applied. The implication is that spiking-related noise will continue to be a factor that influences processes such as decision-making, signal detection, short-term memory, and memory recall even with the quite large networks found in the cerebral cortex. In these networks there are several thousand recurrent collateral synapses onto each neuron. The greater noise with graded firing rate distributions has the advantage that it can increase the speed of operation of cortical circuitry.

  20. The hermunculus: what is known about the representation of the female body in the brain?

    Science.gov (United States)

    Di Noto, Paula M; Newman, Leorra; Wall, Shelley; Einstein, Gillian

    2013-05-01

    The representation of the body in the brain, the homunculus, was posited by Wilder Penfield based on his studies of patients with intractable epilepsy. While he mapped both male and female patients, Penfield reports little about the females. The now iconic illustration of the map is clearly male with testicles, penis, and no breasts. In order to bring attention to this omission and to stimulate studies of female somatosensory cortex (SS), we discuss what is known about the map of the female body in the brain, including Penfield's findings in his female patients and subsequent work by others exploring the human female SS. We reveal that there is much we do not know about how the entire female body is represented in the brain or how it might change with different reproductive life stages, hormones, and experiences. Understanding what is and is not currently known about the female SS is a first step toward fully understanding neurological and physiological sex differences, as well as producing better-informed treatments for pain conditions related to mastectomy, hysterectomy, vulvodynia, and fibromyalgia. We suggest that the time is ripe for a full mapping of the female brain with the production of a hermunculus.

  1. Experience with adults shapes multisensory representation of social familiarity in the brain of a songbird.

    Directory of Open Access Journals (Sweden)

    Isabelle George

    Full Text Available Social animals learn to perceive their social environment, and their social skills and preferences are thought to emerge from greater exposure to and hence familiarity with some social signals rather than others. Familiarity appears to be tightly linked to multisensory integration. The ability to differentiate and categorize familiar and unfamiliar individuals and to build a multisensory representation of known individuals emerges from successive social interactions, in particular with adult, experienced models. In different species, adults have been shown to shape the social behavior of young by promoting selective attention to multisensory cues. The question of what representation of known conspecifics adult-deprived animals may build therefore arises. Here we show that starlings raised with no experience with adults fail to develop a multisensory representation of familiar and unfamiliar starlings. Electrophysiological recordings of neuronal activity throughout the primary auditory area of these birds, while they were exposed to audio-only or audiovisual familiar and unfamiliar cues, showed that visual stimuli did, as in wild-caught starlings, modulate auditory responses but that, unlike what was observed in wild-caught birds, this modulation was not influenced by familiarity. Thus, adult-deprived starlings seem to fail to discriminate between familiar and unfamiliar individuals. This suggests that adults may shape multisensory representation of known individuals in the brain, possibly by focusing the young's attention on relevant, multisensory cues. Multisensory stimulation by experienced, adult models may thus be ubiquitously important for the development of social skills (and of the neural properties underlying such skills in a variety of species.

  2. The brain MRI image sparse representation based on the gradient information and the non-symmetry and anti-packing model.

    Science.gov (United States)

    Liang, Hu; Zhao, Shengrong; Dong, Xiangjun

    2017-12-01

    Nowadays, sparse representation has been widely used in Magnetic Resonance Imaging (MRI). The commonly used sparse representation methods are based on symmetrical partition, which have not considered the complex structure of MRI image. In this paper, we proposed a sparse representation method for the brain MRI image, called GNAMlet transform, which is based on the gradient information and the non-symmetry and anti-packing model. The proposed sparse representation method can reduce the lost detail information, improving the reconstruction accuracy. The experiment results show the superiority of the proposed transform for the brain MRI image representation in comparison with some state-of-the-art sparse representation methods.

  3. Sparse representation of brain aging: extracting covariance patterns from structural MRI.

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    Longfei Su

    Full Text Available An enhanced understanding of how normal aging alters brain structure is urgently needed for the early diagnosis and treatment of age-related mental diseases. Structural magnetic resonance imaging (MRI is a reliable technique used to detect age-related changes in the human brain. Currently, multivariate pattern analysis (MVPA enables the exploration of subtle and distributed changes of data obtained from structural MRI images. In this study, a new MVPA approach based on sparse representation has been employed to investigate the anatomical covariance patterns of normal aging. Two groups of participants (group 1:290 participants; group 2:56 participants were evaluated in this study. These two groups were scanned with two 1.5 T MRI machines. In the first group, we obtained the discriminative patterns using a t-test filter and sparse representation step. We were able to distinguish the young from old cohort with a very high accuracy using only a few voxels of the discriminative patterns (group 1:98.4%; group 2:96.4%. The experimental results showed that the selected voxels may be categorized into two components according to the two steps in the proposed method. The first component focuses on the precentral and postcentral gyri, and the caudate nucleus, which play an important role in sensorimotor tasks. The strongest volume reduction with age was observed in these clusters. The second component is mainly distributed over the cerebellum, thalamus, and right inferior frontal gyrus. These regions are not only critical nodes of the sensorimotor circuitry but also the cognitive circuitry although their volume shows a relative resilience against aging. Considering the voxels selection procedure, we suggest that the aging of the sensorimotor and cognitive brain regions identified in this study has a covarying relationship with each other.

  4. Reorganization of Motor Representations in Patients with Brain Lesions: A Navigated Transcranial Magnetic Stimulation Study.

    Science.gov (United States)

    Bulubas, Lucia; Sollmann, Nico; Tanigawa, Noriko; Zimmer, Claus; Meyer, Bernhard; Krieg, Sandro M

    2018-03-01

    This is an explorative study applying presurgical navigated transcranial magnetic stimulation (nTMS) to investigate the spatial distributions of motor sites to reveal tumor-induced brain plasticity in patients with brain tumors. We analyzed nTMS-based motor maps derived from presurgical mapping of 100 patients with motor eloquently located brain tumors (tumors in the frontal lobe, the precentral gyrus [PrG], the postcentral gyrus [PoG], the remaining parietal lobe, or the temporal lobe). Based on these motor maps, we systematically investigated changes in motor evoked potential (MEP) counts among 4 gyri (PrG, PoG, medial frontal gyrus, and superior frontal gyrus) between subgroups of patients according to the tumor location in order to depict the tumor's influence on reorganization. When comparing patients with different tumor locations, high MEP counts were elicited less frequently by stimulating the PrG in patients with tumors directly affecting the PrG (p motor representations within the primary motor cortex. In contrast, patients with PoG and parietal tumors primarily showed high MEP counts when stimulating the PoG (p motor function from the PrG to adjacent regions but rather leads to a reorganization within anatomical constraints, such as of the PoG. Thus, presurgical nTMS-based motor mapping sensitively depicted the tumor-induced plasticity of the motor cortex.

  5. Bottom-up and top-down processes in body representation: a study of brain-damaged and amputee patients.

    Science.gov (United States)

    Palermo, Liana; Di Vita, Antonella; Piccardi, Laura; Traballesi, Marco; Guariglia, Cecilia

    2014-09-01

    Body representation is a complex process involving different sources of top-down and bottom-up information. Processing the position and the relations among different body parts is necessary to build up a specific body representation, that is, the visuospatial body map (or topological map of the body). Here we aimed to investigate how the loss of peripheral or central information affects this representation by testing amputee and brain-damaged patients. Thirty-two unilateral brain-damaged patients (i.e., left-brain-damaged patients and right-brain-damaged patients who were or were not affected by personal neglect), 18 lower limb amputees and 15 healthy controls took part in the study. The topological body map was assessed by means of the "Frontal body-evocation subtest" (Daurat-Hmeljiak, Stambak, & Berges, 1978), in which participants have to put tiles (each representing a body part) on a small wooden board on which a head is depicted. Group statistical analysis showed that in amputee patients the loss of peripheral information about the right lower limb affects the ability to represent relations among different body parts as much as the loss of top-down information in brain-damaged patients with personal neglect. Single case analysis of brain-damaged patients without personal neglect showed that the topological map of the body was deficient in 1 right-brain-damaged and 2 left-brain-damaged patients. Studying amputee and brain-damaged patients together allowed us to highlight the importance of visuospatial information about one's own limbs and the role of both hemispheres (not only the left one) in creating an efficient topological body representation. (c) 2014 APA, all rights reserved.

  6. Subvoxel segmentation and representation of brain cortex using fuzzy clustering and gradient vector diffusion

    Science.gov (United States)

    Chang, Ming-Ching; Tao, Xiaodong

    2010-03-01

    Segmentation and representation of human brain cortex from Magnetic Resonance (MR) images is an important step for visualization and analysis in many neuro imaging applications. In this paper, we propose an automatic and fast algorithm to segment the brain cortex and to represent it as a geometric surface on which analysis can be carried out. The algorithm works on T1 weighted MR brain images with extracranial tissue removed. A fuzzy clustering algorithm with a parametric bias field model is applied to assign membership values of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) to each voxel. The cortical boundaries, namely the WM-GM and GM-CSF boundary surfaces, are extracted as iso-surfaces of functions derived from these membership functions. The central surface (CS), which traces the peak values (or ridges) of the GM membership function, is then extracted using gradient vector diffusion. Our main contribution is to provide a generic, accurate, fast, yet fully-automatic approach to (i) produce a soft segmentation of the MR brain image with intensity field correction, (ii) extract both the boundary and the center of the cortex in a surface form, where the topology and geometry can be explicitly examined, and (iii) use the extracted surfaces to model the curvy, folding cortical volume, which allows an intuitive measurement of the thickness. As a demonstration, we compute cortical thickness from the surfaces and compare the results with what has been reported in the literature. The entire process from raw MR image to cortical surface reconstruction takes on average between five to ten minutes.

  7. Script-event representation in patients with severe traumatic brain injury.

    Science.gov (United States)

    Allain, Philippe; Fasotti, Luciano; Roy, Arnaud; Chauviré, Valérie; Etcharry-Bouyx, Frédérique; Le Gall, Didier

    2012-10-01

    The aim of the present study was to examine the syntactic and semantic dimensions of script representation in patients with structural damage within the cerebral cortex following a severe traumatic brain injury (TBI). Forty TBI patients and 38 healthy control subjects (HC) were asked to sort cards describing actions belonging to eight scripts according to the script to which they belonged and according to their order of execution. Each script included actions which were low in centrality and distinctiveness (NCA & NDA), and high in centrality (CA), distinctiveness (DA), and CA and DA. Actions were presented in three conditions. In the scripts with headers (SH) condition, the actions were given with each script header written on a separate card. In the scripts without headers condition (SwH) no script header was provided. In the scripts with distractor header (SDH) condition, the actions were given with each script header and a distractor header written on separate cards. The results showed that performance of TBI patients was significantly lower in all conditions. Overall, TBI patients made significantly more sequencing and sorting errors (for all types of actions) than HC subjects. These data are consistent with the view that TBI produces impairment of both the syntactic and semantic dimensions of script representation. Copyright © 2011 Elsevier Srl. All rights reserved.

  8. How does the body representation system develop in the human brain?

    Directory of Open Access Journals (Sweden)

    Aurelie Fontan

    2017-04-01

    Full Text Available Exploration of the body representation system (BRS from kinaesthetic illusions in fMRI has revealed a complex network composed of sensorimotor and frontoparietal components. Here, we evaluated the degree of maturity of this network in children aged 7–11 years, and the extent to which structural factors account for network differences with adults. Brain activation following tendon vibration at 100 Hz (‘illusion’ and 30 Hz (‘no illusion’ were analysed using the two-stage random effects model, with or without white and grey matter covariates. The BRS was already well established in children as revealed by the contrast ‘illusion’ vs ‘no illusion’, although still immature in some aspects. This included a lower level of activation in primary somatosensory and posterior parietal regions, and the exclusive activation of the frontopolar cortex (FPC in children compared to adults. The former differences were related to structure, while the latter difference reflected a functional strategy where the FPC may serve as the ‘top’ in top-down modulation of the activity of the other BRS regions to facilitate the establishment of body representations. Hence, the development of the BRS not only relies on structural maturation, but also involves the disengagement of an executive region not classically involved in body processing.

  9. How does the body representation system develop in the human brain?

    Science.gov (United States)

    Fontan, Aurelie; Cignetti, Fabien; Nazarian, Bruno; Anton, Jean-Luc; Vaugoyeau, Marianne; Assaiante, Christine

    2017-04-01

    Exploration of the body representation system (BRS) from kinaesthetic illusions in fMRI has revealed a complex network composed of sensorimotor and frontoparietal components. Here, we evaluated the degree of maturity of this network in children aged 7-11 years, and the extent to which structural factors account for network differences with adults. Brain activation following tendon vibration at 100Hz ('illusion') and 30Hz ('no illusion') were analysed using the two-stage random effects model, with or without white and grey matter covariates. The BRS was already well established in children as revealed by the contrast 'illusion' vs 'no illusion', although still immature in some aspects. This included a lower level of activation in primary somatosensory and posterior parietal regions, and the exclusive activation of the frontopolar cortex (FPC) in children compared to adults. The former differences were related to structure, while the latter difference reflected a functional strategy where the FPC may serve as the 'top' in top-down modulation of the activity of the other BRS regions to facilitate the establishment of body representations. Hence, the development of the BRS not only relies on structural maturation, but also involves the disengagement of an executive region not classically involved in body processing. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Time scales of representation in the human brain: weighing past information to predict future events.

    Science.gov (United States)

    Harrison, Lee M; Bestmann, Sven; Rosa, Maria Joao; Penny, William; Green, Gary G R

    2011-01-01

    The estimates that humans make of statistical dependencies in the environment and therefore their representation of uncertainty crucially depend on the integration of data over time. As such, the extent to which past events are used to represent uncertainty has been postulated to vary over the cortex. For example, primary visual cortex responds to rapid perturbations in the environment, while frontal cortices involved in executive control encode the longer term contexts within which these perturbations occur. Here we tested whether primary and executive regions can be distinguished by the number of past observations they represent. This was based on a decay-dependent model that weights past observations from a Markov process and Bayesian Model Selection to test the prediction that neuronal responses are characterized by different decay half-lives depending on location in the brain. We show distributions of brain responses for short and long term decay functions in primary and secondary visual and frontal cortices, respectively. We found that visual and parietal responses are released from the burden of the past, enabling an agile response to fluctuations in events as they unfold. In contrast, frontal regions are more concerned with average trends over longer time scales within which local variations are embedded. Specifically, we provide evidence for a temporal gradient for representing context within the prefrontal cortex and possibly beyond to include primary sensory and association areas.

  11. Time scales of representation in the human brain: weighing past information to predict future events

    Directory of Open Access Journals (Sweden)

    Lee eHarrison

    2011-04-01

    Full Text Available The estimates that humans make of statistical dependencies in the environment and therefore their representation of uncertainty crucially depend on the integration of data over time. As such, the extent to which past events are used to represent uncertainty has been postulated to vary over the cortex. For example, primary visual cortex responds to rapid perturbations in the environment, while frontal cortices involved in executive control encode the longer term contexts within which these perturbations occur. Here we tested whether primary and executive regions can be distinguished by the number of past observations they represent. This was based on a decay-dependent model that weights past observations from a Markov process and Bayesian Model Selection (BMS to test the prediction that neuronal responses are characterised by different decay half-lives depending on location in the brain. We show distributions of brain responses for short and long term decay functions in primary and secondary visual and frontal cortices, respectively. We found that visual and parietal responses are released from the burden of the past, enabling an agile response to fluctuations in events as they unfold. In contrast, frontal regions are more concerned with average trends over longer time scales within which local variations are embedded. Specifically, we provide evidence for a temporal gradient for representing context within the prefrontal cortex and possibly beyond to include primary sensory and association areas.

  12. The Ethics of Ambiguity

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    Ronald E. Domen MD

    2016-06-01

    Full Text Available Understanding and embracing uncertainty are critical for effective teacher–learner relationships as well as for shared decision-making in the physician–patient relationship. However, ambiguity has not been given serious consideration in either the undergraduate or graduate medical curricula or in the role it plays in patient-centered care. In this article, the author examines the ethics of ambiguity and argues for a pedagogy that includes education in the importance of, and tolerance of, ambiguity that is inherent in medical education and practice. Common threads running through the ethics of ambiguity are the virtue of respect, and the development of a culture of respect is required for the successful understanding and implementation of a pedagogy of ambiguity.

  13. Determinants of translation ambiguity

    Science.gov (United States)

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M.; Arêas da Luz Fontes, Ana B.; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals. PMID:27882188

  14. Stimulus ambiguity elicits response conflict.

    Science.gov (United States)

    Szmalec, Arnaud; Verbruggen, Frederick; Vandierendonck, André; De Baene, Wouter; Verguts, Tom; Notebaert, Wim

    2008-04-18

    Conflict monitoring theory [M.M. Botvinick, T. Braver, D. Barch, C. Carter, J.D. Cohen, Conflict monitoring and cognitive control, Psychol. Rev. 108 (2001) 625-652] assumes that perceptual ambiguity among choice stimuli elicits response conflict in choice reaction. It hence predicts that response conflict is also involved in elementary variants of choice reaction time (RT) tasks, i.e., those variants that, by contrast with the Stroop task or the Go/No-Go task for instance, are rarely associated with cognitive control. In order to test this prediction, an experiment was designed in which participants performed a simple RT task and a regular between-hand 2-choice RT task under three different levels of stimulus ambiguity. The data show that response conflict, as measured by the N2 component of the event-related brain potential (ERP), was elicited in the 2-choice RT task but not in the simple RT task and that the degree of response conflict in the 2-choice RT task was a function of stimulus ambiguity. These results show that response conflict is also present in a regular choice RT task which is traditionally not considered to be a measure of cognitive conflict.

  15. The application of brain-based learning principles aided by GeoGebra to improve mathematical representation ability

    Science.gov (United States)

    Priatna, Nanang

    2017-08-01

    The use of Information and Communication Technology (ICT) in mathematics instruction will help students in building conceptual understanding. One of the software products used in mathematics instruction is GeoGebra. The program enables simple visualization of complex geometric concepts and helps improve students' understanding of geometric concepts. Instruction applying brain-based learning principles is one oriented at the efforts of naturally empowering the brain potentials which enable students to build their own knowledge. One of the goals of mathematics instruction in school is to develop mathematical communication ability. Mathematical representation is regarded as a part of mathematical communication. It is a description, expression, symbolization, or modeling of mathematical ideas/concepts as an attempt of clarifying meanings or seeking for solutions to the problems encountered by students. The research aims to develop a learning model and teaching materials by applying the principles of brain-based learning aided by GeoGebra to improve junior high school students' mathematical representation ability. It adopted a quasi-experimental method with the non-randomized control group pretest-posttest design and the 2x3 factorial model. Based on analysis of the data, it is found that the increase in the mathematical representation ability of students who were treated with mathematics instruction applying the brain-based learning principles aided by GeoGebra was greater than the increase of the students given conventional instruction, both as a whole and based on the categories of students' initial mathematical ability.

  16. Simple adaptive sparse representation based classification schemes for EEG based brain-computer interface applications.

    Science.gov (United States)

    Shin, Younghak; Lee, Seungchan; Ahn, Minkyu; Cho, Hohyun; Jun, Sung Chan; Lee, Heung-No

    2015-11-01

    One of the main problems related to electroencephalogram (EEG) based brain-computer interface (BCI) systems is the non-stationarity of the underlying EEG signals. This results in the deterioration of the classification performance during experimental sessions. Therefore, adaptive classification techniques are required for EEG based BCI applications. In this paper, we propose simple adaptive sparse representation based classification (SRC) schemes. Supervised and unsupervised dictionary update techniques for new test data and a dictionary modification method by using the incoherence measure of the training data are investigated. The proposed methods are very simple and additional computation for the re-training of the classifier is not needed. The proposed adaptive SRC schemes are evaluated using two BCI experimental datasets. The proposed methods are assessed by comparing classification results with the conventional SRC and other adaptive classification methods. On the basis of the results, we find that the proposed adaptive schemes show relatively improved classification accuracy as compared to conventional methods without requiring additional computation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Exploring ambiguous realms

    DEFF Research Database (Denmark)

    Clemensen, Nana

    2016-01-01

    In Hang'ombe Village in rural Zambia, the relative lack of physical boundaries between the activities of family members allow children to observe the actions and discussions of adults on close hand, exposing them to the ambiguities of daily life. Children explore these ambiguities...... in their interactions, testing social roles and conventions. This article explores the vigilance and creative agency displayed by Hang'ombe children, in an environment spurring their acquisition of distinct social and discursive skills....

  18. Body representations in the human brain revealed by kinesthetic illusions and their essential contributions to motor control and corporeal awareness.

    Science.gov (United States)

    Naito, Eiichi; Morita, Tomoyo; Amemiya, Kaoru

    2016-03-01

    The human brain can generate a continuously changing postural model of our body. Somatic (proprioceptive) signals from skeletal muscles and joints contribute to the formation of the body representation. Recent neuroimaging studies of proprioceptive bodily illusions have elucidated the importance of three brain systems (motor network, specialized parietal systems, right inferior fronto-parietal network) in the formation of the human body representation. The motor network, especially the primary motor cortex, processes afferent input from skeletal muscles. Such information may contribute to the formation of kinematic/dynamic postural models of limbs, thereby enabling fast online feedback control. Distinct parietal regions appear to play specialized roles in the transformation/integration of information across different coordinate systems, which may subserve the adaptability and flexibility of the body representation. Finally, the right inferior fronto-parietal network, connected by the inferior branch of the superior longitudinal fasciculus, is consistently recruited when an individual experiences various types of bodily illusions and its possible roles relate to corporeal awareness, which is likely elicited through a series of neuronal processes of monitoring and accumulating bodily information and updating the body representation. Because this network is also recruited when identifying one's own features, the network activity could be a neuronal basis for self-consciousness. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  19. Lexical and syntactic representations in the brain: An fMRI investigation with multi-voxel pattern analyses

    Science.gov (United States)

    Fedorenko, Evelina; Nieto-Castañon, Alfonso; Kanwisher, Nancy

    2011-01-01

    Work in theoretical linguistics and psycholinguistics suggests that human linguistic knowledge forms a continuum between individual lexical items and abstract syntactic representations, with most linguistic representations falling between the two extremes and taking the form of lexical items stored together with the syntactic/semantic contexts in which they frequently occur. Neuroimaging evidence further suggests that no brain region is selectively sensitive to only lexical information or only syntactic information. Instead, all the key brain regions that support high-level linguistic processing have been implicated in both lexical and syntactic processing, suggesting that our linguistic knowledge is plausibly represented in a distributed fashion in these brain regions. Given this distributed nature of linguistic representations, multi-voxel pattern analyses (MVPAs) can help uncover important functional properties of the language system. In the current study we use MVPAs to ask two questions: 1) Do language brain regions differ in how robustly they represent lexical vs. syntactic information?; and 2) Do any of the language bran regions distinguish between “pure” lexical information (lists of words) and “pure” abstract syntactic information (jabberwocky sentences) in the pattern of activity? We show that lexical information is represented more robustly than syntactic information across many language regions (with no language region showing the opposite pattern), as evidenced by a better discrimination between conditions that differ along the lexical dimension (sentences vs. jabberwocky, and word lists vs. nonword lists) than between conditions that differ along the syntactic dimension (sentences vs. word lists, and jabberwocky vs. nonword lists). This result suggests that lexical information may play a more critical role than syntax in the representation of linguistic meaning. We also show that several language regions reliably discriminate between

  20. Representation of the verb's argument-structure in the human brain

    Directory of Open Access Journals (Sweden)

    Assadollahi Ramin

    2008-07-01

    Full Text Available Abstract Background A verb's argument structure defines the number and relationships of participants needed for a complete event. One-argument (intransitive verbs require only a subject to make a complete sentence, while two- and three-argument verbs (transitives and ditransitives normally take direct and indirect objects. Cortical responses to verbs embedded into sentences (correct or with syntactic violations indicate the processing of the verb's argument structure in the human brain. The two experiments of the present study examined whether and how this processing is reflected in distinct spatio-temporal cortical response patterns to isolated verbs and/or verbs presented in minimal context. Results The magnetoencephalogram was recorded while 22 native German-speaking adults saw 130 German verbs, presented one at a time for 150 ms each in experiment 1. Verb-evoked electromagnetic responses at 250 – 300 ms after stimulus onset, analyzed in source space, were higher in the left middle temporal gyrus for verbs that take only one argument, relative to two- and three-argument verbs. In experiment 2, the same verbs (presented in different order were preceded by a proper name specifying the subject of the verb. This produced additional activation between 350 and 450 ms in or near the left inferior frontal gyrus, activity being larger and peaking earlier for one-argument verbs that required no further arguments to form a complete sentence. Conclusion Localization of sources of activity suggests that the activation in temporal and frontal regions varies with the degree by which representations of an event as a part of the verbs' semantics are completed during parsing.

  1. Representation of the verb's argument-structure in the human brain.

    Science.gov (United States)

    Assadollahi, Ramin; Rockstroh, Brigitte S

    2008-07-21

    A verb's argument structure defines the number and relationships of participants needed for a complete event. One-argument (intransitive) verbs require only a subject to make a complete sentence, while two- and three-argument verbs (transitives and ditransitives) normally take direct and indirect objects. Cortical responses to verbs embedded into sentences (correct or with syntactic violations) indicate the processing of the verb's argument structure in the human brain. The two experiments of the present study examined whether and how this processing is reflected in distinct spatio-temporal cortical response patterns to isolated verbs and/or verbs presented in minimal context. The magnetoencephalogram was recorded while 22 native German-speaking adults saw 130 German verbs, presented one at a time for 150 ms each in experiment 1. Verb-evoked electromagnetic responses at 250 - 300 ms after stimulus onset, analyzed in source space, were higher in the left middle temporal gyrus for verbs that take only one argument, relative to two- and three-argument verbs. In experiment 2, the same verbs (presented in different order) were preceded by a proper name specifying the subject of the verb. This produced additional activation between 350 and 450 ms in or near the left inferior frontal gyrus, activity being larger and peaking earlier for one-argument verbs that required no further arguments to form a complete sentence. Localization of sources of activity suggests that the activation in temporal and frontal regions varies with the degree by which representations of an event as a part of the verbs' semantics are completed during parsing.

  2. Ontology: ambiguity and accuracy

    Directory of Open Access Journals (Sweden)

    Marcelo Schiessl

    2012-08-01

    Full Text Available Ambiguity is a major obstacle to information retrieval. It is source of several researches in Information Science. Ontologies have been studied in order to solve problems related to ambiguities. Paradoxically, “ontology” term is also ambiguous and it is understood according to the use by the community. Philosophy and Computer Science seems to have the most accentuated difference related to the term sense. The former holds undisputed tradition and authority. The latter, in despite of being quite recent, holds an informal sense, but pragmatic. Information Science acts ranging from philosophical to computational approaches so as to get organized collections based on balance between users’ necessities and available information. The semantic web requires informational cycle automation and demands studies related to ontologies. Consequently, revisiting relevant approaches for the study of ontologies plays a relevant role as a way to provide useful ideas to researchers maintaining philosophical rigor, and convenience provided by computers.

  3. Lexical ambiguity resolution

    Energy Technology Data Exchange (ETDEWEB)

    Small, S.; Cottrell, G.; Tanenhaus, M.

    1987-01-01

    This book collects much of the best research currently available on the problem of lexical ambiguity resolution in the processing of human language. When taken out of context, sentences are usually ambiguous. When actually uttered in a dialogue or written in text, these same sentences often have unique interpretations. The inherent ambiguity of isolated sentences, becomes obvious in the attempt to write a computer program to understand them. Different views have emerged on the nature of context and the mechanisms by which it directs unambiguous understanding of words and sentences. These perspectives are represented and discussed. Eighteen original papers from a valuable source book for cognitive scientists in AI, psycholinguistics, neuropsychology, or theoretical linguistics.

  4. Mental representation of subjective pleasure of partnered experiences in women's brain conveyed through event-related fMRI.

    Science.gov (United States)

    Bianchi-Demicheli, Francesco; Ortigue, Stephanie

    2009-11-01

    Functional neuroimaging demonstrates a combined role of central and peripheral mechanisms in human sexual response. Nevertheless, inter-individual subjective differences remain unresolved. Since Freud, controversy remains regarding the similarity of each type of partnered sexual pleasure experience. The authors hypothesized that the neural networks sustaining the memory of all types of subjective partnered sexual pleasure experiences might interact with the insula, a key brain area for integrating somatic experiences. Using a 3T Phillips MRI scanner, brain activity elicited when 29 healthy female volunteers were exposed to subliminal presentation of their sexual partner's names, an approach to investigating the brain network sustaining the mental representation of their partner, was assessed. This brain activity was compared with scores from the Female Sexual Functioning Index on satisfaction and the typologies of their partnered orgasmic experiences. No orgasmic responses were recorded during fMRI. This approach allowed the investigation of the memory of the different types of stored partnered orgasmic experiences. The memory of partnered pleasure obtained by clitoral stimulation correlated with brain responses in the left insula only, while that of partnered pleasure by sexual intercourse correlated with the left insula and also with the right superior temporal gyrus, thalamus, and right inferior prefrontal gyrus. The results suggest that the memory of sexual experiences is integrated a posteriori at different levels (i.e. by different neural networks) in a woman's brain. The authors believe these findings will open a new avenue towards understanding inter- and intra-individual differences in woman's sexual mind.

  5. [Children born with ambiguous genitalia].

    Science.gov (United States)

    Diseth, Trond H

    2008-02-28

    For 10 - 12 children born with ambiguous genitalia in Norway annually, the sex cannot be decided directly after birth. The condition is now termed "Disorders of Sex Development" (DSD). Severely undervirilised chromosomal and gonadal boys (46,XY DSD) represent the greatest challenge; the sex assignment has traditionally been female. This review focuses on challenges within diagnostics and treatment and provides an update on the scientific basis for sex assignment in 46,XY DSD children. The article is based on articles retrieved from Pub Med and own clinical experience. During the last decade the scientific basis for sex assignment in children born with ambiguous genitalia has been increasingly questioned. The traditional DSD management has been dominated by the belief that DSD children will develop into the assigned sex regardless of the underlying cause as long as the external genitalia are "normalised" before two years of age. The most severely undervirilised 46,XY DSD children were surgically assigned as females, based on an emphasis of the size and functionality of the phallus being important for later psychosexual development into men. New guidelines for DSD management are now being developed based on recent knowledge about prenatal cerebral exposure to critical sex chromosome genes and hormones that influence foetal brain predisposition for later psychosexual development. Assignment of a sex should be based on a precise diagnosis of the condition's underlying cause and thereby a best possible prediction of future gender identity.

  6. Confronting Ambiguity in Science

    Science.gov (United States)

    Emery, Katherine; Harlow, Danielle; Whitmer, Ali; Gaines, Steven

    2015-01-01

    People are regularly confronted with environmental and science-related issues presented to them in newspapers, on television, or even in their own doctor's office. Often the information they use to inform their decisions on matters of science may be ambiguous and contradictory. This article presents an activity that investigates how students deal…

  7. Semantic ambiguity processing in sentence context: Evidence from event-related fMRI

    NARCIS (Netherlands)

    Zempleni, Monika-Zita; Renken, Remco; Hoeks, John C. J.; Hoogduin, Johannes M.; Stowe, Laurie A.

    2007-01-01

    Lexical semantic ambiguity is the phenomenon when a word has multiple meanings (e.g. 'bank'). The aim of this event-related functional MRI study was to identify those brain areas, which are involved in contextually driven ambiguity resolution. Ambiguous words were selected which have a most

  8. Dual Temporal and Spatial Sparse Representation for Inferring Group-wise Brain Networks from Resting-state fMRI Dataset.

    Science.gov (United States)

    Gong, Junhui; Liu, Xiaoyan; Liu, Tianming; Zhou, Jiansong; Sun, Gang; Tian, Juanxiu

    2017-08-09

    Recently, sparse representation has been successfully used to identify brain networks from task-based fMRI dataset. However, when using the strategy to analyze resting-state fMRI dataset, it is still a challenge to automatically infer the group-wise brain networks under consideration of group commonalities and subject-specific characteristics. In the paper, a novel method based on dual temporal and spatial sparse representation (DTSSR) is proposed to meet this challenge. Firstly, the brain functional networks with subject-specific characteristics are obtained via sparse representation with online dictionary learning for the fMRI time series (temporal domain) of each subject. Next, based on the current brain science knowledge, a simple mathematical model is proposed to describe the complex nonlinear dynamic coupling mechanism of the brain networks, with which the group-wise intrinsic connectivity networks (ICNs) can be inferred by sparse representation for these brain functional networks (spatial domain) of all subjects. Experiments on Leiden_2180 dataset show that most group-wise ICNs obtained by the proposed DTSSR are interpretable by current brain science knowledge and are consistent with previous literature reports. The robustness of DTSSR and the reproducibility of the results are demonstrated by experiments on three different datasets (Leiden_2180, Leiden_2200 and our own dataset). Results of the present work shed new light on exploring the coupling mechanism of BFNs from perspective of information science.

  9. Scope Ambiguity and Inference

    Science.gov (United States)

    1991-07-01

    9) The yacht was often used for social and political events by several presidents until Carter disposed of it. and people don’t seem to have trouble...over an undergrad. 3. World knowledge. For example, one may use facts about the social rules of dating to infer that the most likely interpretation of (1...of equivalence clases , while the semantics of every should be based on pairs. A more illuminating solution would be to assume an ambiguity

  10. The Fifth Mode of Representation

    DEFF Research Database (Denmark)

    Hansen, Per Krogh; Behrendt, Poul Olaf

    2011-01-01

    “The fifth mode of representation: Ambiguous voices in unreliable third person narration”. Sammen med Poul Behrendt. In Per Krogh Hansen, Stefan Iversen, Henrik Skov Nielsen og Rolf Reitan (red.): Strange Voices. Walter de Gruyter, Berlin & New York......“The fifth mode of representation: Ambiguous voices in unreliable third person narration”. Sammen med Poul Behrendt. In Per Krogh Hansen, Stefan Iversen, Henrik Skov Nielsen og Rolf Reitan (red.): Strange Voices. Walter de Gruyter, Berlin & New York...

  11. Ambiguity aversion is not universal

    NARCIS (Netherlands)

    Kocher, M.G.; Lahno, Amrei; Trautmann, Stefan

    Assuming universal ambiguity aversion, an extensive theoretical literature studies how ambiguity can account for market anomalies from the perspective of expected utility-based theories. We provide a systematic experimental assessment of ambiguity attitudes in different likelihood ranges, and in the

  12. Commonality of neural representations of sentences across languages: Predicting brain activation during Portuguese sentence comprehension using an English-based model of brain function.

    Science.gov (United States)

    Yang, Ying; Wang, Jing; Bailer, Cyntia; Cherkassky, Vladimir; Just, Marcel Adam

    2017-02-01

    The aim of the study was to test the cross-language generative capability of a model that predicts neural activation patterns evoked by sentence reading, based on a semantic characterization of the sentence. In a previous study on English monolingual speakers (Wang et al., submitted), a computational model performed a mapping from a set of 42 concept-level semantic features (Neurally Plausible Semantic Features, NPSFs) as well as 6 thematic role markers to neural activation patterns (assessed with fMRI), to predict activation levels in a network of brain locations. The model used two types of information gained from the English-based fMRI data to predict the activation for individual sentences in Portuguese. First, it used the mapping weights from NPSFs to voxel activation levels derived from the model for English reading. Second, the brain locations for which the activation levels were predicted were derived from a factor analysis of the brain activation patterns during English reading. These meta-language locations were defined by the clusters of voxels with high loadings on each of the four main dimensions (factors), namely people, places, actions and feelings, underlying the neural representations of the stimulus sentences. This cross-language model succeeded in predicting the brain activation patterns associated with the reading of 60 individual Portuguese sentences that were entirely new to the model, attaining accuracies reliably above chance level. The prediction accuracy was not affected by whether the Portuguese speaker was monolingual or Portuguese-English bilingual. The model's confusion errors indicated an accurate capture of the events or states described in the sentence at a conceptual level. Overall, the cross-language predictive capability of the model demonstrates the neural commonality between speakers of different languages in the representations of everyday events and states, and provides an initial characterization of the common meta

  13. Toward a song code: evidence for a syllabic representation in the canary brain.

    Science.gov (United States)

    Ribeiro, S; Cecchi, G A; Magnasco, M O; Mello, C V

    1998-08-01

    We show that presentation of individual canary song syllables results in distinct expression patterns of the immediate-early gene ZENK in the caudomedial neostriatum (NCM) of adult canaries. Information on the spatial distribution and labeling of stained cells provides for a classification of ZENK patterns that (1) accords to the organization of stimuli into families, (2) preserves the stimuli intrafamily relationships, and (3) confers salience to natural over artificial stimuli, resulting in a nonclassical tonotopic map. Moreover, complex syllable maps cannot be reduced to any linear combinations of simple syllable maps. These properties arise from the collective response of NCM neurons to auditory stimuli, rather than from the behavior of single neurons. The syllabic representation described here may constitute an important step toward deciphering the rules of birdsong auditory representation.

  14. Right-sided representational neglect after left brain damage in a case without visuospatial working memory deficits.

    Science.gov (United States)

    van Dijck, Jean-Philippe; Gevers, Wim; Lafosse, Christophe; Fias, Wim

    2013-10-01

    Brain damaged patients suffering from representational neglect (RN) fail to report, orient to, or verbally describe contra-lesional elements of imagined environments or objects. So far this disorder has only been reported after right brain damage, leading to the idea that only the right hemisphere is involved in this deficit. A widely accepted account attributes RN to a lateralized impairment in the visuospatial component of working memory. So far, however, this hypothesis has not been tested in detail. In the present paper, we describe, for the first time, the case of a left brain damaged patient suffering from right-sided RN while imagining both known and new environments and objects. An in-depth evaluation of her visuospatial working memory abilities, with special focus on the presence of a lateralized deficit, did not reveal any abnormality. In sharp contrast, her ability to memorize visual information was severely compromised. The implications of these results are discussed in the light of recent insights in the neglect syndrome. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Never resting brain: simultaneous representation of two alpha related processes in humans.

    Directory of Open Access Journals (Sweden)

    Eti Ben-Simon

    Full Text Available Brain activity is continuously modulated, even at "rest". The alpha rhythm (8-12 Hz has been known as the hallmark of the brain's idle-state. However, it is still debated if the alpha rhythm reflects synchronization in a distributed network or focal generator and whether it occurs spontaneously or is driven by a stimulus. This EEG/fMRI study aimed to explore the source of alpha modulations and their distribution in the resting brain. By serendipity, while computing the individually defined power modulations of the alpha-band, two simultaneously occurring components of these modulations were found. An 'induced alpha' that was correlated with the paradigm (eyes open/ eyes closed, and a 'spontaneous alpha' that was on-going and unrelated to the paradigm. These alpha components when used as regressors for BOLD activation revealed two segregated activation maps: the 'induced map' included left lateral temporal cortical regions and the hippocampus; the 'spontaneous map' included prefrontal cortical regions and the thalamus. Our combined fMRI/EEG approach allowed to computationally untangle two parallel patterns of alpha modulations and underpin their anatomical basis in the human brain. These findings suggest that the human alpha rhythm represents at least two simultaneously occurring processes which characterize the 'resting brain'; one is related to expected change in sensory information, while the other is endogenous and independent of stimulus change.

  16. The Inhibitory Mechanism in Learning Ambiguous Words in a Second Language

    OpenAIRE

    Lu, Yao; Wu, Junjie; Dunlap, Susan; Chen, Baoguo

    2017-01-01

    Ambiguous words are hard to learn, yet little is known about what causes this difficulty. The current study aimed to investigate the relationship between the representations of new and prior meanings of ambiguous words in second language (L2) learning, and to explore the function of inhibitory control on L2 ambiguous word learning at the initial stage of learning. During a 4-day learning phase, Chinese–English bilinguals learned 30 novel English words for 30 min per day using bilingual flashc...

  17. Translation Ambiguity but Not Word Class Predicts Translation Performance

    Science.gov (United States)

    Prior, Anat; Kroll, Judith F.; Macwhinney, Brian

    2013-01-01

    We investigated the influence of word class and translation ambiguity on cross-linguistic representation and processing. Bilingual speakers of English and Spanish performed translation production and translation recognition tasks on nouns and verbs in both languages. Words either had a single translation or more than one translation. Translation…

  18. Long-term priming of the meanings of ambiguous words

    Science.gov (United States)

    Rodd, Jennifer M.; Lopez Cutrin, Belen; Kirsch, Hannah; Millar, Allesandra; Davis, Matthew H.

    2013-01-01

    Comprehension of semantically ambiguous words (e.g., "bark") is strongly influenced by the relative frequencies of their meanings, such that listeners are biased towards retrieving the most frequent meaning. These biases are often assumed to reflect a highly stable property of an individual's long-term lexical-semantic representations. We present…

  19. Ambiguity resolution in a Neural Blackboard Architecture for sentence structure

    NARCIS (Netherlands)

    van der Velde, Frank; van der Velde, Frank; de Kamps, Marc; Besold, Tarek R.; Kühnberger, Kai-Uwe

    2015-01-01

    We simulate two examples of ambiguity resolution found in human language processing in a neural blackboard architecture for sentence representation and processing. The architecture also accounts for a related garden path effect. The architecture represents and processes sentences in terms of

  20. Constraints and Ambiguity

    DEFF Research Database (Denmark)

    Dove, Graham; Biskjær, Michael Mose; Lundqvist, Caroline Emilie

    2017-01-01

    Developing creative abilities is an important part of 21st century skills, and yet remains challenging. In this paper we describe a study investigating small-scale creative strategies that groups of Scandinavian high school students use when collaboratively building LEGO models. We recorded thirty...... groups of students building three models each. We studied groups building with traditional plastic bricks and also using a digital environment. The building tasks students undertake, and our subsequent analysis, are informed by the role constraints and ambiguity play in creative processes. Based...... on the insights we gained, we present three strategies for designing tools and environments that support students as they develop creative skills. These strategies relate to: tools and materials, mutual learning, and reflection...

  1. An ambiguous relationship

    DEFF Research Database (Denmark)

    Søndergaard Larsen, Lene; Hedegaard Larsen, Birte; Birkelund, Regner

    2013-01-01

    to qualitative data analysis. Results:  The qualitative meta-synthesis resulted in the heading An Ambiguous Relationship under which three core categories illustrate the hospitalized patients’ different interaction roles. The core categories were as follows: (i) the fellow patient experienced as an enforced......Aim:  The aim of this study was to provide a clear view of the existing knowledge regarding patients’ significance to fellow patients during hospitalization. Method:  Sandelowski and Barroso’s approach to qualitative meta-synthesis was selected and systematically used for collecting and assessing...... companion, (ii) the fellow patient experienced as an expert on illness and hospital life and (iii) the fellow patient experienced as a care provider. Each core category was elaborated through several subcategories. Social interaction among hospitalized patients embedded elements of both enforced...

  2. From "Where" to "What": Distributed Representations of Brand Associations in the Human Brain.

    Science.gov (United States)

    Chen, Yu-Ping; Nelson, Leif D; Hsu, Ming

    2015-08-01

    Considerable attention has been given to the notion that there exists a set of human-like characteristics associated with brands, referred to as brand personality. Here we combine newly available machine learning techniques with functional neuroimaging data to characterize the set of processes that give rise to these associations. We show that brand personality traits can be captured by the weighted activity across a widely distributed set of brain regions previously implicated in reasoning, imagery, and affective processing. That is, as opposed to being constructed via reflective processes, brand personality traits appear to exist a priori inside the minds of consumers, such that we were able to predict what brand a person is thinking about based solely on the relationship between brand personality associations and brain activity. These findings represent an important advance in the application of neuroscientific methods to consumer research, moving from work focused on cataloguing brain regions associated with marketing stimuli to testing and refining mental constructs central to theories of consumer behavior.

  3. Clinically relevant genetic biomarkers from the brain in alcoholism with representation on high resolution chromosome ideograms.

    Science.gov (United States)

    Manzardo, Ann M; McGuire, Austen; Butler, Merlin G

    2015-04-15

    Alcoholism arises from combined effects of multiple biological factors including genetic and non-genetic causes with gene/environmental interaction. Intensive research and advanced genetic technology has generated a long list of genes and biomarkers involved in alcoholism neuropathology. These markers reflect complex overlapping and competing effects of possibly hundreds of genes which impact brain structure, function, biochemical alcohol processing, sensitivity and risk for dependence. We compiled a tabular list of clinically relevant genetic biomarkers for alcoholism targeting expression disturbances in the human brain through an extensive search of keywords related to alcoholism, alcohol abuse, and genetics from peer reviewed medical research articles and related nationally sponsored websites. Gene symbols were then placed on high resolution human chromosome ideograms with gene descriptions in tabular form. We identified 337 clinically relevant genetic biomarkers and candidate genes for alcoholism and alcohol-responsiveness from human brain research. Genetic biomarkers included neurotransmitter pathways associated with brain reward processes for dopaminergic (e.g., DRD2, MAOA, and COMT), serotoninergic (e.g., HTR3A, HTR1B, HTR3B, and SLC6A4), GABAergic (e.g., GABRA1, GABRA2, and GABRG1), glutaminergic (GAD1, GRIK3, and GRIN2C) and opioid (e.g., OPRM1, OPRD1, and OPRK1) pathways which presumably impact reinforcing properties of alcohol. Gene level disturbances in cellular and molecular networks impacted by alcohol and alcoholism pathology include transketolase (TKT), transferrin (TF), and myelin (e.g., MBP, MOBP, and MOG). High resolution chromosome ideograms provide investigators, physicians, geneticists and counselors a convenient visual image of the distribution of alcoholism genetic biomarkers from brain research with alphabetical listing of genes in tabular form allowing comparison between alcoholism-related phenotypes, and clinically-relevant alcoholism

  4. Ambiguity aversion in rhesus macaques

    Directory of Open Access Journals (Sweden)

    Benjamin eHayden

    2010-09-01

    Full Text Available People generally prefer risky options, which have fully specified outcome probabilities, to ambiguous options, which have unspecified probabilities. This preference, formalized in economics, is strong enough that people will reliably prefer a risky option to an ambiguous option with a greater expected value. Explanations for ambiguity aversion often invoke uniquely human faculties like language, self-justification, or a desire to avoid public embarrassment. Challenging these ideas, here we demonstrate that a preference for unambiguous options is shared with rhesus macaques. We trained four monkeys to choose between pairs of options that both offered explicitly cued probabilities of large and small juice outcomes. We then introduced occasional trials where one of the options was obscured and examined their resulting preferences; we ran humans in a parallel experiment on a nearly identical task. We found that monkeys reliably preferred risky options to ambiguous ones, even when this bias was costly, closely matching the behavior of humans in the analogous task. Notably, ambiguity aversion varied parametrically with the extent of ambiguity. As expected, ambiguity aversion gradually declined as monkeys learned the underlying probability distribution of rewards. These data indicate that ambiguity aversion reflects fundamental cognitive biases shared with other animals rather than uniquely human factors guiding decisions.

  5. Ambiguous symbols: why there were no figurines in Neolithic Britain

    Directory of Open Access Journals (Sweden)

    Julian Thomas

    2005-12-01

    Full Text Available In this paper I discuss the scarcity of representational art, and particularly of representations of the human body, in Neolithic Britain, in contrast with the Neolithic of south-east Europe. My suggestion is that this contrast can be linked with differing notions of personal identity and bodily integrity. In later Neolithic Britain, a complex mode of non-representational decoration developed, which elaborated the practice of making reference to absent persons and things by using deliberately ambiguous motifs, which connected past and present as well as remote locations.

  6. Instrument specific brain activation in sensorimotor and auditory representation in musicians.

    Science.gov (United States)

    Gebel, B; Braun, Ch; Kaza, E; Altenmüller, E; Lotze, M

    2013-07-01

    Musicians show a remarkable ability to interconnect motor patterns and sensory processing in the somatosensory and auditory domains. Many of these processes are specific for the instrument used. We were interested in the cerebral and cerebellar representations of these instrument-specific changes and therefore applied functional magnetic resonance imaging (fMRI) in two groups of instrumentalists with different instrumental training for comparable periods (approximately 15 years). The first group (trumpet players) uses tight finger and lip interaction; the second (pianists as control group) uses only the extremities for performance. fMRI tasks were balanced for instructions (piano and trumpet notes), sensory feedback (keypad and trumpet), and hand-lip interaction on the trumpet. During fMRI, both groups switched between different devices (trumpet or keypad) and performance was combined with or without auditory feedback. Playing the trumpet without any tone emission or using the mouthpiece showed an instrument training-specific activation increase in trumpet players. This was evident for the posterior-superior cerebellar hemisphere, the dominant primary sensorimotor cortex, and the left Heschl's gyrus. Additionally, trumpet players showed increased activity in the bilateral Heschl's gyrus during actual trumpet playing, although they showed significantly decreased loudness while playing with the mouthpiece in the scanner compared to pianists. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Ambiguity in urban belonging

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin; Simonsen, Kirsten

    2015-01-01

    Being a ‘stranger’ has become increasingly difficult on the European continent during the latest decades. Populist racism and anti-immigration attitudes have made life difficult, and Denmark has taken the position as one of the iconic cases of this development. But how is that reflected in the ci......Being a ‘stranger’ has become increasingly difficult on the European continent during the latest decades. Populist racism and anti-immigration attitudes have made life difficult, and Denmark has taken the position as one of the iconic cases of this development. But how is that reflected...... in the cities? Does the character of the city as ‘a world of strangers’ open up special possibilities of coexistence? These are the questions addressed in this paper using material from an interpretative analysis conducted among Copenhagen citizens of Pakistani origin. The analysis aims to construe an affective...... mapping of life as an ethnic minority in the city. It revolves around three issues. First, it focuses on the narrators’ experiences of exclusions and blockages in everyday life. This is followed by a focus on urban belonging emphasizing its differential character. Finally, the ambiguity of experiences...

  8. The development of hand-centred visual representations in the primate brain: a computer modelling study using natural visual scenes.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Galeazzi

    2015-12-01

    Full Text Available Neurons that respond to visual targets in a hand-centred frame of reference have been found within various areas of the primate brain. We investigate how hand-centred visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organisation. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localised receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localised receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centred receptive fields decreased their shape selectivity and started responding to a localised region of hand-centred space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localised, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  9. De morseir syndrome presenting as ambiguous genitalia

    Directory of Open Access Journals (Sweden)

    Anubhav Thukral

    2012-01-01

    Full Text Available Background: A 10-year-old boy presented with genital ambiguity, poor linear growth, and delayed milestones. The aim and to highlight that although rare but congenital, hypogonadotropic hypogonadism may rarely present as ambiguity. Materials and Methods: The patient was found to have bilateral cryptorchidism with proximal penile hypospadias, microphallus with a proportionate dwarfism with mildly delayed bone age, and karyotype 46XY. Euthyroid with normal steroid axis, growth hormone insufficient as suggested by auxology, low IGF1, and poor response to clonidine stimulation. MRI brain shows hypoplastic corpus callosum, hypoplastic anterior pituitary, and ectopic posterior pituitary bright spot. Results: The patient underwent laparoscopic removal of right intrabdominal testis and orchidoplexy was performed on the left one. Testicular biopsy revealed no malignancy and growth hormone replacement was initiated. The patient awaits definitive repair of hypospadias. Conclusion: As a provisional diagnosis of combined growth hormone and gonadotropin deficiency, most probable diagnosis is septo-optic dysplasia or de moseir syndrome leading to genital ambiguity.

  10. Enhanced affective brain representations of chocolate in cravers vs. non-cravers.

    Science.gov (United States)

    Rolls, Edmund T; McCabe, Ciara

    2007-08-01

    To examine the neural circuitry involved in food craving, in making food particularly appetitive and thus in driving wanting and eating, we used fMRI to measure the response to the flavour of chocolate, the sight of chocolate and their combination in cravers vs. non-cravers. Statistical parametric mapping (SPM) analyses showed that the sight of chocolate produced more activation in chocolate cravers than non-cravers in the medial orbitofrontal cortex and ventral striatum. For cravers vs. non-cravers, a combination of a picture of chocolate with chocolate in the mouth produced a greater effect than the sum of the components (i.e. supralinearity) in the medial orbitofrontal cortex and pregenual cingulate cortex. Furthermore, the pleasantness ratings of the chocolate and chocolate-related stimuli had higher positive correlations with the fMRI blood oxygenation level-dependent signals in the pregenual cingulate cortex and medial orbitofrontal cortex in the cravers than in the non-cravers. To our knowledge, this is the first study to show that there are differences between cravers and non-cravers in their responses to the sensory components of a craved food in the orbitofrontal cortex, ventral striatum and pregenual cingulate cortex, and that in some of these regions the differences are related to the subjective pleasantness of the craved foods. Understanding individual differences in brain responses to very pleasant foods helps in the understanding of the mechanisms that drive the liking for specific foods and thus intake of those foods.

  11. AmbiguityVis: Visualization of Ambiguity in Graph Layouts.

    Science.gov (United States)

    Wang, Yong; Shen, Qiaomu; Archambault, Daniel; Zhou, Zhiguang; Zhu, Min; Yang, Sixiao; Qu, Huamin

    2016-01-01

    Node-link diagrams provide an intuitive way to explore networks and have inspired a large number of automated graph layout strategies that optimize aesthetic criteria. However, any particular drawing approach cannot fully satisfy all these criteria simultaneously, producing drawings with visual ambiguities that can impede the understanding of network structure. To bring attention to these potentially problematic areas present in the drawing, this paper presents a technique that highlights common types of visual ambiguities: ambiguous spatial relationships between nodes and edges, visual overlap between community structures, and ambiguity in edge bundling and metanodes. Metrics, including newly proposed metrics for abnormal edge lengths, visual overlap in community structures and node/edge aggregation, are proposed to quantify areas of ambiguity in the drawing. These metrics and others are then displayed using a heatmap-based visualization that provides visual feedback to developers of graph drawing and visualization approaches, allowing them to quickly identify misleading areas. The novel metrics and the heatmap-based visualization allow a user to explore ambiguities in graph layouts from multiple perspectives in order to make reasonable graph layout choices. The effectiveness of the technique is demonstrated through case studies and expert reviews.

  12. The representation of inflammatory signals in the brain – a model for subjective fatigue in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Katrin eHanken

    2014-12-01

    Full Text Available In multiple sclerosis (MS patients, fatigue is rated as one of the most common and disabling symptoms. However, the pathophysiology underlying this fatigue is not yet clear. Several lines of evidence suggest that immunological factors, such as elevated levels of proinflammatory cytokines, may contribute to subjective fatigue in MS patients. Proinflammatory cytokines represent primary mediators of immune-to-brain-communication, modulating changes in the neurophysiology of the central nervous system. Recently, we proposed a model arguing that fatigue in MS patients is a subjective feeling which is related to inflammation. Moreover, it implies that fatigue can be measured behaviorally only by applying specific cognitive tasks related to alertness and vigilance. In the present review we focus on the subjective feeling of MS-related fatigue. We examine the hypothesis that the subjective feeling of MS-related fatigue may be a variant of inflammation-induced sickness behavior, resulting from cytokine-mediated activity changes within brain areas involved in interoception and homeostasis including the insula, the anterior cingulate and the hypothalamus. We first present studies demonstrating a relationship between proinflammatory cytokines and subjective fatigue in healthy individuals, in people with inflammatory disorders, and particularly in MS patients. Subsequently, we discuss studies analyzing the impact of anti-inflammatory treatment on fatigue. In the next part of this review we present studies on the transmission and neural representation of inflammatory signals, with a special focus on possible neural concomitants of inflammation-induced fatigue. We also present two of our studies on the relationship between local gray and white matter atrophy and fatigue in MS patients. Finally, we discuss some implications of our findings and future perspectives.

  13. Brain activity underlying negative self- and other-perception in adolescents: The role of attachment-derived self-representations.

    Science.gov (United States)

    Debbané, Martin; Badoud, Deborah; Sander, David; Eliez, Stephan; Luyten, Patrick; Vrtička, Pascal

    2017-06-01

    One of teenagers' key developmental tasks is to engage in new and meaningful relationships with peers and adults outside the family context. Attachment-derived expectations about the self and others in terms of internal attachment working models have the potential to shape such social reorientation processes critically and thereby influence adolescents' social-emotional development and social integration. Because the neural underpinnings of this developmental task remain largely unknown, we sought to investigate them by functional magnetic resonance imaging. We asked n = 44 adolescents (ages 12.01-18.84 years) to evaluate positive and negative adjectives regarding either themselves or a close other during an adapted version of the well-established self-other trait-evaluation task. As measures of attachment, we obtained scores reflecting participants' positive versus negative attachment-derived self- and other-models by means of the Relationship Questionnaire. We controlled for possible confounding factors by also obtaining scores reflecting internalizing/externalizing problems, schizotypy, and borderline symptomatology. Our results revealed that participants with a more negative attachment-derived self-model showed increased brain activity during positive and negative adjective evaluation regarding the self, but decreased brain activity during negative adjective evaluation regarding a close other, in bilateral amygdala/parahippocampus, bilateral anterior temporal pole/anterior superior temporal gyrus, and left dorsolateral prefrontal cortex. These findings suggest that a low positivity of the self-concept characteristic for the attachment anxiety dimension may influence neural information processing, but in opposite directions when it comes to self- versus (close) other-representations. We discuss our results in the framework of attachment theory and regarding their implications especially for adolescent social-emotional development and social integration.

  14. Mirror therapy for phantom limb pain: brain changes and the role of body representation.

    Science.gov (United States)

    Foell, J; Bekrater-Bodmann, R; Diers, M; Flor, H

    2014-05-01

    Phantom limb pain (PLP) is a common consequence of amputation and is difficult to treat. Mirror therapy (MT), a procedure utilizing the visual recreation of movement of a lost limb by moving the intact limb in front of a mirror, has been shown to be effective in reducing PLP. However, the neural correlates of this effect are not known. We investigated the effects of daily mirror training over 4 weeks in 13 chronic PLP patients after unilateral arm amputation. Eleven participants performed hand and lip movements during a functional magnetic resonance imaging (fMRI) measurement before and after MT. The location of neural activity in primary somatosensory cortex during these tasks was used to assess brain changes related to treatment. The treatment caused a significant reduction of PLP (average decrease of 27%). Treatment effects were predicted by a telescopic distortion of the phantom, with those patients who experienced a telescope profiting less from treatment. fMRI data analyses revealed a relationship between change in pain after MT and a reversal of dysfunctional cortical reorganization in primary somatosensory cortex. Pain reduction after mirror training was also related to a decrease of activity in the inferior parietal cortex (IPC). Experienced body appearance seems to be an important predictor of mirror treatment effectiveness. Maladaptive changes in cortical organization are reversed during mirror treatment, which also alters activity in the IPC, a region involved in painful perceptions and in the perceived relatedness to an observed limb. © 2013 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.

  15. Alcohol reduces aversion to ambiguity

    Directory of Open Access Journals (Sweden)

    Tadeusz eTyszka

    2015-01-01

    Full Text Available Several years ago, Cohen, Dearnaley, and Hansel [1] demonstrated that under the influence of alcohol drivers became more risk prone, although their risk perception remained unchanged. Research shows that ambiguity aversion is to some extent positively correlated with risk aversion, though not very highly [2]. The question addressed by the present research is whether alcohol reduces ambiguity aversion. Our research was conducted in a natural setting (a restaurant bar, where customers with differing levels of alcohol intoxication were offered a choice between a risky and an ambiguous lottery. We found that alcohol reduced ambiguity aversion and that the effect occurred in men but not women. We interpret these findings in terms of the risk-as-value hypothesis, according to which, people in Western culture tend to value risk, and suggest that alcohol consumption triggers adherence to socially and culturally valued patterns of conduct different for men and women.

  16. Ambiguities analysis in SAR tomography

    Science.gov (United States)

    Wang, Ziwei; Zhang, Hong; Wang, Chao; Tang, Yixian; Zhang, Bo

    2014-10-01

    Synthetic aperture radar tomography (TomoSAR) is typically used to retrieve elevation, deformation, and other key information by separating scatters of the same slant range in multiple baseline SAR images. In this paper, we investigate two kinds of ambiguities for TomoSAR. Rank-1 ambiguity, as the first one we concerned, is due to the baseline distribution of the SAR image dataset which makes the steering matrix out of full rank. It will result in false alarms appearing in a permanent distance. However, an example using the TomoSAR imaging parameters shows this ambiguity makes no sense in most cases. The second ambiguity refers to the coherence of scatters contained in one pixel. In simulation experiment, the coherence will enhance the side lobes of the spectrum, even make the real peaks fused.

  17. Neuropsychology of Aesthetic Judgment of Ambiguous and Non-Ambiguous Artworks

    Directory of Open Access Journals (Sweden)

    Maddalena Boccia

    2017-03-01

    Full Text Available Several affective and cognitive processes have been found to be pivotal in affecting aesthetic experience of artworks and both neuropsychological as well as psychiatric symptoms have been found to affect artistic production. However, there is a paucity of studies directly investigating effects of brain lesions on aesthetic judgment. Here, we assessed the effects of unilateral brain damage on aesthetic judgment of artworks showing part/whole ambiguity. We asked 19 unilaterally brain-damaged patients (10 left and 9 right brain damaged patients, respectively LBDP and RBDP and 20 age- and education-matched healthy individuals (controls, C to rate 10 Arcimboldo’s ambiguous portraits (AP, 10 realistic Renaissance portraits (RP, 10 still life paintings (SL, and 10 Arcimboldo’s modified portraits where only objects/parts are detectable (AO. They were also administered a Navon task, a facial recognition test, and evaluated on visuo-perceptual and visuo-constructional abilities. Patients included in the study did not show any deficits that could affect the capability to explore and enjoy artworks. SL and RP was not affected by brain damage regardless of its laterality. On the other hand, we found that RBDP liked AP more than the C participants. Furthermore, we found a positive correlation between aesthetic judgment of AP and visuo-perceptual skills even if the single case analyses failed to find a systematic association between neuropsychological deficits and aesthetic judgment of AP. On the whole, the present data suggest that a right hemisphere lesion may affect aesthetic judgment of ambiguous artworks, even in the absence of exploration or constructional deficits.

  18. The ambiguous challenge of intranets

    DEFF Research Database (Denmark)

    Thommesen, Jacob

    2003-01-01

    media, email and the web, partly in the perspective of media richness theory, partly compared with philosophical discussions of classical media. The fourth chapter presents an intranet in a global company, in which problems and challenges related to ambiguity have proven significant.......In this thesis I shall present the argument that intranets increase the role of ambiguity – confrontation between contradicting frames of interpretation – in organisational communication by encouraging processes across organisational borders. In the first chapter I discuss philosophical aspects...

  19. Quantitative representations of an exaggerated anxiety response in the brain of female spider phobics-a parametric fMRI study.

    Science.gov (United States)

    Zilverstand, Anna; Sorger, Bettina; Kaemingk, Anita; Goebel, Rainer

    2017-06-01

    We employed a novel parametric spider picture set in the context of a parametric fMRI anxiety provocation study, designed to tease apart brain regions involved in threat monitoring from regions representing an exaggerated anxiety response in spider phobics. For the stimulus set, we systematically manipulated perceived proximity of threat by varying a depicted spider's context, size, and posture. All stimuli were validated in a behavioral rating study (phobics n = 20; controls n = 20; all female). An independent group participated in a subsequent fMRI anxiety provocation study (phobics n = 7; controls n = 7; all female), in which we compared a whole-brain categorical to a whole-brain parametric analysis. Results demonstrated that the parametric analysis provided a richer characterization of the functional role of the involved brain networks. In three brain regions-the mid insula, the dorsal anterior cingulate, and the ventrolateral prefrontal cortex-activation was linearly modulated by perceived proximity specifically in the spider phobia group, indicating a quantitative representation of an exaggerated anxiety response. In other regions (e.g., the amygdala), activation was linearly modulated in both groups, suggesting a functional role in threat monitoring. Prefrontal regions, such as dorsolateral prefrontal cortex, were activated during anxiety provocation but did not show a stimulus-dependent linear modulation in either group. The results confirm that brain regions involved in anxiety processing hold a quantitative representation of a pathological anxiety response and more generally suggest that parametric fMRI designs may be a very powerful tool for clinical research in the future, particularly when developing novel brain-based interventions (e.g., neurofeedback training). Hum Brain Mapp 38:3025-3038, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Review of Sparse Representation-Based Classification Methods on EEG Signal Processing for Epilepsy Detection, Brain-Computer Interface and Cognitive Impairment

    OpenAIRE

    Wen, Dong; Jia, Peilei; Lian, Qiusheng; Zhou, Yanhong; LU, CHENGBIAO

    2016-01-01

    At present, the sparse representation-based classification (SRC) has become an important approach in electroencephalograph (EEG) signal analysis, by which the data is sparsely represented on the basis of a fixed dictionary or learned dictionary and classified based on the reconstruction criteria. SRC methods have been used to analyze the EEG signals of epilepsy, cognitive impairment and brain computer interface (BCI), which made rapid progress including the improvement in computational accura...

  1. Human Perception of Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

  2. Symbol in View of Ambiguity

    Directory of Open Access Journals (Sweden)

    Mohamad reza Yousefi

    2013-11-01

    Full Text Available Abstract Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.  In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.  In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this

  3. Symbol in View of Ambiguity

    Directory of Open Access Journals (Sweden)

    Sedigheh Rassoulian

    2013-10-01

    Full Text Available  Abstract Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.  In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.  In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or

  4. Mapping cortical hand motor representation using TMS: A method to assess brain plasticity and a surrogate marker for recovery of function after stroke?

    Science.gov (United States)

    Lüdemann-Podubecká, Jitka; Nowak, Dennis Alexander

    2016-10-01

    Stroke is associated with reorganization within motor areas of both hemispheres. Mapping the cortical hand motor representation using transcranial magnetic stimulation may help to understand the relationship between motor cortex reorganization and motor recovery of the affected hand after stroke. A standardized review of the pertinent literature was performed. We identified 20 trials, which analyzed the relationship between the extent and/or location of cortical hand motor representation using transcranial magnetic stimulation and motor function and recovery of the affected hand. Several correlations were found between cortical reorganization and measures of hand motor impairment and recovery. A better understanding of the relationships between the extent and location of cortical hand motor representation and the motor impairment and motor recovery of the affected hand after stroke may contribute to a targeted use of non-invasive brain stimulation protocols. In the future motor mapping may help to guide brain stimulation techniques to the most effective motor area in an affected individual. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Crichton's phase-shift ambiguity

    NARCIS (Netherlands)

    Atkinson, D.; Johnson, P.W.; Mehta, N.; Roo, M. de

    1973-01-01

    A re-examination of the SPD phase-shift ambiguity is made with a view to understanding certain singular features of the elastic unitarity constraint. An explicit solution of Crichton's equations is presented, and certain features of this solution are displayed graphically. In particular, it is shown

  6. Ambiguity Resolution in Lateralized Arabic

    Science.gov (United States)

    Hayadre, Manar; Kurzon, Dennis; Peleg, Orna; Zohar, Eviatar

    2015-01-01

    We examined ambiguity resolution in reading in Arabic. Arabic is an abjad orthography and is morphologically similar to Hebrew. However, Arabic literacy occurs in a diglossic context, and its orthography is more visually complex than Hebrew. We therefore tested to see whether hemispheric differences will be similar or different from previous…

  7. Spectral Ambiguity of Allan Variance

    Science.gov (United States)

    Greenhall, C. A.

    1996-01-01

    We study the extent to which knowledge of Allan variance and other finite-difference variances determines the spectrum of a random process. The variance of first differences is known to determine the spectrum. We show that, in general, the Allan variance does not. A complete description of the ambiguity is given.

  8. GRAPES—Grounding representations in action, perception, and emotion systems: How object properties and categories are represented in the human brain

    Science.gov (United States)

    Martin, Alex

    2016-01-01

    In this article, I discuss some of the latest functional neuroimaging findings on the organization of object concepts in the human brain. I argue that these data provide strong support for viewing concepts as the products of highly interactive neural circuits grounded in the action, perception, and emotion systems. The nodes of these circuits are defined by regions representing specific object properties (e.g., form, color, and motion) and thus are property-specific, rather than strictly modality-specific. How these circuits are modified by external and internal environmental demands, the distinction between representational content and format, and the grounding of abstract social concepts are also discussed. PMID:25968087

  9. GRAPES-Grounding representations in action, perception, and emotion systems: How object properties and categories are represented in the human brain.

    Science.gov (United States)

    Martin, Alex

    2016-08-01

    In this article, I discuss some of the latest functional neuroimaging findings on the organization of object concepts in the human brain. I argue that these data provide strong support for viewing concepts as the products of highly interactive neural circuits grounded in the action, perception, and emotion systems. The nodes of these circuits are defined by regions representing specific object properties (e.g., form, color, and motion) and thus are property-specific, rather than strictly modality-specific. How these circuits are modified by external and internal environmental demands, the distinction between representational content and format, and the grounding of abstract social concepts are also discussed.

  10. Generative Learning: Adults Learning within Ambiguity

    Science.gov (United States)

    Nicolaides, Aliki

    2015-01-01

    This study explored the extent to which ambiguity can serve as a catalyst for adult learning. The purpose of this study is to understand learning that is generated when encountering ambiguity agitated by the complexity of liquid modernity. "Ambiguity," in this study, describes an encounter with an appearance of reality that is at first…

  11. Parse Forest Diagnostics with Dr. Ambiguity

    NARCIS (Netherlands)

    H.J.S. Basten (Bas); J.J. Vinju (Jurgen); J. Saraiva; U. Aßmann; A.M. Sloane

    2011-01-01

    textabstractIn this paper we propose and evaluate a method for locating causes of ambiguity in context-free grammars by automatic analysis of parse forests. A parse forest is the set of parse trees of an ambiguous sentence. % an output of a static ambiguity detection tool that has detected

  12. The Inhibitory Mechanism in Learning Ambiguous Words in a Second Language

    Directory of Open Access Journals (Sweden)

    Baoguo Chen

    2017-04-01

    Full Text Available Ambiguous words are hard to learn, yet little is known about what causes this difficulty. The current study aimed to investigate the relationship between the representations of new and prior meanings of ambiguous words in second language (L2 learning, and to explore the function of inhibitory control on L2 ambiguous word learning at the initial stage of learning. During a 4-day learning phase, Chinese–English bilinguals learned 30 novel English words for 30 min per day using bilingual flashcards. Half of the words to be learned were unambiguous (had one meaning and half were ambiguous (had two semantically unrelated meanings learned in sequence. Inhibitory control was introduced as a subject variable measured by a Stroop task. The semantic representations established for the studied items were probed using a cross-language semantic relatedness judgment task, in which the learned English words served as the prime, and the targets were either semantically related or unrelated to the prime. Results showed that response latencies for the second meaning of ambiguous words were slower than for the first meaning and for unambiguous words, and that performance on only the second meaning of ambiguous words was predicted by inhibitory control ability. These results suggest that, at the initial stage of L2 ambiguous word learning, the representation of the second meaning is weak, probably interfered with by the representation of the prior learned meaning. Moreover, inhibitory control may modulate learning of the new meanings, such that individuals with better inhibitory control may more effectively suppress interference from the first meaning, and thus learn the new meaning more quickly.

  13. The Inhibitory Mechanism in Learning Ambiguous Words in a Second Language.

    Science.gov (United States)

    Lu, Yao; Wu, Junjie; Dunlap, Susan; Chen, Baoguo

    2017-01-01

    Ambiguous words are hard to learn, yet little is known about what causes this difficulty. The current study aimed to investigate the relationship between the representations of new and prior meanings of ambiguous words in second language (L2) learning, and to explore the function of inhibitory control on L2 ambiguous word learning at the initial stage of learning. During a 4-day learning phase, Chinese-English bilinguals learned 30 novel English words for 30 min per day using bilingual flashcards. Half of the words to be learned were unambiguous (had one meaning) and half were ambiguous (had two semantically unrelated meanings learned in sequence). Inhibitory control was introduced as a subject variable measured by a Stroop task. The semantic representations established for the studied items were probed using a cross-language semantic relatedness judgment task, in which the learned English words served as the prime, and the targets were either semantically related or unrelated to the prime. Results showed that response latencies for the second meaning of ambiguous words were slower than for the first meaning and for unambiguous words, and that performance on only the second meaning of ambiguous words was predicted by inhibitory control ability. These results suggest that, at the initial stage of L2 ambiguous word learning, the representation of the second meaning is weak, probably interfered with by the representation of the prior learned meaning. Moreover, inhibitory control may modulate learning of the new meanings, such that individuals with better inhibitory control may more effectively suppress interference from the first meaning, and thus learn the new meaning more quickly.

  14. Updating representations of temporal intervals.

    Science.gov (United States)

    Danckert, James; Anderson, Britt

    2015-12-01

    Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings.

  15. Rocking or rolling--perception of ambiguous motion after returning from space.

    Directory of Open Access Journals (Sweden)

    Gilles Clément

    Full Text Available The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, ±1.7 m/s2 perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions.

  16. How meaning similarity influences ambiguous word processing: the current state of the literature

    Science.gov (United States)

    Tokowicz, Natasha

    2016-01-01

    The majority of words in the English language do not correspond to a single meaning, but rather correspond to two or more unrelated meanings (i.e., are homonyms) or multiple related senses (i.e., are polysemes). It has been proposed that the different types of “semantically-ambiguous words” (i.e., words with more than one meaning) are processed and represented differently in the human mind. Several review papers and books have been written on the subject of semantic ambiguity (e.g., Adriaens, Small, Cottrell, & Tanenhaus, 1988; Burgess & Simpson, 1988; Degani & Tokowicz, 2010; Gorfein, 1989, 2001; Simpson, 1984). However, several more recent studies (e.g., Klein & Murphy, 2001; Klepousniotou, 2002; Klepousniotou & Baum, 2007; Rodd, Gaskell, & Marslen-Wilson, 2002) have investigated the role of the semantic similarity between the multiple meanings of ambiguous words on processing and representation, whereas this was not the emphasis of previous reviews of the literature. In this review, we focus on the current state of the semantic ambiguity literature that examines how different types of ambiguous words influence processing and representation. We analyze the consistent and inconsistent findings reported in the literature and how factors such as semantic similarity, meaning/sense frequency, task, timing, and modality affect ambiguous word processing. We discuss the findings with respect to recent parallel distributed processing (PDP) models of ambiguity processing (Armstrong & Plaut, 2008, 2011; Rodd, Gaskell, & Marslen-Wilson, 2004). Finally, we discuss how experience/instance-based models (e.g., Hintzman, 1986; Reichle & Perfetti, 2003) can inform a comprehensive understanding of semantic ambiguity resolution. PMID:24889119

  17. How meaning similarity influences ambiguous word processing: the current state of the literature.

    Science.gov (United States)

    Eddington, Chelsea M; Tokowicz, Natasha

    2015-02-01

    The majority of words in the English language do not correspond to a single meaning, but rather correspond to two or more unrelated meanings (i.e., are homonyms) or multiple related senses (i.e., are polysemes). It has been proposed that the different types of "semantically-ambiguous words" (i.e., words with more than one meaning) are processed and represented differently in the human mind. Several review papers and books have been written on the subject of semantic ambiguity (e.g., Adriaens, Small, Cottrell, & Tanenhaus, 1988; Burgess & Simpson, 1988; Degani & Tokowicz, 2010; Gorfein, 1989, 2001; Simpson, 1984). However, several more recent studies (e.g., Klein & Murphy, 2001; Klepousniotou, 2002; Klepousniotou & Baum, 2007; Rodd, Gaskell, & Marslen-Wilson, 2002) have investigated the role of the semantic similarity between the multiple meanings of ambiguous words on processing and representation, whereas this was not the emphasis of previous reviews of the literature. In this review, we focus on the current state of the semantic ambiguity literature that examines how different types of ambiguous words influence processing and representation. We analyze the consistent and inconsistent findings reported in the literature and how factors such as semantic similarity, meaning/sense frequency, task, timing, and modality affect ambiguous word processing. We discuss the findings with respect to recent parallel distributed processing (PDP) models of ambiguity processing (Armstrong & Plaut, 2008, 2011; Rodd, Gaskell, & Marslen-Wilson, 2004). Finally, we discuss how experience/instance-based models (e.g., Hintzman, 1986; Reichle & Perfetti, 2003) can inform a comprehensive understanding of semantic ambiguity resolution.

  18. Deliberate ambiguity in slogans: recognition and appreciation

    OpenAIRE

    Lagerwerf, L.

    2002-01-01

    In slogans used in public information, politics, and advertising, and also in titles of books, documentaries, or articles, ambiguity is often employed to pique the interest of the reader in the message that is conveyed. According to several theories of text processing, this deliberate ambiguity may gain greater appreciation than slogans employing other rhetorical means. A special form of deliberate ambiguity is studied in this contribution: slogans that may be taken literally. The notion of s...

  19. Theory-Based Evaluation Meets Ambiguity

    DEFF Research Database (Denmark)

    Dahler-Larsen, Peter

    2017-01-01

    ambiguity as a fruitful perspective that helps TBE face current challenges. Literatures in organization theory and political theory are consulted in order to cultivate the concept of ambiguity. Janus variables (which work in two ways) and other ambiguous aspects of program theories are classified......As theory-based evaluation (TBE) engages in situations where multiple stakeholders help develop complex program theory about dynamic phenomena in politically contested settings, it becomes difficult to develop and use program theory without ambiguity. The purpose of this article is to explore...

  20. Effective ambiguity checking in biosequence analysis

    Directory of Open Access Journals (Sweden)

    Giegerich Robert

    2005-06-01

    Full Text Available Abstract Background Ambiguity is a problem in biosequence analysis that arises in various analysis tasks solved via dynamic programming, and in particular, in the modeling of families of RNA secondary structures with stochastic context free grammars. Several types of analysis are invalidated by the presence of ambiguity. As this problem inherits undecidability (as we show here from the namely problem for context free languages, there is no complete algorithmic solution to the problem of ambiguity checking. Results We explain frequently observed sources of ambiguity, and show how to avoid them. We suggest four testing procedures that may help to detect ambiguity when present, including a just-in-time test that permits to work safely with a potentially ambiguous grammar. We introduce, for the special case of stochastic context free grammars and RNA structure modeling, an automated partial procedure for proving non-ambiguity. It is used to demonstrate non-ambiguity for several relevant grammars. Conclusion Our mechanical proof procedure and our testing methods provide a powerful arsenal of methods to ensure non-ambiguity.

  1. The ambiguous meaning of irreversibility

    CERN Document Server

    De Hemptinne, X

    1995-01-01

    The mechanism driving macroscopic systems toward their state of equilibrium is reconsidered. Ambiguities are detected in the semantics of a number of keywords (irreversibility, isolation etc...). They lead to questionable interpretations. Irreversible expansion of a gas in allegedly isolated (traditional definition) conditions is taken as an example. There are two steps in the global process. One is deterministic (mixing). This step does not alter the information about the initial conditions. It is iso-entropic. Its irreversible character is only apparent. The second step implies exchange with the surroundings where the information is dissipated. It does not occur in strictly isolated conditions. Relaxation is therefore impossible in strictly isolated systems. This latter step is fully irreversible and creates the expected entropy change.

  2. AMBIGUOUS JANUS OF MODERN DEMOCRACY

    Directory of Open Access Journals (Sweden)

    Volodymyr V. Khmil

    2016-06-01

    Full Text Available Purpose. The purpose of the research is to analyze ambiguous concept of  democracy as a phenomenon of political and social formation based on political and instrumental approach. As a result, some deep fundamentals of  human social existence and values as social life basis are blurred. Task. The task of  this investigation is to reveal the concept of democracy in its invariative philosophical  meaning and find the consequences of global social transformations towards social entropy. Methods of investigation. To implement the task an activity approach has been used with further possibility to single out two approaches - politological and philosophical. The focus on democracy from philosophic point of view makes possible to anticipate negative entropic processes that lead  to future ambiguity. Subject matter. Chaotic social processes can result in  ruined family, spiritual, legal and moral formations. Regulatory and legal paradigms are becoming less effective and entail disintegration of spiritual and value constituents of worldview causing necessary conditions for social entropy. Originality and Findings. Possible threats for human freedom that hinder the way to targeted  prospects of mankind have been considered in the paper. Thus, taking into account all positive aspects of democracy, it is simultaneously becoming the tool of continuous differentiation of society into tiny autonomous communities similar to nomadic atomization of society. The concept based on moral substantial existence basis as in “axis time” by K. Jaspers that can prevent social entropy resulting in world anthropologic catastrophes has been grounded in the present research.

  3. Learning and Generalization under Ambiguity: An fMRI Study

    Science.gov (United States)

    Chumbley, J. R.; Flandin, G.; Bach, D. R.; Daunizeau, J.; Fehr, E.; Dolan, R. J.; Friston, K. J.

    2012-01-01

    Adaptive behavior often exploits generalizations from past experience by applying them judiciously in new situations. This requires a means of quantifying the relative importance of prior experience and current information, so they can be balanced optimally. In this study, we ask whether the brain generalizes in an optimal way. Specifically, we used Bayesian learning theory and fMRI to test whether neuronal responses reflect context-sensitive changes in ambiguity or uncertainty about experience-dependent beliefs. We found that the hippocampus expresses clear ambiguity-dependent responses that are associated with an augmented rate of learning. These findings suggest candidate neuronal systems that may be involved in aberrations of generalization, such as over-confidence. PMID:22275857

  4. Children's ambiguous understanding of weak and strong quantifiers

    Directory of Open Access Journals (Sweden)

    Erik-Jan Smits

    2008-02-01

    Full Text Available Despite suggestions in the literature that the semantics of many might be the key for understanding children’s non-adult-like interpretations of quantified sentences (cf. Drozd 2001, Geurts 2003, experimental data on the acquisition of weak quantifiers like many is rare. This paper investigates children’s comprehension of weak (many versus strong (many of, all quantifiers in English. In particular, by means of a truth-value judgment task, taking the semantic and syntactic characteristics of many into account, we tested whether 28 children aged between four and seven understand the ambiguous nature of many as described in the literature (Partee, 1988 and whether they transfer this ambiguity to many of and all. The results show that children have an ambiguous quantifier system for both strong and weak quantifiers. This runs counter the idea that the child always prefers a reading of many in which the arguments seem to ‘switch’ (as for adults in Many French have won the Tour de France, resulting in the interpretation Many Tour de France winners are French, as predicted by Drozd and Van Loosbroek’s (1999 Weak Quantification Hypothesis. On the basis of our experimental results on children’s understanding of both weak and strong quantifiers, we conclude that children’s non-adult interpretations of quantified sentences are due to the ambiguous nature of (weak quantifiers. This presents the language learner with the difficult, but necessary, task to distinguish between those different kinds of readings and understand their different semantic and syntactic representations in order to converge with the target language.

  5. From “Where” to “What”: Distributed Representations of Brand Associations in the Human Brain

    Science.gov (United States)

    Chen, Yu-Ping; Nelson, Leif D.; Hsu, Ming

    2015-01-01

    Considerable attention has been given to the notion that there exists a set of human-like characteristics associated with brands, referred to as brand personality. Here we combine newly available machine learning techniques with functional neuroimaging data to characterize the set of processes that give rise to these associations. We show that brand personality traits can be captured by the weighted activity across a widely distributed set of brain regions previously implicated in reasoning, imagery, and affective processing. That is, as opposed to being constructed via reflective processes, brand personality traits appear to exist a priori inside the minds of consumers, such that we were able to predict what brand a person is thinking about based solely on the relationship between brand personality associations and brain activity. These findings represent an important advance in the application of neuroscientific methods to consumer research, moving from work focused on cataloguing brain regions associated with marketing stimuli to testing and refining mental constructs central to theories of consumer behavior. PMID:27065490

  6. Analyzing Ambiguity of Context-Free Grammars

    DEFF Research Database (Denmark)

    Brabrand, Claus; Giegerich, Robert; Møller, Anders

    2010-01-01

    It has been known since 1962 that the ambiguity problem for context-free grammars is undecidable. Ambiguity in context-free grammars is a recurring problem in language design and parser generation, as well as in applications where grammars are used as models of real-world physical structures. We ...

  7. Deliberate ambiguity in slogans: recognition and appreciation

    NARCIS (Netherlands)

    Lagerwerf, L.

    2002-01-01

    In slogans used in public information, politics, and advertising, and also in titles of books, documentaries, or articles, ambiguity is often employed to pique the interest of the reader in the message that is conveyed. According to several theories of text processing, this deliberate ambiguity may

  8. Analyzing Ambiguity of Context-Free Grammars

    DEFF Research Database (Denmark)

    Brabrand, Claus; Giegerich, Robert; Møller, Anders

    2007-01-01

    It has been known since 1962 that the ambiguity problem for context-free grammars is undecidable. Ambiguity in context-free grammars is a recurring problem in language design and parser generation, as well as in applications where grammars are used as models of real-world physical structures. We...

  9. Analyzing Ambiguity of Context-Free Grammars

    DEFF Research Database (Denmark)

    Brabrand, Claus; Giegerich, Robert; Møller, Anders

    2010-01-01

    It has been known since 1962 that the ambiguity problem for context-free grammars is undecidable. Ambiguity in context-free grammars is a recurring problem in language design and parser generation, as well as in applications where grammars are used as models of real-world physical structures. We...

  10. Ambiguity and Volatility : Asset Pricing Implications

    NARCIS (Netherlands)

    Pataracchia, B.

    2011-01-01

    Using a simple dynamic consumption-based asset pricing model, this paper explores the implications of a representative investor with smooth ambiguity averse preferences [Klibano¤, Marinacci and Mukerji, Econometrica (2005)] and provides a comparative analysis of risk aversion and ambiguity aversion.

  11. Equity Trading under Heterogeneity in Ambiguity

    DEFF Research Database (Denmark)

    Alonso, Irasema; Prado, Mauricio

    We examine the potential importance of heterogeneity in consumers' ambiguity aversion for asset pricing, portfolio allocation, and the wealth distribution. A main focus is to explore a situation in which ambiguity aversion is \\above normal", such as when there has been a sudden inflow of market...... of analyzing such occurrences theoretically, especially when one allows the possibility that different consumers/traders have different amounts of ambiguity aversion. By considering a model with heterogeneity on ambiguity, we explain differences in portfolio allocation, which lead to non......-relevant, but hard-to-interpret information: a situation like that during the onset of the recent crisis in financial markets. During this episode, market participants appeared unsure of the values of a variety of assets, trading all but stopped. Ambiguity aversion, it appears to us, offers a tractable way...

  12. Average activity, but not variability, is the dominant factor in the representation of object categories in the brain.

    Science.gov (United States)

    Karimi-Rouzbahani, Hamid; Bagheri, Nasour; Ebrahimpour, Reza

    2017-03-27

    To categorize the perceived objects, brain utilizes a broad set of its resources and encoding strategies. Yet, it remains elusive how the category information is encoded in the brain. While many classical studies have sought the category information in the across-trial-averaged activity of neurons/neural populations, several recent studies have observed category information also in the within-trial correlated variability of activities between neural populations (i.e. dependent variability). Moreover, other studies have observed that independent variability of activity, which is the variability of the measured neural activity without any influence from correlated variability with other neurons/populations, could also be modulated for improved categorization. However, it was unknown how important each of the three factors (i.e. average activity, dependent and independent variability of activities) was in category encoding. Therefore, we designed an EEG experiment in which human subjects viewed a set of object exemplars from four categories. Using a computational model, we evaluated the contribution of each factor separately in category encoding. Results showed that the average activity played a significant role while the independent variability, although effective, contributed moderately to the category encoding. The inter-channel dependent variability showed an ignorable effect on the encoding. We also investigated the role of those factors in the encoding of variations which showed similar effects. These results imply that the brain, rather than variability, seems to use the average activity to convey information on the category of the perceived objects. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Distributed neural representation of saliency controlled value and category during anticipation of rewards and punishments.

    Science.gov (United States)

    Zhang, Zhihao; Fanning, Jennifer; Ehrlich, Daniel B; Chen, Wenting; Lee, Daeyeol; Levy, Ifat

    2017-12-04

    An extensive literature from cognitive neuroscience examines the neural representation of value, but interpretations of these existing results are often complicated by the potential confound of saliency. At the same time, recent attempts to dissociate neural signals of value and saliency have not addressed their relationship with category information. Using a multi-category valuation task that incorporates rewards and punishments of different nature, we identify distributed neural representation of value, saliency, and category during outcome anticipation. Moreover, we reveal category encoding in multi-voxel blood-oxygen-level-dependent activity patterns of the vmPFC and the striatum that coexist with value signals. These results help clarify ambiguities regarding value and saliency encoding in the human brain and their category independence, lending strong support to the neural "common currency" hypothesis. Our results also point to potential novel mechanisms of integrating multiple aspects of decision-related information.

  14. Harmonic Training and the formation of pitch representation in a neural network model of the auditory brain

    Directory of Open Access Journals (Sweden)

    Nasir eAhmad

    2016-03-01

    Full Text Available Attempting to explain the perceptual qualities of pitch has proven to be, and remains, a difficult problem. The wide range of sounds which illicit pitch and a lack of agreement across neurophysiological studies on how pitch is encoded by the brain have made this attempt more difficult. In describing the potential neural mechanisms by which pitch may be processed, a number of neural networks have been proposed and implemented. However, no unsupervised neural networks with biologically accurate cochlear inputs have yet been demonstrated. This paper proposes a simplified system in which pitch representing neurons are easily produced under a highly biological setting. Purely unsupervised regimes of neural network learning are implemented and these prove to be sufficient in identifying the pitch of sounds with a variety of spectral profiles, including missing fundamental sounds.

  15. Ambiguities in 'killing' and 'letting die'.

    Science.gov (United States)

    Atkinson, G M

    1983-05-01

    In a recent article Carla Kary (1980) attempts to show that there can be a significant moral difference between instances of killing and letting die. I shall maintain in Section I that Kary's argument is somewhat weakened by her failure to note an important ambiguity in the notion of killing a person. I shall also argue in Section II that a similar ambiguity affects the notion of letting someone die, and that failure to note this latter ambiguity also weakens the position developed by Robert Coburn (1980) with regard to defective newborns.

  16. An Effective Information Retrieval for Ambiguous Query

    OpenAIRE

    Roul, R. K.; Sahay, S. K.

    2012-01-01

    Search engine returns thousands of web pages for a single user query, in which most of them are not relevant. In this context, effective information retrieval from the expanding web is a challenging task, in particular, if the query is ambiguous. The major question arises here is that how to get the relevant pages for an ambiguous query. We propose an approach for the effective result of an ambiguous query by forming community vector based on association concept of data minning using vector s...

  17. Emotion and decision-making under uncertainty: Physiological arousal predicts increased gambling during ambiguity but not risk.

    Science.gov (United States)

    FeldmanHall, Oriel; Glimcher, Paul; Baker, Augustus L; Phelps, Elizabeth A

    2016-10-01

    Uncertainty, which is ubiquitous in decision-making, can be fractionated into known probabilities (risk) and unknown probabilities (ambiguity). Although research has illustrated that individuals more often avoid decisions associated with ambiguity compared to risk, it remains unclear why ambiguity is perceived as more aversive. Here we examine the role of arousal in shaping the representation of value and subsequent choice under risky and ambiguous decisions. To investigate the relationship between arousal and decisions of uncertainty, we measure skin conductance response-a quantifiable measure reflecting sympathetic nervous system arousal-during choices to gamble under risk and ambiguity. To quantify the discrete influences of risk and ambiguity sensitivity and the subjective value of each option under consideration, we model fluctuating uncertainty, as well as the amount of money that can be gained by taking the gamble. Results reveal that although arousal tracks the subjective value of a lottery regardless of uncertainty type, arousal differentially contributes to the computation of value-that is, choice-depending on whether the uncertainty is risky or ambiguous: Enhanced arousal adaptively decreases risk-taking only when the lottery is highly risky but increases risk-taking when the probability of winning is ambiguous (even after controlling for subjective value). Together, this suggests that the role of arousal during decisions of uncertainty is modulatory and highly dependent on the context in which the decision is framed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. Ambiguity and violence in adolescent dating relationships.

    Science.gov (United States)

    Draucker, Claire Burke; Martsolf, Donna; Stephenson, Pam Shockey

    2012-08-01

    Little is known about dyadic processes that lead to adolescent dating violence. The purpose of this study was to examine the phenomenon of relationship ambiguity in adolescent dating relationships to better understand how ambiguity contributes to violence and aggression between dating partners. Data were drawn from 88 narratives of young adults who had participated in a study on adolescent dating violence. Interpretive phenomenology was used to produce an in-depth description of the phenomenon of relationship ambiguity. Relationship ambiguity results in differing expectations between partners regarding closeness and intimacy, fidelity, and obligation. These differences lead to conflicts that set the stage for violence and aggression in adolescent dating relationships. A series of recommendations for clinicians working with adolescents are presented. © 2012 Wiley Periodicals, Inc.

  19. Risk Management and Insurance Decisions under Ambiguity

    DEFF Research Database (Denmark)

    Martínez-Correa, Jimmy

    I study the impact of ambiguity on insurance decisions and the optimality of insurance contracts. My tractable approach allows me to study the interaction between risk and ambiguity attitudes. When insurance decisions are made independently of other assets, for a given increase in wealth, both risk...... portfolio theory that assumes Subjective Expected Utility theory; however, it provides hints to a possible solution of the under-diversification puzzle of households. I also identify conditions under which more risk or ambiguity aversion decreases the demand for coinsurance. Additionally, I show...... a counterexample to a classical result in insurance economics where an insurance contract with straight deductible is dominated by a coinsurance contract. Finally, I find that a modified Borch rule characterizes the optimal insurance contract with bilateral risk and ambiguity attitudes and heterogeneity in beliefs....

  20. Good luck, bad luck, and ambiguity aversion

    OpenAIRE

    Pulford, Briony D.; Poonam Gill

    2014-01-01

    We report a series of experiments investigating the influence of feeling lucky or unlucky on people's choice of known-risk or ambiguous options using the traditional Ellsberg Urns decision-making task. We induced a state of feeling lucky or unlucky in subjects by using a rigged wheel-of-fortune game, which just missed either the bankrupt or the jackpot outcome. In the first experiment a large reversal of the usual ambiguity aversion effect was shown, indicating that feeling ...

  1. Ambiguous invitations in the American communicative culture

    OpenAIRE

    Екатерина Борисовна Щелчкова

    2013-01-01

    This paper deals with those features of the speech act of Invitation in the American communicative culture that often cause misunderstanding in cross-cultural communication. Based on an empirical research, it examines the use of the so-called «ambiguous» or «phony» invitations and discusses the criteria which can be used to distinguish ambiguous invitations from unambiguous ones.

  2. Ambiguous invitations in the American communicative culture

    Directory of Open Access Journals (Sweden)

    Екатерина Борисовна Щелчкова

    2013-12-01

    Full Text Available This paper deals with those features of the speech act of Invitation in the American communicative culture that often cause misunderstanding in cross-cultural communication. Based on an empirical research, it examines the use of the so-called «ambiguous» or «phony» invitations and discusses the criteria which can be used to distinguish ambiguous invitations from unambiguous ones.

  3. Role ambiguity, employee gender, and workplace friendship.

    Science.gov (United States)

    Chen, Chien-Yu; Mao, Hsiao-Yen; Hsieh, An-Tien

    2012-06-01

    The importance of workplace friendship is recognized by researchers and practitioners, but its antecedents with respect to work roles are not well understood. Employees' gender might moderate a relationship between work roles and friendships. Data from a survey of 221 international tourist hotel employees showed that a key aspect of job support, role ambiguity, was negatively related to having workplace friendships. However, employees' gender did not moderate this relationship. Role clarity (the opposite of role ambiguity) may facilitate workplace friendships.

  4. Recommendations for reducing ambiguity in written procedures.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.

    2009-11-01

    Previous studies in the nuclear weapons complex have shown that ambiguous work instructions (WIs) and operating procedures (OPs) can lead to human error, which is a major cause for concern. This report outlines some of the sources of ambiguity in written English and describes three recommendations for reducing ambiguity in WIs and OPs. The recommendations are based on commonly used research techniques in the fields of linguistics and cognitive psychology. The first recommendation is to gather empirical data that can be used to improve the recommended word lists that are provided to technical writers. The second recommendation is to have a review in which new WIs and OPs and checked for ambiguities and clarity. The third recommendation is to use self-paced reading time studies to identify any remaining ambiguities before the new WIs and OPs are put into use. If these three steps are followed for new WIs and OPs, the likelihood of human errors related to ambiguity could be greatly reduced.

  5. Ambiguities in representing the concept of energy: a semiotic approach

    Directory of Open Access Journals (Sweden)

    DAMIEN GIVRY

    2015-12-01

    Full Text Available Many researches in science education have shown the importance of the concept of energy and the learning difficulties that students face. Based on a semiotic approach, the current study focuses on the different ways in representing the concept of energy. It examines the ambiguities appear in written text, diagram, photo, graph, corporal acts etc. as vehicles of conveying some aspects of the energy concept. Video of a regular Greek lesson about energy and an usual Greek physics school textbook composed our database. The first results show a conceptual blending between the concepts 'transfer' and 'transformation' due to the lack of specification of which are exactly the physical systems studied in these modes of representation.

  6. Using Distributed Representations to Disambiguate Biomedical and Clinical Concepts

    OpenAIRE

    Tulkens, Stéphan; Šuster, Simon; Daelemans, Walter

    2016-01-01

    In this paper, we report a knowledge-based method for Word Sense Disambiguation in the domains of biomedical and clinical text. We combine word representations created on large corpora with a small number of definitions from the UMLS to create concept representations, which we then compare to representations of the context of ambiguous terms. Using no relational information, we obtain comparable performance to previous approaches on the MSH-WSD dataset, which is a well-known dataset in the bi...

  7. Poetic representation

    DEFF Research Database (Denmark)

    Wulf-Andersen, Trine Østergaard

    2012-01-01

    be written up and disseminated. The article takes a methodological focus, considering general aims and methods of the research project, before turning to the elaboration on how poetic representations have been constructed and employed as a vehicle for certain kinds of participation, representation......, and dialogue, of situated participants. The article includes a lengthy example of a poetic representation of one participant’s story, and the author comments on the potentials of ‘doing’ poetic representations as an example of writing in ways that challenges what sometimes goes unasked in participative social...

  8. Ambiguity and Nominal Group Multiple Post modification in the ...

    African Journals Online (AJOL)

    Administrator

    modification in the Written English of Some. Selected ... outcome of a linguistic study of the continuous writing - essays, letters and .... Some types are commonly identified by many contributors, and these are lexical ambiguity, syntactic ambiguity, phonological ambiguity and semantic ambiguity which are discussed below:.

  9. Phase-shift ambiguities for analytic amplitudes

    CERN Document Server

    Itzykson, C

    1973-01-01

    Ambiguities in reconstructing a unitary elastic amplitude at fixed energy are investigated given the differential cross-section when one assumes analyticity in the cos theta plane. Strong hints are given that not more than a twofold nontrivial ambiguity is present. This is demonstrated for genuine entire functions of finite order. Moreover it is found that within a class of amplitudes which includes polynomials as well as entire functions of order zero, (i) the difference between the two amplitudes with the same cross-section must be a polynomial, (ii) if the cross-section is smaller than 1.38 (4 pi /k/sup 2/) there is no ambiguity. Indications are given on directions for future work. (10 refs).

  10. RELATION OF COACHING BEHAVIOR AND ROLE AMBIGUITY

    Directory of Open Access Journals (Sweden)

    Karamousalidis G.

    2010-08-01

    Full Text Available The purpose of this research was to investigate the relationship between coaching behavior and role ambiguity in defensive responsibilities using interdependent Greek sport teams. Athlete perceptions of role ambiguity (defense were assessed using a questionnaire developed by Beauchamp, Bray, Eys and Carron (2002 andcoaching behavior was assessed using the Coaching Behavior Questionnaire, (Williams, et. al., 2003. The sample consisted of 409 athletes of basketball, volleyball, handball and soccer. Confirmatory factor analysis provided the construct validity of the questionnaires and correlations among the scales confirmed construct validity. The implications of the results are discussed and future research should continue to investigate the multidimensional models of both coaching behavior and role ambiguity in sport settings.

  11. Clarity and ambiguity in strategic corporate communication

    DEFF Research Database (Denmark)

    Gulbrandsen, Ib Tunby

    2018-01-01

    Purpose – The purpose of this paper is to examine the co-existence of clarity and ambiguity in strategic corporate communication. Design/methodology/approach – An exploratory study using interpretive discourse analysis of interviews with employees at a corporate communication department to examine...... how they perceived the writing, reading and enactment of their organization’s new corporate communication strategy. Findings – The analysis reveals the presence of both clarity and ambiguity in the employees’ understanding of the strategy. Both in terms of formulation and implementation. For instance......, there is clarity on the main objectives of the strategy, but ambiguity in relation to how they should be achieved and the extent to which they represent a shift in focus or not. Though this co-presence might cause the members to feel a lack of ownership, it does not impede the department’s practices...

  12. Clarity and ambiguity in strategic corporate communication

    DEFF Research Database (Denmark)

    Gulbrandsen, Ib Tunby

    2017-01-01

    Purpose – The purpose of this paper is to examine the co-existence of clarity and ambiguity in strategic corporate communication. Design/methodology/approach – An exploratory study using interpretive discourse analysis of interviews with employees at a corporate communication department to examine...... how they perceived the writing, reading and enactment of their organization’s new corporate communication strategy. Findings – The analysis reveals the presence of both clarity and ambiguity in the employees’ understanding of the strategy. Both in terms of formulation and implementation. For instance......, there is clarity on the main objectives of the strategy, but ambiguity in relation to how they should be achieved and the extent to which they represent a shift in focus or not. Though this co-presence might cause the members to feel a lack of ownership, it does not impede the department’s practices...

  13. Gene name ambiguity of eukaryotic nomenclatures.

    Science.gov (United States)

    Chen, Lifeng; Liu, Hongfang; Friedman, Carol

    2005-01-15

    With more and more scientific literature published online, the effective management and reuse of this knowledge has become problematic. Natural language processing (NLP) may be a potential solution by extracting, structuring and organizing biomedical information in online literature in a timely manner. One essential task is to recognize and identify genomic entities in text. 'Recognition' can be accomplished using pattern matching and machine learning. But for 'identification' these techniques are not adequate. In order to identify genomic entities, NLP needs a comprehensive resource that specifies and classifies genomic entities as they occur in text and that associates them with normalized terms and also unique identifiers so that the extracted entities are well defined. Online organism databases are an excellent resource to create such a lexical resource. However, gene name ambiguity is a serious problem because it affects the appropriate identification of gene entities. In this paper, we explore the extent of the problem and suggest ways to address it. We obtained gene information from 21 organisms and quantified naming ambiguities within species, across species, with English words and with medical terms. When the case (of letters) was retained, official symbols displayed negligible intra-species ambiguity (0.02%) and modest ambiguities with general English words (0.57%) and medical terms (1.01%). In contrast, the across-species ambiguity was high (14.20%). The inclusion of gene synonyms increased intra-species ambiguity substantially and full names contributed greatly to gene-medical-term ambiguity. A comprehensive lexical resource that covers gene information for the 21 organisms was then created and used to identify gene names by using a straightforward string matching program to process 45,000 abstracts associated with the mouse model organism while ignoring case and gene names that were also English words. We found that 85.1% of correctly retrieved mouse

  14. Creative Brains: Designing in the Real World

    Directory of Open Access Journals (Sweden)

    Vinod eGoel

    2014-04-01

    Full Text Available The process of designing artifacts is a creative activity. It is proposed that, at the cognitive level, one key to understanding design creativity is to understand the array of symbol systems designers utilize. These symbol systems range from being vague, imprecise, abstract, ambiguous, and indeterminate (like conceptual sketches, to being very precise, concrete, unambiguous, and determinate (like contract documents. The former types of symbol systems support associative processes that facilitate lateral (or divergent transformations that broaden the problem space, while the latter types of symbol systems support inference processes facilitating vertical (or convergent transformations that deepen of the problem space. The process of artifact design requires the judicious application of both lateral and vertical transformations. This leads to a dual mechanism model of design problem-solving comprising of an associative engine and an inference engine. It is further claimed that this dual mechanism model is supported by an interesting hemispheric dissociation in human prefrontal cortex. The associative engine and neural structures that support imprecise, ambiguous, abstract, indeterminate representations are lateralized in the right prefrontal cortex, while the inference engine and neural structures that support precise, unambiguous, determinant representations are lateralized in the left prefrontal cortex. At the brain level, successful design of artifacts requires a delicate balance between the two hemispheres of prefrontal cortex.

  15. Creative brains: designing in the real world.

    Science.gov (United States)

    Goel, Vinod

    2014-01-01

    The process of designing artifacts is a creative activity. It is proposed that, at the cognitive level, one key to understanding design creativity is to understand the array of symbol systems designers utilize. These symbol systems range from being vague, imprecise, abstract, ambiguous, and indeterminate (like conceptual sketches), to being very precise, concrete, unambiguous, and determinate (like contract documents). The former types of symbol systems support associative processes that facilitate lateral (or divergent) transformations that broaden the problem space, while the latter types of symbol systems support inference processes facilitating vertical (or convergent) transformations that deepen of the problem space. The process of artifact design requires the judicious application of both lateral and vertical transformations. This leads to a dual mechanism model of design problem-solving comprising of an associative engine and an inference engine. It is further claimed that this dual mechanism model is supported by an interesting hemispheric dissociation in human prefrontal cortex. The associative engine and neural structures that support imprecise, ambiguous, abstract, indeterminate representations are lateralized in the right prefrontal cortex, while the inference engine and neural structures that support precise, unambiguous, determinant representations are lateralized in the left prefrontal cortex. At the brain level, successful design of artifacts requires a delicate balance between the two hemispheres of prefrontal cortex.

  16. Symbol in Point View of Ambiguity

    Directory of Open Access Journals (Sweden)

    Dr. M. R. Yousefi

    Full Text Available Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry; its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this complex world

  17. Discrete ambiguities in phase-shift analysis

    NARCIS (Netherlands)

    Heemskerk, A.C.; Kok, L.P.; Roo, M. de

    1975-01-01

    In two practical examples (α-3He and α-α scattering) we investigate to what extent the elastic amplitude above the first inelastic threshold, determined from phase-shift analysis, is subject to ambiguity. We find that it is extremely difficult to determine the correct physical amplitude uniquely.

  18. Exploring Situated Ambiguity in Students' Entrepreneurial Learning

    Science.gov (United States)

    Kubberød, Elin; Pettersen, Inger Beate

    2017-01-01

    Purpose: Building on entrepreneurial learning research, the purpose of this paper is to argue that the students participating in foreign entrepreneurial education programmes can have realistic entrepreneurial learning experiences. This research addresses two specific questions: how situated ambiguity induced by a foreign culture may contribute to…

  19. Western Military Culture and Counterinsurgency: An Ambiguous ...

    African Journals Online (AJOL)

    The article analyses the further consequences of this conceptual clash between Western military culture and counterinsurgency in the reality of counterinsurgency warfare. It is explained that the contrast between both concepts leads to an ambiguous reality in which soldiers are aware of the specifics of counterinsurgency ...

  20. Quadri-stability of a spatially ambiguous auditory illusion

    Directory of Open Access Journals (Sweden)

    Constance May Bainbridge

    2015-01-01

    Full Text Available In addition to vision, audition plays an important role in sound localization in our world. One way we estimate the motion of an auditory object moving towards or away from us is from changes in volume intensity. However, the human auditory system has unequally distributed spatial resolution, including difficulty distinguishing sounds in front versus behind the listener. Here, we introduce a novel quadri-stable illusion, the Transverse-and-Bounce Auditory Illusion, which combines front-back confusion with changes in volume levels of a nonspatial sound to create ambiguous percepts of an object approaching and withdrawing from the listener. The sound can be perceived as traveling transversely from front to back or back to front, or bouncing to remain exclusively in front of or behind the observer. Here we demonstrate how human listeners experience this illusory phenomenon by comparing ambiguous and unambiguous stimuli for each of the four possible motion percepts. When asked to rate their confidence in perceiving each sound’s motion, participants reported equal confidence for the illusory and unambiguous stimuli. Participants perceived all four illusory motion percepts, and could not distinguish the illusion from the unambiguous stimuli. These results show that this illusion is effectively quadri-stable. In a second experiment, the illusory stimulus was looped continuously in headphones while participants identified its perceived path of motion to test properties of perceptual switching, locking, and biases. Participants were biased towards perceiving transverse compared to bouncing paths, and they became perceptually locked into alternating between front-to-back and back-to-front percepts, perhaps reflecting how auditory objects commonly move in the real world. This multi-stable auditory illusion opens opportunities for studying the perceptual, cognitive, and neural representation of objects in motion, as well as exploring multimodal perceptual

  1. Measuring ambiguity in HLA typing methods.

    Directory of Open Access Journals (Sweden)

    Vanja Paunić

    Full Text Available In hematopoietic stem cell transplantation, donor selection is based primarily on matching donor and patient HLA genes. These genes are highly polymorphic and their typing can result in exact allele assignment at each gene (the resolution at which patients and donors are matched, but it can also result in a set of ambiguous assignments, depending on the typing methodology used. To facilitate rapid identification of matched donors, registries employ statistical algorithms to infer HLA alleles from ambiguous genotypes. Linkage disequilibrium information encapsulated in haplotype frequencies is used to facilitate prediction of the most likely haplotype assignment. An HLA typing with less ambiguity produces fewer high-probability haplotypes and a more reliable prediction. We estimated ambiguity for several HLA typing methods across four continental populations using an information theory-based measure, Shannon's entropy. We used allele and haplotype frequencies to calculate entropy for different sets of 1,000 subjects with simulated HLA typing. Using allele frequencies we calculated an average entropy in Caucasians of 1.65 for serology, 1.06 for allele family level, 0.49 for a 2002-era SSO kit, and 0.076 for single-pass SBT. When using haplotype frequencies in entropy calculations, we found average entropies of 0.72 for serology, 0.73 for allele family level, 0.05 for SSO, and 0.002 for single-pass SBT. Application of haplotype frequencies further reduces HLA typing ambiguity. We also estimated expected confirmatory typing mismatch rates for simulated subjects. In a hypothetical registry with all donors typed using the same method, the entropy values based on haplotype frequencies correspond to confirmatory typing mismatch rates of 1.31% for SSO versus only 0.08% for SBT. Intermediate-resolution single-pass SBT contains the least ambiguity of the methods we evaluated and therefore the most certainty in allele prediction. The presented measure

  2. Representation of Objective Situations in Preschool Children

    Directory of Open Access Journals (Sweden)

    N.Ye. Veraksa

    2015-10-01

    Full Text Available The paper focuses on the types of representations of objective situations, that is, situations which are defined independently of the subject, by certain external perceptible circumstances and social expectations or rules. The author distinguishes between three types of objective situations in which children act: normative, developing and ambiguous. For each of these types there is a corresponding form of representation: sign, dialectical and symbolic. Each form is a product of the subject's cognitive activity, at the core of which lie cognitive abilities — a system of culturally specific means and ways of using them. The paper outlines normative and stabilizing abilities, transformation abilities, and symbolic mediation abilities. They help categorize different objects and features, enable transformation of situations and provide possibilities for orientation in ambiguous situations

  3. Auditory motion capturing ambiguous visual motion

    Directory of Open Access Journals (Sweden)

    Arjen eAlink

    2012-01-01

    Full Text Available In this study, it is demonstrated that moving sounds have an effect on the direction in which one sees visual stimuli move. During the main experiment sounds were presented consecutively at four speaker locations inducing left- or rightwards auditory apparent motion. On the path of auditory apparent motion, visual apparent motion stimuli were presented with a high degree of directional ambiguity. The main outcome of this experiment is that our participants perceived visual apparent motion stimuli that were ambiguous (equally likely to be perceived as moving left- or rightwards more often as moving in the same direction than in the opposite direction of auditory apparent motion. During the control experiment we replicated this finding and found no effect of sound motion direction on eye movements. This indicates that auditory motion can capture our visual motion percept when visual motion direction is insufficiently determinate without affecting eye movements.

  4. Ambiguity in the Acquisition of Lexical Information

    CERN Document Server

    Vanderwende, L

    1995-01-01

    This paper describes an approach to the automatic identification of lexical information in on-line dictionaries. This approach uses bootstrapping techniques, specifically so that ambiguity in the dictionary text can be treated properly. This approach consists of processing an on-line dictionary multiple times, each time refining the lexical information previously acquired and identifying new lexical information. The strength of this approach is that lexical information can be acquired from definitions which are syntactically ambiguous, given that information acquired during the first pass can be used to improve the syntactic analysis of definitions in subsequent passes. In the context of a lexical knowledge base, the types of lexical information that need to be represented cannot be viewed as a fixed set, but rather as a set that will change given the resources of the lexical knowledge base and the requirements of analysis systems which access it.

  5. Learning, Teaching and Ambiguity in Virtual Worlds

    Science.gov (United States)

    Carr, Diane; Oliver, Martin; Burn, Andrew

    What might online communities and informal learning practices teach us about virtual world pedagogy? In this chapter we describe a research project in which learning practices in online worlds such as World of Warcraft and Second LifeTM (SL) were investigated. Working within an action research framework, we employed a range of methods to investigate how members of online communities define the worlds they encounter, negotiate the terms of participation, and manage the incremental complexity of game worlds. The implications of such practices for online pedagogy were then explored through teaching in SL. SL eludes simple definitions. Users, or "residents", of SL partake of a range of pleasures and activities - socialising, building, creating and exhibiting art, playing games, exploring, shopping, or running a business, for instance. We argue that the variable nature of SL gives rise to degrees of ambiguity. This ambiguity impacts on inworld social practices, and has significant implications for online teaching and learning.

  6. Evolution without evolution and without ambiguities

    Science.gov (United States)

    Marletto, C.; Vedral, V.

    2017-02-01

    In quantum theory it is possible to explain time, and dynamics, in terms of entanglement. This is the timeless approach to time, which assumes that the universe is in a stationary state, where two noninteracting subsystems, the "clock" and the "rest," are entangled. As a consequence, by choosing a suitable observable of the clock, the relative state of the rest of the universe evolves unitarily with respect to the variable labeling the clock observable's eigenstates, which is then interpreted as time. This model for an "evolution without evolution" (Page and Wootters, 1983), albeit elegant, has never been developed further, because it was criticized for generating severe ambiguities in the dynamics of the rest of the universe. In this paper we show that there are no such ambiguities; we also update the model, making it amenable to possible new applications.

  7. Ambiguity in the Acquisition of Lexical Information

    OpenAIRE

    Vanderwende, Lucy

    1995-01-01

    This paper describes an approach to the automatic identification of lexical information in on-line dictionaries. This approach uses bootstrapping techniques, specifically so that ambiguity in the dictionary text can be treated properly. This approach consists of processing an on-line dictionary multiple times, each time refining the lexical information previously acquired and identifying new lexical information. The strength of this approach is that lexical information can be acquired from de...

  8. Knowledge representation and natural language processing

    Energy Technology Data Exchange (ETDEWEB)

    Weischedel, R.M.

    1986-07-01

    In principle, natural language and knowledge representation are closely related. This paper investigates this by demonstrating how several natural language phenomena, such as definite reference, ambiguity, ellipsis, ill-formed input, figures of speech, and vagueness, require diverse knowledge sources and reasoning. The breadth of kinds of knowledge needed to represent morphology, syntax, semantics, and pragmatics is surveyed. Furthermore, several current issues in knowledge representation, such as logic versus semantic nets, general-purpose versus special-purpose reasoners, adequacy of first-order logic, wait-and-see strategies, and default reasoning, are illustrated in terms of their relation to natural language processing and how natural language impact the issues.

  9. Ambiguity and Nominal Group Multiple Post modification in the ...

    African Journals Online (AJOL)

    Ambiguity and Nominal Group Multiple Post modification in the Written English of Some Selected Nigerian Polytechnics. ... A syntacticsemantic analysis of the ambiguous expressions resulting from multiple post modification is presented detailing the sources of ambiguities that arise. Finally, possible disambiguation ...

  10. Are the poor worse at dealing with ambiguity?

    NARCIS (Netherlands)

    C. Li (Chen)

    2017-01-01

    markdownabstractThis paper studies the relationship between people’s ambiguity attitudes and income in the field using language as a natural source of ambiguity. It shows that the method of Baillon et al. (2017b) can be adapted for field studies, providing ambiguity measurement tasks that are more

  11. Phonological ambiguity modulates resolution of semantic ambiguity during reading: An fMRI study of Hebrew.

    Science.gov (United States)

    Bitan, Tali; Kaftory, Asaf; Meiri-Leib, Adi; Eviatar, Zohar; Peleg, Orna

    2017-10-01

    The current fMRI study examined the role of phonology in the extraction of meaning from print in each hemisphere by comparing homophonic and heterophonic homographs (ambiguous words in which both meanings have the same or different sounds respectively, e.g., bank or tear). The analysis distinguished between the first phase, in which participants read ambiguous words without context, and the second phase in which the context resolves the ambiguity. Native Hebrew readers were scanned during semantic relatedness judgments on pairs of words in which the first word was either a homophone or a heterophone and the second word was related to its dominant or subordinate meaning. In Phase 1 there was greater activation for heterophones in left inferior frontal gyrus (IFG), pars opercularis, and more activation for homophones in bilateral IFG pars orbitalis, suggesting that resolution of the conflict at the phonological level has abolished the semantic ambiguity for heterophones. Reduced activation for all ambiguous words in temporo-parietal regions suggests that although ambiguity enhances controlled lexical selection processes in frontal regions it reduces reliance on bottom-up mapping processes. After presentation of the context, a larger difference between the dominant and subordinate meaning was found for heterophones in all reading-related regions, suggesting a greater engagement for heterophones with the dominant meaning. Altogether these results are consistent with the prominent role of phonological processing in visual word recognition. Finally, despite differences in hemispheric asymmetry between homophones and heterophones, ambiguity resolution, even toward the subordinate meaning, is largely left lateralized. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Value Representations

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Petersen, Marianne Graves

    2011-01-01

    Stereotypic presumptions about gender affect the design process, both in relation to how users are understood and how products are designed. As a way to decrease the influence of stereotypic presumptions in design process, we propose not to disregard the aspect of gender in the design process......, as the perspective brings valuable insights on different approaches to technology, but instead to view gender through a value lens. Contributing to this perspective, we have developed Value Representations as a design-oriented instrument for staging a reflective dialogue with users. Value Representations...

  13. Representational Machines

    DEFF Research Database (Denmark)

    Petersson, Dag; Dahlgren, Anna; Vestberg, Nina Lager

    to the enterprises of the medium. This is the subject of Representational Machines: How photography enlists the workings of institutional technologies in search of establishing new iconic and social spaces. Together, the contributions to this edited volume span historical epochs, social environments, technological...

  14. Pricing risk and ambiguity: the effect of perspective taking.

    Science.gov (United States)

    Trautmann, Stefan T; Schmidt, Ulrich

    2012-01-01

    In the valuation of uncertain prospects, a difference is often observed between selling and buying perspectives. This paper distinguishes between risk (known probabilities) and ambiguity (unknown probabilities) in decisions under uncertainty and shows that the valuation disparity increases under ambiguity compared to risk. It is found that both the comparative versus noncomparative evaluation of risky and ambiguous prospects and the uniqueness of the valuation perspective (either seller or buyer) moderate this increase in the disparity under ambiguity. The finding is consistent with recent theoretical accounts of pricing under uncertainty. We discuss implications for market behaviour and for the ambiguity paradigm as a research tool.

  15. Ambiguities and conventions in the perception of visual art.

    Science.gov (United States)

    Mamassian, Pascal

    2008-09-01

    Vision perception is ambiguous and visual arts play with these ambiguities. While perceptual ambiguities are resolved with prior constraints, artistic ambiguities are resolved by conventions. Is there a relationship between priors and conventions? This review surveys recent work related to these ambiguities in composition, spatial scale, illumination and color, three-dimensional layout, shape, and movement. While most conventions seem to have their roots in perceptual constraints, those conventions that differ from priors may help us appreciate how visual arts differ from everyday perception.

  16. Potential Ambiguity Translation Performances within Legal Language Institutional Nomenclature

    Directory of Open Access Journals (Sweden)

    Oţăt Diana

    2015-12-01

    Full Text Available Motivated by a paradoxical corollary of ambiguities in legal documents and especially in contract texts, the current paper underpins a dichotomy approach to unintended ambiguities aiming to establish a referential framework for the occurrence rate of translation ambiguities within the legal language nomenclature. The research focus is on a twofold situation since ambiguities may. on the one hand, arise dining the translation process, generated by the translator’s lack of competence, i.e. inadequate use of English regarding the special nature of legal language, or. on the other hand, they may be simply transferred from the source language into the target language without even noticing the potential ambiguous situation, i.e. culture-bound ambiguities. Hence, the paper proposes a contrastive analysis in order to localize the occurrence of lexical, structural, and socio-cultural ambiguities triggered by the use of the term performance and its Romanian equivalents in a number of sales contracts.

  17. A United Methodist approach to end-of-life decisions: intentional ambiguity or ambiguous intentions.

    Science.gov (United States)

    Thobaben, James R

    1997-12-01

    The position of the United Methodist Church on end-of-life decisions is best described as intentional ambiguity or ambiguous intentions or both. The paper analyzes the official position of the denomination and then considers the actions of a U.M.C. bishop who served as a foreman for a trial of Dr. Jack Kevorkian. In an effort to find some common ground within an increasingly divided denomination, the work concludes with a consideration of the work of John Wesley and his approach to human death.

  18. Flexible taxonomic assignment of ambiguous sequencing reads

    Directory of Open Access Journals (Sweden)

    Jansson Jesper

    2011-01-01

    Full Text Available Abstract Background To characterize the diversity of bacterial populations in metagenomic studies, sequencing reads need to be accurately assigned to taxonomic units in a given reference taxonomy. Reads that cannot be reliably assigned to a unique leaf in the taxonomy (ambiguous reads are typically assigned to the lowest common ancestor of the set of species that match it. This introduces a potentially severe error in the estimation of bacteria present in the sample due to false positives, since all species in the subtree rooted at the ancestor are implicitly assigned to the read even though many of them may not match it. Results We present a method that maps each read to a node in the taxonomy that minimizes a penalty score while balancing the relevance of precision and recall in the assignment through a parameter q. This mapping can be obtained in time linear in the number of matching sequences, because LCA queries to the reference taxonomy take constant time. When applied to six different metagenomic datasets, our algorithm produces different taxonomic distributions depending on whether coverage or precision is maximized. Including information on the quality of the reads reduces the number of unassigned reads but increases the number of ambiguous reads, stressing the relevance of our method. Finally, two measures of performance are described and results with a set of artificially generated datasets are discussed. Conclusions The assignment strategy of sequencing reads introduced in this paper is a versatile and a quick method to study bacterial communities. The bacterial composition of the analyzed samples can vary significantly depending on how ambiguous reads are assigned depending on the value of the q parameter. Validation of our results in an artificial dataset confirm that a combination of values of q produces the most accurate results.

  19. A toolbox for representational similarity analysis.

    Directory of Open Access Journals (Sweden)

    Hamed Nili

    2014-04-01

    Full Text Available Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA, which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix encapsulates what distinctions between stimuli are emphasized and what distinctions are de-emphasized in the representation. A model is tested by comparing the representational distance matrix it predicts to that of a measured brain region. RSA also enables us to compare representations between stages of processing within a given brain or model, between brain and behavioral data, and between individuals and species. Here, we introduce a Matlab toolbox for RSA. The toolbox supports an analysis approach that is simultaneously data- and hypothesis-driven. It is designed to help integrate a wide range of computational models into the analysis of multichannel brain-activity measurements as provided by modern functional imaging and neuronal recording techniques. Tools for visualization and inference enable the user to relate sets of models to sets of brain regions and to statistically test and compare the models using nonparametric inference methods. The toolbox supports searchlight-based RSA, to continuously map a measured brain volume in search of a neuronal population code with a specific geometry. Finally, we introduce the linear-discriminant t value as a measure of representational discriminability that bridges the gap between linear decoding analyses and RSA. In order to demonstrate the capabilities of the toolbox, we apply it to both simulated and real fMRI data. The key functions are equally applicable to other modalities of brain-activity measurement. The

  20. Ambiguous Expectations for Intersectoral Action for Health

    DEFF Research Database (Denmark)

    Heering Holt, Ditte; Waldorff, Susanne Boch; Tjørnhøj-Thomsen, Tine

    2018-01-01

    presented as a means to produce better quality services, more cost-effective operations and ensure the future of the welfare state, while at the same time hardly changing much at all. By applying the lens of institutional logics we show how ISA, although being vaguely defined, offer ambiguous normative...... and symbolic repertoires for action. We discuss the implementation challenges associated with this advocacy rhetoric and suggest that the domination of the corporation logic may appear to reduce the political character of ISA and potentially conflict with the ideals of health as a matter of social justice...

  1. Mobile Knowledge, Karma Points and Digital Peers: The Tacit Epistemology and Linguistic Representation of MOOCs

    Science.gov (United States)

    Portmess, Lisa

    2013-01-01

    Media representations of massive open online courses (MOOCs) such as those offered by Coursera, edX and Udacity reflect tension and ambiguity in their bold promise of democratized education and global knowledge sharing. An approach to MOOCs that emphasizes the tacit epistemology of such representations suggests a richer account of the ambiguities…

  2. Notes on the BMS group in three dimensions: II. Coadjoint representation

    Energy Technology Data Exchange (ETDEWEB)

    Barnich, Glenn; Oblak, Blagoje [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes,Campus Plaine C.P. 231, B-1050 Bruxelles (Belgium)

    2015-03-09

    The coadjoint representation of the BMS{sub 3} group, which governs the covariant phase space of three-dimensional asymptotically flat gravity, is investigated. In particular, we classify coadjoint BMS{sub 3} orbits and show that intrinsic angular momentum is free of supertranslation ambiguities. Finally, we discuss the link with induced representations upon geometric quantization.

  3. On coherent-state representations of quantum mechanics: Wave mechanics in phase space

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Jørgensen, Thomas Godsk; Torres-Vega, Gabino

    1997-01-01

    In this article we argue that the state-vector phase-space representation recently proposed by Torres-Vega and co-workers [introduced in J. Chem. Phys. 98, 3103 (1993)] coincides with the totality of coherent-state representations for the Heisenberg-Weyl group. This fact leads to ambiguities when...

  4. Management of ambiguities in magnetostratigraphic correlation

    Science.gov (United States)

    Lallier, Florent; Antoine, Christophe; Charreau, Julien; Caumon, Guillaume; Ruiu, Jeremy

    2013-06-01

    Magnetostratigraphy is a powerful tool to provide absolute dating of sediments enabling robust and detailed chronostratigraphic correlations. It is based on the correlation of a magnetic polarity column, observed and measured in a given sediment section, to a magnetic polarity reference scale where polarity changes are well dated via other independent methods. However, magnetostratigraphic correlations are loose as they are only constrained by binary magnetic chrons (i.e. normal or reversal) and their thickness, which are both defined from depth variations of the magnetic remanent directions. The thickness of a given magnetic polarity zone is a function of time and sediment accumulation rate, which may not be stationary, leading to ambiguities when performing the correlations. To address these ambiguities, a numerical method based on the Dynamic Time Warping algorithm is proposed. Magnetostratigraphic correlations are computed in order to minimise the local variation of the accumulation rate. The main advantage of the proposed method is to automatically provide a set of reasonably likely correlations. This set can then be scrutinised for further analysis and interpretation. However, the likelihood of a correlation should be handled carefully as it depends on the information content of the magnetostratigraphic section itself and remain ultimately valid by ancillary constraint. Nevertheless, the method gives consistent results on difficult synthetic cases that simulate abrupt variations of the sedimentation rate. Insights on true sections debated by previous authors are also given.

  5. The importance and types of ambiguity in the researches

    Directory of Open Access Journals (Sweden)

    Dr. Gh. Shiri

    2011-01-01

    Full Text Available In the Old Persian literature, ambiguity is of little importance. Only when talking of the figure of paradox, always along with two other synonymous terms i.e. Towjih and zoowajhein, at times ـand not very often ـ they refer to ambiguity which is a fourth term for the very unusual figure of speech in Persian and Arabic literature. This is while in the old literary texts up to now ambiguity is considered one of the most frequent figures of speech, which goes hand in hand by simile and metaphor. Firstly, This paper intends to give an exact definition of ambiguity, and then to provide a literature review on the previous research papers relevant to the subject and, finally along with clarifying different types of ambiguity determine the importance of the impact of four fundamental elements of text, reader, environment, and author ـ four basic pillars of the structure of a text ـ on ambiguity.

  6. Finding Home: Landmark Ambiguity in Human Navigation

    Directory of Open Access Journals (Sweden)

    Simon Jetzschke

    2017-07-01

    Full Text Available Memories of places often include landmark cues, i.e., information provided by the spatial arrangement of distinct objects with respect to the target location. To study how humans combine landmark information for navigation, we conducted two experiments: To this end, participants were either provided with auditory landmarks while walking in a large sports hall or with visual landmarks while walking on a virtual-reality treadmill setup. We found that participants cannot reliably locate their home position due to ambiguities in the spatial arrangement when only one or two uniform landmarks provide cues with respect to the target. With three visual landmarks that look alike, the task is solved without ambiguity, while audio landmarks need to play three unique sounds for a similar performance. This reduction in ambiguity through integration of landmark information from 1, 2, and 3 landmarks is well modeled using a probabilistic approach based on maximum likelihood estimation. Unlike any deterministic model of human navigation (based e.g., on distance or angle information, this probabilistic model predicted both the precision and accuracy of the human homing performance. To further examine how landmark cues are integrated we introduced systematic conflicts in the visual landmark configuration between training of the home position and tests of the homing performance. The participants integrated the spatial information from each landmark near-optimally to reduce spatial variability. When the conflict becomes big, this integration breaks down and precision is sacrificed for accuracy. That is, participants return again closer to the home position, because they start ignoring the deviant third landmark. Relying on two instead of three landmarks, however, goes along with responses that are scattered over a larger area, thus leading to higher variability. To model the breakdown of integration with increasing conflict, the probabilistic model based on a

  7. Azimuth Phase Coding for Range Ambiguity Suppression in SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Kusk, Anders

    2004-01-01

    excels by actually eliminating the ambiguities rather than just defocusing them as most other techniques do. This makes the proposed technique applicable to distributed targets. The range ambiguity suppression permits the pulse repetition frequency (PRF) to exceed the upper limit otherwise defined...... by the antenna elevation dimension. The fundamental antenna area constraint still applies, but the PRF can be chosen with more freedom. In addition to ambiguity suppression, potential applications include nadir return elimination and signal-to-noise ratio improvement....

  8. VALUING AMBIGUITY: THE CASE OF GENETICALLY ENGINEERED GROWTH ENHANCERS

    OpenAIRE

    Buhr,Brian L.; Hayes, Dermot J.; Jason F. Shogren; Kliebenstein, James B.

    1993-01-01

    A split-valuation method is developed and implemented to elicit the willingness to pay to consume- or avoid consuming- a product of ambiguous quality. The split-valuation method uses experimental auction markets to separate and value the positive and negative attributes of the ambiguous good. The results show that the method can be used to successfully value a good ambiguous quality. Our application reveals that for a sample of students at a midwestern land-grant institution, the average resp...

  9. Ambiguous Loss Experienced by Transnational Mexican Immigrant Families.

    Science.gov (United States)

    Solheim, Catherine; Zaid, Samantha; Ballard, Jaime

    2016-06-01

    In this study, an ambiguous loss framework as described by Boss (1999, Ambiguous loss: Learning to live with unresolved grief, First Harvard University Press, Cambridge, MA) was used to examine and understand the family experiences of Mexican immigrant agricultural workers in Minnesota. Transcripts from interviews with 17 workers in Minnesota and 17 family members in Mexico were analyzed using qualitative methodology to identify experiences of ambiguous loss in the participants' narratives. Key dimensions of ambiguous loss identified in the transcripts include: psychological family, feelings of chronic/recurring loss, finding support, and meaning making. In the category of psychological family, participants in both Mexico and the United States mourned the physical absence of their family members and experienced ambiguity regarding family responsibilities, but worked to maintain their psychological roles within the family. In the category of chronic/recurring loss, participants in both countries experienced chronic worry from not knowing if family members were safe, ambiguity regarding when the immigrant would return, and chronic stressors that compounded these feelings of loss. Participants in both countries coped with both real and ambiguous losses by accessing family support and by using ambiguous communication to minimize worry. Participants in Mexico also accessed work and community-based support. Participants in both countries made meaning of the ambiguous loss by identifying ways their lives were improved and goals were met as a result of the immigration for agricultural work in Minnesota. © 2015 Family Process Institute.

  10. Ambiguity Detection for Programming Language Grammars

    NARCIS (Netherlands)

    H.J.S. Basten (Bas)

    2011-01-01

    textabstractContext-free grammars are the most suitable and most widely used method for describing the syntax of programming languages. They can be used to generate parsers, which transform a piece of source code into a tree-shaped representation of the code's syntactic structure. These parse

  11. A study of ultraviolet renormalon ambiguities in the determination of $\\alpha_{s}$ from $\\tau$ decay

    CERN Document Server

    Altarelli, Guido; Ridolfi, G; Nason, P; Ridolfi, G

    1995-01-01

    The divergent large-order behaviour of the perturbative series relevant for the determination of \\as from \\tau decay is controlled by the leading ultraviolet (UV) renormalon. Even in the absence of the first infrared (IR) renormalon, an ambiguity of order \\Lambda^2/m_\\tau^2 is introduced. We make a quantitative study of the practical implications of this ambiguity. We discuss the magnitude of UV renormalon corrections obtained in the large-N_f limit, which, although unrealistic, is nevertheless interesting to some extent. We then study a number of improved approximants for the perturbative series, based on a change of variable in the Borel representation, such as to displace the leading UV renormalon singularity at a larger distance from the origin than the first IR renormalon. The spread of the resulting values of \\as(m^2_\\tau) obtained by different approximants, at different renormalization scales, is exhibited as a measure of the underlying ambiguities. Finally, on the basis of mathematical models, we disc...

  12. Interpretation of ambiguous information in clinical depression.

    Science.gov (United States)

    Mogg, Karin; Bradbury, Katherine E; Bradley, Brendan P

    2006-10-01

    The present study used two cognitive tasks--a text comprehension task and a homophone task--to investigate whether clinically depressed individuals have a negative bias when interpreting ambiguous information. Previous research indicates that both tasks are sensitive to anxiety-related interpretive biases, and that the former is less prone to response bias effects. Negative memory biases were also assessed. Results showed that, compared with normal controls, depressed individuals made more negative interpretations on the homophone task, and they also showed an enhanced negative recall bias. However, the groups did not differ in interpretative bias on the text comprehension task. Possible explanations of the results are discussed, including the potential influences of self-referent processing and response bias.

  13. Possible resolution of the lattice Gribov ambiguity

    Science.gov (United States)

    Mandula, Jeffrey E.; Ogilvie, Michael C.

    1990-04-01

    The Gribov ambiguity in lattice gauge theory is discussed. The Landau gauge and the finite-temperature temporal gauge (∂4A4=0) are formulated as maximization conditions on the lattice. This formulation is shown to eliminate Gribov copies from the temporal gauge. The possibility that it also eliminates copies from the Landau gauge is discussed. An algorithm which will eliminate Gribov copies from the lattice implementation of the Landau gauge, in case any remain, is introduced and studied via Monte Carlo simulation. The algorithm involves a noncovariant intermediate step and so eliminates the copies at the cost of the possible introduction of a violation of lattice Poincaré symmetry. The covariance of this algorithm is studied numerically and no evidence is found for symmetry violation, which indicates that either the maximization form of the lattice Landau gauge is free of copies, or that the modified algorithm selects one in an acceptably covariant way.

  14. Possible resolution of the lattice Gribov ambiguity

    Energy Technology Data Exchange (ETDEWEB)

    Mandula, J.E. (Department of Energy, Division of High Energy Physics, Washington, District of Columbia 20545 (USA)); Ogilvie, M.C. (Department of Physics, Washington University, St. Louis, MO (USA))

    1990-04-15

    The Gribov ambiguity in lattice gauge theory is discussed. The Landau gauge and the finite-temperature temporal gauge ({partial derivative}{sub 4}{ital A4}=0) are formulated as maximization conditions on the lattice. This formulation is shown to eliminate Gribov copies from the temporal gauge. The possibility that it also eliminates copies from the Landau gauge is discussed. An algorithm which will eliminate Gribov copies from the lattice implementation of the Landau gauge, in case any remain, is introduced and studied via Monte Carlo simulation. The algorithm involves a noncovariant intermediate step and so eliminates the copies at the cost of the possible introduction of a violation of lattice Poincare symmetry. The covariance of this algorithm is studied numerically and no evidence is found for symmetry violation, which indicates that either the maximization form of the lattice Landau gauge is free of copies, or that the modified algorithm selects one in an acceptably covariant way.

  15. Integration, differentiation and ambiguity in safety cultures

    DEFF Research Database (Denmark)

    Richter, Anne; Koch, Christian

    2004-01-01

    This article discusses safety cultures, drawing on the differentiation, integration and ambiguity-scheme introduced by scholars of organizational culture. An ethnographic approach has been applied in the study of meaning and symbols relating to work, hazards, occupational accidents and prevention....... The application of this approach is demonstrated through a multifacetted analysis of safety cultures. Case studies in Danish manufacturing show that it usually is necessary to differentiate between several safety cultures dispersed throughout the shop floor and other parts of the manufacturing organization....... Although some common elements are present across cultures, they are indeed a multiple configuration of cultures. The article illustrates this by providing one case showing a configuration of three cultures, metaphorically labelled Production, Welfare and Master. For example, the former views risk...

  16. Resolving deconvolution ambiguity in gene alternative splicing

    Directory of Open Access Journals (Sweden)

    Hubbell Earl

    2009-08-01

    Full Text Available Abstract Background For many gene structures it is impossible to resolve intensity data uniquely to establish abundances of splice variants. This was empirically noted by Wang et al. in which it was called a "degeneracy problem". The ambiguity results from an ill-posed problem where additional information is needed in order to obtain an unique answer in splice variant deconvolution. Results In this paper, we analyze the situations under which the problem occurs and perform a rigorous mathematical study which gives necessary and sufficient conditions on how many and what type of constraints are needed to resolve all ambiguity. This analysis is generally applicable to matrix models of splice variants. We explore the proposal that probe sequence information may provide sufficient additional constraints to resolve real-world instances. However, probe behavior cannot be predicted with sufficient accuracy by any existing probe sequence model, and so we present a Bayesian framework for estimating variant abundances by incorporating the prediction uncertainty from the micro-model of probe responsiveness into the macro-model of probe intensities. Conclusion The matrix analysis of constraints provides a tool for detecting real-world instances in which additional constraints may be necessary to resolve splice variants. While purely mathematical constraints can be stated without error, real-world constraints may themselves be poorly resolved. Our Bayesian framework provides a generic solution to the problem of uniquely estimating transcript abundances given additional constraints that themselves may be uncertain, such as regression fit to probe sequence models. We demonstrate the efficacy of it by extensive simulations as well as various biological data.

  17. Representation of identities and the politics of representation in cognition

    Directory of Open Access Journals (Sweden)

    Kanavillil Rajagopalan

    2001-02-01

    Full Text Available

    In this paper, I make a plea for viewing representation as first and foremost a political matter. I argue that by so doing we may avoid the many of pitfalls of contemporary theories of cognition as they attempt to tackle the issue of representation. Most of these problems have to do with the fact that representation is treated exclusively as a mimetic or theatrical question. The fact of the matter is however that representation also has a political dimension. Indeed it has always had this political dimension which, counterintuitive though it may seem at first glimpse, manifests itself even in very the attempt to aestheticise the whole issue of representation (as in some versions of postmodernism or to deny its role altogether as a tertium quid between the external world and the cognising mind (as in contemporary neo-pragmatism. I also contend that, by recognising the political nature of representation, we also pave the way for endorsing the thesis that the mind is a social construct, thereby taking some steam out of the thesis of "mind-brain identity" (so-called "identity theory of mind".

  18. Quantitative representations of an exaggerated anxiety response in the brain of female spider phobics-a parametric fMRI study

    NARCIS (Netherlands)

    Zilverstand, Anna; Sorger, Bettina; Kaemingk, Anita; Goebel, R.

    2017-01-01

    We employed a novel parametric spider picture set in the context of a parametric fMRI anxiety provocation study, designed to tease apart brain regions involved in threat monitoring from regions representing an exaggerated anxiety response in spider phobics. For the stimulus set, we systematically

  19. Medieval theories of mental representation.

    Science.gov (United States)

    Kemp, S

    1998-11-01

    Throughout most of the Middle ages, it was generally held that stored mental representations of perceived objects or events preserved the forms or species of such objects. This belief was consistent with a metaphor used by Plato. It was also consistent with the medieval belief that a number of cognitive processes took place in the ventricles of the brain and with the phenomenology of afterimages and imagination itself. In the 14th century, William of Ockham challenged this belief by claiming that mental representations are not stored but instead constructed in the basis of past learned experiences.

  20. Implicit perceptual memory modulates early visual processing of ambiguous images.

    Science.gov (United States)

    de Jong, Maartje C; Brascamp, Jan W; Kemner, Chantal; van Ee, Raymond; Verstraten, Frans A J

    2014-07-23

    The way we perceive the present visual environment is influenced by past visual experiences. Here we investigated the neural basis of such experience dependency. We repeatedly presented human observers with an ambiguous visual stimulus (structure-from-motion) that can give rise to two distinct perceptual interpretations. Past visual experience is known to influence the perception of such stimuli. We recorded fast dynamics of neural activity shortly after stimulus onset using event-related electroencephalography. The number of previous occurrences of a certain percept modulated early posterior brain activity starting as early as 50 ms after stimulus onset. This modulation developed across hundreds of percept repetitions, reflecting several minutes of accumulating perceptual experience. Importantly, there was no such modulation when the mere number of previous stimulus presentations was considered regardless of how they were perceived. This indicates that the effect depended on previous perception rather than previous visual input. The short latency and posterior scalp location of the effect suggest that perceptual history modified bottom-up stimulus processing in early visual cortex. We propose that bottom-up neural responses to a given visual presentation are shaped, in part, by feedback modulation that occurred during previous presentations, thus allowing these responses to be biased in light of previous perceptual decisions. Copyright © 2014 the authors 0270-6474/14/349970-12$15.00/0.

  1. Decoding covert shifts of attention induced by ambiguous visuospatial cues

    Directory of Open Access Journals (Sweden)

    Romain eTrachel

    2015-06-01

    Full Text Available Simple and unambiguous visual cues (e.g. an arrow can be used to trigger covert shifts of visual attention away from the center of gaze. The processing of visual stimuli is enhanced at the attended location. Covert shifts of attention modulate the power of cerebral oscillations in the alpha band over parietal and occipital regions. These modulations are sufficiently robust to be decoded on a single trial basis from electro-encephalography (EEG signals. It is often assumed that covert attention shifts are under voluntary control, and also occur in more natural and complex environments, but there is no direct evidence to support this assumption. We address this important issue by using random-dot stimuli to cue one of two opposite locations, where a visual target is presented. We contrast two conditions in which the random-dot motion is either predictive of the target location or contains ambiguous information. Behavioral results show attention shifts in anticipation of the visual target, in both conditions. In addition, these attention shifts involve similar neural sources, and the EEG can be decoded on a single trial basis. These results shed a new light on the behavioral and neural correlates of visuospatial attention, with implications for Brain-Computer Interfaces (BCI based on covert attention shifts.

  2. Representational Thickness

    DEFF Research Database (Denmark)

    Mullins, Michael

    to improve design conditions for architects, thereby increasing the “thickness of representation”. The study commences from a broader theoretical enquiry, a review of previous research and examples of relevant context in which virtual reality has been used in practice. It develops from this discussion three......Contemporary communicational and informational processes contribute to the shaping of our physical environment by having a powerful influence on the process of design. Applications of virtual reality (VR) are transforming the way architecture is conceived and produced by introducing dynamic...... elements into the process of design. Through its immersive properties, virtual reality allows access to a spatial experience of a computer model very different to both screen based simulations as well as traditional forms of architectural representation. The dissertation focuses on processes of the current...

  3. Top-Down Influence in Young Children's Linguistic Ambiguity Resolution

    Science.gov (United States)

    Rabagliati, Hugh; Pylkkanen, Liina; Marcus, Gary F.

    2013-01-01

    Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's…

  4. The Learning Teacher: Role of Ambiguity in Education

    Science.gov (United States)

    Suzawa, Gilbert S.

    2013-01-01

    Life is full of ambiguities, but as teachers we generally try to teach our students in a manner that sanitizes knowledge of all of its ambiguities. In doing so, we create an educational environment which forces students to learn in a rather meaningless fashion and this in turn leads to a lack of vitality and relevance within the academy. This need…

  5. Examining English-German Translation Ambiguity Using Primed Translation Recognition

    Science.gov (United States)

    Eddington, Chelsea M.; Tokowicz, Natasha

    2013-01-01

    Many words have more than one translation across languages. Such "translation-ambiguous" words are translated more slowly and less accurately than their unambiguous counterparts. We examine the extent to which word context and translation dominance influence the processing of translation-ambiguous words. We further examine how these factors…

  6. Ambiguity Tolerance and Perceptual Learning Styles of Chinese EFL Learners

    Science.gov (United States)

    Li, Haishan; He, Qingshun

    2016-01-01

    Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…

  7. Children's Understanding of Ambiguous Idioms and Conversational Perspective-Taking

    Science.gov (United States)

    Le Sourn-Bissaoui, Sandrine; Caillies, Stephanie; Bernard, Stephane; Deleau, Michel; Brule, Lauriane

    2012-01-01

    The aim of this study was to test the hypothesis that conversational perspective-taking is a determinant of unfamiliar ambiguous idiom comprehension. We investigated two types of ambiguous idiom, decomposable and nondecomposable expressions, which differ in the degree to which the literal meanings of the individual words contribute to the overall…

  8. Cognitive Flexibility Supports Preschoolers' Detection of Communicative Ambiguity

    Science.gov (United States)

    Gillis, Randall; Nilsen, Elizabeth S.

    2014-01-01

    To become successful communicators, children must be sensitive to the clarity/ambiguity of language. Significant gains in children's ability to detect communicative ambiguity occur during the early school-age years. However, little is known about the cognitive abilities that support this development. Relations between cognitive flexibility and…

  9. Examining ambiguities in film titles: the Nigerian situation | Nwala ...

    African Journals Online (AJOL)

    The paper investigated ambiguous film titles with specific reference to films in Nigeria. It observed that film titles which are meant to serve as initial appraisal and forerunners of films that light up the interest of the consumers and promote patronage are usually scripted in mind-boggling ambiguous expressions, which make ...

  10. A novel constrained ambiguity resolution approach for Beidou attitude determination

    Science.gov (United States)

    Li, Qingsong; Zhang, Liang; Wu, Jie; Wang, Dingjie; Dong, Yi

    2017-12-01

    This paper develops a novel approach to obtain the fixed ambiguity solution with orthonormal constraints for Beidou attitude determination. The approach extends the traditional attitude model by taking the attitude matrix elements as unknown parameters directly. The orthonormal property of the attitude matrix is used as constraints to assist in calculating the float ambiguity solution and its corresponding variance-covariance matrix. An iteration algorithm with the linearization of orthonormal constraints is developed to solve the nonlinear conditional extremum problem and a sequential filtering multi-epoch ambiguity resolution method is derived for real-time applications. Long-time static experiments with three antennas tracing Beidou signals are employed to demonstrate the reliability and effectiveness of the proposed approach. The results indicate that, compared to unconstrained ambiguity resolution, the proposed approach can improve the reliability of the integer ambiguity vectors for single epochs and can also decrease the time to fix for multiple epochs.

  11. Ambiguity aversion and household portfolio choice puzzles: Empirical evidence*

    Science.gov (United States)

    Dimmock, Stephen G.; Kouwenberg, Roy; Mitchell, Olivia S.; Peijnenburg, Kim

    2017-01-01

    We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks. PMID:28458446

  12. The Ethics of Strategic Ambiguity: Contrasting Teleologically and Deontologically Based Experiences.

    Science.gov (United States)

    Paul, Jim; And Others

    This paper describes ethical considerations in the use of strategic ambiguity in organizational communication. Ambiguity is defined as "experienced ambiguity" and is distinct from uncertainty and equivocality which are properties of a stimulus. Strategic ambiguity is the use of "calculated ambiguity" in organizations to achieve…

  13. Modulating the Activity of the DLPFC and OFC Has Distinct Effects on Risk and Ambiguity Decision-Making: A tDCS Study

    Directory of Open Access Journals (Sweden)

    Xiaolan Yang

    2017-08-01

    Full Text Available Human beings are constantly exposed to two types of uncertainty situations, risk and ambiguity. Neuroscientific studies suggest that the dorsolateral prefrontal cortex (DLPFC and the orbital frontal cortex (OFC play significant roles in human decision making under uncertainty. We applied the transcranial direct current stimulation (tDCS device to modulate the activity of participants’ DLPFC and OFC separately, comparing the causal relationships between people’s behaviors and the activity of the corresponding brain cortex when confronted with situations of risk and ambiguity. Our experiment employed a pre–post design and a risk/ambiguity decision-making task, from which we could calculate the preferences via an estimation model. We found evidences that modulating the activity of the DLPFC using right anodal/left cathodal tDCS significantly enhanced the participants’ preferences for risk, whereas modulating the activity of the OFC with right anodal/left cathodal tDCS significantly decreased the participants’ preferences for ambiguity. The reverse effects were also observed in the reversed tDCS treatments on the two areas. Our results suggest that decision-making processes under risk and ambiguity are complicated and may be encoded in two distinct circuits in our brains as the DLPFC primarily impacts decisions under risk whereas the OFC affects ambiguity.

  14. Commonalities and differences in the neural representations of English, Portuguese, and Mandarin sentences: When knowledge of the brain-language mappings for two languages is better than one.

    Science.gov (United States)

    Yang, Ying; Wang, Jing; Bailer, Cyntia; Cherkassky, Vladimir; Just, Marcel Adam

    2017-12-01

    This study extended cross-language semantic decoding (based on a concept's fMRI signature) to the decoding of sentences across three different languages (English, Portuguese and Mandarin). A classifier was trained on either the mapping between words and activation patterns in one language or the mappings in two languages (using an equivalent amount of training data), and then tested on its ability to decode the semantic content of a third language. The model trained on two languages was reliably more accurate than a classifier trained on one language for all three pairs of languages. This two-language advantage was selective to abstract concept domains such as social interactions and mental activity. Representational Similarity Analyses (RSA) of the inter-sentence neural similarities resulted in similar clustering of sentences in all the three languages, indicating a shared neural concept space among languages. These findings identify semantic domains that are common across these three languages versus those that are more language or culture-specific. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Chimpanzees and bonobos distinguish between risk and ambiguity.

    Science.gov (United States)

    Rosati, Alexandra G; Hare, Brian

    2011-02-23

    Although recent research has investigated animal decision-making under risk, little is known about how animals choose under conditions of ambiguity when they lack information about the available alternatives. Many models of choice behaviour assume that ambiguity does not impact decision-makers, but studies of humans suggest that people tend to be more averse to choosing ambiguous options than risky options with known probabilities. To illuminate the evolutionary roots of human economic behaviour, we examined whether our closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), share this bias against ambiguity. Apes chose between a certain option that reliably provided an intermediately preferred food type, and a variable option that could vary in the probability that it provided a highly preferred food type. To examine the impact of ambiguity on ape decision-making, we interspersed trials in which chimpanzees and bonobos had no knowledge about the probabilities. Both species avoided the ambiguous option compared with their choices for a risky option, indicating that ambiguity aversion is shared by humans, bonobos and chimpanzees.

  16. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults.

    Science.gov (United States)

    Groch, Sabine; McMakin, Dana; Guggenbühl, Patrick; Rasch, Björn; Huber, Reto; Wilhelm, Ines

    2016-02-01

    The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued) during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants' age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults

    Directory of Open Access Journals (Sweden)

    Sabine Groch

    2016-02-01

    Full Text Available The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants’ age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed.

  18. Multiple priming of lexically ambiguous and unambiguous targets in the cerebral hemispheres: the coarse coding hypothesis revisited.

    Science.gov (United States)

    Kandhadai, Padmapriya; Federmeier, Kara D

    2007-06-11

    The coarse coding hypothesis postulates that the cerebral hemispheres differ in their breadth of semantic activation, with the left hemisphere activating a narrow, focused semantic field and the right weakly activating a broader semantic field. In support of coarse coding, studies investigating priming for multiple senses of a lexically ambiguous word have reported a right hemisphere benefit. However, studies of mediated priming have failed to find a right hemisphere advantage for processing distantly linked, unambiguous words. To address this debate, the present study made use of a multiple priming paradigm in which two primes either converged onto the single meaning of an unambiguous, lexically associated target (LION-STRIPES-TIGER) or diverged onto different meanings of an ambiguous target (KIDNEY-PIANO-ORGAN). In two experiments, participants either made lexical decisions to lateralized targets (Experiment 1) or made a semantic relatedness judgment between primes and targets (Experiment 2). In both tasks, for both ambiguous and unambiguous triplets we found equivalent priming strengths and patterns across the two visual fields, counter to the predictions of the coarse coding hypothesis. Priming patterns further suggested that both hemispheres made use of lexical level representations in the lexical decision task and semantic representations in the semantic judgment task.

  19. Consistent representations of and conversions between 3D rotations

    Science.gov (United States)

    Rowenhorst, D.; Rollett, A. D.; Rohrer, G. S.; Groeber, M.; Jackson, M.; Konijnenberg, P. J.; De Graef, M.

    2015-12-01

    In materials science the orientation of a crystal lattice is described by means of a rotation relative to an external reference frame. A number of rotation representations are in use, including Euler angles, rotation matrices, unit quaternions, Rodrigues-Frank vectors and homochoric vectors. Each representation has distinct advantages and disadvantages with respect to the ease of use for calculations and data visualization. It is therefore convenient to be able to easily convert from one representation to another. However, historically, each representation has been implemented using a set of often tacit conventions; separate research groups would implement different sets of conventions, thereby making the comparison of methods and results difficult and confusing. This tutorial article aims to resolve these ambiguities and provide a consistent set of conventions and conversions between common rotational representations, complete with worked examples and a discussion of the trade-offs necessary to resolve all ambiguities. Additionally, an open source Fortran-90 library of conversion routines for the different representations is made available to the community.

  20. Sparse time-frequency representations.

    Science.gov (United States)

    Gardner, Timothy J; Magnasco, Marcelo O

    2006-04-18

    Auditory neurons preserve exquisite temporal information about sound features, but we do not know how the brain uses this information to process the rapidly changing sounds of the natural world. Simple arguments for effective use of temporal information led us to consider the reassignment class of time-frequency representations as a model of auditory processing. Reassigned time-frequency representations can track isolated simple signals with accuracy unlimited by the time-frequency uncertainty principle, but lack of a general theory has hampered their application to complex sounds. We describe the reassigned representations for white noise and show that even spectrally dense signals produce sparse reassignments: the representation collapses onto a thin set of lines arranged in a froth-like pattern. Preserving phase information allows reconstruction of the original signal. We define a notion of "consensus," based on stability of reassignment to time-scale changes, which produces sharp spectral estimates for a wide class of complex mixed signals. As the only currently known class of time-frequency representations that is always "in focus" this methodology has general utility in signal analysis. It may also help explain the remarkable acuity of auditory perception. Many details of complex sounds that are virtually undetectable in standard sonograms are readily perceptible and visible in reassignment.

  1. Ambiguity in Tactile Apparent Motion Perception.

    Directory of Open Access Journals (Sweden)

    Emanuela Liaci

    Full Text Available In von Schiller's Stroboscopic Alternative Motion (SAM stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio ("AR", i.e. the relation between vertical and horizontal dot distances. Further, with equal horizontal and vertical dot distances (AR = 1 perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion.We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants' forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames.Increasing the tactile SAM's AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias.Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual strategy of the individual

  2. Reading comprehension of ambiguous sentences by school-age children with autism spectrum disorder.

    Science.gov (United States)

    Davidson, Meghan M; Ellis Weismer, Susan

    2017-08-22

    Weak central coherence (processing details over gist), poor oral language abilities, poor suppression, semantic interference, and poor comprehension monitoring have all been implicated to affect reading comprehension in individuals with autism spectrum disorder (ASD). This study viewed the contributions of different supporting skills as a collective set of skills necessary for context integration-a multi-component view-to examine individual differences in reading comprehension in school-age children (8-14 years) with ASD (n = 23) and typically developing control peers (n = 23). Participants completed a written ambiguous sentence comprehension task in which participants had to integrate context to determine the correct homonym meaning via picture selection. Both comprehension products (i.e., offline representations after reading) and processes (i.e., online processing during reading) were evaluated. Results indicated that children with ASD, similar to their TD peers, integrated the context to access the correct homonym meanings while reading. However, after reading the sentences, when participants were asked to select the meanings, both groups experienced semantic interference between the two meanings. This semantic interference hindered the children with ASD's sentence representation to a greater degree than their peers. Individual differences in age/development, word recognition, vocabulary breadth (i.e., number of words in the lexicon), and vocabulary depth (i.e., knowledge of the homonym meanings) contributed to sentence comprehension in both children with ASD and their peers. Together, this evidence supports a multi-component view, and that helping children with ASD develop vocabulary depth may have cascading effects on their reading comprehension. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Like their peers, children with ASD were able to integrate context, or link words while reading sentences with

  3. Extent of the Immirzi ambiguity in quantum general relativity

    Energy Technology Data Exchange (ETDEWEB)

    Marugan, Guillermo A Mena [Centro de Fisica Miguel A Catalan, IMAFF, CSIC, Serrano 121, 28006 Madrid (Spain)

    2002-04-21

    The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism based on each of these canonical sets leads to different predictions. This phenomenon is called the Immirzi ambiguity. It has been recently argued that this ambiguity could be generalized to the extent of a spatially dependent function instead of a parameter. This would ruin the predictability of loop quantum gravity. We prove that such expectations are not realized, so that the Immirzi ambiguity introduces exclusively a freedom in the choice of a real number. (letter to the edit0008.

  4. Robust portfolio choice with ambiguity and learning about return predictability

    DEFF Research Database (Denmark)

    Larsen, Linda Sandris; Branger, Nicole; Munk, Claus

    2013-01-01

    We analyze the optimal stock-bond portfolio under both learning and ambiguity aversion. Stock returns are predictable by an observable and an unobservable predictor, and the investor has to learn about the latter. Furthermore, the investor is ambiguity-averse and has a preference for investment...... strategies that are robust to model misspecifications. We derive a closed-form solution for the optimal robust investment strategy. We find that both learning and ambiguity aversion impact the level and structure of the optimal stock investment. Suboptimal strategies resulting either from not learning...

  5. Robust Portfolio Choice with Ambiguity and Learning About Return Predictability

    DEFF Research Database (Denmark)

    Branger, Nicole; Larsen, Linda Sandris; Munk, Claus

    2013-01-01

    We analyze the optimal stock-bond portfolio under both learning and ambiguity aversion. Stock returns are predictable by an observable and an unobservable predictor, and the investor has to learn about the latter. Furthermore, the investor is ambiguity-averse and has a preference for investment...... strategies that are robust to model misspecifications. We derive a closed-form solution for the optimal robust investment strategy. We find that both learning and ambiguity aversion impact the level and structure of the optimal stock investment. Suboptimal strategies resulting either from not learning...

  6. A method to reduce ambiguities of qualitative reasoning for conceptual design applications

    NARCIS (Netherlands)

    D'Amelio, V.; Chmarra, M.K.; Tomiyama, T.

    2013-01-01

    Qualitative reasoning can generate ambiguous behaviors due to the lack of quantitative information. Despite many different research results focusing on ambiguities reduction, fundamentally it is impossible to totally remove ambiguities with only qualitative methods and to guarantee the consistency

  7. "Her Very Own Howl": The Ambiguities of Representation in Recent Women's Fiction.

    Science.gov (United States)

    Homans, Margaret

    1983-01-01

    Assesses American and French feminist theory. Considers several novels that reflect in varying ways their authors' ambivalence about appropriating the dominant (male) discourse and about what alternatives to this discourse may exist. (CMG)

  8. Neural Imaginaries and Clinical Epistemology: Rhetorically Mapping the Adolescent Brain in the Clinical Encounter

    Science.gov (United States)

    Buchbinder, Mara

    2014-01-01

    The social work of brain images has taken center stage in recent theorizing of the intersections between neuroscience and society. However, neuroimaging is only one of the discursive modes through which public representations of neurobiology travel. This article adopts an expanded view toward the social implications of neuroscientific thinking to examine how neural imaginaries are constructed in the absence of visual evidence. Drawing on ethnographic fieldwork conducted over 18 months (2008–2009) in a United States multidisciplinary pediatric pain clinic, I examine the pragmatic clinical work undertaken to represent ambiguous symptoms in neurobiological form. Focusing on one physician, I illustrate how, by rhetorically mapping the brain as a therapeutic tool, she engaged in a distinctive form of representation that I call neural imagining. In shifting my focus away from the purely material dimensions of brain images, I juxtapose the cultural work of brain scanning technologies with clinical neural imaginaries in which the teenage brain becomes a space of possibility, not to map things as they are, but rather, things as we hope they might be. These neural imaginaries rely upon a distinctive clinical epistemology that privileges the creative work of the imagination over visualization technologies in revealing the truths of the body. By creating a therapeutic space for adolescents to exercise their imaginative faculties and a discursive template for doing so, neural imagining relocates adolescents’ agency with respect to epistemologies of bodily knowledge and the role of visualization practices therein. In doing so, it provides a more hopeful alternative to the dominant popular and scientific representations of the teenage brain that view it primarily through the lens of pathology. PMID:24780561

  9. Interpretation of Ambiguous Information in Girls at Risk for Depression

    Science.gov (United States)

    Dearing, Karen F.

    2010-01-01

    Research has consistently documented that depressed individuals process information in a negatively biased manner. There is little evidence, however, concerning whether these biases represent risk factors for depression, as is hypothesized by cognitive models. In the present study we investigated whether a particular cognitive bias observed in currently depressed individuals, the tendency to interpret ambiguous information negatively, characterizes daughters of depressed mothers, a population known to be at increased risk for depression. Following a negative mood induction, young daughters of depressed and never-disordered mothers completed two information-processing tasks in which their interpretations of emotionally ambiguous stimuli were evaluated. Daughters of depressed mothers interpreted ambiguous words more negatively and less positively, and ambiguous stories more negatively, than did daughters of never-disordered mothers. These results provide support for cognitive vulnerability models of depression. PMID:18679791

  10. Tradition and Japanese vegetables: history, locality, geography, and discursive ambiguity

    Directory of Open Access Journals (Sweden)

    Yuta Uchiyama

    2017-09-01

    Conclusion: Origins of traditional Japanese vegetables and relationships with their regions have innumerable ambiguous points. The results of the analysis of two types of traditional vegetables show that quality standards and definitions strongly influence branding and brand management.

  11. Process ambiguities in Sino-Danish Business Negotiations

    DEFF Research Database (Denmark)

    Kumar, Rajesh; Worm, Verner

    2004-01-01

    The article analyzes the role played by process ambiguities in Sino-Danish business negotiations. Process ambiguities refer to perceived expectational inconsistencies concerning (1) appropriate forms of behavior; (ii) attributional judgments; and (iii) structuring of the negotiation process....... These ambiguities stem from differences in negotiation scripts across Danish and Chinese cultures. The essential argument being advanced here is that it is the effective and/or the ineffective management of process ambiguities that shapes the evolution of the negotiating dynamic between the Danish and the Chinese...... businesspeople. An inductive model of sino-Danish negotiations is developed that is based on 24 interviews conducted with Danish expatriate managers in China and 4 interviews with Chinese working in Danish companies. Implications for research and practice are discussed...

  12. Individual differences in risk-taking tendencies modulate the neural processing of risky and ambiguous decision-making in adolescence.

    Science.gov (United States)

    Blankenstein, N E; Schreuders, E; Peper, J S; Crone, E A; van Duijvenvoorde, A C K

    2018-02-02

    Although many neuroimaging studies have investigated adolescent risk taking, few studies have dissociated between decision-making under risk (known probabilities) and ambiguity (unknown probabilities). Furthermore, which brain regions are sensitive to individual differences in task-related and self-reported risk taking remains elusive. We presented 198 adolescents (11-24 years, an age-range in which individual differences in risk taking are prominent) with an fMRI paradigm that separated decision-making (choosing to gamble or not) and reward outcome processing (gains, no gains) under risky and ambiguous conditions, and related this to task-related and self-reported risk taking. We observed distinct neural mechanisms underlying risky and ambiguous gambling, with risk more prominently associated with activation in parietal cortex, and ambiguity more prominently with dorsolateral prefrontal cortex (PFC), as well as medial PFC during outcome processing. Individual differences in task-related risk taking were positively associated with ventral striatum activation in the decision phase, specifically for risk, and negatively associated with insula and dorsomedial PFC activation, specifically for ambiguity. Moreover, dorsolateral PFC activation in the outcome phase seemed a prominent marker for individual differences in task-related risk taking under ambiguity as well as self-reported daily-life risk taking, in which greater risk taking was associated with reduced activation in dorsolateral PFC. Together, this study demonstrates the importance of considering multiple risk-taking measures, and contextual moderators, in understanding the neural mechanisms underlying adolescent risk taking. Copyright © 2018. Published by Elsevier Inc.

  13. Top-down influences on ambiguous perception: the role of stable and transient states of the observer

    Directory of Open Access Journals (Sweden)

    Lisa eScocchia

    2014-12-01

    Full Text Available The world as it appears to the viewer is the result of a complex process of inference performed by the brain. The validity of this apparently counter-intuitive assertion becomes evident whenever we face noisy, feeble or ambiguous visual stimulation: in these conditions, the state of the observer may play a decisive role in determining what is currently perceived. On this background, ambiguous perception and its amenability to top-down influences can be employed as an empirical paradigm to explore the principles of perception. Here we offer an overview of both classical and recent contributions on how stable and transient states of the observer can impact ambiguous perception. As to the influence of the stable states of the observer, we show that what is currently perceived can be influenced (1 by cognitive and affective aspects, such as meaning, prior knowledge, motivation and emotional content and (2 by individual differences, such as gender, handedness, genetic inheritance, clinical conditions and personality traits and by (3 learning and conditioning. As to the impact of transient states of the observer, we outline the effects of (4 attention and (5 voluntary control, which have attracted much empirical work along the history of ambiguous perception. In the huge literature on the topic we trace a difference between the observer’s ability to control dominance (i.e: the maintenance of a specific percept in visual awareness and reversal rate (i.e: the switching between two alternative percepts. Other transient states of the observer that have more recently drawn researchers’ attention regard (6 the effects of imagery and visual working memory. (7 Furthermore, we describe the transient effects of prior history of perceptual dominance. (8 Finally, we address the currently available computational models of ambiguous perception and how they can take into account the crucial share played by the state of the observer in perceiving ambiguous

  14. Top-down influences on ambiguous perception: the role of stable and transient states of the observer

    Science.gov (United States)

    Scocchia, Lisa; Valsecchi, Matteo; Triesch, Jochen

    2014-01-01

    The world as it appears to the viewer is the result of a complex process of inference performed by the brain. The validity of this apparently counter-intuitive assertion becomes evident whenever we face noisy, feeble or ambiguous visual stimulation: in these conditions, the state of the observer may play a decisive role in determining what is currently perceived. On this background, ambiguous perception and its amenability to top-down influences can be employed as an empirical paradigm to explore the principles of perception. Here we offer an overview of both classical and recent contributions on how stable and transient states of the observer can impact ambiguous perception. As to the influence of the stable states of the observer, we show that what is currently perceived can be influenced (1) by cognitive and affective aspects, such as meaning, prior knowledge, motivation, and emotional content and (2) by individual differences, such as gender, handedness, genetic inheritance, clinical conditions, and personality traits and by (3) learning and conditioning. As to the impact of transient states of the observer, we outline the effects of (4) attention and (5) voluntary control, which have attracted much empirical work along the history of ambiguous perception. In the huge literature on the topic we trace a difference between the observer's ability to control dominance (i.e., the maintenance of a specific percept in visual awareness) and reversal rate (i.e., the switching between two alternative percepts). Other transient states of the observer that have more recently drawn researchers' attention regard (6) the effects of imagery and visual working memory. (7) Furthermore, we describe the transient effects of prior history of perceptual dominance. (8) Finally, we address the currently available computational models of ambiguous perception and how they can take into account the crucial share played by the state of the observer in perceiving ambiguous displays. PMID

  15. Comparing Tolerance of Ambiguity in Veterinary and Medical Students.

    Science.gov (United States)

    Hancock, Jason; Hammond, Jennifer A; Roberts, Martin; Mattick, Karen

    2017-01-01

    Current guidelines suggest that educators in both medical and veterinary professions should do more to ensure that students can tolerate ambiguity. Designing curricula to achieve this requires the ability to measure and understand differences in ambiguity tolerance among and within professional groups. Although scales have been developed to measure tolerance of ambiguity in both medical and veterinary professions, no comparative studies have been reported. We compared the tolerance of ambiguity of medical and veterinary students, hypothesizing that veterinary students would have higher tolerance of ambiguity, given the greater patient diversity and less well-established evidence base underpinning practice. We conducted a secondary analysis of questionnaire data from first- to fourth-year medical and veterinary students. Tolerance of ambiguity scores were calculated and compared using the TAMSAD scale (29 items validated for the medical student population), the TAVS scale (27 items validated for the veterinary student population), and a scale comprising the 22 items common to both scales. Using the TAMSAD and TAVS scales, medical students had a significantly higher mean tolerance of ambiguity score than veterinary students (56.1 vs. 54.1, p<.001 and 60.4 vs. 58.5, p=.002, respectively) but no difference was seen when only the 22 shared items were compared (56.1 vs. 57.2, p=.513). The results do not support our hypothesis and highlight that different findings can result when different tools are used. Medical students may have slightly higher tolerance of ambiguity than veterinary students, although this depends on the scale used.

  16. Removing Ambiguities of IP Telephony Traffic Using Protocol Scrubbers

    Directory of Open Access Journals (Sweden)

    Bazara I. A. Barry

    2012-10-01

    Full Text Available Network intrusion detection systems (NIDSs face the serious challenge of attacks such as insertion and evasion attacks that are caused by ambiguous network traffic. Such ambiguity comes as a result of the nature of network traffic which includes protocol implementation variations and errors alongside legitimate network traffic. Moreover, attackers can intentionally introduce further ambiguities in the traffic. Consequently, NIDSs need to be aware of these ambiguities when detection is performed and make sure to differentiate between true attacks and protocol implementation variations or errors; otherwise, detection accuracy can be affected negatively. In this paper we present the design and implementation of tools that are called protocol scrubbers whose main functionality is to remove ambiguities from network traffic before it is presented to the NIDS. The proposed protocol scrubbers are designed for session initiation and data transfer protocols in IP telephony systems. They guarantee that the traffic presented to NIDSs is unambiguous by eliminating ambiguous behaviors of protocols using well-designed protocol state machines, and walking through packet headers of protocols to make sure packets will be interpreted in the desired way by the NIDS. The experimental results shown in this paper demonstrate the good quality and applicability of the introduced scrubbers.

  17. GNSS antenna array-aided CORS ambiguity resolution

    Science.gov (United States)

    Li, Bofeng; Teunissen, Peter J. G.

    2014-04-01

    Array-aided precise point positioning is a measurement concept that uses GNSS data, from multiple antennas in an array of known geometry, to realize improved GNSS parameter estimation proposed by Teunissen (IEEE Trans Signal Process 60:2870-2881, 2012). In this contribution, the benefits of array-aided CORS ambiguity resolution are explored. The mathematical model is formulated to show how the platform-array data can be reduced and how the variance matrix of the between-platform ambiguities can profit from the increased precision of the reduced platform data. The ambiguity resolution performance will be demonstrated for varying scenarios using simulation. We consider single-, dual- and triple-frequency scenarios of geometry-based and geometry-free models for different number of antennas and different standard deviations of the ionosphere-weighted constraints. The performances of both full and partial ambiguity resolution (PAR) are presented for these different scenarios. As the study shows, when full advantage is taken of the array antennas, both full and partial ambiguity resolution can be significantly improved, in some important cases even enabling instantaneous ambiguity resolution. PAR widelaning and its suboptimal character are hereby also illustrated.

  18. Young children show representational flexibility when interpreting drawings.

    Science.gov (United States)

    Allen, Melissa L; Nurmsoo, Erika; Freeman, Norman

    2016-02-01

    Drawings can be ambiguous and represent more than one entity. In three experiments, we examine whether young children show representational flexibility by allowing one picture to be called by a second name. We also evaluate the hypothesis that children who are representationally flexible see the artist's intention as binding, rather than changeable. In Experiment 1, an artist declared what she intended to draw (e.g. a balloon) but then produced an ambiguous drawing. Children were asked whether the drawings could be interpreted differently (e.g. 'could this be a lollipop?') in the presence of a perceptually similar or dissimilar distractor (e.g., lollipop or snake). Six-year-olds accepted two labels for drawings in both conditions, but four-year-olds only did so in the dissimilar condition. Experiment 2 probed each possible interpretation more deeply by asking property questions (e.g., 'does it float?, does it taste good?'). Preschoolers who understood that the ambiguous drawing could be given two interpretations nevertheless mostly endorsed only properties associated with the prior intent. Experiment 3 provided converging evidence that 4-year-olds were representationally flexible using a paradigm that did not rely upon modal questioning. Taken together, our results indicate that even 4-year-olds understand that pictures may denote more than one referent, they still think of the symbol as consistent with the artist's original intention. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Representation as the representation of experience

    NARCIS (Netherlands)

    Ankersmit, FR

    This essay deals, mainly, with the notion of representation. Representation is associated with texts and, as such, is contrasted to the true singular statement. It is argued that the relationship between the text and what the text represents can never be modeled on the relationship between the true

  20. Interpretation in Social Anxiety: When Meaning Precedes Ambiguity.

    Science.gov (United States)

    Beard, Courtney; Amir, Nader

    2009-01-01

    Cognitive models of anxiety posit that negative beliefs influence socially anxious individuals' interpretation of ambiguous social cues. However, paradigms used to assess interpretation bias in social anxiety have not addressed such beliefs. Furthermore, studies have assessed interpretation with either self-report or reaction time paradigms, rather than using both methods. In the current study, socially anxious and non-anxious participants completed the Word Sentence Association Paradigm (WSAP). In the WSAP, participants decide whether or not a word (implying a threat or benign interpretation) is related to an ambiguous sentence. Threat or benign meanings preceded the ambiguity in order to examine the influence of positive and negative beliefs on interpretation of ambiguous information. The WSAP results in two types of interpretation indices: (1) response latency to make relatedness decisions for threat and benign interpretations, and (2) endorsement rates of the relatedness of threat and benign interpretations to ambiguous sentences. Results revealed a threat interpretation bias and a lack of a benign interpretation bias in both reaction time and self-report data. Threat and benign biases were not strongly correlated. These findings support the distinction between threat and benign interpretation biases.

  1. Increasing Statistical Literacy by Exploiting Lexical Ambiguity of Technical Terms

    Directory of Open Access Journals (Sweden)

    Jennifer Kaplan

    2018-01-01

    Full Text Available Instructional inattention to language poses a barrier for students in entry-level science courses, in part because students may perceive a subject as difficult solely based on the lack of understanding of the vocabulary. In addition, the technical use of terms that have different everyday meanings may cause students to misinterpret statements made by instructors, leading to an incomplete or incorrect understanding of the domain. Terms that have different technical and everyday meanings are said to have lexical ambiguity and statistics, as a discipline, has many lexically ambiguous terms. This paper presents a cyclic process for designing activities to address lexical ambiguity in statistics. In addition, it describes three short activities aimed to have high impact on student learning associated with two different lexically ambiguous words or word pairs in statistics. Preliminary student-level data are used to assess the efficacy of the activities, and future directions for development of activities and research about lexical ambiguity in statistics in particular and STEM in general are discussed.

  2. Shape representation using a fuzzy morphological thinning algorithm

    Science.gov (United States)

    Gupta, Madan M.; Knopf, George K.

    1994-10-01

    The primary task of machine vision is to utilize a variety of techniques to segment a digital image into meaningful regions, extract the corresponding edges, compute the various features (e.g., area, centroids) and primitives (e.g. lines, corners, curves) that exist in the image, and finally develop some decision rules or grammar structures for interpreting the image content. In conventional vision systems, the operations performed involve making crisp (yes or no) decisions about the regions, features, primitives, regional relationships and overall scene interpretation. However, various degrees of uncertainty exist at each and every stage of the vision system process because these decisions are often based on data that is inexact or ambiguous in nature. Much of the incertitude in the image information can be interpreted in terms of either grayness ambiguity (deciding on the intensity of a pixel) or spatial ambiguity (deciding on the shape and geometry of the regions within the image). Fuzzy morphology is a mathematical tool developed to deal with imprecise or ambiguous information that arises during a subjective evaluation process such as scene interpretation. This mathematical approach transforms a gray scale image into a two-dimensional array of fuzzy singletons called a fuzzy image. The value of each fuzzy singleton reflects the degree to which the pixel possesses some property such as brightness, edgeness, redness, or surface uniformity (i.e., texture). A variety of morphological operations can be performed on the singletons in order to modify the ambiguity associated with the desired property. For the efficient shape representation of objects in a scene, a thinning algorithm for fuzzy images is proposed in this paper. Once the object shape has been thinned to a skeleton-like representation, curve descriptors can be used to transform the generalized shape into a coded form. In essence, this thinning algorithm is used to reduce, or compress, the structural shape

  3. Text Association Analysis and Ambiguity in Text Mining

    Science.gov (United States)

    Bhonde, S. B.; Paikrao, R. L.; Rahane, K. U.

    2010-11-01

    Text Mining is the process of analyzing a semantically rich document or set of documents to understand the content and meaning of the information they contain. The research in Text Mining will enhance human's ability to process massive quantities of information, and it has high commercial values. Firstly, the paper discusses the introduction of TM its definition and then gives an overview of the process of text mining and the applications. Up to now, not much research in text mining especially in concept/entity extraction has focused on the ambiguity problem. This paper addresses ambiguity issues in natural language texts, and presents a new technique for resolving ambiguity problem in extracting concept/entity from texts. In the end, it shows the importance of TM in knowledge discovery and highlights the up-coming challenges of document mining and the opportunities it offers.

  4. Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity

    DEFF Research Database (Denmark)

    Munk, Claus; Rubtsov, Alexey Vladimirovich

    -Jacobi-Bellman equation in closed form and derive and illustrate a number of interesting properties of the solution. For example, ambiguity aversion affects the optimal portfolio through the correlation of price level with the stock index, a bond, and the expected inflation rate. Furthermore, unlike other settings......We solve a stock-bond-cash portfolio choice problem for a risk- and ambiguity-averse investor in a setting where the inflation rate and interest rates are stochastic. The expected inflation rate is unobservable, but the investor may learn about it from realized inflation and observed stock and bond...

  5. Representations of Circular Words

    Directory of Open Access Journals (Sweden)

    László Hegedüs

    2014-05-01

    Full Text Available In this article we give two different ways of representations of circular words. Representations with tuples are intended as a compact notation, while representations with trees give a way to easily process all conjugates of a word. The latter form can also be used as a graphical representation of periodic properties of finite (in some cases, infinite words. We also define iterative representations which can be seen as an encoding utilizing the flexible properties of circular words. Every word over the two letter alphabet can be constructed starting from ab by applying the fractional power and the cyclic shift operators one after the other, iteratively.

  6. Distinguishing Representations as Origin and Representations as Input: Roles for Individual Cells

    Directory of Open Access Journals (Sweden)

    Jonathan C.W. Edwards

    2016-09-01

    input interaction between signals and consumer. The acceptance of this necessity provides a basis for resolving the problem that representations appear both as distributed (representation-as-origin and local (representation-as-input. The key implications are that representations in brain are massively multiple both in series and in parallel, and that individual cells play specific semantic roles. These roles are discussed in relation to traditional concepts of ‘gnostic’ cell types.

  7. Tracking down abstract linguistic meaning: neural correlates of spatial frame of reference ambiguities in language.

    Directory of Open Access Journals (Sweden)

    Gabriele Janzen

    Full Text Available This functional magnetic resonance imaging (fMRI study investigates a crucial parameter in spatial description, namely variants in the frame of reference chosen. Two frames of reference are available in European languages for the description of small-scale assemblages, namely the intrinsic (or object-oriented frame and the relative (or egocentric frame. We showed participants a sentence such as "the ball is in front of the man", ambiguous between the two frames, and then a picture of a scene with a ball and a man--participants had to respond by indicating whether the picture did or did not match the sentence. There were two blocks, in which we induced each frame of reference by feedback. Thus for the crucial test items, participants saw exactly the same sentence and the same picture but now from one perspective, now the other. Using this method, we were able to precisely pinpoint the pattern of neural activation associated with each linguistic interpretation of the ambiguity, while holding the perceptual stimuli constant. Increased brain activity in bilateral parahippocampal gyrus was associated with the intrinsic frame of reference whereas increased activity in the right superior frontal gyrus and in the parietal lobe was observed for the relative frame of reference. The study is among the few to show a distinctive pattern of neural activation for an abstract yet specific semantic parameter in language. It shows with special clarity the nature of the neural substrate supporting each frame of spatial reference.

  8. Psychometric Analysis of Role Conflict and Ambiguity Scales in Academia

    Science.gov (United States)

    Khan, Anwar; Yusoff, Rosman Bin Md.; Khan, Muhammad Muddassar; Yasir, Muhammad; Khan, Faisal

    2014-01-01

    A comprehensive Psychometric Analysis of Rizzo et al.'s (1970) Role Conflict & Ambiguity (RCA) scales were performed after its distribution among 600 academic staff working in six universities of Pakistan. The reliability analysis includes calculation of Cronbach Alpha Coefficients and Inter-Items statistics, whereas validity was determined by…

  9. Processing Deliberate Ambiguity in Newspaper Headlines: Double Grounding

    Science.gov (United States)

    Brone, Geert; Coulson, Seana

    2010-01-01

    Two experiments investigated the processing and appreciation of double grounding, a form of intentional ambiguity often used in the construction of headlines. For example, in "Russia takes the froth off Carlsberg results," the key element, "takes the froth off," is significant both metaphorically, where it refers to the…

  10. Syntactic Structure Guides Prosody in Temporarily Ambiguous Sentences

    Science.gov (United States)

    Anderson, Catherine; Carlson, Katy

    2010-01-01

    A pair of speaking and listening studies investigated the prosody of sentences with temporary Object/Clause and Late/Early Closure ambiguities. Speakers reliably produced prosodic cues that allowed listeners to disambiguate Late/Early Closure sentences, but only infrequently produced prosody that disambiguated Object/Clause sentences, as shown by…

  11. Prosody and the Interpretation of Hierarchically Ambiguous Discourse

    Science.gov (United States)

    Tyler, Joseph

    2014-01-01

    Although significant attention has been devoted to prosody in discourse production, relatively little is known about prosody's effect on discourse interpretation. This article explores the ability of synthetic manipulations of prosody to bias interpretation of discourse ambiguities where a first sentence is linked to two following sentences either…

  12. A Lexico-Grammatical Interpretation of Ambiguity and ...

    African Journals Online (AJOL)

    This paper analyses semantic ambiguous headlines stating their communicative effectiveness with regards to print media. The concentration of this paper is on the multiple meaning of headlines. Hence, we have realized that multiple meanings of a word or sentence can be analysed semantically based on the syntactic ...

  13. GLONASS CDMA L3 ambiguity resolution and positioning

    NARCIS (Netherlands)

    Zaminpardaz, Safoora; Teunissen, P.J.G.; Nadarajah, Nandakumaran

    2016-01-01

    A first assessment of GLONASS CDMA L3 ambiguity resolution and positioning performance is provided. Our analyses are based on GLONASS L3 data from the satellite pair SVNs 755-801, received by two JAVAD receivers at Curtin University, Perth, Australia. In our analyses, four different versions of

  14. Fear of Success Revisited: Introducing an Ambiguous Cue.

    Science.gov (United States)

    Gravenkemper, Stephen A.; Paludi, Michele A.

    1983-01-01

    M.S. Horner has been criticized for defining "success" to her subjects in her research on fear-of-success. The present study, which provided an ambiguous verbal lead, showed low incidence of fear-of-success, because subjects themselves were allowed to define "success." (GC)

  15. Children's Use of Gesture in Ambiguous Pronoun Interpretation

    Science.gov (United States)

    Goodrich Smith, Whitney; Hudson Kam, Carla L.

    2015-01-01

    This study explores whether children can use gesture to inform their interpretation of ambiguous pronouns. Specifically, we ask whether four- to eight-year-old English-speaking children are sensitive to information contained in co-referential localizing gestures in video narrations. The data show that the older (7-8 years of age) but not younger…

  16. A Mindfulness Experiential Small Group to Help Students Tolerate Ambiguity

    Science.gov (United States)

    Bohecker, Lynn; Vereen, Linwood G.; Wells, Pamela C.; Wathen, Cristen C.

    2016-01-01

    This study explored the lived experiences of 20 counselors-in-training (CITs) in a mindfulness experiential small group. Using grounded theory, the authors described a 5-dimensional model for navigating ambiguity. Findings suggest mindfulness training provides CITs self-reflection skills and a greater ability to manage cognitive complexity.

  17. Multitarget particle filter addressing ambiguous radar data in TBD

    NARCIS (Netherlands)

    Bocquel, Melanie; Driessen, H.; Bagchi, Arunabha

    2012-01-01

    In this paper, we have addressed the problem of multiple target tracking in Track-Before-Detect (TBD) context using ambiguous Radar data. TBD is a method which uses raw measurement data, i.e. reflected target power, to track targets. Tracking can be defined as the estimation of the state of a moving

  18. The ambiguity of simplicity in quantum and classical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Aghamohammadi, Cina, E-mail: caghamohammadi@ucdavis.edu; Mahoney, John R., E-mail: jrmahoney@ucdavis.edu; Crutchfield, James P., E-mail: chaos@ucdavis.edu

    2017-04-11

    Highlights: • Simplicity depends on whether a system is represented classically or quantally. • We demonstrate that simplicity is unavoidably ambiguous. • Relative simplicity changes order moving between classical and quantum descriptions. • Ambiguity of simplicity bears directly on model selection. - Abstract: A system's perceived simplicity depends on whether it is represented classically or quantally. This is not so surprising, as classical and quantum physics are descriptive frameworks built on different assumptions that capture, emphasize, and express different properties and mechanisms. What is surprising is that, as we demonstrate, simplicity is ambiguous: the relative simplicity between two systems can change sign when moving between classical and quantum descriptions. Here, we associate simplicity with small model-memory. We see that the notions of absolute physical simplicity at best form a partial, not a total, order. This suggests that appeals to principles of physical simplicity, via Ockham's Razor or to the “elegance” of competing theories, may be fundamentally subjective. Recent rapid progress in quantum computation and quantum simulation suggest that the ambiguity of simplicity will strongly impact statistical inference and, in particular, model selection.

  19. The Ambiguity of Musical Expression Marks and the Challenges of ...

    African Journals Online (AJOL)

    The Ambiguity of Musical Expression Marks and the Challenges of Teaching and Learning Keyboard Instruments: The Nnamdi Azikiwe University Experience. ... the fact that some of the performance marks demand subjective expressions from the performer such as, 'furiously', 'fiercely' 'with agitation' 'brightly', tenderly, etc.

  20. Projection Effects and Strategic Ambiguity in Electoral Competition

    DEFF Research Database (Denmark)

    Jensen, Thomas

    projection. If voters' perceptions are not counterfactual and voting is based on perceived policy positions then projection gives a generally liked candidate an incentive to be ambiguous. In this paper we construct and analyze a formal model to investigate under which conditions this incentive survives...

  1. Projection effects and strategic ambiguity in electoral competition

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2009-01-01

    projection. If voters' perceptions are not counterfactual and voting is based on perceived policy positions then projection gives generally liked candidates an incentive to be ambiguous. In this paper we extend the standard Downsian model in order to investigate under what conditions this incentive survives...

  2. A life-cycle model with ambiguous survival beliefs

    NARCIS (Netherlands)

    Groneck, Max; Ludwig, Alexander; Zimper, Alexander

    Based on a cognitive notion of neo-additive capacities reflecting likelihood insensitivity with respect to survival chances, we construct a Choquet Bayesian learning model over the life-cycle that generates a motivational notion of neo-additive survival beliefs expressing ambiguity attitudes. We

  3. Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity

    DEFF Research Database (Denmark)

    Munk, Claus; Rubtsov, Alexey Vladimirovich

    2014-01-01

    We solve, in closed form, a stock-bond-cash portfolio problem of a risk- and ambiguity-averse investor when interest rates and the inflation rate are stochastic. The expected inflation rate is unobservable, but the investor can learn about it from observing realized inflation and stock and bond...

  4. Doctoral Dissertation Defences: Performing Ambiguity between Ceremony and Assessment

    NARCIS (Netherlands)

    van der Heide, Arjen; Rufas, Alix; Supper, Alexandra

    2016-01-01

    Dissertation defenses are ambiguous affairs, which mark both the end of a long process of doctoral education and the inauguration of a doctoral candidate into a body of experts. At Maastricht University (and other Dutch universities), the decision to award a doctoral degree is made on the basis of

  5. Implicit perceptual memory modulates early visual processing of ambiguous images

    NARCIS (Netherlands)

    de Jong, Maartje C.; Brascamp, Jan W.; Kemner, Chantal; van Ee, Raymond; Verstraten, Frans A J

    2014-01-01

    The way we perceive the present visual environment is influenced by past visual experiences. Here we investigated the neural basis of such experience dependency.Werepeatedly presentedhumanobservers with an ambiguous visual stimulus (structure-from-motion) that can give rise to two distinct

  6. Ambiguity of the equivalence principle and Hawking's temperature

    NARCIS (Netherlands)

    Hooft, G. 't

    1984-01-01

    There are two inequivalent ways in which the laws of physics in a gravitational field can be related to the laws in an inertial frame, when quantum mechanical effects are taken into account. This leads to an ambiguity in the derivation of Hawking's radiation temperature for a black hole: it could be

  7. Sublexical Ambiguity Effect in Reading Chinese Disyllabic Compounds

    Science.gov (United States)

    Huang, Hsu-Wen; Lee, Chia-Ying; Tsai, Jie-Li; Tzeng, Ovid J.-L.

    2011-01-01

    For Chinese compounds, neighbors can share either both orthographic forms and meanings, or orthographic forms only. In this study, central presentation and visual half-field (VF) presentation methods were used in conjunction with ERP measures to investigate how readers solve the sublexical semantic ambiguity of the first constituent character in…

  8. In Praise of Vagueness: Uncertainty, ambiguity and archaeological methodology

    DEFF Research Database (Denmark)

    Sørensen, Tim Flohr

    2016-01-01

    the appreciation of difficult experiences. However, the recent archaeological (re)turn to science as the main provider of knowledge of the past renders vagueness futile as an empirical occurrence through its exorcism of elusiveness and ambiguity in the notorious pursuit of absolute, exact and quantifiable facts...

  9. Difficulty Processing Temporary Syntactic Ambiguities in Lewy Body Spectrum Disorder

    Science.gov (United States)

    Grossman, Murray; Gross, Rachel G.; Moore, Peachie; Dreyfuss, Michael; McMillan, Corey T.; Cook, Philip A.; Ash, Sherry; Siderowf, Andrew

    2012-01-01

    While grammatical aspects of language are preserved, executive deficits are prominent in Lewy body spectrum disorder (LBSD), including Parkinson's disease (PD), Parkinson's dementia (PDD) and dementia with Lewy bodies (DLB). We examined executive control during sentence processing in LBSD by assessing temporary structural ambiguities. Using an…

  10. "What Happened?" Teaching Attribution Theory through Ambiguous Prompts

    Science.gov (United States)

    McArthur, John

    2011-01-01

    The concept of attribution, "the act of explaining why something happens or why a person acts a particular way," is typically an abstract concept. This 35-50-minute activity invites students to make a series of attributions by asking them "What happened?" in ambiguous scenes presented in class. Then, students retrospectively identify what…

  11. CSR and the Mediated Emergence of Strategic Ambiguity

    DEFF Research Database (Denmark)

    Guthey, Eric; Morsing, Mette

    2014-01-01

    We develop a framework for understanding how lack of clarity in business press coverage of corporate social responsibility functions as a mediated and emergent form of strategic ambiguity. Many stakeholders expect CSR to exhibit clarity, consistency, and discursive closure. But stakeholders also...

  12. Cognitive representation of orientation: a case study.

    Science.gov (United States)

    Valtonen, Jussi; Dilks, Daniel D; McCloskey, Michael

    2008-10-01

    Although object orientation in the human brain has been discussed extensively in the literature, the nature of the underlying cognitive representation(s) remains uncertain. We investigated orientation perception in BC, a patient with bilateral occipital and parietal damage from a herpes encephalitis infection. Our results show that in addition to general inaccuracy in discriminating and reproducing line orientations, her errors take the form of left-right mirror reflections across a vertical coordinate axis. We propose that in BC, the cognitive impairment is in failing to represent the direction of tilt for line orientations. Our results suggest that there exists a level of representation in the human brain at which line orientations are represented compositionally, such that the direction of a line orientation's tilt from a vertical mental reference meridian is coded independently of the magnitude of its angular displacement. Reflection errors across a vertical axis were observed both in visual and tactile line orientation tasks, demonstrating that these errors arise at a supra-modal level of representation not restricted to vision, or, alternatively, that visual-like representations are being constructed from the tactile input.

  13. Social representations of women

    Directory of Open Access Journals (Sweden)

    Álvaro Estramiana, José Luis

    2006-05-01

    Full Text Available Social Representations is one of the most important theories in contemporary social psychology. Since the social psychologist Serge Moscovici developed his theory of social representations to explain how a scientific theory such as the psychoanalysis turns into a common sense knowledge many studies have been done by different social psychologists. The analysis of the social representations of women as represented in myths and popular beliefs is an excellent opportunity to study how this theory can be applied to this representational field. At the same time it makes possible to understand the formation of attitudes towards women

  14. AMBIGUITY IN AUTOBIGRAPHICAL NARRATIVES IN NIGERIA: VALORIZING SEXISM AND DISPLACEMENT IN OGONI COSMOLOGY

    Directory of Open Access Journals (Sweden)

    Christopher Babatunde Ogunyemi

    2016-12-01

    Full Text Available This paper focuses on the examination of ambiguity in autobiographical writings in Nigeria. It underscores the architectonic discourse, cultural alienation and ‘self-elevation’ in some selected autobiographies. Ambiguity in this instance visualizes that these male narratives hinge on something, which is what we now wish to excavate as an area of serious academic endeavour. And it also hinges on how Saro Wiwa’s autobiographies who happen to be male is inevitably sexist in orientation, this will, however, be shown when examining in particular the structuring (narratological devices of the texts. This work valorizes the cardinal representations of self and male gender in enhancing identity for people of diverse perspectives without appreciating female voices which constitute an integral part of the literary history and ideologue. ‘Negating women in art is negating history because history is the main discipline through which we can understand gender’ (Brereton, 1998, p. 17. This paper encapsulates the motif of dominance and oppression of women because women were only made to be seen and not heard or even represented in such art. However, this situation is disheartening because while the ‘African feminist accommodates men and make them its central assurance, love and care’ (Chukwuma, 1990, p. 15, men who are fickle minded literary ideologues delight in over projecting self using the instrument of ‘I’ in autobiographies without recourse to women who hold some basis to their existence. This research work entails a close analysis of the question of gender and displacement originating from these autobiographical writings originating from Nigeria and the configuration of the motif of metaphor in male dominated gender in five autobiographical writings in line with narratology and Butler’s Theory of performativity.

  15. Community representation in hospital decision making: a literature review.

    Science.gov (United States)

    Murray, Zoë

    2015-06-01

    Advancing quality in health services requires structures and processes that are informed by consumer input. Although this agenda is well recognised, few researchers have focussed on the establishment and maintenance of customer input throughout the structures and processes used to produce high-quality, safe care. We present an analysis of literature outlining the barriers and enablers involved in community representation in hospital governance. The review aimed to explore how community representation in hospital governance is achieved. Studies spanning 1997-2012 were analysed using Donabedian' s model of quality systems as a guide for categories of interest: structure, in relation to administration of quality; process, which is particularly concerned with cooperation and culture; and outcome, considered, in this case, to be the achievement of effective community representation on quality of care. There are limited published studies on community representation in hospital governance in Australia. What can be gleaned from the literature is: 1) quality subcommittees set up to assist Hospital Boards are a key structure for involving community representation in decision making around quality of care, and 2) there are a number of challenges to effectively developing the process of community representation in hospital governance: ambiguity and the potential for escalated indecision; inadequate value and consideration given to it by decision makers resulting in a lack of time and resources needed to support the community engagement strategy (time, facilitation, budgets); poor support and attitude amongst staff; and consumer issues, such as feeling isolated and intimidated by expert opinion. The analysis indicates that: quality subcommittees set up to assist boards are a key structure for involving community representation in decision making around quality of care. There are clearly a number of challenges to effectively developing the process of community representation in

  16. Relation between students' problem-solving performance and representational format

    Science.gov (United States)

    Meltzer, David E.

    2005-05-01

    An analysis is presented of data on students' problem-solving performance on similar problems posed in diverse representations. Five years of classroom data on 400 students collected in a second-semester algebra-based general physics course are presented. Two very similar Newton's third-law questions, one posed in a verbal representation and one in a diagrammatic representation using vector diagrams, were given to students at the beginning of the course. The proportion of correct responses on the verbal question was consistently higher than on the diagrammatic question, and the pattern of incorrect responses on the two questions also differed consistently. Two additional four-question quizzes were given to students during the semester; each quiz had four very similar questions posed in the four representations: verbal, diagrammatic, mathematical/symbolic, and graphical. In general, the error rates for the four representations were very similar, but there was substantial evidence that females had a slightly higher error rate on the graphical questions relative to the other representations, whereas the evidence for male students was more ambiguous. There also was evidence that females had higher error rates on circuit-diagram problems in comparison with males, although both males and females had received identical instruction .

  17. Concept of representation and mental symptoms. The case of theory of mind.

    Science.gov (United States)

    Rejón Altable, Carlos; Vidal Castro, Carol; López Santín, J M

    2009-01-01

    Most current theories explaining theory of mind (ToM) rely on the concept of 'representation', as it is usually employed in cognitive science, and is thus affected by its epistemic shortcoming, namely its incapacity to use 'sub-signifier' level information. This shortcoming is responsible for the lack of specificity of ToM deficits, which are now found in very different syndromes, from schizophrenia to bipolar disorder or borderline personality disorder, in spite of its original formulation being restricted to childhood autism. Representation, its shortcomings and the way they may affect clinical/research programs undergo a conceptual analysis, which shows how representational-founded semiology leave out information that is essential for symptom specificity and correct symptom assessment. Schizophrenic autism, delusional perception and axial syndromes are studied as examples of both the difficulties that have arisen and possible ways of dealing with them. Transfers of properties between different meanings of 'representation' together with a systematic ambiguity in the use of 'representation' are proposed as the main ways for representational approaches to assure stability to their proposals in spite of the violence exerted on clinical phenomena. It is exposed how systematic ambiguity and epistemic shortcomings both affect Leslie's formulation of ToM and, further, the importance of these characteristics of the concept of 'representation' for general issues in psychiatric semiology. 2009 S. Karger AG, Basel.

  18. Does language ambiguity in clinical practice justify the introduction of standard terminology? An integrative review

    NARCIS (Netherlands)

    Stallinga, H.A.; Napel, H. ten; Jansen, G.J; Geertzen, J.H.; Vries Robbé, P.F. de; Roodbol, P.F.

    2015-01-01

    AIMS AND OBJECTIVES: To research the use of ambiguous language in written information concerning patients' functioning and to identify problems resulting from the use of ambiguous language in clinical practice. BACKGROUND: Many projects that aimed to introduce standard terminology concerning

  19. Does language ambiguity in clinical practice justify the introduction of standard terminology? An integrative review

    NARCIS (Netherlands)

    Stallinga, Hillegonda A.; ten Napel, Huib; Jansen, Gerard J.; Geertzen, Jan H. B.; Robbe, Pieter F. de Vries; Roodbol, Petrie F.

    Aims and objectives. To research the use of ambiguous language in written information concerning patients' functioning and to identify problems resulting from the use of ambiguous language in clinical practice. Background. Many projects that aimed to introduce standard terminology concerning

  20. Syntactic computations in the language network: Characterising dynamic network properties using representational similarity analysis

    Directory of Open Access Journals (Sweden)

    Lorraine Komisarjevsky Tyler

    2013-05-01

    Full Text Available The core human capacity of syntactic analysis involves a left hemisphere network involving left inferior frontal gyrus (LIFG and posterior middle temporal gyrus (LMTG and the anatomical connections between them. Here we use MEG to determine the spatio-temporal properties of syntactic computations in this network. Listeners heard spoken sentences containing a local syntactic ambiguity (e.g. …landing planes…, at the offset of which they heard a disambiguating verb and decided whether it was an acceptable/unacceptable continuation of the sentence. We charted the time-course of processing and resolving syntactic ambiguity by measuring MEG responses from the onset of each word in the ambiguous phrase and the disambiguating word. We used representational similarity analysis (RSA to characterize syntactic information represented in the LIFG and LpMTG over time and to investigate their relationship to each other. Testing a variety of lexico-syntactic and ambiguity models against the MEG data, our results suggest early lexico-syntactic responses in the LpMTG and later effects of ambiguity in the LIFG, pointing to a clear differentiation in the functional roles of these two regions. Our results suggest the LpMTG represents and transmits lexical information to the LIFG, which responds to and resolves the ambiguity.

  1. Ambiguity of care in the experience of drug consumers.

    Science.gov (United States)

    Sena, Edite Lago da Silva; Araújo, Mitze Lopes; Ribeiro, Bárbara Santos; Santos, Vanessa Thamyris Carvalho Dos; Malhado, Sâmia de Carliris Barbosa; Soares, Carine de Jesus; Carvalho, Patrícia Anjos Lima de

    2017-07-20

    To understand the perception of users of a Psychosocial Care Center about care in the context of drug use. Study based on the Phenomenology of Maurice Merleau-Ponty, developed in the Center for Psychosocial Care Alcohol and Other Drugs. The data has been submitted to the Analytical Technique of Ambiguity. The drug use sometimes provides the consumer with pleasurable feelings, sometimes contributing to the occurrence of biopsychosocial harm and/or new possibilities for relationship with the drug. The drug use is an ambiguous process, which corresponds to the perception of different care profiles in the relationship between the consumer and the drug. It is up to the health professionals to recognize the diverse possibilities of care and to favor the construction of therapeutic projects based on listening and respecting the needs of drug users.

  2. Polysemy, syntactic constraints and reduction of ambiguity in controlled languages

    Directory of Open Access Journals (Sweden)

    Krzysztof Bogacki

    2015-01-01

    Full Text Available The article considers such peculiarities of the controlled languages as the choice of lexical units and constraints on their syntax. We review various difficulties that arise during the selection of forms we would like to put in the lexicon of a controlled language. We compare the index of multiple meanings of the words used to form the vocabulary of a controlled language before and after the lexical control and calculate the change in the ambiguity rate of sentences due to the elimination of polysemy. The words allowed in the lexicon of a controlled language usually have a high polysemy index in the standard language. This is evident especially as far as grammatical and non-technical words are concerned. In contrast, technical terms are much more often monosemic. Thus the observation of the “one token = one meaning” principle in the lexicon for the controlled language has a great effect on the decline of ambiguity.

  3. Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity

    DEFF Research Database (Denmark)

    Munk, Claus; Rubtsov, Alexey Vladimirovich

    We solve a stock-bond-cash portfolio choice problem for a risk- and ambiguity-averse investor in a setting where the inflation rate and interest rates are stochastic. The expected inflation rate is unobservable, but the investor may learn about it from realized inflation and observed stock and bond...... prices. The investor is aware that his model for the observed inflation is potentially misspecified, and he seeks an investment strategy that maximizes his expected utility from real terminal wealth and is also robust to inflation model misspecification. We solve the corresponding robust Hamilton......-Jacobi-Bellman equation in closed form and derive and illustrate a number of interesting properties of the solution. For example, ambiguity aversion affects the optimal portfolio through the correlation of price level with the stock index, a bond, and the expected inflation rate. Furthermore, unlike other settings...

  4. The ambiguity of simplicity in quantum and classical simulation

    Science.gov (United States)

    Aghamohammadi, Cina; Mahoney, John R.; Crutchfield, James P.

    2017-04-01

    A system's perceived simplicity depends on whether it is represented classically or quantally. This is not so surprising, as classical and quantum physics are descriptive frameworks built on different assumptions that capture, emphasize, and express different properties and mechanisms. What is surprising is that, as we demonstrate, simplicity is ambiguous: the relative simplicity between two systems can change sign when moving between classical and quantum descriptions. Here, we associate simplicity with small model-memory. We see that the notions of absolute physical simplicity at best form a partial, not a total, order. This suggests that appeals to principles of physical simplicity, via Ockham's Razor or to the ;elegance; of competing theories, may be fundamentally subjective. Recent rapid progress in quantum computation and quantum simulation suggest that the ambiguity of simplicity will strongly impact statistical inference and, in particular, model selection.

  5. Obstetricians' choice of cesarean delivery in ambiguous cases

    DEFF Research Database (Denmark)

    Fuglenes, Dorthe; Oian, Pål; Kristiansen, Ivar Sønbø

    2009-01-01

    OBJECTIVE: The aim of this study was to test the hypothesis that obstetricians' choice of delivery method is influenced by their risk attitude and perceived risk of complaints and malpractice litigation. STUDY DESIGN: The choice of delivery method in ambiguous cases was studied in a nationwide...... survey of Norwegian obstetricians (n = 716; response rate, 71%) using clinical scenarios. The risk attitude was measured by 6 items from the Jackson Personality Inventory-Revised. RESULTS: The proportion of obstetricians consenting to the cesarean request varied both within and across the scenarios....... The perceived risk of complaints and malpractice litigation was a clear determinant of obstetricians' choice of cesarean in all of the clinical scenarios, whereas no impact was observed for risk attitude. CONCLUSION: Obstetricians' judgments about cesarean request in ambiguous clinical cases vary considerably...

  6. Immirzi ambiguity, boosts and conformal frames for black holes

    Energy Technology Data Exchange (ETDEWEB)

    Garay, Luis J; Marugan, Guillermo A Mena [Centro de Fisica Miguel A Catalan, IMAFF, CSIC, Serrano 121, 28006 Madrid (Spain)

    2003-04-21

    We analyse changes of the Immirzi parameter in loop quantum gravity and compare their consequences with those of Lorentz boosts and constant conformal transformations in black-hole physics. We show that the effective value deduced for the Planck length in local measurements of vacuum black holes by an asymptotic observer may depend on its conformal or Lorentz frame. This introduces an apparent ambiguity in the expression of the black-hole entropy which is analogous to that produced by the Immirzi parameter. For quantities involving a notion of energy, the similarity between the implications of the Immirzi ambiguity and a conformal scaling disappears, but the parallelism with boosts is maintained. (letter to the editor)

  7. The ambiguity of confidentiality in a psychoanalytic institute.

    Science.gov (United States)

    Dulchin, J; Segal, A J

    1982-02-01

    Traditionally, psychoanalytic training institutes have used the knowledge which faculty gained in the psychoanalyses of their student patients to evaluate the progress of those students. The training institute that we shall call Eastern Institute regarded such a practice as unacceptable, and organized its program with the intention that analysis would exercise no power over their student patients' careers. The institute's commitment to the confidentiality of psychoanalytic relationships led to an ambiguous definition of confidentiality. This ambiguity meant that some faculty members violated the confidentiality of the analytic relationship even though they believed thye were sustaining it. This paper examines the ways in which confidential information was managed, the conditions under which it was compromised, and the significance of this paradoxical situation in the life of the Institute and in the wider psychoanalytic world.

  8. An Example and Analysis for Ambiguity Resolution in the Indoor ZigBee Positioning System

    Science.gov (United States)

    Janicka, Joanna; Rapinski, Jacek

    2017-06-01

    This paper presents ambiguity resolution in the range-based ZigBee positioning system. The system is using the phase shift measurements to determine the distances between user and anchors. In this paper, the ambiguity is defined as the number of full reps of a certain distance added to the measurement result. The way of resolving ambiguities in the positioning system is described and an experiment results are presented. Featured algorithm is successful in finding ambiguities and correct location of the user.

  9. Exploiting Network Topology Information to Mitigate Ambiguities in VMP Localization

    DEFF Research Database (Denmark)

    Pedersen, Claus; Pedersen, Troels; Fleury, Bernard Henri

    2011-01-01

    We investigate an extension to the probabilistic model of a wireless sensor network (WSN) in the variational message passing localization algorithm. This extension exploits network topology information to mitigate ambiguities in WSN localization schemes. In a simulation case study we show...... that this extension in some cases improves the location estimates produced by the algorithm. The final version of the paper will present quantitative results from more extensive investigations that will document the extent of this improvement....

  10. Coach and athlete perceptions of ambiguous behaviors and sexual harassment

    OpenAIRE

    Hassall, CE; Bringer, JD; Johnston, LH; Brackenridge, CH

    2002-01-01

    The purpose of this study was to examine the perceptions of coaches and athletes of ambiguous behaviors (i.e. actions which may or may not be construed as sexual harassment) in order to inform curriculum development in coach education. This study replicates and extends a previous American study which examined perceptions and experiences of sexual harassment among 210 female college athletes in the USA (Volkwein, et al., 1997). The Americans’ research design was based on earlier work in educat...

  11. Ambiguities: residents' experience of 'nursing home as my home'.

    Science.gov (United States)

    Nakrem, Sigrid; Vinsnes, Anne G; Harkless, Gene E; Paulsen, Bård; Seim, Arnfinn

    2013-09-01

    Residential care in nursing homes continues to be necessary for those individuals who are no longer able to live at home. Uncovering what nursing home residents' view as quality of care in nursing homes will help further understanding of how best to provide high quality, person-centred care. To describe residents' experiences of living in a nursing home related to quality of care. The study utilises a descriptive exploratory design. In-depth interviews were undertaken with 15 residents who were not cognitively impaired, aged 65 and over and living in one of four nursing homes. The interviews were transcribed verbatim and analysed by categorising of meaning. Residents perceived the nursing home as their home, but at the same time not 'a home'. This essential ambiguity created the tension from which the categories of perceptions of quality emerged. Four main categories of quality of care experience were identified: 'Being at home in a nursing home', 'Paying the price for 24-hour care', 'Personal habits and institutional routines', and 'Meaningful activities for a meaningful day'. Ambiguities concerning the nursing home as a home and place to live, a social environment in which the residents experience most of their social life and the institution where professional health service is provided were uncovered. High-quality care was when ambiguities were managed well and a home could be created within the institution. Implication for practice. Achieving quality care in nursing homes requires reconciling the ambiguities of the nursing home as a home. This implies helping residents to create a private home distinct from the professional home, allowing residents' personal habits to guide institutional routines and supporting meaningful activities. Using these resident developed quality indicators is an important step in improving nursing home services. © 2012 Blackwell Publishing Ltd.

  12. The fog of fraud: Mitigating fraud by strategic ambiguity

    OpenAIRE

    Lang, Matthias; Wambach, Achim

    2011-01-01

    Most insurance companies publish few data on the occurrence and detection of insurance fraud. This stands in contrast to the previous literature on costly state verification, which has shown that it is optimal to commit to an auditing strategy, as the credible announcement of thoroughly auditing claim reports might act as a powerful deterrent. We show that uncertainty about fraud detection can be an effective strategy to deter ambiguity-averse agents from reporting false insurance claims. If,...

  13. Representation and Reference

    NARCIS (Netherlands)

    Ankersmit, F.R.

    2010-01-01

    This essay focuses on the historical text as a whole. It does so by conceiving of the historical text as representation - in the way the we may say of a photo or a painting that it represents the person depicted on it. It is argued that representation cannot be properly understood by modelling it on

  14. Wigner's Symmetry Representation Theorem

    Indian Academy of Sciences (India)

    IAS Admin

    This article elucidates the important role the no- tion of symmetry has played in physics. It dis- cusses the proof of one of the important theorems of quantum mechanics, viz., Wigner's Symmetry. Representation Theorem. It also shows how the representations of various continuous and dis- crete symmetries follow from the ...

  15. MORPHOLOGICAL REPRESENTATION AND SEMANTIC ...

    African Journals Online (AJOL)

    MORPHOLOGICAL REPRESENTATION AND SEMANTIC INTERPRETATION. Rudolf P. Botha. Introduction ... The morphological representation assigned to a complex word must provide the formal structure required ..... It has been argued in the literature that "markedness" claims such as. (16)(a) and (b) are unacceptable ...

  16. Resolution of ambiguous radar measurements using a floating bin correlator

    Science.gov (United States)

    Addison, E. R.; Frost, E. L.

    It is pointed out that the Chinese Remainder Theorem (Mooney and Skillman, 1970) can be used to yield unambiguous measurements by comparing outputs allocated to fixed integer number bins using integer arithmetic to modulo to the correct bin number. In general, targets straddling two or more bins or the assignment of an incorrect bin number will yield incorrect parameter values. An ambiguity resolution technique using multiple pulse repetition frequency (PRF) data and a sliding floating point window or 'floating bin' to correlate ambiguous centroided Doppler measurements is proposed. An advantage of the technique is that false targets are much less prevalent than in classical techniques. What is more, the same technique may be employed to resolve ambiguous range wherein centroided range measurements are moduloed with the pulse repetition interval associated with each PRF. Results demonstrate that this method is better than conventional approaches in that the number of false targets produced is significantly lower while simultaneoulsy providing a high probability of correlation. In addition, the correlation can be effected in real time.

  17. Teaching weight to explicitly address language ambiguities and conceptual difficulties

    Directory of Open Access Journals (Sweden)

    Rex Taibu

    2017-06-01

    Full Text Available Language ambiguities in concept meanings can exacerbate student learning difficulties and conceptual understanding of physics concepts. This is especially true for the concept of “weight,” which has multiple meanings in both scientific and everyday usage. The term weight has been defined in several different ways, with nuances, but in textbooks and teaching the term is almost always defined in one of two ways: operationally either as the contact force between an object and a measuring scale or as the gravitational force on an object due to some other body such as Earth. The use of the same name for different concepts leads to much confusion, especially in accelerating situations, and to conflicting notions of “weightlessness” in free fall situations. In the present paper, we share an innovative approach that initially avoids the term weight entirely while teaching the physics of each situation, and then teaches the language ambiguities explicitly. We developed an instructional module with this approach and implemented it over two terms in three sections of an introductory physics course for preservice elementary teachers. Learning gains for content understanding were assessed using pretests and post-tests. Participants achieved remarkably high gains for both static and accelerating situations. Surveys pre- and postinstruction showed substantially improved appreciation of language issues and ambiguities associated with weight, weightlessness, and free fall. Interviews with instructors teaching the module provided additional insight into the advantages and teaching demands of the new approach.

  18. Textbook presentations of weight: Conceptual difficulties and language ambiguities

    Science.gov (United States)

    Taibu, Rex; Rudge, David; Schuster, David

    2015-06-01

    The term "weight" has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. This poses both conceptual and language difficulties for learners, especially for accelerating objects where the scale reading is different from the gravitational force. But while the underlying physical constructs behind the two referents for the term weight (and their relation to each other) are well understood scientifically, it is unclear how the concept of weight should be introduced to students and how the language ambiguities should be dealt with. We investigated treatments of weight in a sample of twenty introductory college physics textbooks, analyzing and coding their content based on the definition adopted, how the distinct constructs were dealt with in various situations, terminologies used, and whether and how language issues were handled. Results indicate that language-related issues, such as different, inconsistent, or ambiguous uses of the terms weight, "apparent weight," and "weightlessness," were prevalent both across and within textbooks. The physics of the related constructs was not always clearly presented, particularly for accelerating bodies such as astronauts in spaceships, and the language issue was rarely addressed. Our analysis of both literature and textbooks leads us to an instructional position which focuses on the physics constructs before introducing the term weight, and which explicitly discusses the associated language issues.

  19. Teaching weight to explicitly address language ambiguities and conceptual difficulties

    Science.gov (United States)

    Taibu, Rex; Schuster, David; Rudge, David

    2017-06-01

    Language ambiguities in concept meanings can exacerbate student learning difficulties and conceptual understanding of physics concepts. This is especially true for the concept of "weight," which has multiple meanings in both scientific and everyday usage. The term weight has been defined in several different ways, with nuances, but in textbooks and teaching the term is almost always defined in one of two ways: operationally either as the contact force between an object and a measuring scale or as the gravitational force on an object due to some other body such as Earth. The use of the same name for different concepts leads to much confusion, especially in accelerating situations, and to conflicting notions of "weightlessness" in free fall situations. In the present paper, we share an innovative approach that initially avoids the term weight entirely while teaching the physics of each situation, and then teaches the language ambiguities explicitly. We developed an instructional module with this approach and implemented it over two terms in three sections of an introductory physics course for preservice elementary teachers. Learning gains for content understanding were assessed using pretests and post-tests. Participants achieved remarkably high gains for both static and accelerating situations. Surveys pre- and postinstruction showed substantially improved appreciation of language issues and ambiguities associated with weight, weightlessness, and free fall. Interviews with instructors teaching the module provided additional insight into the advantages and teaching demands of the new approach.

  20. Cross-linguistic scope ambiguity: When two systems meet

    Directory of Open Access Journals (Sweden)

    Gregory Scontras

    2017-04-01

    Full Text Available Accurately recognizing and resolving ambiguity is a hallmark of linguistic ability. English is a language with scope ambiguities in doubly-quantified sentences like 'A shark ate every pirate'; this sentence can either describe a scenario with a single shark eating all of the pirates, or a scenario with many sharks—a potentially-different one eating each pirate. In Mandarin Chinese, the corresponding sentence is unambiguous, as it can only describe the single-shark scenario. We present experimental evidence to this effect, comparing native speakers of English with native speakers of Mandarin in their interpretations of doubly-quantified sentences. Having demonstrated the difference between these two languages in their ability for inverse scope interpretations, we then probe the robustness of the grammar of scope by extending our experiments to English-dominant adult heritage speakers of Mandarin. Like native speakers of Mandarin, heritage Mandarin speakers lack inverse scope in Mandarin. Crucially, these speakers also lack inverse scope in English, their dominant language in adulthood. We interpret these results as evidence for the pressure to simplify the grammar of scope, decreasing ambiguity when possible. In other words, when two systems meet—as in the case of heritage speakers—the simpler system prevails. This article is part of the special collection: Quantifier Scope

  1. Another Kind of Ambiguous Loss: Seventh-Day Adventist Women in Mixed-Orientation Marriages

    Science.gov (United States)

    Hernandez, Barbara C.; Wilson, Colwick M.

    2007-01-01

    Narratives of five Seventh-day Adventist heterosexual women whose mixed-orientation marriages ended were analyzed through the lens of ambiguous loss. Thematic coding identified a wave-like process of changing emotional foci that emerged from their experience during marital dissolution. Elements of ambiguous loss included boundary ambiguity,…

  2. Ambiguous Loss after Lesbian Couples with Children Break up: A Case for Same-Gender Divorce

    Science.gov (United States)

    Allen, Katherine R.

    2007-01-01

    The theory of ambiguous loss is applied to structural ambiguity and personal transcendence in the parent-child relationship following a same-gender relational ending. Working recursively through the six guidelines of ambiguous loss (finding meaning, tempering mastery, reconstructing identity, normalizing ambivalence, revising attachment, and…

  3. Embedded data representations

    DEFF Research Database (Denmark)

    Willett, Wesley; Jansen, Yvonne; Dragicevic, Pierre

    2017-01-01

    We introduce embedded data representations, the use of visual and physical representations of data that are deeply integrated with the physical spaces, objects, and entities to which the data refers. Technologies like lightweight wireless displays, mixed reality hardware, and autonomous vehicles...... are making it increasingly easier to display data in-context. While researchers and artists have already begun to create embedded data representations, the benefits, trade-offs, and even the language necessary to describe and compare these approaches remain unexplored. In this paper, we formalize the notion...... of physical data referents – the real-world entities and spaces to which data corresponds – and examine the relationship between referents and the visual and physical representations of their data. We differentiate situated representations, which display data in proximity to data referents, and embedded...

  4. Group and representation theory

    CERN Document Server

    Vergados, J D

    2017-01-01

    This volume goes beyond the understanding of symmetries and exploits them in the study of the behavior of both classical and quantum physical systems. Thus it is important to study the symmetries described by continuous (Lie) groups of transformations. We then discuss how we get operators that form a Lie algebra. Of particular interest to physics is the representation of the elements of the algebra and the group in terms of matrices and, in particular, the irreducible representations. These representations can be identified with physical observables. This leads to the study of the classical Lie algebras, associated with unitary, unimodular, orthogonal and symplectic transformations. We also discuss some special algebras in some detail. The discussion proceeds along the lines of the Cartan-Weyl theory via the root vectors and root diagrams and, in particular, the Dynkin representation of the roots. Thus the representations are expressed in terms of weights, which are generated by the application of the elemen...

  5. Businesswomen, dabblers, revivalists or conmen? : representation of selling and salespeople within academic, network marketing practitioner and media discourses

    OpenAIRE

    Oksanen-Ylikoski, Elina

    2006-01-01

    Representation of selling and salespeople within academic, network marketing practitioner and media discourses In this study, my purpose is to explore conflicting representations of selling and especially network marketing (NM). My first objective is to identify the fundamental features of sales discourses within academic and practitioner communities. The second objective is to understand in what ways the combination and contestation of these discourses produce ambiguous images of selling and...

  6. Identifying bilingual semantic neural representations across languages

    Science.gov (United States)

    Buchweitz, Augusto; Shinkareva, Svetlana V.; Mason, Robert A.; Mitchell, Tom M.; Just, Marcel Adam

    2015-01-01

    The goal of the study was to identify the neural representation of a noun's meaning in one language based on the neural representation of that same noun in another language. Machine learning methods were used to train classifiers to identify which individual noun bilingual participants were thinking about in one language based solely on their brain activation in the other language. The study shows reliable (p languages. It also shows that the stable voxels used to classify the brain activation were located in areas associated with encoding information about semantic dimensions of the words in the study. The identification of the semantic trace of individual nouns from the pattern of cortical activity demonstrates the existence of a multi-voxel pattern of activation across the cortex for a single noun common to both languages in bilinguals. PMID:21978845

  7. Unraveling the Symmetry Ambiguity in a Hexamer: Calculation of the R6 Human Insulin Structure

    DEFF Research Database (Denmark)

    O'Donoghue, Sean I.; Chang, Xiaoqing; Abseher, Roger

    2000-01-01

    ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers......ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers...

  8. Media theory: Representations and examples

    National Research Council Canada - National Science Library

    Ovchinnikov, Sergei

    2008-01-01

    In this paper we develop a representational approach to media theory. We construct representations of media by well-graded families of sets and partial cubes and establish the uniqueness of these representations...

  9. Decision-Making under Ambiguity Is Modulated by Visual Framing, but Not by Motor vs. Non-Motor Context. Experiments and an Information-Theoretic Ambiguity Model.

    Science.gov (United States)

    Grau-Moya, Jordi; Ortega, Pedro A; Braun, Daniel A

    2016-01-01

    A number of recent studies have investigated differences in human choice behavior depending on task framing, especially comparing economic decision-making to choice behavior in equivalent sensorimotor tasks. Here we test whether decision-making under ambiguity exhibits effects of task framing in motor vs. non-motor context. In a first experiment, we designed an experience-based urn task with varying degrees of ambiguity and an equivalent motor task where subjects chose between hitting partially occluded targets. In a second experiment, we controlled for the different stimulus design in the two tasks by introducing an urn task with bar stimuli matching those in the motor task. We found ambiguity attitudes to be mainly influenced by stimulus design. In particular, we found that the same subjects tended to be ambiguity-preferring when choosing between ambiguous bar stimuli, but ambiguity-avoiding when choosing between ambiguous urn sample stimuli. In contrast, subjects' choice pattern was not affected by changing from a target hitting task to a non-motor context when keeping the stimulus design unchanged. In both tasks subjects' choice behavior was continuously modulated by the degree of ambiguity. We show that this modulation of behavior can be explained by an information-theoretic model of ambiguity that generalizes Bayes-optimal decision-making by combining Bayesian inference with robust decision-making under model uncertainty. Our results demonstrate the benefits of information-theoretic models of decision-making under varying degrees of ambiguity for a given context, but also demonstrate the sensitivity of ambiguity attitudes across contexts that theoretical models struggle to explain.

  10. Contorted and ordinary body postures in the human brain

    NARCIS (Netherlands)

    Cross, E.S.; Mackie, E.C.; Wolford, G.; Hamilton, A.F.D.C.

    2010-01-01

    Social interaction and comprehension of non-verbal behaviour requires a representation of people's bodies. Research into the neural underpinnings of body representation implicates several brain regions including extrastriate and fusiform body areas (EBA and FBA), superior temporal sulcus (STS),

  11. Representational similarity analysis - connecting the branches of systems neuroscience

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available A fundamental challenge for systems neuroscience is to quantitatively relate its three major branches of research: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g. single-cell recordings or voxels from functional magnetic resonance imaging (fMRI. Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement, and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices, which characterize the information carried by a given representation in a brain or model. We propose a new experimental and data-analytical framework called representational similarity analysis (RSA, in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing representational dissimilarity matrices. We demonstrate RSA by relating representations of visual objects as measured with fMRI to computational models spanning a wide range of complexities. We argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience.

  12. Graphic representation of data of coal deposits

    Directory of Open Access Journals (Sweden)

    Honìk Josef

    2002-09-01

    Full Text Available Entirely new method of graphic representation of data stored in database is elaborated within frame of processing of system for rapid evaluation of coal deposits. Petrographic and geological symbols have been generated mostly by creation of singular pattern for each rock type including its impurities and other features. However, such a conventional symbols do not allow represent number of combinations of features typical for rocks in real occurrences. Any further information (for instance calcareous impurity, coal fragments etc. multiplies the existing number of patterns. The consequence is that there are many patterns for only most frequently occurring coal, rock and transitory rock types. The main principle of new symbol creation is based on mutual combining of symbols. Thereby all essential characteristics of coals and rocks can be represented graphically in whatever combination while preserving lucidity and non-ambiguity conditions. Representation of particular proportions of three-grain sized components in rock indicating by adverbial expressions of highly, slightly and medium (for instance slightly sandy highly silt clay is enabled. Particular types of coal occurring in transition rocks are represented by appropriate graphical symbols according to genetic type. Problems with old terms of coals and rocks according to other types of classification were taken into consideration. At elaboration of the system, hitherto valid regulations, usage and standards were consulted. The resultant system is simple and easy to control in face of options it enables.

  13. Mapping phantom movement representations in the motor cortex of amputees.

    Science.gov (United States)

    Mercier, Catherine; Reilly, Karen T; Vargas, Claudia D; Aballea, Antoine; Sirigu, Angela

    2006-08-01

    Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a phantom limb endowed with sensory and motor qualities. How can cortical reorganization after amputation be reconciled with the maintenance of a motor representation of the phantom limb in the brain? In an attempt to answer this question we explored the relationship between the cortical representation of the remaining arm muscles and that of phantom movements. Using transcranial magnetic stimulation (TMS) we systematically mapped phantom movement perceptions while simultaneously recording stump muscle activity in three above-elbow amputees. TMS elicited sensations of movement in the phantom hand when applied over the presumed hand area of the motor cortex. In one subject the amplitude of the perceived movement was positively correlated with the intensity of stimulation. Interestingly, phantom limb movements that the patient could not produce voluntarily were easily triggered by TMS, suggesting that the inability to voluntarily move the phantom is not equivalent to a loss of the corresponding movement representation. We suggest that hand movement representations survive in the reorganized motor area of amputees even when these cannot be directly accessed. The activation of these representations is probably necessary for the experience of phantom movement.

  14. Ambiguity and Investment Decisions: An Empirical Analysis on Mutual Fund Investor Behaviour

    Directory of Open Access Journals (Sweden)

    Chao Tang

    2017-09-01

    Full Text Available The paper empirically studies the relationship between ambiguity and mutual fund investor behaviour. Theoretical models for investment decisions incorporating ambiguity motivate our analyses. While the models indicate that investors would less likely to invest in financial markets when ambiguity increases, there is rare empirical evidence in natural occurring financial data to examine this hypothesis. In this paper, we test the hypothesis with equity fund flow data as for investment decisions and ambiguity with the degree of disagreement in equity analysts’ prediction about asset returns. Our results support the hypothesis that increases in ambiguity could lead to less fund flows and this result remains consistently when adding various control variables affecting fund flows. Besides, we find that heterogeneous impacts of ambiguity: equity funds with high yield targets and active management style are affected more than funds investing in stable stocks; funds with larger proportion of institutional investors are more sensitive and affected by the ambiguity.

  15. Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities

    Science.gov (United States)

    Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

    2014-01-01

    Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901

  16. Nest-representable tolerances

    OpenAIRE

    Lipparini, Paolo

    2017-01-01

    We introduce the notion of a nest-representable tolerance and show that some results from our former paper "From congruence identities to tolerance identities" [CT] can be extended to this more general setting.

  17. Hyperfinite representation of distributions

    Indian Academy of Sciences (India)

    Hyperfinite representation of distributions is studied following the method introduced by Kinoshita [2, 3], although we use a different approach much in the vein of [4]. Products and Fourier transforms of representatives of distributions are also analysed.

  18. Wigner's Symmetry Representation Theorem

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 10. Wigner's Symmetry Representation Theorem: At the Heart of Quantum Field Theory! Aritra Kr Mukhopadhyay. General Article Volume 19 Issue 10 October 2014 pp 900-916 ...

  19. Boundary representation modelling techniques

    CERN Document Server

    2006-01-01

    Provides the most complete presentation of boundary representation solid modelling yet publishedOffers basic reference information for software developers, application developers and users Includes a historical perspective as well as giving a background for modern research.

  20. Switch-Independent Task Representations in Frontal and Parietal Cortex.

    Science.gov (United States)

    Loose, Lasse S; Wisniewski, David; Rusconi, Marco; Goschke, Thomas; Haynes, John-Dylan

    2017-08-16

    Alternating between two tasks is effortful and impairs performance. Previous fMRI studies have found increased activity in frontoparietal cortex when task switching is required. One possibility is that the additional control demands for switch trials are met by strengthening task representations in the human brain. Alternatively, on switch trials, the residual representation of the previous task might impede the buildup of a neural task representation. This would predict weaker task representations on switch trials, thus also explaining the performance costs. To test this, male and female participants were cued to perform one of two similar tasks, with the task being repeated or switched between successive trials. Multivoxel pattern analysis was used to test which regions encode the tasks and whether this encoding differs between switch and repeat trials. As expected, we found information about task representations in frontal and parietal cortex, but there was no difference in the decoding accuracy of task-related information between switch and repeat trials. Using cross-classification, we found that the frontoparietal cortex encodes tasks using a generalizable spatial pattern in switch and repeat trials. Therefore, task representations in frontal and parietal cortex are largely switch independent. We found no evidence that neural information about task representations in these regions can explain behavioral costs usually associated with task switching.SIGNIFICANCE STATEMENT Alternating between two tasks is effortful and slows down performance. One possible explanation is that the representations in the human brain need time to build up and are thus weaker on switch trials, explaining performance costs. Alternatively, task representations might even be enhanced to overcome the previous task. Here, we used a combination of fMRI and a brain classifier to test whether the additional control demands under switching conditions lead to an increased or decreased strength

  1. Exergy representations in thermodynamics

    OpenAIRE

    Favrat, Daniel; Maréchal, François

    2015-01-01

    The paper reviews various representations of exergy and exergy losses in energy systems going from simple heat exchanger (heat transfer, dissipation and embedded exergy) to the exergy of full energy systems from fossil or non fossil resources (including the diffusion exergy). The systems shown include shell in tube heat exchangers, thermal power cycles, cogeneration, heat pump direct heating systems and cryogenic systems. The representations include simple gravitational analogies to extended ...

  2. Textbook presentations of weight: Conceptual difficulties and language ambiguities

    Directory of Open Access Journals (Sweden)

    Rex Taibu

    2015-06-01

    Full Text Available The term “weight” has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. This poses both conceptual and language difficulties for learners, especially for accelerating objects where the scale reading is different from the gravitational force. But while the underlying physical constructs behind the two referents for the term weight (and their relation to each other are well understood scientifically, it is unclear how the concept of weight should be introduced to students and how the language ambiguities should be dealt with. We investigated treatments of weight in a sample of twenty introductory college physics textbooks, analyzing and coding their content based on the definition adopted, how the distinct constructs were dealt with in various situations, terminologies used, and whether and how language issues were handled. Results indicate that language-related issues, such as different, inconsistent, or ambiguous uses of the terms weight, “apparent weight,” and “weightlessness,” were prevalent both across and within textbooks. The physics of the related constructs was not always clearly presented, particularly for accelerating bodies such as astronauts in spaceships, and the language issue was rarely addressed. Our analysis of both literature and textbooks leads us to an instructional position which focuses on the physics constructs before introducing the term weight, and which explicitly discusses the associated language issues.

  3. Dressed skeleton expansion and the coupling scale ambiguity problem

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hung Jung.

    1992-09-01

    Perturbative expansions in quantum field theories are usually expressed in powers of a coupling constant. In principle, the infinite sum of the expansion series is independent of the renormalization scale of the coupling constant. In practice, there is a remnant dependence of the truncated series on the renormalization scale. This scale ambiguity can severely restrict the predictive power of theoretical calculations. The dressed skeleton expansion is developed as a calculational method which avoids the coupling scale ambiguity problem. In this method, physical quantities are expressed as functional expansions in terms of a coupling vertex function. The arguments of the vertex function are given by the physical momenta of each process. These physical momenta effectively replace the unspecified renormalization scale and eliminate the ambiguity problem. This method is applied to various field theoretical models and its main features and limitations are explored. For quantum chromodynamics, an expression for the running coupling constant of the three-gluon vertex is obtained. The effective coupling scale of this vertex is shown to be essentially given by [mu][sup 2] [approximately] Q[sub min][sup 2]Q[sub med][sup 2]/Q[sub max][sup 2] where Q[sub min][sup 2]Q[sub med][sup 2]/Q[sub max][sup 2] are respectively the smallest, the next-to-smallest and the largest scale among the three gluon virtualities. This functional form suggests that the three-gluon vertex becomes non-perturbative at asymmetric momentum configurations. Implications for four-jet physics is discussed.

  4. Dressed skeleton expansion and the coupling scale ambiguity problem

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hung Jung

    1992-09-01

    Perturbative expansions in quantum field theories are usually expressed in powers of a coupling constant. In principle, the infinite sum of the expansion series is independent of the renormalization scale of the coupling constant. In practice, there is a remnant dependence of the truncated series on the renormalization scale. This scale ambiguity can severely restrict the predictive power of theoretical calculations. The dressed skeleton expansion is developed as a calculational method which avoids the coupling scale ambiguity problem. In this method, physical quantities are expressed as functional expansions in terms of a coupling vertex function. The arguments of the vertex function are given by the physical momenta of each process. These physical momenta effectively replace the unspecified renormalization scale and eliminate the ambiguity problem. This method is applied to various field theoretical models and its main features and limitations are explored. For quantum chromodynamics, an expression for the running coupling constant of the three-gluon vertex is obtained. The effective coupling scale of this vertex is shown to be essentially given by {mu}{sup 2} {approximately} Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} where Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} are respectively the smallest, the next-to-smallest and the largest scale among the three gluon virtualities. This functional form suggests that the three-gluon vertex becomes non-perturbative at asymmetric momentum configurations. Implications for four-jet physics is discussed.

  5. SAR antenna design for ambiguity and multipath suppression

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz; Dich, Mikael

    1993-01-01

    A high resolution airborne synthetic aperture radar (SAR) has been developed at the Electromagnetics Institute (EMI) for remote sensing applications. The paper considers the radiation of antennas for a SAR system from a systems perspective. The basic specifications of an idealised antenna...... are obtained from the required swath and the azimuth footprint needed for the SAR processing. The radiation from a real antenna causes unwanted signal returns that lead to intensity variations (multipath) and ghost echoes (ambiguity). Additional specifications are deduced by considering these signals...

  6. Resolving the sign ambiguity in the singular value decomposition.

    Energy Technology Data Exchange (ETDEWEB)

    Bro, Rasmus (University of Copenhagen, Frederiksberg C, Denmark); Acar, Evrim (Rensselaer Polytechnic Institute, Troy, NY); Kolda, Tamara Gibson

    2007-10-01

    Many modern data analysis methods involve computing a matrix singular value decomposition (SVD) or eigenvalue decomposition (EVD). Principal components analysis is the time-honored example, but more recent applications include latent semantic indexing, hypertext induced topic selection (HITS), clustering, classification, etc. Though the SVD and EVD are well-established and can be computed via state-of-the-art algorithms, it is not commonly mentioned that there is an intrinsic sign indeterminacy that can significantly impact the conclusions and interpretations drawn from their results. Here we provide a solution to the sign ambiguity problem and show how it leads to more sensible solutions.

  7. Role of MRI in the evaluation of ambiguous genitalia

    Energy Technology Data Exchange (ETDEWEB)

    Secaf, E. (Dept. of Radiology, Univ. of California School of Medicine, San Francisco, CA (United States) Dept. de Radiologia, Faculdade de Medicina da Univ. de Sao Paulo (Brazil)); Hricak, H. (Dept. of Radiology, Univ. of California School of Medicine, San Francisco, CA (United States) Dept. of Urology, Univ. of California School of Medicine, San Francisco, CA (United States)); Gooding, C.A. (Dept. of Radiology, Univ. of California School of Medicine, San Francisco, CA (United States) Dept. of Pediatrics, Univ. of California School of Medicine, San Francisco, CA (United States)); Ho, V.W. (Dept. of Radiology, Univ. of California School of Medicine, San Francisco, CA (United States)); Gorczyca, D.P. (Dept. of Radiology, Univ. of California School of Medicine, San Francisco, CA (United States) Dept. of Radiology, Univ. of California, Los Angeles, CA (United States)); Ringertz, H. (Dept. of Diagnostic Radiology, Karolinska Hospital, Stockholm (Sweden)); Conte, F.A. (Dept. of Pediatr

    1994-08-01

    Diagnostic accuracy of magnetic resonance imaging (MRI) interpretation was assessed prospectively in patients with ambiguous genitalia or intersex problems. MRI depiction of the uterus was possible in 93 %, the vagina in 95 %, the penis in 100 %, the testis in 88 %, and the ovary in 74 % of patients. The strength of MRI lies in the multiplanar capability and tissue characterization by means of T1- and T2-weighted sequences. MRI contributes to accurate morphologic evaluation of muellerian duct structures, the gonads, and the development of the phallus, all of which are essential for appropriate gender assignment and planning of surgical reconstruction. (orig.)

  8. Gribov ambiguities at the Landau-maximal Abelian interpolating gauge

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Antonio D.; Sobreiro, Rodrigo F. [UFF-Universidade Federal Fluminense, Instituto de Fisica, Niteroi, RJ (Brazil)

    2014-08-15

    In a previous work, we presented a new method to account for the Gribov ambiguities in non-Abelian gauge theories. The method consists on the introduction of an extra constraint which directly eliminates the infinitesimal Gribov copies without the usual geometric approach. Such strategy allows one to treat gauges with non-hermitian Faddeev-Popov operator. In this work, we apply this method to a gauge which interpolates among the Landau and maximal Abelian gauges. The result is a local and power counting renormalizable action, free of infinitesimal Gribov copies. Moreover, the interpolating tree-level gluon propagator is derived. (orig.)

  9. Sibling jealousy and aesthetic ambiguity in Austen's Pride and Prejudice.

    Science.gov (United States)

    Hanly, Margaret Ann Fitzpatrick

    2009-04-01

    Jane Austen's most popular novel, Pride and Prejudice (1813), illuminates and is illuminated by psychoanalytic aesthetics. When Austen dramatizes unconscious oedipal/sibling rivalries, irony acts as a type of aesthetic ambiguity (E. Kris 1952). A psychoanalytic perspective shows that Austen uses a grammar of negatives (negation, denial, minimization) to achieve the dual meanings of irony, engaging the reader's unconscious instinctual satisfactions, while at the same time protecting the reader from unpleasant affects. Austen's plot, which portrays regressions driven by sibling jealousy, reveals that a new tolerance of remorse and depression in her heroine and hero leads to psychic growth.

  10. Resolving ambiguities in reconstructed grain maps using discrete tomography

    DEFF Research Database (Denmark)

    Alpers, A.; Knudsen, E.; Poulsen, H.F.

    2005-01-01

    The so-called 3DXRD microscope, implemented at the European Synchrotron Radiation Facility in Grenoble, France, utilizes the principle of X-ray diffraction for mapping the crystalline grains within hard materials such as metals or ceramics. Present algorithms, using continuous models, roughly...... reconstruct the image from diffraction data, but they are often unable to assign unambiguous values to all pixels. We present an approach that resolves these ambiguous pixels by using a Monte Carlo technique that exploits the discrete nature of the problem and utilizes proven methods of discrete tomography...

  11. Representational models: A common framework for understanding encoding, pattern-component, and representational-similarity analysis.

    Directory of Open Access Journals (Sweden)

    Jörn Diedrichsen

    2017-04-01

    Full Text Available Representational models specify how activity patterns in populations of neurons (or, more generally, in multivariate brain-activity measurements relate to sensory stimuli, motor responses, or cognitive processes. In an experimental context, representational models can be defined as hypotheses about the distribution of activity profiles across experimental conditions. Currently, three different methods are being used to test such hypotheses: encoding analysis, pattern component modeling (PCM, and representational similarity analysis (RSA. Here we develop a common mathematical framework for understanding the relationship of these three methods, which share one core commonality: all three evaluate the second moment of the distribution of activity profiles, which determines the representational geometry, and thus how well any feature can be decoded from population activity. Using simulated data for three different experimental designs, we compare the power of the methods to adjudicate between competing representational models. PCM implements a likelihood-ratio test and therefore provides the most powerful test if its assumptions hold. However, the other two approaches-when conducted appropriately-can perform similarly. In encoding analysis, the linear model needs to be appropriately regularized, which effectively imposes a prior on the activity profiles. With such a prior, an encoding model specifies a well-defined distribution of activity profiles. In RSA, the unequal variances and statistical dependencies of the dissimilarity estimates need to be taken into account to reach near-optimal power in inference. The three methods render different aspects of the information explicit (e.g. single-response tuning in encoding analysis and population-response representational dissimilarity in RSA and have specific advantages in terms of computational demands, ease of use, and extensibility. The three methods are properly construed as complementary components

  12. Contacts de langues et representations (Language Contacts and Representations).

    Science.gov (United States)

    Matthey, Marinette, Ed.

    1997-01-01

    Essays on language contact and the image of language, entirely in French, include: "Representations 'du' contexte et representations 'en' contexte? Eleves et enseignants face a l'apprentissage de la langue" ("Representations 'of' Context or Representations 'in' Context? Students and Teachers Facing Language Learning" (Laurent…

  13. The representation of erroneously perceived stimuli in the primary visual cortex

    NARCIS (Netherlands)

    Roelfsema, P. R.; Spekreijse, H.

    2001-01-01

    In order to attain a correct interpretation of an ambiguous visual stimulus, the brain may have to elaborate on the sensory evidence. Are the neurons that carry the sensory evidence also involved in generating an interpretation? To address this question, we studied the activity of neurons in the

  14. The feeling of movement: EEG evidence for mirroring activity during the observations of static, ambiguous stimuli in the Rorschach cards.

    Science.gov (United States)

    Giromini, Luciano; Porcelli, Piero; Viglione, Donald J; Parolin, Laura; Pineda, Jaime A

    2010-10-01

    The mirror neuron system (MNS) is considered the best explanation for the neural basis of embodied simulation. To date no study has investigated if it may be activated not only by actual but by the "feeling of movement". The Rorschach test cards were used to investigate evidence of EEG mu wave suppression at central areas, an index of MNS activity, since human movement responses (M) to the Rorschach elicit such feelings of movement. Nineteen healthy volunteers observed different sets of Rorschach stimuli during attribution, identification, and observation of human movements and different scenarios while their EEG were recorded. Significant mu suppression occurred when subjects perceived movement, regardless of the experimental condition. These results show that mirroring can be activated by static, ambiguous stimuli such as Rorschach cards, suggesting that internal representation of the "feeling of movement" may be sufficient to trigger MNS activity even when minimal external cues are present. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Does movement influence representations of time and space?

    Directory of Open Access Journals (Sweden)

    Jonna Loeffler

    Full Text Available Embodied cognition posits that abstract conceptual knowledge such as mental representations of time and space are at least partially grounded in sensorimotor experiences. If true, then the execution of whole-body movements should result in modulations of temporal and spatial reference frames. To scrutinize this hypothesis, in two experiments participants either walked forward, backward or stood on a treadmill and responded either to an ambiguous temporal question (Experiment 1 or an ambiguous spatial question (Experiment 2 at the end of the walking manipulation. Results confirmed the ambiguousness of the questions in the control condition. Nevertheless, despite large power, walking forward or backward did not influence the answers or response times to the temporal (Experiment 1 or spatial (Experiment 2 question. A follow-up Experiment 3 indicated that this is also true for walking actively (or passively in free space (as opposed to a treadmill. We explore possible reasons for the null-finding as concerns the modulation of temporal and spatial reference frames by movements and we critically discuss the methodological and theoretical implications.

  16. From expert generalists to ambiguity masters: using ambiguity tolerance theory to redefine the practice of rural nurses.

    Science.gov (United States)

    Knight, Kaye; Kenny, Amanda; Endacott, Ruth

    2016-06-01

    To redefine the practice of rural nurses and describe a model that conceptualises the capabilities and characteristics required in the rural environment. The way in which the practice of rural nurses has been conceptualised is problematic. Definitions of rural nursing have been identified primarily through the functional context of rural health service delivery. The expert generalist term has provided a foundation theory for rural nurses with understandings informed by the scope of practice needed to meet service delivery requirements. However, authors exploring intrinsic characteristics of rural nurses have challenged this definition, as it does not adequately address the deeper, intangible complexities of practice required in the rural context. Despite this discourse, an alternative way to articulate the distinctive nature of rural nursing practice has eluded authors in Australia and internationally. A theoretical paper based on primary research. The development of the model was informed by the findings of a study that explored the nursing practice of managing telephone presentations in rural health services in Victoria, Australia. The study involved policy review from State and Federal governments, nursing and medical professional bodies, and five rural health services; semi-structured interviews with eight Directors of Nursing, seven registered nurses and focus group interviews with eight registered nurses. An ambiguity tolerance model drawn from corporate global entrepreneurship theory was adapted to explain the findings of the study. The adapted model presents capabilities and characteristics used by nurses to successfully manage the ambiguity of providing care in the rural context. Redefining the practice of rural nurses, through an adapted theory of ambiguity tolerance, highlights nursing characteristics and capabilities required in the rural context. This perspective offers new ways of thinking about the work of rural nurses, rural nurse policy, education

  17. Interpreting ambiguous 'trace' results in Schistosoma mansoni CCA Tests: Estimating sensitivity and specificity of ambiguous results with no gold standard.

    Science.gov (United States)

    Clements, Michelle N; Donnelly, Christl A; Fenwick, Alan; Kabatereine, Narcis B; Knowles, Sarah C L; Meité, Aboulaye; N'Goran, Eliézer K; Nalule, Yolisa; Nogaro, Sarah; Phillips, Anna E; Tukahebwa, Edridah Muheki; Fleming, Fiona M

    2017-12-01

    The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities. A point-of-care circulating cathodic antigen (CCA) test has been shown to be more sensitive than KK. However, CCA can return an ambiguous 'trace' result between 'positive' and 'negative', and much debate has focused on interpretation of traces results. We show how LCA can be extended to include ambiguous trace results and analyse S. mansoni studies from both Côte d'Ivoire (CdI) and Uganda. We compare the diagnostic performance of KK and CCA and the observed results by each test to the estimated infection prevalence in the population. Prevalence by KK was higher in CdI (13.4%) than in Uganda (6.1%), but prevalence by CCA was similar between countries, both when trace was assumed to be negative (CCAtn: 11.7% in CdI and 9.7% in Uganda) and positive (CCAtp: 20.1% in CdI and 22.5% in Uganda). The estimated sensitivity of CCA was more consistent between countries than the estimated sensitivity of KK, and estimated infection prevalence did not significantly differ between CdI (20.5%) and Uganda (19.1%). The prevalence by CCA with trace as positive did not differ significantly from estimates of infection prevalence in either country, whereas both KK and CCA with trace as negative significantly underestimated infection prevalence in both countries. Incorporation of ambiguous results into an LCA enables the effect of different treatment thresholds to be directly assessed and is applicable in many fields. Our results showed that CCA with trace as positive most accurately estimated infection prevalence.

  18. Lexical is as lexical does: computational approaches to lexical representation

    Science.gov (United States)

    Woollams, Anna M.

    2015-01-01

    In much of neuroimaging and neuropsychology, regions of the brain have been associated with ‘lexical representation’, with little consideration as to what this cognitive construct actually denotes. Within current computational models of word recognition, there are a number of different approaches to the representation of lexical knowledge. Structural lexical representations, found in original theories of word recognition, have been instantiated in modern localist models. However, such a representational scheme lacks neural plausibility in terms of economy and flexibility. Connectionist models have therefore adopted distributed representations of form and meaning. Semantic representations in connectionist models necessarily encode lexical knowledge. Yet when equipped with recurrent connections, connectionist models can also develop attractors for familiar forms that function as lexical representations. Current behavioural, neuropsychological and neuroimaging evidence shows a clear role for semantic information, but also suggests some modality- and task-specific lexical representations. A variety of connectionist architectures could implement these distributed functional representations, and further experimental and simulation work is required to discriminate between these alternatives. Future conceptualisations of lexical representations will therefore emerge from a synergy between modelling and neuroscience. PMID:25893204

  19. Lexical and prosodic effects on syntactic ambiguity resolution in aphasia.

    Science.gov (United States)

    DeDe, Gayle

    2012-10-01

    The purpose of this study was to determine whether and when individuals with aphasia and healthy controls use lexical and prosodic information during on-line sentence comprehension. Individuals with aphasia and controls (n = 12 per group) participated in a self-paced listening experiment. The stimuli were early closure sentences, such as "While the parents watched(,) the child sang a song." Both lexical and prosodic cues were manipulated. The cues were biased toward the subject- or object- of the ambiguous noun phrase (the child). Thus, there were two congruous conditions (in which both lexical cues and prosodic cues were consistent) and two incongruous conditions (in which lexical and prosodic cues conflicted). The results showed that the people with aphasia had longer listening times for the ambiguous noun phrase (the child) when the cues were conflicting, rather than consistent. The controls showed effects earlier in the sentence, at the subordinate verb (watched or danced). Both groups showed evidence of reanalysis at the main verb (sang). These effects demonstrate that the aphasic group was sensitive to the lexical and prosodic cues, but used them on a delayed time course relative to the control group.

  20. AMBIGUITY RESOLUTION IN PRECISE POINT POSITIONING TECHNIQUE: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Nistor S.

    2015-05-01

    Full Text Available Because of the dynamics of the GPS technique used in different domains like geodesy, near real-time GPS meteorology, geodynamics, the precise point positioning (PPP becomes more than a powerful method for determining the position, or the delay caused by the atmosphere. The main idea of this method is that we need only one receiver – preferably that have dual frequencies pseudorange and carrier-phase capabilities – to obtain the position. Because we are using only one receiver the majority of the residuals that are eliminated in double differencing method, we have to estimate them in PPP. The development of the PPP method allows us, to use precise satellite clock estimates, and precise orbits, resulting in a much more efficient way to deal with the disadvantages of this technique, like slow convergence time, or ambiguity resolution. Because this two problem are correlated, to achieve fast convergence we need to resolve the problem of ambiguity resolution. But the accuracy of the PPP results are directly influenced by presence of the uncalibrated phase delays (UPD originating in the receivers and satellites. In this article we present the GPS errors and biases, the zenith wet delay and the necessary time for obtaining the convergence. The necessary correction are downloaded by using the IGS service.

  1. Flow Ambiguity: A Path Towards Classically Driven Blind Quantum Computation

    Science.gov (United States)

    Mantri, Atul; Demarie, Tommaso F.; Menicucci, Nicolas C.; Fitzsimons, Joseph F.

    2017-07-01

    Blind quantum computation protocols allow a user to delegate a computation to a remote quantum computer in such a way that the privacy of their computation is preserved, even from the device implementing the computation. To date, such protocols are only known for settings involving at least two quantum devices: either a user with some quantum capabilities and a remote quantum server or two or more entangled but noncommunicating servers. In this work, we take the first step towards the construction of a blind quantum computing protocol with a completely classical client and single quantum server. Specifically, we show how a classical client can exploit the ambiguity in the flow of information in measurement-based quantum computing to construct a protocol for hiding critical aspects of a computation delegated to a remote quantum computer. This ambiguity arises due to the fact that, for a fixed graph, there exist multiple choices of the input and output vertex sets that result in deterministic measurement patterns consistent with the same fixed total ordering of vertices. This allows a classical user, computing only measurement angles, to drive a measurement-based computation performed on a remote device while hiding critical aspects of the computation.

  2. The ambiguous pulmonary venoatrial junction: a new perspective.

    Science.gov (United States)

    Konin, Gabrielle P; Jain, Vineet R; Fisher, John D; Haramati, Linda B

    2008-04-01

    The pulmonary venoatrial junction (PVAJ) has recently received attention due to the widespread use of catheter ablation for atrial fibrillation. However, the literature lacks a consensus in the definition of the PVAJ. We aim to review the inconsistent definitions for the PVAJ and related implications in imaging and catheter ablation for atrial fibrillation. The PVAJ as described by embryology, gross anatomy, histology and imaging is ambiguous, leading to disparities in its definition. Because of differing definitions of the PVAJ, there is a broad range in the prevalence of anatomic variations, including (1) percentage of common pulmonary veins (10-79% on the left), (2) supernumerary pulmonary veins (10-42%) and (3) ostial diameter and shape. We postulate several reasons for this broad range in the described prevalence of anatomic variation of the PV as follows: (1) different definitions of the PVAJ, (2) different vantage points, (3) different imaging modalities, and (4) different prevalence of anatomic variants among different study populations. The ambiguous PVAJ with its gradual transition from the left atrium to the pulmonary veins defies precise definition even though it plays an important role in the management of atrial fibrillation. Physicians should be aware of variability in the language used to describe the PVAJ and resultant discrepancy in reported anatomical information.

  3. Removing label ambiguity in learning-based visual saliency estimation.

    Science.gov (United States)

    Li, Jia; Xu, Dong; Gao, Wen

    2012-04-01

    Visual saliency is a useful clue to depict visually important image/video contents in many multimedia applications. In visual saliency estimation, a feasible solution is to learn a "feature-saliency" mapping model from the user data obtained by manually labeling activities or eye-tracking devices. However, label ambiguities may also arise due to the inaccurate and inadequate user data. To process the noisy training data, we propose a multi-instance learning to rank approach for visual saliency estimation. In our approach, the correlations between various image patches are incorporated into an ordinal regression framework. By iteratively refining a ranking model and relabeling the image patches with respect to their mutual correlations, the label ambiguities can be effectively removed from the training data. Consequently, visual saliency can be effectively estimated by the ranking model, which can pop out real targets and suppress real distractors. Extensive experiments on two public image data sets show that our approach outperforms 11 state-of-the-art methods remarkably in visual saliency estimation.

  4. A Computational Model of Syntactic Processing Ambiguity Resolution from Interpretation

    CERN Document Server

    Niv, M

    1994-01-01

    Syntactic ambiguity abounds in natural language, yet humans have no difficulty coping with it. In fact, the process of ambiguity resolution is almost always unconscious. But it is not infallible, however, as example 1 demonstrates. 1. The horse raced past the barn fell. This sentence is perfectly grammatical, as is evident when it appears in the following context: 2. Two horses were being shown off to a prospective buyer. One was raced past a meadow. and the other was raced past a barn. ... Grammatical yet unprocessable sentences such as 1 are called `garden-path sentences.' Their existence provides an opportunity to investigate the human sentence processing mechanism by studying how and when it fails. The aim of this thesis is to construct a computational model of language understanding which can predict processing difficulty. The data to be modeled are known examples of garden path and non-garden path sentences, and other results from psycholinguistics. It is widely believed that there are two distinct loci...

  5. Vaccine hesitancy: clarifying a theoretical framework for an ambiguous notion.

    Science.gov (United States)

    Peretti-Watel, Patrick; Larson, Heidi J; Ward, Jeremy K; Schulz, William S; Verger, Pierre

    2015-02-25

    Today, according to many public health experts, public confidence in vaccines is waning. The term "vaccine hesitancy" (VH) is increasingly used to describe the spread of such vaccine reluctance. But VH is an ambiguous notion and its theoretical background appears uncertain. To clarify this concept, we first review the current definitions of VH in the public health literature and examine its most prominent characteristics. VH has been defined as a set of beliefs, attitudes, or behaviours, or some combination of them, shared by a large and heterogeneous portion of the population and including people who exhibit reluctant conformism (they may either decline a vaccine, delay it or accept it despite their doubts) and vaccine-specific behaviours. Secondly, we underline some of the ambiguities of this notion and argue that it is more a catchall category than a real concept. We also call into question the usefulness of understanding VH as an intermediate position along a continuum ranging from anti-vaccine to pro-vaccine attitudes, and we discuss its qualification as a belief, attitude or behaviour. Thirdly, we propose a theoretical framework, based on previous literature and taking into account some major structural features of contemporary societies, that considers VH as a kind of decision-making process that depends on people's level of commitment to healthism/risk culture and on their level of confidence in the health authorities and mainstream medicine.

  6. Ambivalence and Ambiguity in The Autobiography of Miss Jane Pittman

    Directory of Open Access Journals (Sweden)

    Monica Michlin

    2006-05-01

    Full Text Available This close reading of the text highlights how Miss Jane, in her double role as protagonist and narrator, shows considerable ambivalence towards friend and foe alike, with the result that the apparently transparent ideological meaning of entire episodes is blurred by what some critics have merely put down to “conservatism.” I examine Miss Jane’s almost constant suppression of emotion, and frequent displays of ambivalence towards other black people; her ambiguous relationship to oppressive, but familiar whites like Albert Cluveau or Robert Samson; and her conflicted relation to black heroes and heroics. Is the leading character a variation on the “mammy” who has internalized racist figures of speech, and uses contradictory images that undermine black heroics and validate white oppression? Or is Gaines’s point to undo the “retrick” of heroics and of alienation alike, and, against of backdrop of constant, ordinary destruction of black lives, to cast the adult Miss Jane as a Brer Rabbit-like figure, for whom survival and resistance are both dialectically connected and opposed? Is there a contradiction between her “progress” towards resistance shown in the last section, and her metadiscursive comments in the present, and does her literally walking out of her own story give a conclusive meaning to her narrative, or does it point to the author’s not having been able to resolve the ambivalence and ambiguities within the text?

  7. Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

    Directory of Open Access Journals (Sweden)

    Maria Paula Roncaglia-Denissen

    Full Text Available In the current event-related potential (ERP study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first. Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing.

  8. Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

    Science.gov (United States)

    Roncaglia-Denissen, Maria Paula; Schmidt-Kassow, Maren; Kotz, Sonja A

    2013-01-01

    In the current event-related potential (ERP) study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first). Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing.

  9. Psychoanalytic and musical ambiguity: the tritone in gee, officer krupke.

    Science.gov (United States)

    Jaffee Nagel, Julie

    2010-02-01

    The poignant and timeless Broadway musical West Side Story is viewed from the standpoint of taking musical forms as psychoanalytic data. The musical configuration of notes called the tritone (or diabolus in musica) is taken as a sonic metaphor expressing ambiguity both in musical vocabulary and in mental life. The tritone, which historically and harmonically represents instability, is heard throughout the score and emphasizes the intrapsychic, interpersonal, and social dramas that unfold within and between the two gangs in West Side Story. Particular emphasis is given to the comic but exceedingly sober song Gee, Officer Krupke. Bernstein's sensitivity to the ambiguity and tension inherent in the tritone in West Side Story is conceptualized as an intersection of music theory and theories of mind; this perspective holds implications for clinical practice and transports psychoanalytic concepts from the couch to the Broadway stage and into the community to address the complexities of love, hate, aggression, prejudice, and violence. Ultimately, West Side Story cross-pollinates music and theater, as well as music and psychoanalytic concepts.

  10. Questions of Representations in Architecture

    DEFF Research Database (Denmark)

    2015-01-01

    Questions of Representations in Architecture is the first major Danish contribution to the current international discussion on architects' use of representations and the significance of visual media for architecture.......Questions of Representations in Architecture is the first major Danish contribution to the current international discussion on architects' use of representations and the significance of visual media for architecture....

  11. Realizations of the canonical representation

    Indian Academy of Sciences (India)

    This representation is called the canonical representation. The terminology comes from. Quantum Mechanics where the derived (Lie algebra) representation is known as the 'canon- ical commutation relation'. Traditionally, the canonical representation is realized on the Hilbert space L2(Rn) by the action. (ρ(x, y, z)f )(t) = ze.

  12. Resolution of ambiguities in cartoons as an illustration of the role of pragmatics in natural language understanding by computers

    Energy Technology Data Exchange (ETDEWEB)

    Mazlack, L.J.; Paz, N.M.

    1983-01-01

    Newspaper cartoons can graphically display the result of ambiguity in human speech; the result can be unexpected and funny. Likewise, computer analysis of natural language statements also needs to successfully resolve ambiguous situations. Computer techniques already developed use restricted world knowledge in resolving ambiguous language use. This paper illustrates how these techniques can be used in resolving ambiguous situations arising in cartoons. 8 references.

  13. Representation Elements of Spatial Thinking

    Science.gov (United States)

    Fiantika, F. R.

    2017-04-01

    This paper aims to add a reference in revealing spatial thinking. There several definitions of spatial thinking but it is not easy to defining it. We can start to discuss the concept, its basic a forming representation. Initially, the five sense catch the natural phenomenon and forward it to memory for processing. Abstraction plays a role in processing information into a concept. There are two types of representation, namely internal representation and external representation. The internal representation is also known as mental representation; this representation is in the human mind. The external representation may include images, auditory and kinesthetic which can be used to describe, explain and communicate the structure, operation, the function of the object as well as relationships. There are two main elements, representations properties and object relationships. These elements play a role in forming a representation.

  14. Operator representations of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Hasannasab, Marzieh

    2017-01-01

    The purpose of this paper is to consider representations of frames {fk}k∈I in a Hilbert space ℋ of the form {fk}k∈I = {Tkf0}k∈I for a linear operator T; here the index set I is either ℤ or ℒ0. While a representation of this form is available under weak conditions on the frame, the analysis...... of the properties of the operator T requires more work. For example it is a delicate issue to obtain a representation with a bounded operator, and the availability of such a representation not only depends on the frame considered as a set, but also on the chosen indexing. Using results from operator theory we show...... that by embedding the Hilbert space ℋ into a larger Hilbert space, we can always represent a frame via iterations of a bounded operator, composed with the orthogonal projection onto ℋ. The paper closes with a discussion of an open problem concerning representations of Gabor frames via iterations of a bounded...

  15. Class Representation of Shapes Using Qualitative-codes

    Directory of Open Access Journals (Sweden)

    Ashraf Fouad Hafez Ismail

    2001-01-01

    Full Text Available This paper introduces our qualitative shape representation formalism that is devised to overcome, as we have argued, the class abstraction problems created by numeric schemes. The numeric shape representation method used in conventional geometric modeling systems reveals difficulties in several aspects of architectural designing. Firstly, numeric schemes strongly require complete and detailed information for any simple task of object modeling. This requirement of information completeness makes it hard to apply numeric schemes to shapes in sketch level drawings that are characteristically ambiguous and have non-specific limitations on shape descriptions. Secondly, Cartesian coordinate-based quantitative shape representation schemes show restrictions in the task of shape comparison and classification that are inevitably involved in abstract concepts related to shape characteristics. One of the reasons why quantitative schemes are difficult to apply to the abstraction of individual shape information into its classes and categories is the uniqueness property, meaning that an individual description in a quantitative scheme should refer to only one object in the domain of representation. A class representation, however, should be able to indicate not only one but also a group of objects sharing common characteristics. Thirdly, it is difficult or inefficient to apply numeric shape representation schemes based on the Cartesian coordinate system to preliminary shape analysis and modeling tasks because of their emphasis on issues, such as detail, completeness, uniqueness and individuality, which can only be accessed in the final stages of designing. Therefore, we face the need for alternative shape representation schemes that can handle class representation of objects in order to manage the shapes in the early stages of designing. We consider shape as a boundary description consisting of a set of connected and closed lines. Moreover, we need to consider

  16. Introduction to computer data representation

    CERN Document Server

    Fenwick, Peter

    2014-01-01

    Introduction to Computer Data Representation introduces readers to the representation of data within computers. Starting from basic principles of number representation in computers, the book covers the representation of both integer and floating point numbers, and characters or text. It comprehensively explains the main techniques of computer arithmetic and logical manipulation. The book also features chapters covering the less usual topics of basic checksums and 'universal' or variable length representations for integers, with additional coverage of Gray Codes, BCD codes and logarithmic repre

  17. Representation Discovery using Harmonic Analysis

    CERN Document Server

    Mahadevan, Sridhar

    2008-01-01

    Representations are at the heart of artificial intelligence (AI). This book is devoted to the problem of representation discovery: how can an intelligent system construct representations from its experience? Representation discovery re-parameterizes the state space - prior to the application of information retrieval, machine learning, or optimization techniques - facilitating later inference processes by constructing new task-specific bases adapted to the state space geometry. This book presents a general approach to representation discovery using the framework of harmonic analysis, in particu

  18. Mobilities and Representations

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2017-01-01

    , literature, and film. Moreover, we hope the authors of future reviews will reflect on the ways they approached those representations. Such commentaries would provide valuable methodological insights, and we hope to begin that effort with this interview. We have asked four prominent mobility scholars......As the centerpiece of the eighth T2M yearbook, the following interview about representations of mobility signals a new and exciting focus area for Mobility in History. In future issues we hope to include reviews that grapple more with how mobilities have been imagined and represented in the arts...... to consider how they and their peers are currently confronting representations of mobility. This is particularly timely given the growing academic focus on practices, material mediation, and nonrepresentational theories, as well as on bodily reactions, emotions, and feelings that, according to those theories...

  19. Post-representational cartography

    Directory of Open Access Journals (Sweden)

    Rob Kitchin

    2010-03-01

    Full Text Available Over the past decade there has been a move amongst critical cartographers to rethink maps from a post-representational perspective – that is, a vantage point that does not privilege representational modes of thinking (wherein maps are assumed to be mirrors of the world and automatically presumes the ontological security of a map as a map, but rather rethinks and destabilises such notions. This new theorisation extends beyond the earlier critiques of Brian Harley (1989 that argued maps were social constructions. For Harley a map still conveyed the truth of a landscape, albeit its message was bound within the ideological frame of its creator. He thus advocated a strategy of identifying the politics of representation within maps in order to circumnavigate them (to reveal the truth lurking underneath, with the ontology of cartographic practice remaining unquestioned.

  20. Memetics of representation

    Directory of Open Access Journals (Sweden)

    Roberto De Rubertis

    2012-06-01

    Full Text Available This article will discuss about the physiological genesis of representation and then it will illustrate the developments, especially in evolutionary perspective, and it will show how these are mainly a result of accidental circumstances, rather than of deliberate intention of improvement. In particular, it will be argue that the representation has behaved like a meme that has arrived to its own progressive evolution coming into symbiosis with the different cultures in which it has spread, and using in this activity human work “unconsciously”. Finally it will be shown how in this action the geometry is an element key, linked to representation both to construct images using graphics operations and to erect buildings using concrete operations.

  1. Lexical ambiguity resolution for Turkish in direct transfer machine translation models

    OpenAIRE

    Tantuğ, A. Cüneyd; Tantug, A. Cuneyd; Oflazer, Kemal; Adalı, Eşref; Adali, Esref

    2006-01-01

    This paper presents a statistical lexical ambiguity resolution method in direct transfer machine translation models in which the target language is Turkish. Since direct transfer MT models do not have full syntactic information, most of the lexical ambiguity resolution methods are not very helpful. Our disambiguation model is based on statistical language models. We have investigated the performances of some statistical language model types and parameters in lexical ambiguity resolution for o...

  2. Understanding representations in design

    DEFF Research Database (Denmark)

    Bødker, Susanne

    1998-01-01

    Representing computer applications and their use is an important aspect of design. In various ways, designers need to externalize design proposals and present them to other designers, users, or managers. This article deals with understanding design representations and the work they do in design....... The article is based on a series of theoretical concepts coming out of studies of scientific and other work practices and on practical experiences from design of computer applications. The article presents alternatives to the ideas that design representations are mappings of present or future work situations...

  3. Additive and polynomial representations

    CERN Document Server

    Krantz, David H; Suppes, Patrick

    1971-01-01

    Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

  4. On the spinor representation

    Energy Technology Data Exchange (ETDEWEB)

    Hoff da Silva, J.M.; Rogerio, R.J.B. [Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil); Villalobos, C.H.C. [Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil); Universidade Federal Fluminense, Instituto de Fisica, Niteroi, RJ (Brazil); Rocha, Roldao da [Universidade Federal do ABC-UFABC, Centro de Matematica, Computacao e Cognicao, Santo Andre (Brazil)

    2017-07-15

    A systematic study of the spinor representation by means of the fermionic physical space is accomplished and implemented. The spinor representation space is shown to be constrained by the Fierz-Pauli-Kofink identities among the spinor bilinear covariants. A robust geometric and topological structure can be manifested from the spinor space, wherein the first and second homotopy groups play prominent roles on the underlying physical properties, associated to fermionic fields. The mapping that changes spinor fields classes is then exemplified, in an Einstein-Dirac system that provides the spacetime generated by a fermion. (orig.)

  5. Impact of stoichiometry representation on simulation of genotype-phenotype relationships in metabolic networks

    DEFF Research Database (Denmark)

    Brochado, Ana Rita; Andrejev, Sergej; Maranas, Costas D.

    2012-01-01

    linear combination of selected fluxes is widely used for formulating metabolic objective functions, we show that the resulting optimization problem is sensitive towards stoichiometry representation of the metabolic network. This undesirable sensitivity leads to different simulation results when using...... numerically different but biochemically equivalent stoichiometry representations and thereby makes biological interpretation intrinsically subjective and ambiguous. We hereby propose a new method, Minimization of Metabolites Balance (MiMBl), which decouples the artifacts of stoichiometry representation from...... the formulation of the desired objective functions, by casting objective functions using metabolite turnovers rather than fluxes. By simulating perturbed metabolic networks, we demonstrate that the use of stoichiometry representation independent algorithms is fundamental for unambiguously linking modeling results...

  6. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.E.

    1994-09-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different {open_quotes}realities{close_quotes} lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques attempt to resolve some of these ambiguities by appropriately coupling complementary images to eliminate possible inverse mappings. What constitutes the best MSI technique is dependent on the given application domain, available sensors, and task requirements. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) {open_quotes}detail enhancement,{close_quotes} wherein the relative information content of the original images is less rich than the desired representation; (2) {open_quotes}data enhancement,{close_quotes} wherein the MSI techniques are concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) {open_quotes}conceptual enhancement,{close_quotes} wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail.

  7. Lexical ambiguity resolution during sentence processing in Parkinson's disease: An event-related potential study.

    Directory of Open Access Journals (Sweden)

    Anthony J Angwin

    Full Text Available Event-related potentials (ERPs were recorded to investigate lexical ambiguity resolution during sentence processing in 16 people with Parkinson's disease (PD and 16 healthy controls. Sentences were presented word-by-word on computer screen, and participants were required to decide if a subsequent target word was related to the meaning of the sentence. The task consisted of related, unrelated and ambiguous trials. For the ambiguous trials, the sentence ended with an ambiguous word and the target was related to one of the meanings of that word, but not the one captured by the sentence context (e.g., 'He dug with the spade', Target 'ACE'. Both groups demonstrated slower reaction times and lower accuracy for the ambiguous condition relative to the unrelated condition, however accuracy was impacted by the ambiguous condition to a larger extent in the PD group. These results suggested that PD patients experience increased difficulties with contextual ambiguity resolution. The ERP results did not reflect increased ambiguity resolution difficulties in PD, as a similar N400 effect was evident for the unrelated and ambiguous condition in both groups. However, the magnitude of the N400 for these conditions was correlated with a measure of inhibition in the PD group, but not the control group. The ERP results suggest that semantic processing may be more compromised in PD patients with increased response inhibition deficits.

  8. Translation norms for English and Spanish: The role of lexical variables, word class, and L2 proficiency in negotiating translation ambiguity

    Science.gov (United States)

    Prior, Anat; MacWhinney, Brian; Kroll, Judith F.

    2014-01-01

    We present a set of translation norms for 670 English and 760 Spanish nouns, verbs and class ambiguous items that varied in their lexical properties in both languages, collected from 80 bilingual participants. Half of the words in each language received more than a single translation across participants. Cue word frequency and imageability were both negatively correlated with number of translations. Word class predicted number of translations: Nouns had fewer translations than did verbs, which had fewer translations than class-ambiguous items. The translation probability of specific responses was positively correlated with target word frequency and imageability, and with its form overlap with the cue word. Translation choice was modulated by L2 proficiency: Less proficient bilinguals tended to produce lower probability translations than more proficient bilinguals, but only in forward translation, from L1 to L2. These findings highlight the importance of translation ambiguity as a factor influencing bilingual representation and performance. The norms can also provide an important resource to assist researchers in the selection of experimental materials for studies of bilingual and monolingual language performance. These norms may be downloaded from www.psychonomic.org/archive. PMID:18183923

  9. Parents' experiences of having a baby with ambiguous genitalia.

    Science.gov (United States)

    Oliveira, Mailme de Souza; de Paiva-e-Silva, Roberto Benedito; Guerra-Junior, Gil; Maciel-Guerra, Andréa Trevas

    2015-07-01

    Health professionals must be aware of the impact on parents of the birth of children with ambiguous genitalia. This study aimed to analyze the experiences and perceptions of such parents. Parents of 30 children who were evaluated in a reference center for disorders of sex development (DSD) were interviewed. The questionnaire covered the prenatal period, the moment they were told about the disorder, initial management by health professionals, and problems they experienced. Only two cases were detected during pregnancy. The news was usually given to the mother alone by pediatricians. Most parents kept it secret and avoided exposing the baby to the prejudice of others. Parents of children who were referred without sex assignment usually held a personal belief of their child's sex. Previous assignment was based on clinical examination and/or karyotype. Spreading knowledge about DSD could increase awareness of this issue, thus reducing parents' shock and societal stigma. Training of neonatal care teams is required to avoid assignment before evaluation.

  10. [Technological innovation and healthcare professionals' workloads: an ambiguous relationship].

    Science.gov (United States)

    de Pires, Denise Elvira Pires; Bertoncini, Judite Hennemann; Trindade, Letícia de Lima; Matos, Eliane; Azambuja, Eliana; Borges, Ana Maria Fernandes

    2012-03-01

    This is an integrative review with the aim of tracing the scientific production concerning the influence of technological innovation in health care professionals' workloads. Fifty-seven (57) publications presented from 2004 to 2009 were selected from the LILACS and PubMed databases. In the selected studies field research using qualitative approaches and carried out in hospitals predominated. No study had the purpose to analyze the relationship between technological innovation and workloads. In studies involving technological innovation, publications concerning information and communication technologies and new forms of work organizations were highlighted studies concerning conditions which promote stress and Burnout predominated in the workloads theme. Results show an ambiguous relationship between technological innovation and workloads, which are either increased or diminished by innovations.

  11. Ambiguous loss and incomplete abduction narratives in Kosovo.

    Science.gov (United States)

    Kajtazi-Testa, Laura; Hewer, Christopher J

    2018-02-01

    Ten mothers of men and boys who were abducted and listed as missing during the war in Kosovo in 1998/1999 were interviewed in Kosovo in the spring of 2012. Although the missing are presumed dead by the authorities, the mothers continue to live in a state of emotional ambiguity where a presumption of death is balanced with the hope of being reunited. In the absence of absolute proof, finding the remains of their loved ones becomes a major preoccupation. Using a social phenomenological approach, this study explored the social and political complexities existing within the life-world of these women. The findings suggest that they live in a continual state of psychological distress, and even when remains are returned, the unknown elements of the narrative of their abduction and murder only add to their distress and force many into self-imposed emotional exile away from community and close family.

  12. Doppler Ambiguity Resolution Based on Random Sparse Probing Pulses

    Directory of Open Access Journals (Sweden)

    Yunjian Zhang

    2015-01-01

    Full Text Available A novel method for solving Doppler ambiguous problem based on compressed sensing (CS theory is proposed in this paper. A pulse train with the random and sparse transmitting time is transmitted. The received signals after matched filtering can be viewed as randomly sparse sampling from the traditional fixed-pulse repetition frequency (PRF echo signals. The whole target echo could be reconstructed via CS recovery algorithms. Through refining the sensing matrix, which is equivalent to increase the sampling frequency of target characteristic, the Doppler unambiguous range is enlarged. In particular, Complex Approximate Message Passing (CAMP algorithm is developed to estimate the unambiguity Doppler frequency. Cramer-Rao lower bound expressions are derived for the frequency. Numerical simulations validate the effectiveness of the proposed method. Finally, compared with traditional methods, the proposed method only requires transmitting a few sparse probing pulses to achieve a larger Doppler frequency unambiguous range and can also reduce the consumption of the radar time resources.

  13. The ambiguity of US foreign policy towards Africa

    DEFF Research Database (Denmark)

    Olsen, Gorm Rye

    2017-01-01

    with the Pentagon and the State Department playing prominent roles. The paper argues that in the current century, evangelical Christian lobby groups have gained increasing influence on policymaking on Africa. Because policymaking has been influenced by a number of different actors, the American Africa policy may...... appear incoherent and ambiguous if judged narrowly on the expectation that it only aims to take care of US national security concerns and economic self-interests. The paper concludes that Africa was important to the United States during the presidencies of George W. Bush and Barack Obama because......Since 9/11, the American policy towards Africa has been strongly influenced by national security interests and in particular by the fight against international terrorism and Islamic radicalisation. Traditionally, the American Africa policy has been the result of bureaucratic policymaking...

  14. Sensorimotor Adaptations Following Exposure to Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Wood, S. J.; Harm, D. L.; Reschke, M. F.; Rupert, A. H.; Clement, G. R.

    2009-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translation responses. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation.

  15. In Praise of Ambiguity: Musical Subtlety and Merleau-Ponty

    Directory of Open Access Journals (Sweden)

    Tiger C. Roholt

    2013-01-01

    Full Text Available When a jazz, rock, or hip-hop drummer strikes certain notes in each measure slightly late, instead of hearing the degree to which those notes are late, we typically hear the effects of those variations; namely, a groove, the "feel" of a rhythm. Slight variations of pitch function similarly. In this essay, I argue that certain analytic theorists go astray due to their preoccupation with the variations themselves. By invoking Maurice Merleau-Ponty's insights into subtle visual perceptions, and his notion of perceptual indeterminacy, I avoid an account of musical subtlety suggested by Daniel Dennett that is too coarse-grained, as well as the bleak conclusion that certain musical subtleties are ineffable, Diana Raffman's view. I conclude that elements of music that are perceived ambiguously can perform a positive function in such aesthetic experiences: they can mediate or foster emergent qualities; moreover, they must be perceived in this way to do so.

  16. Lifting the Gribov ambiguity in Yang-Mills theories

    Energy Technology Data Exchange (ETDEWEB)

    Serreau, J., E-mail: serreau@apc.univ-paris7.fr [APC, AstroParticule et Cosmologie, Universite Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cite, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France); Tissier, M. [LPTMC, Laboratoire de Physique Theorique de la Matiere Condensee, CNRS UMR 7600, Universite Pierre et Marie Curie, boite 121, 4 pl. Jussieu, 75252 Paris Cedex 05 (France)

    2012-05-30

    We propose a new one-parameter family of Landau gauges for Yang-Mills theories which can be formulated by means of functional integral methods and are thus well suited for analytic calculations, but which are free of Gribov ambiguities and avoid the Neuberger zero problem of the standard Faddeev-Popov construction. The resulting gauge-fixed theory is perturbatively renormalizable in four dimensions and, for what concerns the calculation of ghost and gauge field correlators, it reduces to a massive extension of the Faddeev-Popov action. We study the renormalization group flow of this theory at one-loop and show that it has no Landau pole in the infrared for some - including physically relevant - range of values of the renormalized parameters.

  17. Ambiguity as an Essential Aesthetic Principle in Musical Listening

    DEFF Research Database (Denmark)

    Bonde, Anders

    2006-01-01

    in truth is continuous, if we only expand our musical thought beyond a superficial examination. Rather, I want to emphasize the assumption that the important musical experience is to be found in the ambiguity itself, caused by an aporetic relation between the apparent discontinuous gestures...... as a superficial feature. In the compositional structure, there are several indications of connection and development which can be explored. Hence a ‘continuity-after-all’ comprehension has been an important principle guiding most commentators, from Edward Cone’s threefold conception of ‘stratification......’, ‘interlocking’, and ‘synthesis’ (Cone, 1962: 19f), to Jonathan Kramer’s accentuation of discontinuity as a ‘profound musical experience’ with the ‘proportional lengths of moments as the one remaining principle of formal coherence’ (Kramer, 1978: 182). Though, the general attempt to reveal the music’s ‘secret...

  18. New Hamiltonians for loop quantum cosmology with arbitrary spin representations

    Science.gov (United States)

    Ben Achour, Jibril; Brahma, Suddhasattwa; Geiller, Marc

    2017-04-01

    In loop quantum cosmology, one has to make a choice of SU(2) irreducible representation in which to compute holonomies and regularize the curvature of the connection. The systematic choice made in the literature is to work in the fundamental representation, and very little is known about the physics associated with higher spin labels. This constitutes an ambiguity of which the understanding, we believe, is fundamental for connecting loop quantum cosmology to full theories of quantum gravity like loop quantum gravity, its spin foam formulation, or cosmological group field theory. We take a step in this direction by providing here a new closed formula for the Hamiltonian of flat Friedmann-Lemaître-Robertson-Walker models regularized in a representation of arbitrary spin. This expression is furthermore polynomial in the basic variables which correspond to well-defined operators in the quantum theory, takes into account the so-called inverse-volume corrections, and treats in a unified way two different regularization schemes for the curvature. After studying the effective classical dynamics corresponding to single and multiple-spin Hamiltonians, we study the behavior of the critical density when the number of representations is increased and the stability of the difference equations in the quantum theory.

  19. Audio Spatial Representation Around the Body.

    Science.gov (United States)

    Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica

    2017-01-01

    Studies have found that portions of space around our body are differently coded by our brain. Numerous works have investigated visual and auditory spatial representation, focusing mostly on the spatial representation of stimuli presented at head level, especially in the frontal space. Only few studies have investigated spatial representation around the entire body and its relationship with motor activity. Moreover, it is still not clear whether the space surrounding us is represented as a unitary dimension or whether it is split up into different portions, differently shaped by our senses and motor activity. To clarify these points, we investigated audio localization of dynamic and static sounds at different body levels. In order to understand the role of a motor action in auditory space representation, we asked subjects to localize sounds by pointing with the hand or the foot, or by giving a verbal answer. We found that the audio sound localization was different depending on the body part considered. Moreover, a different pattern of response was observed when subjects were asked to make actions with respect to the verbal responses. These results suggest that the audio space around our body is split in various spatial portions, which are perceived differently: front, back, around chest, and around foot, suggesting that these four areas could be differently modulated by our senses and our actions.

  20. Compact Information Representations

    Science.gov (United States)

    2016-08-02

    detections (e.g., DDoS attacks), machine learning, databases, and search. Fundamentally, compact data representations are highly beneficial because they...engineering problems in data stream computations, real-time network monitoring & anomaly detections (e.g., DDoS attacks), machine learning, databases, and

  1. Hyperfinite representation of distributions

    Indian Academy of Sciences (India)

    A nonstandard treatment of the theory of distributions in terms of a hyperfinite representa- tion has been presented in papers [2,3] by Kinoshita. A further exploitation of this treatment in an N-dimensional context has been given by Grenier [1]. In the present paper we offer a different approach to the hyperfinite representation, ...

  2. Reflection on Political Representation

    DEFF Research Database (Denmark)

    Kusche, Isabel

    2017-01-01

    This article compares how Members of Parliament in the United Kingdom and Ireland reflect on constituency service as an aspect of political representation. It differs from existing research on the constituency role of MPs in two regards. First, it approaches the question from a sociological...

  3. Between Representation and Eternity

    DEFF Research Database (Denmark)

    Atzbach, Rainer

    2016-01-01

    . At death, an indi- vidual’s corpse and burial primarily reflect the social act of representation during the funeral. The position of the arms, which have incorrectly been used as a chronological tool in Scandinavia, may indicate an evolution from a more collective act of prayer up to the eleventh century...

  4. Representation of the Divine

    DEFF Research Database (Denmark)

    Loddegaard, Anne

    2009-01-01

    out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...

  5. Representation of the Divine

    DEFF Research Database (Denmark)

    Loddegaard, Anne

    2012-01-01

    out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...

  6. Moment graphs and representations

    DEFF Research Database (Denmark)

    Jantzen, Jens Carsten

    2012-01-01

    Moment graphs and sheaves on moment graphs are basically combinatorial objects that have be used to describe equivariant intersectiion cohomology. In these lectures we are going to show that they can be used to provide a direct link from this cohomology to the representation theory of simple Lie ...

  7. Representation in dynamical agents.

    Science.gov (United States)

    Ward, Ronnie; Ward, Robert

    2009-04-01

    This paper extends experiments by Beer [Beer, R. D. (1996). Toward the evolution of dynamical neural networks for minimally cognitive behavior. In P. Maes, M. Mataric, J. Meyer, J. Pollack, & S. Wilson (Eds.), From animals to animats 4: Proceedings of the fourth international conference on simulation of adaptive behavior (pp. 421-429). MIT Press; Beer, R. D. (2003). The dynamics of active categorical perception in an evolved model agent (with commentary and response). Adaptive Behavior, 11 (4), 209-243] with an evolved, dynamical agent to further explore the question of representation in cognitive systems. Beer's environmentally-situated visual agent was controlled by a continuous-time recurrent neural network, and evolved to perform a categorical perception task, discriminating circles from diamonds. Despite the agent's high levels of discrimination performance, Beer found no evidence of internal representation in the best-evolved agent's nervous system. Here we examine the generality of this result. We evolved an agent for shape discrimination, and performed extensive behavioral analyses to test for representation. In this case we find that agents developed to discriminate equal-width shapes exhibit what Clark [Clark, A. (1997). The dynamical challenge. Cognitive Science, 21 (4), 461-481] calls "weak-substantive representation". The agent had internal configurations that (1) were understandably related to the object in the environment, and (2) were functionally used in a task relevant way when the target was not visible to the agent.

  8. The Problem of Representation

    Science.gov (United States)

    Tervo, Juuso

    2012-01-01

    In "Postphysical Vision: Art Education's Challenge in an Age of Globalized Aesthetics (AMondofesto)" (2008) and "Beyond Aesthetics: Returning Force and Truth to Art and Its Education" (2009), jan jagodzinski argued for politics that go "beyond" representation--a project that radically questions visual culture…

  9. Sociocognitive Perspectives on Representation.

    Science.gov (United States)

    Jacob, Elin K.; Shaw, Debora

    1998-01-01

    Discusses research dealing with the cognitive aspects of formal systems of knowledge representation. Highlights include the origins and theoretical foundations of the cognitive viewpoint; cognition and information science; cognitivism, mentalism, and subjective individualism; categorization; mental models; and sociocognitive approaches to indexing…

  10. Women and political representation.

    Science.gov (United States)

    Rathod, P B

    1999-01-01

    A remarkable progress in women's participation in politics throughout the world was witnessed in the final decade of the 20th century. According to the Inter-Parliamentary Union report, there were only eight countries with no women in their legislatures in 1998. The number of women ministers at the cabinet level worldwide doubled in a decade, and the number of countries without any women ministers dropped from 93 to 48 during 1987-96. However, this progress is far from satisfactory. Political representation of women, minorities, and other social groups is still inadequate. This may be due to a complex combination of socioeconomic, cultural, and institutional factors. The view that women's political participation increases with social and economic development is supported by data from the Nordic countries, where there are higher proportions of women legislators than in less developed countries. While better levels of socioeconomic development, having a women-friendly political culture, and higher literacy are considered favorable factors for women's increased political representation, adopting one of the proportional representation systems (such as a party-list system, a single transferable vote system, or a mixed proportional system with multi-member constituencies) is the single factor most responsible for the higher representation of women.

  11. Images of Galois representations

    NARCIS (Netherlands)

    Anni, Samuele

    2013-01-01

    In this thesis we investigate $2$-dimensional, continuous, odd, residual Galois representations and their images. This manuscript consists of two parts. In the first part of this thesis we analyse a local\\--global problem for elliptic curves over number fields. Let $E$ be an elliptic curve over a

  12. Animating Brains

    Science.gov (United States)

    Borck, Cornelius

    2016-01-01

    A recent paper famously accused the rising field of social neuroscience of using faulty statistics under the catchy title ‘Voodoo Correlations in Social Neuroscience’. This Special Issue invites us to take this claim as the starting point for a cross-cultural analysis: in which meaningful ways can recent research in the burgeoning field of functional imaging be described as, contrasted with, or simply compared to animistic practices? And what light does such a reading shed on the dynamics and effectiveness of a century of brain research into higher mental functions? Reviewing the heated debate from 2009 around recent trends in neuroimaging as a possible candidate for current instances of ‘soul catching’, the paper will then compare these forms of primarily image-based brain research with older regimes, revolving around the deciphering of the brain’s electrical activity. How has the move from a decoding paradigm to a representational regime affected the conceptualisation of self, psyche, mind and soul (if there still is such an entity)? And in what ways does modern technoscience provide new tools for animating brains? PMID:27292322

  13. Brain Basics

    Medline Plus

    Full Text Available ... About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain Brain ... called the hypothalamic-pituitary-adrenal (HPA) axis. Brain Basics in Real Life Brain Basics in Real Life— ...

  14. Semantic activation and verbal working memory maintenance in schizophrenic thought disorder: insights from electrophysiology and lexical ambiguity.

    Science.gov (United States)

    Salisbury, Dean F

    2008-04-01

    We have examined language processing using ambiguous words (homographs like panel or toast) and rapid or slow presentation rates while recording event-related brain potentials (ERPs). Homographs allow for tracking the train of thought at points of lexical ambiguity and detecting modulation of associative threads by previous context. Rapid presentation rates stress automatic semantic activation, and slow rates stress controlled verbal working memory contextual modulation. In conjunction with reaction times and performance, ERPs allow for objective measurement of activity related to language processing from word presentation through overt behavioral response. Smaller N400 to related and unrelated items at short stimulus onset asynchronies (SOAs), the presence of a semantic bias, and large N400 to related and unrelated items at long SOAs are present in schizophrenia. We describe a model of initial semantic memory hyper-priming and subsequent decay of information in verbal working memory stores, the activation-maintenance model of schizophrenic thought disorder hypothesized to underlie the thought disorder in schizophrenia.

  15. Caravaggio four centuries later: psychoanalytic portraits of ambivalence and ambiguity.

    Science.gov (United States)

    Szajnberg, Nathan M

    2013-04-01

    Rome celebrated the four hundredth anniversary of Michelangelo Marisi da Caravaggio's death with an historical exhibition of his brief lifetime's work. Yet psychoanalysis has not studied this work extensively, despite the artist's compelling portrayal of a full range of human affects, including ambivalence. Psychoanalysis has studied artistic pioneers such as da Vinci (Freud 1910) and Michelangelo (Freud 1914), Giotto's use of blue sky as psychologically innovative (Blatt 1994), and Magritte's play with external reality (Spitz 1994). What can we learn about Caravaggio's work-including innovative contributions such as visual representation of expressed emotions, particularly negative emotions, including ambivalence, and remarkably candid, even critical, self-representations-and how can this late-sixteenth-century artist teach us about the development of the concept of mind underlying psychoanalysis?

  16. Realizations of the canonical representation

    Indian Academy of Sciences (India)

    A characterisation of the maximal abelian subalgebras of the bounded operators on Hilbert space that are normalised by the canonical representation of the Heisenberg group is given. This is used to classify the perfect realizations of the canonical representation.

  17. Minority Representation, Empowerment, and Participation

    NARCIS (Netherlands)

    Banducci, S.A.; Donovan, Todd; Karp, J.A.

    2004-01-01

    According to the minority empowerment thesis, minority representation strengthens representational links, fosters more positive attitudes toward government, and encourages political participation. We examine this theory from a cross-national perspective, making use of surveys that sampled minorities

  18. How Hispanic Patients Address Ambiguous versus Unambiguous Bias in the Doctor's Office

    OpenAIRE

    Bean, Meghan G.; Covarrubias, Rebecca; Stone, Jeff

    2014-01-01

    Two studies examined Hispanic individuals’ preferences for using ten different bias reduction strategies when interacting with a doctor whose beliefs about their group were either ambiguous or clearly biased. Consistent with predictions, participants who imagined interacting with a doctor whose beliefs were ambiguous preferred strategies that facilitate positive doctor-patient interactions, whereas participants whose doctor explicitly endorsed negative stereotypes about their group preferred ...

  19. Understandings of Environmental Quality: Ambiguities and Values Held by Environmental Professionals

    Science.gov (United States)

    R. Bruce Hull; David Richert; Erin Seekamp; David Robertson; Gregory J. Buhyoff

    2003-01-01

    The terms used to describe and negotiate environmental quality are both ambiguous and value-laden. Stakeholders intimately and actively involved in the management of forested lands were interviewed and found to use ambiguous, tautological, and value-laden definitions of terms such as health, biodiversity, sustainability, and naturalness. This confusing language...

  20. In the Face of Uncertainty: A Twin Study of Ambiguous Information, Anxiety and Depression in Children

    Science.gov (United States)

    Eley, Thalia C.; Gregory, Alice M.; Lau, Jennifer Y. F.; McGuffin, Peter; Napolitano, Maria; Rijsdijk, Fruhling V.; Clark, David M.

    2008-01-01

    Anxiety and depression share genetic influences, and have been associated with similar cognitive biases. Psychological theories of anxiety and depression highlight threat interpretations of ambiguity. Little is known about whether genes influence cognitive style, or its links to symptoms. We assessed ambiguous word and scenario interpretations,…

  1. Structural Ambiguities and Written Advertisements: An Inventory of Tools for More Resourceful Advertisements in English.

    Science.gov (United States)

    Oaks, Dallin D.

    1995-01-01

    Discusses some types of writing tasks, such as advertising, in which a writer might want to create ambiguous wordplays. States that a more conscious understanding of the structure of a language could make the generation of structural ambiguities easier. Examines some structural features of English that could prove useful to advertisers who wish to…

  2. Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

    Science.gov (United States)

    Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

    2013-06-01

    Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: pressure, select, adapt, need, and must. We utilized a new technological tool known as the Assessment Cascade System (ACS) to investigate the frequency with which biology majors spontaneously used lexically ambiguous language in evolutionary explanations, as well as their definitions and explanations of what they meant when they used such terms. Three categories of language were identified and examined in this study: terms with Dual Ambiguity, Incompatible Ambiguity, and Unintended Ambiguity. In the sample of 1282 initial evolutionary explanations, 81 % of students spontaneously incorporated lexically ambiguous language at least once. Furthermore, the majority of these initial responses were judged to be inaccurate from a scientific point of view. While not significantly related to gender, age, or reading/writing ability, students' use of contextually appropriate evolutionary language ( pressure and adapt) was significantly associated with academic performance in biology. Comparisons of initial responses to follow-up responses demonstrated that the majority of student explanations were not reinterpreted after consideration of the follow-up response; nevertheless, a sizeable minority was interpreted differently. Most cases of interpretation change were a consequence of resolving initially ambiguous responses, rather than a change of accuracy, resulting in an increased understanding of students' evolutionary explanations. We discuss a series of implications of lexical ambiguity for evolution education.

  3. Morpho-Semantic Processing in Word Recognition: Evidence from Balanced and Biased Ambiguous Morphemes

    Science.gov (United States)

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    The role of morphemic meaning in Chinese word recognition was examined with the masked and unmasked priming paradigms. Target words contained ambiguous morphemes biased toward the dominant or the subordinate meanings. Prime words either contained the same ambiguous morphemes in the subordinate interpretations or were unrelated to the targets. In…

  4. Early Morphological Processing Is Sensitive to Morphemic Meanings: Evidence from Processing Ambiguous Morphemes

    Science.gov (United States)

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    In three priming experiments, we investigated whether the meanings of ambiguous morphemes were activated during word recognition. Using a meaning generation task, Experiment 1 demonstrated that the dominant meaning of individually presented ambiguous morphemes was reported more often than did other less frequent meanings. Also, participants tended…

  5. The Issue of Ambiguity in the Igbo Language | Thecla-Obiora ...

    African Journals Online (AJOL)

    The Issue of Ambiguity in the Igbo Language. ... AFRREV LALIGENS: An International Journal of Language, Literature and Gender Studies ... The findings reveal the ambiguities in the Igbo language arise from homonyms, homophones, homographs and from anaphoric pronouns, dialectal differences, among other things.

  6. Multiple ambiguity and an impression formation focus make inapplicable primes useful

    NARCIS (Netherlands)

    Stapel, DA; Koomen, W

    Two studies demonstrated that accessible knowledge can affect judgments of ambiguous targets, even when this knowledge is descriptively inapplicable to these targets. Study I showed that when the target stimulus is ambiguous on multiple dimensions rather than on a single dimension, the priming of

  7. Exploring the Relationship between Tolerance of Ambiguity of EFL Learners and Their Vocabulary Knowledge

    Science.gov (United States)

    Basöz, Tutku

    2015-01-01

    Learning a new language is akin to exploring an unknown land as ambiguous situations are prevalent in language learning. Ambiguity tolerance, which can hinder or facilitate language learning, is considered as an important learning style. The purpose of the present study was to understand how tolerant/intolerant EFL learners are of foreign language…

  8. Emotions facilitate the communication of ambiguous group memberships.

    Science.gov (United States)

    Tskhay, Konstantin O; Rule, Nicholas O

    2015-12-01

    It is well known that emotions intersect with obvious social categories (e.g., race), influencing both how targets are categorized and the emotions that are read from their faces. Here, we examined the influence of emotional expression on the perception of less obvious group memberships for which, in the absence of obvious and stable physical markers, emotion may serve as a major avenue for group categorization and identification. Specifically, we examined whether emotions are embedded in the mental representations of sexual orientation and political affiliation, and whether people may use emotional expressions to communicate these group memberships to others. Using reverse correlation methods, we found that mental representations of gay and liberal faces were characterized by more positive facial expressions than mental representations of straight and conservative faces (Study 1). Furthermore, participants were evaluated as expressing more positive emotions when enacting self-defined "gay" and "liberal" versus "straight" and "conservative" facial expressions in the lab (Study 2). In addition, neutral faces morphed with happiness were perceived as more gay than when morphed with anger, and when compared to unmorphed controls (Study 3). Finally, we found that affect facilitated perceptions of sexual orientation and political affiliation in naturalistic settings (Study 4). Together, these studies suggest that emotion is a defining characteristic of person construal that people tend to use both when signaling their group memberships and when receiving those signals to categorize others. (c) 2015 APA, all rights reserved).

  9. Harmonic Analysis and Group Representation

    CERN Document Server

    Figa-Talamanca, Alessandro

    2011-01-01

    This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.

  10. Consistency of Border-Ownership Cells across Artificial Stimuli, Natural Stimuli, and Stimuli with Ambiguous Contours.

    Science.gov (United States)

    Hesse, Janis K; Tsao, Doris Y

    2016-11-02

    Segmentation and recognition of objects in a visual scene are two problems that are hard to solve separately from each other. When segmenting an ambiguous scene, it is helpful to already know the present objects and their shapes. However, for recognizing an object in clutter, one would like to consider its isolated segment alone to avoid confounds from features of other objects. Border-ownership cells (Zhou et al., 2000) appear to play an important role in segmentation, as they signal the side-of-figure of artificial stimuli. The present work explores the role of border-ownership cells in dorsal macaque visual areas V2 and V3 in the segmentation of natural object stimuli and locally ambiguous stimuli. We report two major results. First, compared with previous estimates, we found a smaller percentage of cells that were consistent across artificial stimuli used previously. Second, we found that the average response of those neurons that did respond consistently to the side-of-figure of artificial stimuli also consistently signaled, as a population, the side-of-figure for borders of single faces, occluding faces and, with higher latencies, even stimuli with illusory contours, such as Mooney faces and natural faces completely missing local edge information. In contrast, the local edge or the outlines of the face alone could not always evoke a significant border-ownership signal. Our results underscore that border ownership is coded by a population of cells, and indicate that these cells integrate a variety of cues, including low-level features and global object context, to compute the segmentation of the scene. To distinguish different objects in a natural scene, the brain must segment the image into regions corresponding to objects. The so-called "border-ownership" cells appear to be dedicated to this task, as they signal for a given edge on which side the object is that owns it. Here, we report that individual border-ownership cells are unreliable when tested across

  11. Perceptual and categorical decision making: goal-relevant representation of two domains at different levels of abstraction.

    Science.gov (United States)

    Shankar, Swetha; Kayser, Andrew S

    2017-06-01

    To date it has been unclear whether perceptual decision making and rule-based categorization reflect activation of similar cognitive processes and brain regions. On one hand, both map potentially ambiguous stimuli to a smaller set of motor responses. On the other hand, decisions about perceptual salience typically concern concrete sensory representations derived from a noisy stimulus, while categorization is typically conceptualized as an abstract decision about membership in a potentially arbitrary set. Previous work has primarily examined these types of decisions in isolation. Here we independently varied salience in both the perceptual and categorical domains in a random dot-motion framework by manipulating dot-motion coherence and motion direction relative to a category boundary, respectively. Behavioral and modeling results suggest that categorical (more abstract) information, which is more relevant to subjects' decisions, is weighted more strongly than perceptual (more concrete) information, although they also have significant interactive effects on choice. Within the brain, BOLD activity within frontal regions strongly differentiated categorical salience and weakly differentiated perceptual salience; however, the interaction between these two factors activated similar frontoparietal brain networks. Notably, explicitly evaluating feature interactions revealed a frontal-parietal dissociation: parietal activity varied strongly with both features, but frontal activity varied with the combined strength of the information that defined the motor response. Together, these data demonstrate that frontal regions are driven by decision-relevant features and argue that perceptual decisions and rule-based categorization reflect similar cognitive processes and activate similar brain networks to the extent that they define decision-relevant stimulus-response mappings.NEW & NOTEWORTHY Here we study the behavioral and neural dynamics of perceptual categorization when decision

  12. A 2.5-D Representation of the Human Hand

    Science.gov (United States)

    Longo, Matthew R.; Haggard, Patrick

    2012-01-01

    Primary somatosensory maps in the brain represent the body as a discontinuous, fragmented set of two-dimensional (2-D) skin regions. We nevertheless experience our body as a coherent three-dimensional (3-D) volumetric object. The links between these different aspects of body representation, however, remain poorly understood. Perceiving the body's…

  13. Eye movement-invariant representations in the human visual system.

    Science.gov (United States)

    Nishimoto, Shinji; Huth, Alexander G; Bilenko, Natalia Y; Gallant, Jack L

    2017-01-01

    During natural vision, humans make frequent eye movements but perceive a stable visual world. It is therefore likely that the human visual system contains representations of the visual world that are invariant to eye movements. Here we present an experiment designed to identify visual areas that might contain eye-movement-invariant representations. We used functional MRI to record brain activity from four human subjects who watched natural movies. In one condition subjects were required to fixate steadily, and in the other they were allowed to freely make voluntary eye movements. The movies used in each condition were identical. We reasoned that the brain activity recorded in a visual area that is invariant to eye movement should be similar under fixation and free viewing conditions. In contrast, activity in a visual area that is sensitive to eye movement should differ between fixation and free viewing. We therefore measured the similarity of brain activity across repeated presentations of the same movie within the fixation condition, and separately between the fixation and free viewing conditions. The ratio of these measures was used to determine which brain areas are most likely to contain eye movement-invariant representations. We found that voxels located in early visual areas are strongly affected by eye movements, while voxels in ventral temporal areas are only weakly affected by eye movements. These results suggest that the ventral temporal visual areas contain a stable representation of the visual world that is invariant to eye movements made during natural vision.

  14. Constructing visual representations

    DEFF Research Database (Denmark)

    Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh

    2014-01-01

    The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings......, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only...... tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants’ actions during the development of their visual representations...

  15. Determinants of translation ambiguity: A within and cross-language comparison.

    Science.gov (United States)

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M; Arêas da Luz Fontes, Ana B; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals.

  16. Ambiguity Tolerance in Organizations: Definitional Clarification and Perspectives on Future Research

    Directory of Open Access Journals (Sweden)

    David L Mclain

    2015-04-01

    Full Text Available Ambiguity tolerance is an increasingly popular subject for study in a wide variety of fields. The definition of ambiguity tolerance has changed since its inception, and accompanying that change are changes in measurement and the research questions that interest researchers. There is a wealth of opportunity for research related to ambiguity tolerance and recent advances in neuroscience, measurement, trait research, perception, problem solving, and other fields highlight areas of interest and point to issues that need further attention. The future of ambiguity tolerance research is promising and it is expected that future studies will yield new insights into individual differences in reactions to the complex, unfamiliar, confusing, indeterminate, and incomplete stimuli that fall within the conceptual domain of ambiguity.

  17. Finding meaning in art: Preferred levels of ambiguity in art appreciation

    Science.gov (United States)

    Jakesch, Martina; Leder, Helmut

    2011-01-01

    Uncertainty is typically not desirable in everyday experiences, but uncertainty in the form of ambiguity may be a defining feature of aesthetic experiences of modern art. In this study, we examined different hypotheses concerning the quantity and quality of information appreciated in art. Artworks were shown together with auditorily presented statements. We tested whether the amount of information, the amount of matching information, or the proportion of matching to nonmatching statements apparent in a picture (levels of ambiguity) affect liking and interestingness. Only the levels of ambiguity predicted differences in the two dependent variables. These findings reveal that ambiguity is an important determinant of aesthetic appreciation and that a certain level of ambiguity is appreciable. PMID:19565431

  18. Deconvolutional Paragraph Representation Learning

    OpenAIRE

    Zhang, Yizhe; Shen, Dinghan; Wang, Guoyin; Gan, Zhe; Henao, Ricardo; Carin, Lawrence

    2017-01-01

    Learning latent representations from long text sequences is an important first step in many natural language processing applications. Recurrent Neural Networks (RNNs) have become a cornerstone for this challenging task. However, the quality of sentences during RNN-based decoding (reconstruction) decreases with the length of the text. We propose a sequence-to-sequence, purely convolutional and deconvolutional autoencoding framework that is free of the above issue, while also being computationa...

  19. Valensbaserad semantisk representation

    OpenAIRE

    Lönngren, Lennart

    2010-01-01

    This is a brief outline of a semantic representation of linguistic objects in Russian—words, phrases, sentences—based on the concept of valency. Valency is explored as a property of all kinds of linguistic signs: words, parts of words, signs with non-phonological expression, and completely implicit signs. An important distinction is made between semantic and syntactic signs, and amongst semantic signs between signs with and without valency (signs denoting "facts" versus signs denoting "things...

  20. Representation of Knowledge

    Science.gov (United States)

    1980-03-01

    methodology involves the design of programs that exhibit Intelligent behavior, Al researchers have often taken a rather pragmatic approach to the subject...This article has not been about representation formalisms per se, but rather about the pragmatics of epistemology, the study of the nature of knowledge...1977. Levels of complexity In discourse for anaphora disambiguation and speech act interpretation. IJCAI 3, 43-49. Carbonell, J. R. 1970. Al in CAI: An

  1. Non-Representational Theory

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2016-01-01

    Dette kapitel gennemgår den såkaldte ”Non-Representational Theory” (NRT), der primært er kendt fra den Angelsaksiske humangeografi, og som særligt er blevet fremført af den engelske geograf Nigel Thrift siden midten af 2000 årtiet. Da positionen ikke kan siges at være specielt homogen vil kapitlet...

  2. The Knowledge Representation Project

    Science.gov (United States)

    1989-07-01

    representing k nowledge. I,- ONE was designed to represent the kinds of knowlodge constriicts encountered by developers of natural language processing systems...project called Empirically Valid Knowledge Representation in 1986. One of the first tasks of the new project was to translate NIKL into Common LISP -- a...constraints -- the syntactic structures that appear in LOO% :constraints or implies clauses translate into knowledge structures for which we have

  3. Learning Multisensory Representations

    Science.gov (United States)

    2016-05-23

    how the use of these representations influences perceptual judgements and decision making. The program focuses on people’s performances in visual ...organization of visual short-term memory . Psychological Review, 120, 297-328. Yildirim, I. & Jacobs, R. A. (2013). Transfer of object category...in visual short-term memory research. Attention, Perception, & Psychophysics, 76, 2158-2170. Orhan, A. E., Sims, C. R., Jacobs, R. A., & Knill, D. C

  4. Representations of orthogonal polynomials

    OpenAIRE

    Koepf, Wolfram; Schmersau, Dieter

    1998-01-01

    Zeilberger's algorithm provides a method to compute recurrence and differential equations from given hypergeometric series representations, and an adaption of Almquist and Zeilberger computes recurrence and differential equations for hyperexponential integrals. Further versions of this algorithm allow the computation of recurrence and differential equations from Rodrigues type formulas and from generating functions. In particular, these algorithms can be used to compute the differential/diffe...

  5. Translation between representation languages

    Science.gov (United States)

    Vanbaalen, Jeffrey

    1994-01-01

    A capability for translating between representation languages is critical for effective knowledge base reuse. A translation technology for knowledge representation languages based on the use of an interlingua for communicating knowledge is described. The interlingua-based translation process consists of three major steps: translation from the source language into a subset of the interlingua, translation between subsets of the interlingua, and translation from a subset of the interlingua into the target language. The first translation step into the interlingua can typically be specified in the form of a grammar that describes how each top-level form in the source language translates into the interlingua. In cases where the source language does not have a declarative semantics, such a grammar is also a specification of a declarative semantics for the language. A methodology for building translators that is currently under development is described. A 'translator shell' based on this methodology is also under development. The shell has been used to build translators for multiple representation languages and those translators have successfully translated nontrivial knowledge bases.

  6. Pioneers of representation theory

    CERN Document Server

    Curtis, Charles W

    1999-01-01

    The year 1897 was marked by two important mathematical events: the publication of the first paper on representations of finite groups by Ferdinand Georg Frobenius (1849-1917) and the appearance of the first treatise in English on the theory of finite groups by William Burnside (1852-1927). Burnside soon developed his own approach to representations of finite groups. In the next few years, working independently, Frobenius and Burnside explored the new subject and its applications to finite group theory. They were soon joined in this enterprise by Issai Schur (1875-1941) and some years later, by Richard Brauer (1901-1977). These mathematicians' pioneering research is the subject of this book. It presents an account of the early history of representation theory through an analysis of the published work of the principals and others with whom the principals' work was interwoven. Also included are biographical sketches and enough mathematics to enable readers to follow the development of the subject. An introductor...

  7. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements.

    Directory of Open Access Journals (Sweden)

    Helene Kreysa

    Full Text Available A speaker's gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., "sniffer dogs cannot smell the difference between identical twins". Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze.

  8. Expressive intent, ambiguity, and aesthetic experiences of music and poetry.

    Science.gov (United States)

    Margulis, Elizabeth Hellmuth; Levine, William H; Simchy-Gross, Rhimmon; Kroger, Carolyn

    2017-01-01

    A growing number of studies are investigating the way that aesthetic experiences are generated across different media. Empathy with a perceived human artist has been suggested as a common mechanism [1]. In this study, people heard 30 s excerpts of ambiguous music and poetry preceded by neutral, positively valenced, or negatively valenced information about the composer's or author's intent. The information influenced their perception of the excerpts-excerpts paired with positive intent information were perceived as happier and excerpts paired with negative intent information were perceived as sadder (although across intent conditions, musical excerpts were perceived as happier than poetry excerpts). Moreover, the information modulated the aesthetic experience of the excerpts in different ways for the different excerpt types: positive intent information increased enjoyment and the degree to which people found the musical excerpts to be moving, but negative intent information increased these qualities for poetry. Additionally, positive intent information was judged to better match musical excerpts and negative intent information to better match poetic excerpts. These results suggest that empathy with a perceived human artist is indeed an important shared factor across experiences of music and poetry, but that other mechanisms distinguish the generation of aesthetic appreciation between these two media.

  9. Transcriptional and Microenvironmental Regulation of Lineage Ambiguity in Leukemia

    Directory of Open Access Journals (Sweden)

    Tianyuan Hu

    2017-11-01

    Full Text Available Leukemia is characterized by the uncontrolled production of leukemic cells and impaired normal hematopoiesis. Although the combination of chemotherapies and hematopoietic stem cell transplantation has significantly improved the outcome of leukemia patients, a proportion of patients still suffer from relapse after treatment. Upon relapse, a phenomenon termed “lineage switch” is observed in a subset of leukemia patients, in which conversion of lymphoblastic leukemia to myeloid leukemia or vice versa is observed. A rare entity of leukemia called mixed-phenotype acute leukemia exhibits co-expression of markers representing two or three lineages. These two phenotypes regarding the lineage ambiguity suggest that the fate of some leukemia retain or acquire a certain degree of plasticity. Studies using animal models provide insight into how lineage specifying transcription factors can enforce or convert a fate in hematopoietic cells. Modeling lineage conversion in normal hematopoietic progenitor cells may improve our current understanding of how lineage switch occurs in leukemia. In this review, we will summarize the role of transcription factors and microenvironmental signals that confer fate plasticity to normal hematopoietic progenitor cells, and their potential to regulate lineage switching in leukemias. Future efforts to uncover the mechanisms contributing to lineage conversion in both normal hematopoiesis and leukemia may pave the way to improve current therapeutic strategies.

  10. Sexual Orientation Self-Concept Ambiguity: Scale Adaptation and Validation.

    Science.gov (United States)

    Talley, Amelia E; Stevens, Jordan E

    2017-07-01

    The current article describes the adaptation of a measure of sexual orientation self-concept ambiguity (SSA) from an existing measure of general self-concept clarity. Latent "trait" scores of SSA reflect the extent to which a person's beliefs about their own sexual orientation are perceived as inconsistent, unreliable, or incongruent. Sexual minority and heterosexual women ( n = 348), ages 18 to 30, completed a cross-sectional survey. Categorical confirmatory factor analysis guided the selection of items to form a 10-item, self-report measure of SSA. In the current report, we also examine (a) reliability of the 10-item scale score, (b) measurement invariance based on respondents' sexual identity status and age group, and (c) correlations with preexisting surveys that purport to measure similar constructs and theoretical correlates. Evidence for internal reliability, measurement invariance (based on respondent sex), and convergent validity was also investigated in an independent, validation sample. The lowest SSA scores were reported by women who self-ascribed an exclusively heterosexual or exclusively lesbian/gay sexual identity, whereas those who reported a bisexual, mostly lesbian/gay, or mostly heterosexual identity, reported relatively higher SSA scores.

  11. Ambiguous Capture: Collaborative Capitalism and the Meningitis Vaccine Project.

    Science.gov (United States)

    Graham, Janice

    2016-01-01

    The primary health care approach advanced at Alma Ata to address social determinants of health was replaced by selective health care a year later at Bellagio. Subsequently, immunization was endorsed as a cost-effective technical intervention to combat targeted infectious diseases. Multilateral efforts to collaborate on immunization as a universal public health good ambiguously capture the interests of the world's governments as well as private, public, and not-for-profit institutions. Global assemblages of scientists, governments, industry and nongovernmental organizations now work in public-private partnerships to develop and make essential vaccines accessible, with vaccines marketed as single fix solutions for global health. Drawing from ethnographic fieldwork in France and Burkina Faso that followed the development, regulation, and implementation of the group A meningococcal conjugate vaccine for sub-Saharan Africa, in this article I describe events during and after the development of MenAfriVac. A technological success narrative steeped in collaborative capitalist rhetoric disguises neglected health care systems.

  12. Ethical assumptions and ambiguities in the Americans With Disabilities Act.

    Science.gov (United States)

    Kopelman, L M

    1996-04-01

    The Americans With Disabilities Act (ADA) promotes social justice by protecting disabled persons from discrimination and prejudice. It seeks equality of opportunity for them and protects their well being by giving them fair access to goods, services and benefits. These rights are circumscribed in the ADA, however, by constraints of cost, efficiency, utility, and certain social mores. The ADA offers little direction about how to set priorities when these values come into conflict, or about whether equality or opportunity favors equivalent or preferential treatment for disadvantaged people. Until these ambiguities and potential value conflicts are resolved, a central moral and social problem remains unresolved: How can we demonstrate commitment to the rights and welfare of those with severe disabilities while placing fair limits upon their claims? Five special concerns are discussed: (1) eligibility and the allocation of health care; (2) the meaning of 'qualified but disabled' in employing people with mental disabilities; (3) equal opportunity and problems of envy and malingering; (4) ADA accommodation and public protection through testing and licensure; and (5) ADA protection and problems of backlash. Rather than simply wait to see what courts and administrative agencies decide, we should evaluate the moral conflicts, articulate criteria, and help make some difficult choices on morally defensible grounds.

  13. Expressive intent, ambiguity, and aesthetic experiences of music and poetry.

    Directory of Open Access Journals (Sweden)

    Elizabeth Hellmuth Margulis

    Full Text Available A growing number of studies are investigating the way that aesthetic experiences are generated across different media. Empathy with a perceived human artist has been suggested as a common mechanism [1]. In this study, people heard 30 s excerpts of ambiguous music and poetry preceded by neutral, positively valenced, or negatively valenced information about the composer's or author's intent. The information influenced their perception of the excerpts-excerpts paired with positive intent information were perceived as happier and excerpts paired with negative intent information were perceived as sadder (although across intent conditions, musical excerpts were perceived as happier than poetry excerpts. Moreover, the information modulated the aesthetic experience of the excerpts in different ways for the different excerpt types: positive intent information increased enjoyment and the degree to which people found the musical excerpts to be moving, but negative intent information increased these qualities for poetry. Additionally, positive intent information was judged to better match musical excerpts and negative intent information to better match poetic excerpts. These results suggest that empathy with a perceived human artist is indeed an important shared factor across experiences of music and poetry, but that other mechanisms distinguish the generation of aesthetic appreciation between these two media.

  14. Expressive intent, ambiguity, and aesthetic experiences of music and poetry

    Science.gov (United States)

    Margulis, Elizabeth Hellmuth; Levine, William H.; Simchy-Gross, Rhimmon; Kroger, Carolyn

    2017-01-01

    A growing number of studies are investigating the way that aesthetic experiences are generated across different media. Empathy with a perceived human artist has been suggested as a common mechanism [1]. In this study, people heard 30 s excerpts of ambiguous music and poetry preceded by neutral, positively valenced, or negatively valenced information about the composer's or author’s intent. The information influenced their perception of the excerpts—excerpts paired with positive intent information were perceived as happier and excerpts paired with negative intent information were perceived as sadder (although across intent conditions, musical excerpts were perceived as happier than poetry excerpts). Moreover, the information modulated the aesthetic experience of the excerpts in different ways for the different excerpt types: positive intent information increased enjoyment and the degree to which people found the musical excerpts to be moving, but negative intent information increased these qualities for poetry. Additionally, positive intent information was judged to better match musical excerpts and negative intent information to better match poetic excerpts. These results suggest that empathy with a perceived human artist is indeed an important shared factor across experiences of music and poetry, but that other mechanisms distinguish the generation of aesthetic appreciation between these two media. PMID:28746376

  15. Contesting Double Genealogy: Representing Rebellion Ambiguity in Babad Tanah Jawi

    Directory of Open Access Journals (Sweden)

    Achmad Fawaid

    2016-01-01

    Full Text Available Since firstly written in 1612 until the “final version” in 1836, Babad Tanah Jawi had a special place among intellectual debates, partly, in regard with its “functions” as mythical genre, ancient prophecy, historical narrative of Java, genealogical prototype, and typical structure with previous texts. However, little attention was given to the fact that Mataram, largely depicted in Babad Tanah Jawi, is considered as having ‘problematic’ double genealogy, which partly resulted from a double familial lineage of Batara Guru and the Prophet Adam, and the synthetic power of Demak and Majapahit. This study attempts to depict a scholarly contestation of the double genealogy of Mataram and its implication on ambivalent narratives of rebellion in the text.  Constructed as ex post facto in the universum of historical references, Babad Tanah Jawi seemingly takes its dual position in providing a subjectively constructed cosmology of Javanese characters and in attempting to objectively illustrate historical events. In some ways, it impacts on the way the text justified Javanese rulers by providing supernatural genesis of ancestors, and ‘purifying’ genealogical defects. The result is a distorted story of those who failed and succeeded to take over the Javanese kingdoms. The ambiguity lies on the way it has to maintain mythological genealogy of rebelling descendants and to perceive such rebellion as subversive.

  16. Categorification and higher representation theory

    CERN Document Server

    Beliakova, Anna

    2017-01-01

    The emergent mathematical philosophy of categorification is reshaping our view of modern mathematics by uncovering a hidden layer of structure in mathematics, revealing richer and more robust structures capable of describing more complex phenomena. Categorified representation theory, or higher representation theory, aims to understand a new level of structure present in representation theory. Rather than studying actions of algebras on vector spaces where algebra elements act by linear endomorphisms of the vector space, higher representation theory describes the structure present when algebras act on categories, with algebra elements acting by functors. The new level of structure in higher representation theory arises by studying the natural transformations between functors. This enhanced perspective brings into play a powerful new set of tools that deepens our understanding of traditional representation theory. This volume exhibits some of the current trends in higher representation theory and the diverse te...

  17. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics provides information on how the brain works, how mental illnesses ...

  18. Brain Basics

    Science.gov (United States)

    ... Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... Events About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  20. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  1. Application of Quaternion in improving the quality of global sequence alignment scores for an ambiguous sequence target in Streptococcus pneumoniae DNA

    Science.gov (United States)

    Lestari, D.; Bustamam, A.; Novianti, T.; Ardaneswari, G.

    2017-07-01

    DNA sequence can be defined as a succession of letters, representing the order of nucleotides within DNA, using a permutation of four DNA base codes including adenine (A), guanine (G), cytosine (C), and thymine (T). The precise code of the sequences is determined using DNA sequencing methods and technologies, which have been developed since the 1970s and currently become highly developed, advanced and highly throughput sequencing technologies. So far, DNA sequencing has greatly accelerated biological and medical research and discovery. However, in some cases DNA sequencing could produce any ambiguous and not clear enough sequencing results that make them quite difficult to be determined whether these codes are A, T, G, or C. To solve these problems, in this study we can introduce other representation of DNA codes namely Quaternion Q = (PA, PT, PG, PC), where PA, PT, PG, PC are the probability of A, T, G, C bases that could appear in Q and PA + PT + PG + PC = 1. Furthermore, using Quaternion representations we are able to construct the improved scoring matrix for global sequence alignment processes, by applying a dot product method. Moreover, this scoring matrix produces better and higher quality of the match and mismatch score between two DNA base codes. In implementation, we applied the Needleman-Wunsch global sequence alignment algorithm using Octave, to analyze our target sequence which contains some ambiguous sequence data. The subject sequences are the DNA sequences of Streptococcus pneumoniae families obtained from the Genebank, meanwhile the target DNA sequence are received from our collaborator database. As the results we found the Quaternion representations improve the quality of the sequence alignment score and we can conclude that DNA sequence target has maximum similarity with Streptococcus pneumoniae.

  2. Sensitivity to Referential Ambiguity in Discourse: The Role of Attention, Working Memory, and Verbal Ability.

    Science.gov (United States)

    Boudewyn, Megan A; Long, Debra L; Traxler, Matthew J; Lesh, Tyler A; Dave, Shruti; Mangun, George R; Carter, Cameron S; Swaab, Tamara Y

    2015-12-01

    The establishment of reference is essential to language comprehension. The goal of this study was to examine listeners' sensitivity to referential ambiguity as a function of individual variation in attention, working memory capacity, and verbal ability. Participants listened to stories in which two entities were introduced that were either very similar (e.g., two oaks) or less similar (e.g., one oak and one elm). The manipulation rendered an anaphor in a subsequent sentence (e.g., oak) ambiguous or unambiguous. EEG was recorded as listeners comprehended the story, after which participants completed tasks to assess working memory, verbal ability, and the ability to use context in task performance. Power in the alpha and theta frequency bands when listeners received critical information about the discourse entities (e.g., oaks) was used to index attention and the involvement of the working memory system in processing the entities. These measures were then used to predict an ERP component that is sensitive to referential ambiguity, the Nref, which was recorded when listeners received the anaphor. Nref amplitude at the anaphor was predicted by alpha power during the earlier critical sentence: Individuals with increased alpha power in ambiguous compared with unambiguous stories were less sensitive to the anaphor's ambiguity. Verbal ability was also predictive of greater sensitivity to referential ambiguity. Finally, increased theta power in the ambiguous compared with unambiguous condition was associated with higher working-memory span. These results highlight the role of attention and working memory in referential processing during listening comprehension.

  3. Dispositional sources of sanction perceptions: Emotionality, cognitive style, intolerance of ambiguity, and self-efficacy.

    Science.gov (United States)

    Pickett, Justin T; Bushway, Shawn D

    2015-12-01

    This study contributes to efforts to identify the sources of arrest risk perceptions and ambiguity (or lack of confidence) in such perceptions. Drawing on dual-process theories of reasoning, we argue that arrest risk perceptions often represent intuitive judgments that are influenced by cognitive heuristics and dispositional attributes. Multivariate regression models are estimated with data from 3 national surveys to test 6 hypotheses about the relationships between specific dispositional attributes and perceived arrest risk and ambiguity. We find evidence that dispositional positive affect and intolerance of ambiguity are both positively related to perceived arrest risk, and are also both negatively related to ambiguity. We also find evidence that cognitive reflection and general self-efficacy are, respectively, positively and negatively associated with ambiguity. Mixed evidence emerges about whether cognitive reflection is related to risk perceptions, and about whether either dispositional negative affect or thoughtfully reflective decision making correlate with ambiguity. Taken together, the results provide partial support for each of our hypotheses, and suggest that dispositional attributes are important sources of perceptions of arrest risk as well as of ambiguity in such perceptions. (c) 2015 APA, all rights reserved).

  4. Pigeons and the Ambiguous-Cue Problem: A Riddle that Remains Unsolved

    Directory of Open Access Journals (Sweden)

    Óscar García-Leal

    2017-06-01

    Full Text Available The ambiguous-cue task is composed of two-choice simultaneous discriminations involving three stimuli: positive (P, ambiguous (A, and negative (N. Two different trial types are presented: PA and NA. The ambiguous cue (A served as an S- in PA trials, but as an S+ in NA trials. When using this procedure, it is typical to observe a less accurate performance in PA trials than in NA trials. This is called the ambiguous-cue effect. Recently, it was reported in starlings that the ambiguous-cue effect decreases when the stimuli are presented on an angled (120° panel. The hypothesis is that the angled panel facilitates that the two cues from each discrimination are perceived as a compound, precluding value transfer via a second-order conditioning mechanism. In this experiment, we used pigeons and a flat panel. Nevertheless, our data were quite similar to the previous data in starlings. We conclude that the form of the panel cannot explain the ambiguous-cue effect. Several alternatives to be explored in future experiments are suggested. The riddle of the ambiguous-cue problem still remains unsolved.

  5. Going beyond representational anthropology

    DEFF Research Database (Denmark)

    Winther, Ida Wentzel

    Going beyond representational anthropology: Re-presenting bodily, emotional and virtual practices in everyday life. Separated youngsters and families in Greenland Greenland is a huge island, with a total of four high-schools. Many youngsters (age 16-18) move far away from home in order to get...... transformation work into the young people and their families. In this presentation I want to screen two sequences from the film, in order to show and clarify how mobility and transformation are made and dealt with both from the youngsters’ and their parents’ perspectives, but in asynchronous loups. I want...

  6. Representations of commonsense knowledge

    CERN Document Server

    Davis, Ernest

    1990-01-01

    Representations of Commonsense Knowledge provides a rich language for expressing commonsense knowledge and inference techniques for carrying out commonsense knowledge. This book provides a survey of the research on commonsense knowledge.Organized into 10 chapters, this book begins with an overview of the basic ideas on artificial intelligence commonsense reasoning. This text then examines the structure of logic, which is roughly analogous to that of a programming language. Other chapters describe how rules of universal validity can be applied to facts known with absolute certainty to deduce ot

  7. Representations of body and space: theoretical concepts and controversies.

    Science.gov (United States)

    Trojan, Jörg

    2015-09-01

    Recent years have seen a revived interest in how body and space are represented perceptually and how they affect human cognition and behaviour. Various conceptualisations of body and space have been proposed, alternately stressing neurophysiological, cognitive, or social aspects, but unified approaches are scarce. This short paper will give an overview of different views on body and space. At least three relevant dimensions can be identified in which concepts of body and space may differ: (1) perspective: while we conceptually differentiate between body and space perception, they imply each other and the underlying mechanisms overlap. (2) Level: representations of body and space may emerge at different processing levels, from spinal mechanisms guiding reflex movements to those we construct in our imagination. (3) Affect: representations of body and space are closely linked to affect, but this relationship has not received enough attention yet. Despite many empirical findings, our current views on body and space representations remain ambiguous. One problem may lie in the implicit diversity of "bodies" and "spaces" examined in different studies. Specifications of these concepts may help understand existing results better and are important for guiding future research.

  8. Azimuth Ambiguities Removal in Littoral Zones Based on Multi-Temporal SAR Images

    Directory of Open Access Journals (Sweden)

    Xiangguang Leng

    2017-08-01

    Full Text Available Synthetic aperture radar (SAR is one of the most important techniques for ocean monitoring. Azimuth ambiguities are a real problem in SAR images today, which can cause performance degradation in SAR ocean applications. In particular, littoral zones can be strongly affected by land-based sources, whereas they are usually regions of interest (ROI. Given the presence of complexity and diversity in littoral zones, azimuth ambiguities removal is a tough problem. As SAR sensors can have a repeat cycle, multi-temporal SAR images provide new insight into this problem. A method for azimuth ambiguities removal in littoral zones based on multi-temporal SAR images is proposed in this paper. The proposed processing chain includes co-registration, local correlation, binarization, masking, and restoration steps. It is designed to remove azimuth ambiguities caused by fixed land-based sources. The idea underlying the proposed method is that sea surface is dynamic, whereas azimuth ambiguities caused by land-based sources are constant. Thus, the temporal consistence of azimuth ambiguities is higher than sea clutter. It opens up the possibilities to use multi-temporal SAR data to remove azimuth ambiguities. The design of the method and the experimental procedure are based on images from the Sentinel data hub of Europe Space Agency (ESA. Both Interferometric Wide Swath (IW and Stripmap (SM mode images are taken into account to validate the proposed method. This paper also presents two RGB composition methods for better azimuth ambiguities visualization. Experimental results show that the proposed method can remove azimuth ambiguities in littoral zones effectively.

  9. Does language ambiguity in clinical practice justify the introduction of standard terminology? An integrative review.

    Science.gov (United States)

    Stallinga, Hillegonda A; ten Napel, Huib; Jansen, Gerard J; Geertzen, Jan H B; de Vries Robbé, Pieter F; Roodbol, Petrie F

    2015-02-01

    To research the use of ambiguous language in written information concerning patients' functioning and to identify problems resulting from the use of ambiguous language in clinical practice. Many projects that aimed to introduce standard terminology concerning patients' functioning in clinical practice are unsuccessful because standard terminology is rarely used in clinical practice. These projects mainly aim to improve communication by reducing ambiguous language. Considering their lack of success, the validity of the argument that language ambiguity is used in clinical practice is questioned. An integrative literature review. A systematic search of the MEDLINE (1950-2012) and CINAHL (1982-2012) databases was undertaken, including empirical and theoretical literature. The selected studies were critically appraised using a data assessment and extraction form. Seventeen of 767 papers were included in the review and synthesis. The use of ambiguous language in written information concerning patients' functioning was demonstrated. Problems resulting from the use of ambiguous language in clinical practice were not identified. However, several potential problems were suggested, including hindered clinical decision-making and limited research opportunities. The results of this review demonstrated the use of ambiguous language concerning patients' functioning, but health professionals in clinical practice did not experience this issue as a problem. This finding might explain why many projects aimed at introducing standard terminology concerning functioning in clinical practice to solve problems caused by ambiguous language are often unsuccessful. Language ambiguity alone is not a valid argument to justify the introduction of standard terminology. The introduction of standard terminology concerning patients' functioning will only be successful when clinical practice requires the aggregation and reuse of data from electronic patient records for different purposes, including

  10. THE SOCIAL REPRESENTATION OF PHYSICAL PUNISHMENT AMONG PARENTS OF PRIMARY CLASSES CHILDREN

    Directory of Open Access Journals (Sweden)

    Otilia STAMATIN

    2017-05-01

    Full Text Available The research was focused on studying the content of social representations (SR among parents of childrenfrom primary classes’, highlighting by gender the constitutive elements of this representations. We used the free association and prototypecategory techniques, the EVOC program. The conductedresearch exposed: central elements of SR (fear, stress, hatred; peripheral ones (torture, intimidation, tension, shouting, elements with ambiguous status, characterized by low frequency and low rank of importance (beating,punishment, and also elements with ambiguous status, characterized by high frequency and high rank of importance (pain, humiliation, tears, shame, violence. The majority elements evokeda negative shadowwhich reflects the parents’ tendency to disapprove the physical punishment of children. Simultaneously, the ambiguous area, which are closer to the periphery, contains elements of beating and punishment, meaning that some parents accept and practice such disciplinary method. The gender differences were established. The term beating is missing in the women SR structure, evoked solely by males. In the central core, only women assign the status of violence to beating. Also, fear has bigger gravity in the female SR structure, but men evoked it only once. In peripheral region of SR, women includeterms as pain, humiliation, tension. Those elements could be changed, if women it will be trained to control their emotions and to use socially desirable austere forms to educate children. The male attitude could be changed by a tougher involvement of legal regulations against abusers.

  11. The Ambiguity of Justice: Paul Ricoeur on Universalism and Evil

    Directory of Open Access Journals (Sweden)

    Geoffrey Dierckxsens

    2016-01-01

    Full Text Available In this article I will examine Ricœur’s idea of the universal in his understanding of justice. Scholars recently discussed the extent to which Ricœur understands universal moral norms and universal rules of justice in his anthropology of human action (e.g., J. Michel, Paul Ricœur: une philosophie de l’agir humain, Paris: Les Éditions du Cerf, 2006, and argue that Ricœur stresses too much the idea of universal moral norms with regard to cultural and moral diversity (e.g., G. H. Taylor, “Ricoeur versus Ricoeur? Between the Universal and the Contextual,” From Ricoeur to Action. The Socio-Political Significance of Ricoeur’s Thinking, Todd S. Mei and David Lewin (eds., (London and New York: Bloomsbury, 2012. G. H. Taylor, “Reenvisioning Justice,” Lo Squarda 12 (2013: 65-80. In this article I will take part in the debate about universalism and approach Ricœur’s idea of the universal from a different angle, in placing it in light of his idea of evil. The point I will aim to make in this article is that Ricœur’s idea of the relation between justice and evil demonstrates what I understand as the ambiguity of justice, which highlights the difficulty of defining universal rules of justice. I will argue that this ambiguity is the following: justice aims at the establishment of social peace and in that sense it is the necessary remedy against human evil, but justice also implies power, and possibly violence, over others in that it relates to violent feelings of vengeance, to institutional mechanism of authority, and to a struggle of values. Yet if rules of justice relate to evil in the sense of power over others, so I argue, then it is problematic to define absolute criteria for rules of justice, i.e., for rules for social peace: because justice relates to particular values, which means that the risk of violence is inherent to institutional rules of justice, there is no ultimate universal set of such rules. This article therefore

  12. Effects of motion speed in action representations.

    Science.gov (United States)

    van Dam, Wessel O; Speed, Laura J; Lai, Vicky T; Vigliocco, Gabriella; Desai, Rutvik H

    2017-05-01

    Grounded cognition accounts of semantic representation posit that brain regions traditionally linked to perception and action play a role in grounding the semantic content of words and sentences. Sensory-motor systems are thought to support partially abstract simulations through which conceptual content is grounded. However, which details of sensory-motor experience are included in, or excluded from these simulations, is not well understood. We investigated whether sensory-motor brain regions are differentially involved depending on the speed of actions described in a sentence. We addressed this issue by examining the neural signature of relatively fast (The old lady scurried across the road) and slow (The old lady strolled across the road) action sentences. The results showed that sentences that implied fast motion modulated activity within the right posterior superior temporal sulcus and the angular and middle occipital gyri, areas associated with biological motion and action perception. Sentences that implied slow motion resulted in greater signal within the right primary motor cortex and anterior inferior parietal lobule, areas associated with action execution and planning. These results suggest that the speed of described motion influences representational content and modulates the nature of conceptual grounding. Fast motion events are represented more visually whereas motor regions play a greater role in representing conceptual content associated with slow motion. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Processing ambiguous Spanish se in a minimal chain.

    Science.gov (United States)

    Meseguer, Enrique; Acuña-Fariña, Carlos; Carreiras, Manuel

    2009-04-01

    The recovery of pieces of information that are not linguistically expressed is a constant feature of the process of language comprehension. In the processing literature, such missing information is generally referred to as "gaps". Usually, one resolves gaps by finding "fillers" in either the sentence or the context. For instance, in Peter seemed to be upset, Peter is really the subject of being upset but appears as surface subject of seems. Sometimes constituents move, leaving gaps behind. Various Romance languages such as Spanish or Italian have a grammatical particle se/si, which, as it is extremely ambiguous, licenses different sorts of gaps. In Spanish, se can encode at least reflexive, impersonal, and passive meanings. In an eye-tracking experiment we contrast reflexive structures containing postverbal subjects with impersonal structures with no subjects (GAP se vendó apresuradamente el corredor/"the runner bandaged himself hurriedly" vs. GAP se vendó apresuradamente al corridor/"(someone) bandaged the runner hurriedly"). In a second manipulation we contrast the presence of an extra argument with se-passives (GAP se vendó el tobillo el corredor/"the runner bandaged his ankle" vs. GAP se vendó el tobillo al corridor/"the runner's ankle was bandaged"). Our comparisons involve contrasting standard transitive structures with nonstandard word order (postverbal subject and a preverbal subject gap) against inherently complex and less habitual structures such as impersonals (with no subject) or se-passives (with subjects in canonical object position). We evaluate the minimal chain principle (de Vincenzi, 1991), according to which displacement is costly because it entails complex (derivational) "chains" that must be undone before phrasal packaging can commence. We show the minimal chain principle to be essentially correct when contrasting more complex but more frequent structures with less complex but less frequent structures. A noteworthy feature of this research

  14. Individual Representation: A Different Approach to Political Representation

    OpenAIRE

    Ruedin, Didier

    2012-01-01

    This article presents a new conceptualisation and measure of political representation to complement conventional approaches. Individual representation scores place the individual rather than the legislature at the centre, providing a fresh perspective on the relationship between inequality and representation. They are calculated by comparing first the position of the individual with other citizens, and second the position of the individual with the legislature. The article outlines how to mak...

  15. Social Representations of Intelligence

    Directory of Open Access Journals (Sweden)

    Elena Zubieta

    2016-02-01

    Full Text Available The article stresses the relationship between Explicit and Implicit theories of Intelligence. Following the line of common sense epistemology and the theory of Social Representations, a study was carried out in order to analyze naive’s explanations about Intelligence Definitions. Based on Mugny & Carugati (1989 research, a self-administered questionnaire was designed and filled in by 286 subjects. Results are congruent with the main hyphotesis postulated: A general overlap between explicit and implicit theories showed up. According to the results Intelligence appears as both, a social attribute related to social adaptation and as a concept defined in relation with contextual variables similar to expert’s current discourses. Nevertheless, conceptions based on “gifted ideology” still are present stressing the main axes of Intelligence debate: biological and sociological determinism. In the same sense, unfamiliarity and social identity are reaffirmed as organizing principles of social representation. The distance with the object -measured as the belief in intelligence differences as a solve/non solve problem- and the level of implication with the topic -teachers/no teachers- appear as discriminating elements at the moment of supporting specific dimensions. 

  16. Representation of identities and the politics of representation in cognition

    OpenAIRE

    Kanavillil Rajagopalan

    2001-01-01

    In this paper, I make a plea for viewing representation as first and foremost a political matter. I argue that by so doing we may avoid the many of pitfalls of contemporary theories of cognition as they attempt to tackle the issue of representation. Most of these problems have to do with the fact that representation is treated exclusively as a mimetic or theatrical question. The fact of the matter is however that representation also has a political dimension. Indeed it has always had...

  17. Task alters category representations in prefrontal but not high-level visual cortex.

    Science.gov (United States)

    Bugatus, Lior; Weiner, Kevin S; Grill-Spector, Kalanit

    2017-07-15

    A central question in neuroscience is how cognitive tasks affect category representations across the human brain. Regions in lateral occipito-temporal cortex (LOTC), ventral temporal cortex (VTC), and ventro-lateral prefrontal cortex (VLFPC) constitute the extended "what" pathway, which is considered instrumental for visual category processing. However, it is unknown (1) whether distributed responses across LOTC, VTC, and VLPFC explicitly represent category, task, or some combination of both, and (2) in what way representations across these subdivisions of the extended 'what' pathway may differ. To fill these gaps in knowledge, we scanned 12 participants using fMRI to test the effect of category and task on distributed responses across LOTC, VTC, and VLPFC. Results reveal that task and category modulate responses in both high-level visual regions, as well as prefrontal cortex. However, we found fundamentally different types of representations across the brain. Distributed responses in high-level visual regions are more strongly driven by category than task, and exhibit task-independent category representations. In contrast, distributed responses in prefrontal cortex are more strongly driven by task than category, and contain task-dependent category representations. Together, these findings of differential representations across the brain support a new idea that LOTC and VTC maintain stable category representations allowing efficient processing of visual information, while prefrontal cortex contains flexible representations in which category information may emerge only when relevant to the task. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Integral geometry and representation theory

    CERN Document Server

    Gel'fand, I M; Vilenkin, N Ya

    1966-01-01

    Generalized Functions, Volume 5: Integral Geometry and Representation Theory is devoted to the theory of representations, focusing on the group of two-dimensional complex matrices of determinant one.This book emphasizes that the theory of representations is a good example of the use of algebraic and geometric methods in functional analysis, in which transformations are performed not on the points of a space, but on the functions defined on it. The topics discussed include Radon transform on a real affine space, integral transforms in the complex domain, and representations of the group of comp

  19. Logic without unique readability - a study of semantic and syntactic ambiguity

    DEFF Research Database (Denmark)

    Bentzen, Martin Mose

    not hold true universally. Whereas e.g. scope ambiguities in natural languages have been studied extensively, ambiguous formal languages have not been the focus of in depth research. Here, we lift the assumption of unique readability by omitting the brackets from propositional logic, making it possible...... to formally distinguish between syntactic and semantic ambiguity. A valuation then amounts to a semantic disambiguation, and rather than a unique valuation (truth value), there is a set of valuations corresponding to ways a formula could have been constructed. We show what happens to familiar concepts...... of logic such as definability, satisfiability and validity. Here follows two simple examples illustrating the relation between syntactic and semantic ambiguity. In some cases unique readability can be regained through careful construction of formulas. E.g., although an attempt to define p → q as ¬p ∨ q...

  20. The processing of lexical ambiguity: homonymy and polysemy in the mental lexicon.

    Science.gov (United States)

    Klepousniotou, Ekaterini

    2002-01-01

    Under the theoretical assumption that lexical ambiguity is not a homogeneous phenomenon, but rather that it is subdivided into two distinct types, namely homonymy and polysemy, the present study investigated whether these different types of lexical ambiguity are psychologically real. Four types of ambiguous words, homonymous words (e.g., "pen"), polysemous words with metaphorical extensions (e.g., "eye"), polysemous words with a count/mass metonymic extension (e.g., "turkey"), and polysemous words with a producer/product metonymic extension (e.g., "Dali"), were used in a cross-modal sentence-priming lexical decision task. Overall, the theoretical distinction between homonymy and polysemy was reflected in the results of the present study, which revealed differential processing depending on the type of ambiguity. Copyright 2001 Elsevier Science (USA).

  1. Perceptions of boundary ambiguity in the process of leaving an abusive partner.

    Science.gov (United States)

    Khaw, Lyndal; Hardesty, Jennifer L

    2015-06-01

    The process of leaving an abusive partner has been theorized using the Stages of Change Model. Although useful, this model does not account for changes in relational boundaries unique to the process of leaving. Using family stress and feminist perspectives, this study sought to integrate boundary ambiguity into the Stages of Change Model. Boundary ambiguity is defined as a perception of uncertainty as to who is in or out of a family system (Boss & Greenberg, 1984). Twenty-five mothers who had temporarily or permanently left their abusers were interviewed. Data were analyzed using constructivist grounded theory methods. Results identify types, indicators of, and mothers' responses to boundary ambiguity throughout the five stages of change. Most mothers and abusers fluctuated between physical and psychological presence and absence over multiple separations. The integration of boundary ambiguity into the Stages of Change Model highlights the process of leaving an abusive partner as systemic, fluid, and nonlinear. © 2014 Family Process Institute.

  2. Role conflict and ambiguity of CEOs in international joint ventures: a transaction cost perspective.

    Science.gov (United States)

    Gong, Y; Shenkar, O; Luo, Y; Nyaw, M K

    2001-08-01

    Insights from transaction cost economics were used to study the boundary conditions underlying the role conflict and ambiguity of 265 CEOs in Chinese-based international joint ventures. Role conflict and ambiguity were lower when the contract between parents was more complete. Contract completeness fully mediated the effects of parent objective gap and parent formalization on role ambiguity but only partially so in the case of role conflict. Role conflict was lower when the foreign parent was dominant in the venture but higher when the local parent was dominant. Role conflict and ambiguity were inversely related to cultural distance. Neither construct had a detrimental effect on international joint venture performance. Implications for role theory are discussed.

  3. Four-dimensional aether-like Lorentz-breaking QED revisited and problem of ambiguities

    Energy Technology Data Exchange (ETDEWEB)

    Baeta Scarpelli, A.P. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Rua Hugo D' Antola, 95, Lapa, Sao Paulo (Brazil); Mariz, T. [Universidade Federal de Alagoas, Instituto de Fisica, Maceio, Alagoas (Brazil); Nascimento, J.R.; Petrov, A.Yu. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, Paraiba (Brazil)

    2013-08-15

    In this paper, we consider the perturbative generation of the CPT-even aether-like Lorentz-breaking term in the extended Lorentz-breaking QED within different approaches and discuss its ambiguities. (orig.)

  4. Resolving the Theoretical Ambiguities of Social Exclusion with reference to Polarisation and Conflict

    NARCIS (Netherlands)

    A.M. Fischer (Andrew Martín)

    2008-01-01

    textabstractThis paper addresses several ambiguities in the social exclusion literature that fuel the common criticism that the concept is redundant with respect to already existing poverty approaches, particularly more multidimensional and processual approaches such as relative or capability

  5. Choledochal cyst, polysplenia and situs ambiguous: A rare and new association

    Directory of Open Access Journals (Sweden)

    Francesca Destro

    2017-09-01

    Conclusions: A careful evaluation of patients with situs ambiguous is important to exclude associated anomalies and to plan the most appropriate surgical approach. The association with choledochal cyst should be taken into account.

  6. Identification and definition of lexically ambiguous words in statistics by tutors and students

    Science.gov (United States)

    Richardson, Alice M.; Dunn, Peter K.; Hutchins, Rene

    2013-10-01

    Lexical ambiguity arises when a word from everyday English is used differently in a particular discipline, such as statistics. This paper reports on a project that begins by identifying tutors' perceptions of words that are potentially lexically ambiguous to students, in two different ways. Students' definitions of nine lexically ambiguous words are also collected at the beginning and end of a semester of introductory statistics study, in a complex design taking account of multiple tutors and multiple words in multiple contexts. Tutor perceptions and actual student difficulties at the beginning of a semester are compared. The lexical ambiguity associated with the word 'significance' is shown to be evident in students even after completing an introductory statistics course.

  7. More than visual literacy: art and the enhancement of tolerance for ambiguity and empathy.

    Science.gov (United States)

    Bentwich, Miriam Ethel; Gilbey, Peter

    2017-11-10

    Comfort with ambiguity, mostly associated with the acceptance of multiple meanings, is a core characteristic of successful clinicians. Yet past studies indicate that medical students and junior physicians feel uncomfortable with ambiguity. Visual Thinking Strategies (VTS) is a pedagogic approach involving discussions of art works and deciphering the different possible meanings entailed in them. However, the contribution of art to the possible enhancement of the tolerance for ambiguity among medical students has not yet been adequately investigated. We aimed to offer a novel perspective on the effect of art, as it is experienced through VTS, on medical students' tolerance of ambiguity and its possible relation to empathy. Quantitative method utilizing a short survey administered after an interactive VTS session conducted within mandatory medical humanities course for first-year medical students. The intervention consisted of a 90-min session in the form of a combined lecture and interactive discussions about art images. The VTS session and survey were filled by 67 students in two consecutive rounds of first-year students. 67% of the respondents thought that the intervention contributed to their acceptance of multiple possible meanings, 52% thought their visual observation ability was enhanced and 34% thought that their ability to feel the sufferings of other was being enhanced. Statistically significant moderate-to-high correlations were found between the contribution to ambiguity tolerance and contribution to empathy (0.528-0.744; p ≤ 0.01). Art may contribute especially to the development of medical students' tolerance of ambiguity, also related to the enhancement of empathy. The potential contribution of visual art works used in VTS to the enhancement of tolerance for ambiguity and empathy is explained based on relevant literature regarding the embeddedness of ambiguity within art works, coupled with reference to John Dewey's theory of learning. Given the

  8. Scene statistics: neural representation of real-world structure in rapid visual perception

    NARCIS (Netherlands)

    Groen, I.I.A.

    2014-01-01

    How does the brain represent our visual environment? Research has revealed brain areas that respond to specific information such as faces and objects, but how a representation of an entire visual scene is formed is still unclear. This thesis explores the idea that scene statistics play an important

  9. Statistical analysis of the ambiguities in the asteroid period determinations

    Science.gov (United States)

    Butkiewicz, M.; Kwiatkowski, T.; Bartczak, P.; Dudziński, G.

    2014-07-01

    A synodic period of an asteroid can be derived from its lightcurve by standard methods like Fourier-series fitting. A problem appears when results of observations are based on less than a full coverage of a lightcurve and/or high level of noise. Also, long gaps between individual lightcurves create an ambiguity in the cycle count which leads to aliases. Excluding binary systems and objects with non-principal-axis rotation, the rotation period is usually identical to the period of the second Fourier harmonic of the lightcurve. There are cases, however, where it may be connected with the 1st, 3rd, or 4th harmonic and it is difficult to choose among them when searching for the period. To help remove such uncertainties we analysed asteroid lightcurves for a range of shapes and observing/illuminating geometries. We simulated them using a modified internal code from the ISAM service (Marciniak et al. 2012, A&A 545, A131). In our computations, shapes of asteroids were modeled as Gaussian random spheres (Muinonen 1998, A&A, 332, 1087). A combination of Lommel-Seeliger and Lambert scattering laws was assumed. For each of the 100 shapes, we randomly selected 1000 positions of the spin axis, systematically changing the solar phase angle with a step of 5°. For each lightcurve, we determined its peak-to-peak amplitude, fitted the 6th-order Fourier series and derived the amplitudes of its harmonics. Instead of the number of the lightcurve extrema, which in many cases is subjective, we characterized each lightcurve by the order of the highest-amplitude Fourier harmonic. The goal of our simulations was to derive statistically significant conclusions (based on the underlying assumptions) about the dominance of different harmonics in the lightcurves of the specified amplitude and phase angle. The results, presented in the Figure, can be used in individual cases to estimate the probability that the obtained lightcurve is dominated by a specified Fourier harmonic. Some of the

  10. Intentionality, Representation, and Anticipation

    Science.gov (United States)

    De Preester, Helena

    2002-09-01

    Both Brentano and Merleau-Ponty have developed an account of intentionality, which nevertheless differ profoundly in the following respect. According to Brentano, intentionality mainly is a matter of mental presentations. This marks the beginning of phenomenology's difficult relation with the nature of the intentional reference. Merleau-Ponty, on the other hand, has situated intentionality on the level of the body, a turn which has important implications for the nature of intentionality. Intentionality no longer is primarily based on having (re)presentations, but is rooted in the dynamics of the living body. To contrast those approaches enables us to make clear in what way intentionality is studied nowadays. On the one hand, intentionality is conceived of as a matter of formal-syntactical causality in cognitive science, and in particular in classical-computational theory. On the other hand, a interactivist approach offers a more Merleau-Ponty-like point of view, in which autonomy, embodiment and interaction are stressed.

  11. Resource representation in COMPASS

    Science.gov (United States)

    Fox, Barry R.

    1991-01-01

    A set of viewgraphs on resource representation in COMPASS is given. COMPASS is an incremental, interactive, non-chronological scheduler written in Ada with an X-windows user interface. Beginning with an empty schedule, activities are added to the schedule one at a time, taking into consideration the placement of the activities already on the timeline and the resources that have been reserved for them. The order that the activities are added to the timeline and their location on the timeline are controlled by selection and placement commands invoked by the user. The order that activities are added to the timeline and their location are independent. The COMPASS code library is a cost effective platform for the development of new scheduling applications. It can be effectively used off the shelf for compatible scheduling applications or it can be used as a parts library for the development of custom scheduling systems.

  12. Brain herniation

    Science.gov (United States)

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  13. Role Conflict and Role Ambiguity of Chief Executive Officers in International Joint Ventures

    OpenAIRE

    Oded Shenkar; Yoram Zeira

    1992-01-01

    This study examines the organizational and personal correlates of role conflict and role ambiguity of chief executive officers heading international joint ventures. Role conflict was found to be lower when the number of parent firms was higher and when the CEO had spent more years with the organization. Role ambiguity was found to be lower when the CEO had more years of education, when the Power Distance and Masculinity/Femininity gap between parents were lower, and when the Individualism/Col...

  14. Scanning and Parsing Languages with Ambiguities and Constraints: The Lamb and Fence Algorithms

    OpenAIRE

    Quesada, Luis; Berzal, Fernando; Cortijo, Francisco J.

    2015-01-01

    Traditional language processing tools constrain language designers to specific kinds of grammars. In contrast, model-based language processing tools decouple language design from language processing. These tools allow the occurrence of lexical and syntactic ambiguities in language specifications and the declarative specification of constraints for resolving them. As a result, these techniques require scanners and parsers able to parse context-free grammars, handle ambiguities, and enforce con...

  15. How Vestibular Neurons Solve the Tilt/Translation Ambiguity: Comparison of Brainstem, Cerebellum, and Thalamus

    OpenAIRE

    Dora E. Angelaki; Yakusheva, Tatyana A.

    2009-01-01

    The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinat...

  16. Motor memory consolidation in sleep shapes more effective neuronal representations.

    Science.gov (United States)

    Fischer, Stefan; Nitschke, Matthias F; Melchert, Uwe H; Erdmann, Christian; Born, Jan

    2005-12-07

    Learning a motor skill involves a latent process of consolidation that develops after training to enhance the skill in the absence of any practice and crucially depends on sleep. Here, we show that this latent consolidation during sleep changes the brain representation of the motor skill by reducing overall the neocortical contributions to the representation. Functional magnetic resonance brain imaging was performed during initial training and 48 h later, at retesting, on a sequential finger movement task with training followed by either a night of regular sleep or sleep deprivation. An additional night of sleep for all subjects served to rule out unspecific effects of sleep loss at retrieval testing. Posttraining sleep, but not sleep deprivation, led to improved motor skill performance at retrieval. This sleep-dependent improvement was linked to greatly reduced brain activation in prefrontal, premotor, and primary motor cortical areas, along with a stronger involvement of left parietal cortical regions. Our findings indicate that storing a motor skill during sleep reorganizes its brain representation toward enhanced efficacy.

  17. Representational similarity analysis - connecting the branches of systems neuroscience.

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Mur, Marieke; Bandettini, Peter

    2008-01-01

    A FUNDAMENTAL CHALLENGE FOR SYSTEMS NEUROSCIENCE IS TO QUANTITATIVELY RELATE ITS THREE MAJOR BRANCHES OF RESEARCH: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g., single-cell recordings or voxels from functional magnetic resonance imaging (fMRI). Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement (e.g., fMRI and invasive or scalp electrophysiology), and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices (RDMs), which characterize the information carried by a given representation in a brain or model. Building on a rich psychological and mathematical literature on similarity analysis, we propose a new experimental and data-analytical framework called representational similarity analysis (RSA), in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing RDMs. We demonstrate RSA by relating representations of visual objects as measured with fMRI in early visual cortex and the fusiform face area to computational models spanning a wide range of complexities. The RDMs are simultaneously related via second-level application of multidimensional scaling and tested using randomization and bootstrap techniques. We discuss the broad potential of RSA, including novel approaches to experimental design, and argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience.

  18. Representational Similarity Analysis – Connecting the Branches of Systems Neuroscience

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Mur, Marieke; Bandettini, Peter

    2008-01-01

    A fundamental challenge for systems neuroscience is to quantitatively relate its three major branches of research: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g., single-cell recordings or voxels from functional magnetic resonance imaging (fMRI). Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement (e.g., fMRI and invasive or scalp electrophysiology), and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices (RDMs), which characterize the information carried by a given representation in a brain or model. Building on a rich psychological and mathematical literature on similarity analysis, we propose a new experimental and data-analytical framework called representational similarity analysis (RSA), in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing RDMs. We demonstrate RSA by relating representations of visual objects as measured with fMRI in early visual cortex and the fusiform face area to computational models spanning a wide range of complexities. The RDMs are simultaneously related via second-level application of multidimensional scaling and tested using randomization and bootstrap techniques. We discuss the broad potential of RSA, including novel approaches to experimental design, and argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience. PMID:19104670

  19. A study of potential sources of linguistic ambiguity in written work instructions.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.

    2009-11-01

    This report describes the results of a small experimental study that investigated potential sources of ambiguity in written work instructions (WIs). The English language can be highly ambiguous because words with different meanings can share the same spelling. Previous studies in the nuclear weapons complex have shown that ambiguous WIs can lead to human error, which is a major cause for concern. To study possible sources of ambiguity in WIs, we determined which of the recommended action verbs in the DOE and BWXT writer's manuals have numerous meanings to their intended audience, making them potentially ambiguous. We used cognitive psychology techniques to conduct a survey in which technicians who use WIs in their jobs indicated the first meaning that came to mind for each of the words. Although the findings of this study are limited by the small number of respondents, we identified words that had many different meanings even within this limited sample. WI writers should pay particular attention to these words and to their most frequent meanings so that they can avoid ambiguity in their writing.

  20. The inertial attitude augmentation for ambiguity resolution in SF/SE-GNSS attitude determination.

    Science.gov (United States)

    Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

    2014-06-26

    The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation.