38 research outputs found

    Manipulation of Pre-Target Activity on the Right Frontal Eye Field Enhances Conscious Visual Perception in Humans

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    The right Frontal Eye Field (FEF) is a region of the human brain, which has been consistently involved in visuo-spatial attention and access to consciousness. Nonetheless, the extent of this cortical site’s ability to influence specific aspects of visual performance remains debated. We hereby manipulated pre-target activity on the right FEF and explored its influence on the detection and categorization of low-contrast near-threshold visual stimuli. Our data show that pre-target frontal neurostimulation has the potential when used alone to induce enhancements of conscious visual detection. More interestingly, when FEF stimulation was combined with visuo-spatial cues, improvements remained present only for trials in which the cue correctly predicted the location of the subsequent target. Our data provide evidence for the causal role of the right FEF pre-target activity in the modulation of human conscious vision and reveal the dependence of such neurostimulatory effects on the state of activity set up by cue validity in the dorsal attentional orienting network

    Tracking Down Abstract Linguistic Meaning: Neural Correlates of Spatial Frame of Reference Ambiguities in Language

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    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

    Two new species of Odontostilbe historically hidden under O. microcephala (Characiformes: Cheirodontinae)

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    Specimens historically identified as Odontostilbe microcephala from the upper rio Paraná and Andean piedmont tributaries of the río Paraguay are reviewed and split in three species. We found that the distribution of O. microcephala is restricted to the Andean slope of the río Paraguay basin. The species is distinguished from congeners with subterminal mouth by the elongate body, usually 10-12 gill rakers on upper branch and smaller horizontal orbital diameter (24.6-32.8 % HL, mean 28.7%). Specimens from upper rio Paraná constitute two new species, diagnosed from other Cheirodontinae by the presence of mesopterygoid teeth, grouped on median portion and forming a continuous row. The new species are distinguished from each other by having premaxillary teeth with five cusps vs. nine cusps and by the number of lamellae in left and right sides of central median raphe of olfactory rosette with 20-21 vs. 11-12.Espécimes historicamente identificados com Odontostilbe microcephala do rio Paraná e tributários do río Paraguay, foram revisados e separados em três espécies. A distribuição de O. microcephala é restrita ao sopé andino da bacia do río Paraguay. A espécie é distinta das congêneres com boca subterminal pela forma alongada, geralmente 10-12 rastros branquiais no ramo superior e menor diâmetro horizontal da órbita (24,6-32,8 % CC, média 28,7%). Espécimes do alto rio Paraná constituem duas espécies novas diagnosticadas de outros Cheirodontinae pela presença de dentes no mesopterigoide, agrupados em sua porção média e formando uma fileira continua. As novas espécies distinguem-se por ter dentes premaxilares com cinco cúspides vs. nove cúspides e pelo número de lamelas nos lados esquerdo e direito da rafe central da roseta olfativa com 20-21 vs. 11-12

    Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

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    Four-Dimensional Consciousness

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    Quality of life changes with duration of chronic breathlessness: a random sample of community-dwelling people

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    INTRODUCTION:Chronic breathlessness is associated with poorer quality of life (QoL). This population study aimed to define dimensions of QoL and duration and dominant causes of breathlessness that most diminished QoL. METHODS:This cross-sectional, population-based, and randomized survey of adults (n = 2977) in South Australia collected data on demographics, modified Medical Research Council (mMRC) breathlessness, and QoL (EuroQoL five-dimension five-level [EQ-5D-5L] measure; Short Form 12 quality-of-life measure). Data weighted to the census were analyzed for relationships between EQ-5D-5L and its dimensions with mMRC. Regression models controlled for age, sex, education, rurality, and body mass index. RESULTS:About 2883 responses were analyzed: 49% were males; mean age was 48 years (SD 19). As mMRC worsened, EQ-5D-5L and its dimensions worsened. More severe chronic breathlessness was iteratively associated with lower mobility, daily activities, and worse pain/discomfort. For self-care and anxiety/depression, impairment was only with the most severe breathlessness. Respondents who had chronic breathlessness for two to six years had the worst QoL scores. People who attributed their breathlessness to cardiac failure had poorer QoL. Respondents who reported a cardiac cause for their breathlessness had worse mobility, poorer usual activities, and more pain than the other causes. The regression analyses showed that worse chronic breathlessness was associated with worsening QoL in each dimension of EQ-5D-5L, with the exception of the self-care, which only worsened with the most severe breathlessness. CONCLUSIONS:This is the first study to report on chronic breathlessness and impairment across dimensions of QoL and differences by its duration. Mobility, usual activity, and pain drive these reductions
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