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    When living things and other 'sensory quality' categories behave in the same fashion: a novel category specificity effect

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    In this study, the performance on semantic tests of five patients with a diagnosis of probable herpes simplex encephalitis was examined. Only one of the patients, MU, showed a marked category-specific deficit for living things, unlike the other patients. Results which closely mirrored those obtained with the category living things were found in each of the five patients for the other categories, edible substances, materials, and liquids, selected for a prior! theoretical reasons. The processing of these additional categories was investigated with tasks involving naming abilities in different modalities, matching to sample, and questionnaires exploring the status of the patients' knowledge about the semantic features of both living things and exemplars of novel 'sensory quality' categories. MU showed in all tasks a comparable impairment for both living things and the other three new categories, in spite of a performance closely equivalent to that of the other four patients with man-made artefacts. This finding supports an explanation of MU's performance in terms of an impairment relating to categories highly dependent on the sensory quality of stimuli. In addition, his difficulty involved all aspects of the processing of the impaired categories

    Semantic access processing in a supra-modal deficit: a single case study

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    The case is presented of a semantic dementia patient, who shows a deficit selective for (i) conceptual class (living things), (ii) attribute processing (visual features) and affecting (iii) input-output modalities at the same processing stage (matching stored representation to attributes). The first experimental part aims at exploring the specific stage/process at which semantic knowledge breaks down through multi-modality tasks, devised to tap different levels within the semantic elaboration flow. The second focuses on the differences between category vs. attribute knowledge across various modalities. The core nature of the patient's deficit is investigated through a close comparison of her damage to a specific processing stage across modalities in the light of her class and attribute-specific impairment. The complex pattern of findings is discussed according to current theoretical accounts of semantic memory organization. Finally, the relevance of the adoption of a broad perspective when dealing with semantic memory impairments is highlighted. (C) 2003 Elsevier Science (USA). All rights reserved

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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