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PubMed2002

Cognitive performance in very old diabetic persons: the impact of semantic structure, preclinical dementia, and impending death.

The authors examined the associations of diabetes mellitus with cognitive performance in a population-based sample of nondemented and nondepressed very old persons. Diabetic participants (n = 31) were compared with nondiabetic controls (n = 307), adjusting for age, educational level, and related vascular diseases and signs. Results showed that diabetic persons performed significantly worse on tests of verbal fluency and episodic memory but that the effects on both types of abilities were less pronounced in tasks involving higher degrees of semantic structure. Follow-up analyses further revealed that preclinical dementia and impending death accounted for much of the observed associations. The results suggest that cognitive deficits among very old diabetics are most likely detected by tasks that draw less on semantic structures and that the most robust effects may be found in letter fluency performance.

Aged↗
PubMedDate not supplied

Learning to divide the labor between syntax and semantics: a connectionist account of deficits in light and heavy verb production.

In aphasic subjects who demonstrate difficulty producing verbs, a double dissociation has been observed between light verbs (e.g., GO) and heavy verbs (e.g., FLY). A simple connectionist model of sentence production, lesioned to simulate agrammatic- and anomic-like deficits, suggests that this dissociation arises from light verbs learning to rely more on syntactic cues and heavy verbs learning to rely more on semantic cues. Systematic manipulations of the variables which distinguish light and heavy verbs reveal that it is primarily the greater frequency of occurrence of light verbs, and the fact that they are specified by fewer semantic features, which cause them to depend more on syntactic information. Implications are discussed for models of lexical access in both normal and aphasic populations.

Anomia↗
PubMed2002

Semantic and letter fluency in Spanish-English bilinguals.

Spanish-English bilinguals and English monolinguals completed 12 semantic, 10 letter, and 2 proper name fluency categories. Bilinguals produced fewer exemplars than monolinguals on all category types, but the difference between groups was larger (and more consistent) on semantic categories. Bilinguals and monolinguals produced the same number of errors across all category types. The authors discuss 2 accounts of the similarities and differences between groups and the interaction with category type, including (a) cross-language interference and (b) relatively weak connections in the bilingual lexical system because of reduced use of words specific to each language. Surprisingly, bilinguals' fluency scores did not improve when they used words in both languages. This result suggests that voluntary language switching incurs a processing cost.

Adult↗
PubMed2002

Representing nested semantic information in a linear string of text using XML.

XML has been widely adopted as an important data interchange language. The structure of XML enables sharing of data elements with variable degrees of nesting as long as the elements are grouped in a strict tree-like fashion. This requirement potentially restricts the usefulness of XML for marking up written text, which often includes features that do not properly nest within other features. We encountered this problem while marking up medical text with structured semantic information from a Natural Language Processor. Traditional approaches to this problem separate the structured information from the actual text mark up. This paper introduces an alternative solution, which tightly integrates the semantic structure with the text. The resulting XML markup preserves the linearity of the medical texts and can therefore be easily expanded with additional types of information.

Programming Languages↗
PubMed2003

Cerebral hemodynamics during discrimination of prosodic and semantic emotion in speech studied by transcranial doppler ultrasonography.

Simultaneous measurement of blood flow velocity (BFV) in the middle cerebral arteries was achieved by transcranial Doppler ultrasonography in 36 right-handed volunteers who were instructed to identify the emotion conveyed by prosody or semantics of a number of sentences. The tasks were performed under 2 levels of interference: neutral versus discordant affective value of the modality that had to be ignored. A multivariate analysis of variance showed a significant bilateral increase in BFV during the discordant conditions reflecting increased attentional demand. A significant left-hemispheric lateralization of BFV was observed as emotional semantics were labeled. When attention was shifted to affective prosody, the lateralization effect disappeared as a result of a marked increase in right-hemispheric BFV.

Adult↗
PubMed2004

Semantic couplets as an expression of cultural identity.

Semantic couplets in the Nahuatl language can function as discourse markers that have the pragmatic function of building identities among speech communities. The subsistence of these linguistic structures in present day institutional discourses points to similarities, not only in social, religious but also in linguistic practices of speech communities that are distant in time. Semantic couplets are presented as evidence that links modern speech events with those from pre-Hispanic times.

Anthropology, Cultural↗
PubMed2002

Therapy for anomia in semantic dementia.

Semantic dementia is a commonly accepted term for a language disorder resulting from neurodegenerative changes due to frontotemporal dementia. An intervention program was designed to halt and/or decelerate the effects of progressive anomia in AK, a 63-year-old female with semantic dementia. Pictorial stimuli were selected and labeled with their respective names and a description most relevant to AK's experience. Daily homework assignments were carried out, during which AK looked at the picture, read the label aloud, and read the description. Positive short-term effects of treatment were observed on treated items.

Anomia↗
PubMed2004

Coping with medical polysemy in the semantic web: the role of ontologies.

Polysemy is the linguistic phenomenon by which a term has more than one meaning. It is not a negligible issue in information management, since an effective and unambiguous sharing of the semantic content of data among different databases or knowledge repositories is needed. The paper illustrates a case of polysemy (concerning inflammation), and puts it within the framework provided by the DOLCE+ foundational ontology. This solution enables us to formally represent several senses of inflammation, and their interrelationships. This we take as a demonstration of how ontologies play an essential role in providing precisely the conceptual foundations that are needed in order to make the intended meaning of natural language expressions available to all the (artificial or human) agents that could be involved in the semantic web

Humans↗
PubMed2004

Mapping various information sources to a semantic network.

Giessen Data Dictionary Server (GDDS) provides context sensitive information services to disparate clinical applications by automatically navigating a semantic network that stores medical knowledge. Mapping multiple information sources to single clinical application becomes a challenge due to different organization of semi-structured information sources. Linking huge unstructured information sources such as medical literature is even more challenging because we need to develop a mechanism to organize unstructured information and take into account the scalability issue. In this paper, we have successfully mapped two drug information sources by developing an independent subnet for each source and linking them at proper nodes. For medical literature, we have demonstrated that the semantic network of the Unified Medical Language Systems and human assigned topics to each document can be used to organize the large amount of medical literature into the framework of the GDDS service.

Dictionaries, Medical as Topic↗
PubMed2004

A surgeon can operate or approach a complicated integral calculus instead of a renal one: implications for conceptual and lexical semantic disambiguation.

This paper approaches lexical semantic disambiguation and polysemy in the context of medical language understanding. These issues have been addressed as linguistic and cognitive requirements to build a knowledge extraction tool that turns natural language input into conceptual graphs. Previous results obtained with semantic analysis of medical terms in the domain of transplantation and organ failure prompt us to check the capabilities of our prototype to deal with ambiguities and polysemy. Starting from linguistic observation, we attempt to demonstrate how the respect of ambiguities when the co-text is not sufficient for disambiguation implies to introduce a void type in the concept type lattice. Then we show how the "creative use of words" (i.e. new senses in novel context) imposes to dynamically allocate type, categories and roles with the co-text.

Linguistics↗
PubMed2005

Semantic challenges in database Federation: lessons learned.

In this project an integrated analysis of data from disparate surgery and anaesthesiology departmental information systems was carried out. Due to the lack of shared primary keys, a multi-stage "soft" matching method was implemented. Results of the matching steps are described in detail. Inconsistencies were shown to exist for identifying data, semantic definition of documentation content and documented data itself. Minimum requirements for interdisciplinary documentation in autonomous systems should include shared semantic definitions of documentation content as well as robust and regularly validated interfaces for identifying data.

Database Management Systems↗
PubMed2006

[Developmental changes of N400 event related potential of a semantic category decision task and modality specific findings in patients with developmental dyslexia].

We investigated modality-specific changes in N400 event related potential using a semantic category decision task in 38 control subjects and 8 patients with developmental dyslexia. In control children under 10 years old, auditory N400 showed a negative deflection over the fronto-centro-parietal areas with substantial amplitude. Control children over 10 years old showed a similar pattern of N400 waves in a visual and an auditory-visual modality, suggesting that the visual modality becomes dominant in the late teens. Dyslexic children showed more errors on a visual than auditory modality task with poorer N400 waves for visual stimuli. However, peak latencies of N400 in an auditory-visual modality were almost the same for auditory stimuli in control children. Differences in the N400 pattern in children might reflect the fragility and reversibility of the semantic processes through stimulus modalities.

Adolescent↗
PubMed2006

Intelligent semantic interoperability: Integrating knowledge, terminology and information models to support stroke care.

INTRODUCTION: Electronic patient record (EPR) systems for the continuity of care for stroke patient are under development. These systems are based on standards such as for clinical practice, vocabularies, and the HL7 information model. PROBLEM STATEMENT: In order to achieve intelligent semantic interoperability, knowledge about evidence based patient care, vocabulary and information models need to be integrated. METHODOLOGY: A format was developed in which the clinical knowledge, clinical terminology, and standard information models are integrated as specification for the technical implementation of electronic health systems and electronic messages. This format is verified by clinicians and technicians. RESULTS: The document structure consists of meta-information such as version control and changes, purpose of the clinical content, evidence from the literature, variables and values, terminology used, guidelines for application and interpretation, HL7 message models, coding, and technical data specification. Further, XML message excerpts, archetypes and screen designs are developed from these documents to facilitate implementation. CONCLUSION: The combination of these aspects in one document creates valuable content for intelligent semantic interoperability by means of development of messages and systems.

Continuity of Patient Care↗
PubMed1991

Sensory and semantic factors in recognition memory for odors and graphic stimuli: elderly versus young persons.

In four experiments, young (18-26 years, M = 21) and elderly (over 65 years, M = 72) people were compared for recognition memory of (a) graphic stimuli (faces of presidents and vice presidents, engineering symbols, and free forms) and (b) everyday odors. On graphic stimuli, the elderly consistently matched the young, but on odors the performance of the elderly was worse. Their poorer olfactory performance was observed after only 26 s, but became truly marked after 1 hr or more. Somewhere between 1 hr and 2 weeks, their odor performance fell to chance, but their graphic performance remained well above chance. Although the young did forget both graphic and odor materials progressively, their performance always stayed above chance over a 6-month period. Experiments 1 and 2 revealed that the elderly are less sensitive to odors than the young (with thresholds about 10-fold higher), which may explain, in part, their poorer olfactory memory performance. Knowledge that the subjects brought to the tasks by way of familiarity with and ability to name odors and faces played a positive role in recognition memory. Because of this positive role, together with the negative role played by verbal distraction, we conclude that odor recognition memory depends, perhaps heavily, on semantic processing. Impaired semantic processing may result even when odors are simply rendered desaturated, or pastel because of the weakening of olfactory sensitivity with aging.

Adolescent↗
PubMed1990

[Formal and semantic lexical evocation in normal subjects. Performance and dynamics of production as a function of sex, age and educational level].

A protocol of formal lexical evocation (words beginning with a letter) and semantic evocation was applied to 168 normal subjects evenly distributed on the basis of three factors (sex, three age classes and two levels of education). Correct answers, their distribution within the allotted time (proportions of correct answers in four thirty-second periods) and errors were analysed globally and in relation to the said factors. Level of education had a decisive influence in all tests; age had no influence on performance in formal evocation, whereas the subjects in the middle age class presented the best performance in semantic evocation. Distribution of the answers over time was unrelated to any of the factors considered. Errors were related to age in half the test.

Adult↗
PubMed1990

Beyond semantics: a clinical and theoretical study of isolation.

Theories of Freud, Piaget, Fonagy and Kristeva have been drawn on to argue that the concept of isolation should not be restricted to a delimited defence mechanism associated with obsessional/compulsive neurosis, as is the usual psychoanalytic conception. From a semiological point of view isolation may be seen as a disturbance of the relationship between signifier and the signified embracing affective communication ranging from the most primitive bodily expression via sound and intonation to a semantic level where affects are expressed through the content of words and ideas. As affects isolated on a pre-verbal level are deprived of expression on a semantic-symbolic level, they are not likely to be modified by content of interpretations alone. They can only be fully activated and brought into therapeutic dialogue through the quality of the speech sound of the analyst.

Adult↗
PubMed1986

[Changes occurring in psychotherapy measured by the Osgood semantic differential--methodologic elaboration].

General recall on Osgood's semantic differential. Motive and way of integrating it in research on the effects of psychotherapies. Report of some preliminary results from a transversal study of normal, neurotic and schizophrenic subjects and from a longitudinal study of normal and neurotic subjects. These first results strengthen the assumption that the semantic differential provides an appreciably adequate picture of mental state, for both its stable and evolutive components.

Adult↗