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Results for “Natural Language Processing”

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PubMed2000

The design and development of an integrated natural products screening database.

We designed and developed NEXUS--a new natural products screening database and related suite of software applications--to utilize the spectacular increases in assay capacity of the modern high throughput screening (HTS) environment. NEXUS not only supports seamless integration with separate HTS systems, but supports user-customized integration with external laboratory automation, particularly sample preparation systems. Designed and developed based on a detailed process model for natural products drug discovery, NEXUS comprises two integrated parts: (1) a single schema of Oracle tables and callable procedures and functions, and (2) software "front-ends" to the database developed using Microsoft Excel and Oracle Discovery/2000. Many of the back-end processing functions were written in Programming Language/Structured Query Language (PL/SQL) to provide an Application Programmer's Interface, which allows end users to create custom applications with little input from information technology professionals.

Biological Products↗

PubMed1991

Poststroke depression: neurologic, physiologic, diagnostic, and treatment implications.

Poststroke depression is a serious disorder that can compromise the overall rehabilitative process, including speech-language treatment. To provide patients with the maximum opportunity for recovery and therapeutic gains, speech-language pathologists need to increase their awareness of depression and understand the neurologic, physiologic, diagnostic, and treatment implications of this disorder. This article defines depression and reviews the theories that explain the nature of the disorder as well as methods for diagnosing and treating stroke patients who are clinically depressed.

Cerebrovascular Disorders↗

PubMed2004

Integration of letters and speech sounds in the human brain.

Most people acquire literacy skills with remarkable ease, even though the human brain is not evolutionarily adapted to this relatively new cultural phenomenon. Associations between letters and speech sounds form the basis of reading in alphabetic scripts. We investigated the functional neuroanatomy of the integration of letters and speech sounds using functional magnetic resonance imaging (fMRI). Letters and speech sounds were presented unimodally and bimodally in congruent or incongruent combinations. Analysis of single-subject data and group data aligned on the basis of individual cortical anatomy revealed that letters and speech sounds are integrated in heteromodal superior temporal cortex. Interestingly, responses to speech sounds in a modality-specific region of the early auditory cortex were modified by simultaneously presented letters. These results suggest that efficient processing of culturally defined associations between letters and speech sounds relies on neural mechanisms similar to those naturally evolved for integrating audiovisual speech.

Adult↗

PubMed2007

The perception of FM sweeps by Chinese and English listeners.

Frequency-modulated (FM) signals are an integral acoustic component of ecologically natural sounds and are analyzed effectively in the auditory systems of humans and animals. Linearly frequency-modulated tone sweeps were used here to evaluate two questions. First, how rapid a sweep can listeners accurately perceive? Second, is there an effect of native language insofar as the language (phonology) is differentially associated with processing of FM signals? Speakers of English and Mandarin Chinese were tested to evaluate whether being a speaker of a tone language altered the perceptual identification of non-speech tone sweeps. In two psychophysical studies, we demonstrate that Chinese subjects perform better than English subjects in FM direction identification, but not in an FM discrimination task, in which English and Chinese speakers show similar detection thresholds of approximately 20 ms duration. We suggest that the better FM direction identification in Chinese subjects is related to their experience with FM direction analysis in the tone-language environment, even though supra-segmental tonal variation occurs over a longer time scale. Furthermore, the observed common discrimination temporal threshold across two language groups supports the conjecture that processing auditory signals at durations of approximately 20 ms constitutes a fundamental auditory perceptual threshold.

Acoustic Stimulation↗

PubMed2003

Histological image retrieval based on semantic content analysis.

The demand for automatically recognizing and retrieving medical images for screening, reference, and management is growing faster than ever. In this paper, we present an intelligent content-based image retrieval system called I-Browse, which integrates both iconic and semantic content for histological image analysis. The I-Browse system combines low-level image processing technology with high-level semantic analysis of medical image content through different processing modules in the proposed system architecture. Similarity measures are proposed and their performance is evaluated. Furthermore, as a byproduct of semantic analysis, I-Browse allows textual annotations to be generated for unknown images. As an image browser, apart from retrieving images by image example, it also supports query by natural language.

Diagnostic Imaging↗

PubMed1992

Connectedness versus separateness: applicability of family therapy to Japanese families.

This article, a product of the two authors' multicultural experiences, contrasts British and Japanese families in order to examine the applicability of the Western model of family therapy to Japanese families and therapists. Areas where the Western model is incompatible are identified, and modifications to fit the Japanese indigenous model are suggested. The most significant difference in value systems between the two cultures is the Japanese preference for connectedness. The Japanese person is seen as a part of the embedded interconnectedness of relationships, whereas British norms prioritize separateness and clear boundaries in relationships, individuality, and autonomy. This value orientation is manifested in the Japanese language, hierarchical nature of the family structure, the family life cycle, and the implicit communication style. Systemic thinking, which deals with the pattern of relationships, is valid for all families regardless of cultural differences. But therapists should note that the preferred direction of change for Japanese families in therapy, is toward a process of integration--how a person can be effectively integrated into the given system--rather than a process of differentiation. An authoritative therapist style, the use of individual sessions, silence, and other nonverbal techniques are relevant to bringing about the desired change toward better integration of the individual with his or her networks.

Adolescent↗

PubMed1986

Acquired epileptic aphasia. Diagnostic aspects of progressive language loss in preschool children.

A case of acquired epileptic aphasia presenting as language delay and hyperactivity is presented and clinical aspects reviewed. Acquired epileptic aphasia is a diffuse neurologic process of unknown etiology that presents in preschool children. Although progressive language loss and seizures are the major manifestations, deficits in attention and socialization may be noted. The electroencephalogram is usually diagnostic. While almost all (80%) children develop seizures, approximately half present as language delay without seizures. Recognition of the progressive and global nature of the language dysfunction may permit earlier diagnosis and intervention.

Aphasia↗

PubMedDate not supplied

Longitudinal progression of subclinical structural brain disease in normal aging.

OBJECTIVE: The authors describe four types of brain structural change in "normal aging:" cortical atrophy, central atrophy, deep white-matter hyperintensities (DWMH), and periventricular hyperintensities (PVH). Cross-sectional investigations have reported that greater volumes of these forms of "subclinical structural brain disease" (SSBD) were found with increasing age. Greater volumes were also associated with poorer cognition, even though subjects performed within the normal range. The natural history of these forms of SSBD and their functional impact are not well established. METHODS: Twenty-nine normal subjects, ages 60-89, were examined longitudinally by volumetric magnetic resonance imagery, with two assessments performed at least 2 years apart; 26 also completed neuropsychological testing to evaluate processing speed, executive functions, language, and other cognitive functions. Associations between structure and function were evaluated with regression models. RESULTS: For most subjects, the volumes for signs of all types of SSBD were found to have increased; for many subjects, increases were small, and a few showed no change or small decreases. PVH and DWMH increases were predicted by baseline cerebrovascular risk factors. Cognitive test performance changed little over time for these normal subjects. CONCLUSIONS: SSBD volumes increased for most subjects over time, with small average increases for most types. Pretreatment cerebrovascular risk factors were associated with greater increases of PVH and DWMH, suggesting that progression of these types of SSBD may be amenable to intervention.

Aged↗

PubMedDate not supplied

Sound change in child language: a study of inter-world variation.

The goal of this study is to retrace in minute detail a single step forward in the phonological development of a German-speaking child. The sound change under focus is the acquisition of velar stops in word-initial positions. Naturalistic data were collected on a daily basis over a period of approximately one year (3;4.9 - 4;3.20) until the process was nearly completed. Production accuracy was found to be under the influence of four factors--the nature of the velar stop (voiced or voiceless), the subsequent context, lexical stress and the individual word in which the critical consonant appeared. Progress was made not globally but in different subdomains at different points in time. Each phonological constellation gave rise to a distinct acquisitional pattern. While the velar stops were accurately produced before the alveolar nasal, they tended to be omitted before the rhotic and supplanted by the alveolar stops before the lateral. An attempt is made to identify the locus of the changes in a developing processing system consisting of linguistic units (nodes) and their interrelationships (associations). A comparison of the effects of inefficient nodes and those of inefficient associations suggests that learning in this child takes place by strengthening the associations rather than increasing the efficiency of processing on the nodes. Because modifying individual associations is quite a local repair process, it is argued that the acquisition of a new segment does not normally occur across the board. Instead, it is more appropriately conceived of as a gradual spread through the lexicon.

Child Language↗

PubMed2003

Magnetoencephalography detection of early syntactic processing in humans: comparison between L1 speakers and L2 learners of English.

In previous brain imaging studies of human syntax processing, only phrase structure (grammatical category) violations have been shown to elicit a very early (approximately 140 ms) neural response. This has led to interpretations about the nature of phrase structure encoding in the brain, particularly its relationship to early automatic brain processes. Utilizing different sentence structures that contrasted within- vs. across-phrase violations, the current study examined whether an early response could be elicited by non-phrase-structure violations. Magnetoencephalography fields were recorded, while both first-language speakers (L1) and second-language learners (L2) were tested. A prominent syntactic magnetic field component, peaking at around 150 ms post-onset (labeled 'SF-M150'), was observed in both hemispheres of only the L1 speakers in response to within-phrase violations but not across-phrase violations. The results provide evidence that L1 speakers possess the ability for automated detection of non-phrase-structure violations, particularly within-phrase violations, and that L2 learners may not have sufficient neural representation available for an early automated response to the target violations.

Adult↗

PubMedDate not supplied

How children use input to acquire a lexicon.

The contributions of social processes and computational processes to early lexical development were evaluated. A re-analysis and review of previous research cast doubt on the sufficiency of social approaches to word learning. An empirical investigation of the relation of social-pragmatic and data-providing features of input to the productive vocabulary of sixty-three 2-year-old children revealed benefits of data provided in mother-child conversation, but no effects of social aspects of those conversations. The findings further revealed that the properties of data that benefit lexical development in 2-year-olds are quantity, lexical richness, and syntactic complexity. The nature of the computational mechanisms implied by these findings is discussed. An integrated account of the roles of social and computational processes to lexical development is proposed.

Child, Preschool↗

PubMed2000

Using fMRI to study recovery from acquired dysphasia.

We have used functional magnetic resonance imaging (fMRI) to characterize brain activations associated with two distinct language tasks performed by a 28-year-old woman after partial recovery from dysphasia due to a left frontal hemispheric ischemic stroke. MRI showed that her ischemic lesion extended posteriorly from the left inferior frontal to the perisylvian cortex. fMRI scans of both language tasks revealed substantial differences in activation pattern relative to controls. The nature of this difference was task-specific. During performance of a verbal semantic decision task, the patient, in contrast to controls, activated a network of brain areas that excluded the inferior frontal gyrus (in either hemisphere). A second task involving rhyme judgment was designed to place a heavier cognitive load on language production processes and activated the left inferior frontal gyrus (Broca's area) strongly in normal controls. During this task, the most prominent frontal activation in the patient occurred in the right homologue of Broca's area. Subsequent analysis of this data by methods able to deal with responses of changing amplitude revealed additional, less sustained recruitment by the patient of cortex adjacent to the infarct in the region inferior to Broca's area during rhyming. These results suggest that in addition to changes in cognitive strategy, recovery from dysphasia could be mediated by both the preservation of neuronal networks in and around the infarct and the use of homologous regions in the contralateral hemisphere.

Adult↗

PubMed2002

Reliability testing of the hospital anxiety and depression (HAD) scale in the English, Maltese and back-translation versions.

This paper discusses the translation of the hospital anxiety and depression (HAD) scale (Zigmond, Snaith, Acta Psychiatr. Scand. 67 (1983) 361) into the Maltese language. The HAD scale is a well-validated and reliable measure of anxiety and depression originating in the United Kingdom. To ensure accuracy in the translation of the tool, the translation process was based on the Maltese Translation Guidelines issued by Chetcuti (Tahrig ghall-ezamijiet tal-Malti. Biex taghmel traduzzjoni tajba, Veritas Press, Malta, 1975, pp. 9-10) and those of Sechrest et al. (J. Cross-Cultural Psychol., 3 (1) (1972) 41). The composition of the Maltese language, which is Semitic in nature, is described and examples from different languages are given. The Maltese version of the HAD scale will facilitate the investigation of mood states in future studies on patients. Reliability testing of the HAD scale is then performed on the English version, the Maltese version and on the back-translation. The test-retest reliability of the three versions is examined using cross-tabulations of each item (pre values with post values), all of which gave highly significant values of chi-squared (p=0.0000). These cross-tabulations also yielded high values for the Kappa measure of reliability and for Spearman's coefficient of correlation ( kappa > or =0.8 and rho > or =0.9 for most items of anxiety and depression in all the three versions). The internal consistency of the three versions is also examined statistically using Cronbach's alpha and factor analysis. Both the anxiety and the depression subscales in the Maltese version can each be parsimoniously described by one factor. Each subscale therefore has a dimensionality of one. This explains why good levels of internal consistency are observed for the Maltese translation of the HAD scale ( alpha=0.79 for the anxiety subscale, 0.70 for depression, and 0.85 for both subscales together). This validates the Maltese version of the HAD scale, which can thus be used safely in future studies on Maltese patients. The anxiety subscale is also unidimensional in the original and in the back-translation, and also showed satisfactory values for Cronbach's alpha (0.73 and 0.74, respectively).Unfortunately, for the depression subscale, correlations between its items were rather low, thus leading to low alphas (about 0.45 and 0.51, respectively) for the internal consistency of this subscale in these versions.

Anxiety Disorders↗

PubMed2004

Dissociation of lexical syntax and semantics: evidence from focal cortical degeneration.

The question of whether information relevant to meaning (semantics) and structure (syntax) relies on a common language processor or on separate subsystems has proved difficult to address definitively because of the confounds involved in comparing the two types of information. At the sentence level syntactic and semantic judgments make different cognitive demands, while at the single word level, the most commonly used syntactic distinction (between nouns and verbs) is confounded with a fundamental semantic difference (between objects and actions). The present study employs a different syntactic contrast (between count nouns and mass nouns), which is crossed with a semantic difference (between naturally occurring and man-made substances) applying to words within a circumscribed semantic field (foodstuffs). We show, first, that grammaticality judgments of a patient with semantic dementia are indistinguishable from those of a group of age-matched controls, and are similar regardless of the status of his semantic knowledge about the item. In a second experiment we use the triadic task in a group of age-matched controls to show that similarity judgments are influenced not only by meaning (natural vs. manmade), but also implicitly by syntactic information (count vs. mass). Using the same task in a patient with semantic dementia we show that the semantic influences on the syntactic dimension are unlikely to account for this pattern in normals. These data are discussed in relation to modular vs. nonmodular models of language processing, and in particular to the semantic-syntactic distinction.

Cerebral Cortex↗

PubMed2005

Specificity and characteristics of learning disabilities.

BACKGROUND: The specificity of impairments in specific reading disabilities (SRD) and specific language impairments (SLI) has recently been questioned, with many children recruited for studies of SRD and SLI demonstrating impairments in both reading and oral language development. This has implications for the results of SRD and SLI studies where both reading and oral language skills are not assessed. Thus there is a need to compare the profiles of children with both oral language and reading impairments to groups of children with SRD and SLI. METHODS: The reading, oral language, short-term auditory memory, phonological processing, spelling, and maths abilities of 151 children (aged between 7 and 12 years) drawn from a Learning Disabilities Clinic were assessed. RESULTS: Five groups were identified, including children who demonstrated either a specific reading disability or a specific language impairment and children who showed evidence of both reading and oral language impairments. Differences were found between the groups on maths, phonological processing, short-term auditory memory, and spelling measures, with the children displaying both language and reading deficits generally performing at a lower level than the children with specific reading or language deficits. CONCLUSIONS: It was concluded that more careful screening needs to be conducted in both clinical and research settings to accurately identify the nature of deficits in children with reading and oral language difficulties. Furthermore, a third and separate category of children with a mixed pattern of impairments needs to be considered.

Analysis of Variance↗

PubMed2001

The analyst's knowledge and authority: a critique of the "new view" in psychoanalysis.

A critical assessment is presented of positions recently taken by Mitchell and Renik, who are taken as representatives of a "new view" in psychoanalysis. One article by Mitchell and two by Renik are examined as paradigmatic of certain ways of construing the nature of mind, the analyst's knowledge and authority, and the analytic process that are unduly influenced by the postmodern turn in psychoanalysis. Although "new view" theorists have made valid criticisms of traditional psychoanalytic theory and practice, they wind up taking untenable positions. Specifically called into question are their views on the relation between language and interpretation, on the one hand, and the mental contents of the patient on the other. A disjunction is noted between their discussion of clinical material and their conceptual stance, and their idiosyncratic redefinitions of truth and objectivity are criticized. Finally, a "humble realism" is suggested as the most appropriate philosophical position for psychoanalysts to adopt.

Humans↗

PubMed1990

The babel of the unconscious.

This paper illustrates our clinical and personal experiences concerning the vast and complex theme of 'Polylingualism in psychoanalysis'. The issue of polylingualism and polyglotism reintroduces some general psychoanalytic hypotheses. For instance, is the nature of the unconscious predominantly pre-verbal, or is it structured as a language? What occurs if some languages are known since very early childhood, and belong to a pre-symbolic structural patrimony closely bound to bodily sensations and concrete experiences? How does the learning of new languages, later on, affect or modify thought processes? How do new and old unconscious 'thing' and 'word' representations interact with each other? What are the related problems regarding repression and memory? Our paper illustrates and discusses problems of communication and comprehension within the clinical situation, in cases when the analytic language is not the mother-tongue of the analyst, or of the patient, or of either of them.

Adult↗

PubMed2001

Relative language proficiency modulates BOLD signal change when bilinguals perform semantic judgments. Blood oxygen level dependent.

The effect of relative language proficiency on the spatial distribution and magnitude of BOLD signal change was evaluated by studying two groups of right-handed English-Mandarin bilingual participants with contrasting language proficiencies as they made semantic judgments with words and characters. Greater language proficiency corresponded to shorter response times and greater accuracy in the semantic judgment task. Within the left prefrontal and parietal regions, the change in BOLD signal was smaller in a participant's more proficient language. The least proficient performance was associated with right, in addition to left, inferior frontal activation. The results highlight the importance of taking into consideration nature of task and relative language proficiency when drawing inferences from functional imaging studies of bilinguals.

Adult↗