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PubMed1999

Comprehension regularity in Broca's aphasia? There's more of it than you ever imagined.

We analyze the comprehension data in Broca's aphasia, pooled together by Berndt, Mitchum, and Haendinges (1996). We show that once analyzed properly, these data have statistical structure that is very similar to that revealed by the analysis in Grodzinsky, Pinango, Zurif, and Drai (1999). The suggestion that the latter authors doctored the data to obtain a desired outcome is as false as the claim that the data in Berndt et al. show no regularity. Comprehension scores in Broca's aphasia do have statistical structure, which correlates with syntactic structure. Thus, the role of Broca's area and its vicinity in language processing can be made more precise.

Aphasia, Broca↗

PubMed2000

Syntactic comprehension deficits in Alzheimer's disease.

Syntactic comprehension of German patients with dementia of the Alzheimer type was investigated and compared to healthy controls matched with respect to age, sex, and education. Special attention was directed at syntactic structures, which, in contrast to a language like English, are feasible in a grammatically rich language like German. In a sentence picture matching paradigm, only semantically reversible sentences were used. Syntactic complexity ranged from simple active voice sentences to more complex sentences like center-embedded object relative sentences. In comparison to their controls, patients showed a deficit in nearly all categories. Their performance was not influenced by age, but was heavily influenced by the degree of cognitive impairment. Patients with mild cognitive impairment, as defined by a MMSE score of 20 or higher, showed only slight difficulties in syntactic processing, whereas patients with moderate to severe impairment (MMSE < 20) did not perform above chance limits in most syntactic categories. It appears as though syntactic comprehension is only mildly affected in the early stages of Alzheimer's disease and is rather severely impaired in more advanced stages. In the present report, results are discussed in terms of working memory demands for syntactic processing.

Aged↗

PubMed2000

Auditory language comprehension: an event-related fMRI study on the processing of syntactic and lexical information.

The functional specificity of different brain areas recruited in auditory language processing was investigated by means of event-related functional magnetic resonance imaging (fMRI) while subjects listened to speech input varying in the presence or absence of semantic and syntactic information. There were two sentence conditions containing syntactic structure, i.e., normal speech (consisting of function and content words), syntactic speech (consisting of function words and pseudowords), and two word-list conditions, i.e., real words and pseudowords. The processing of auditory language, in general, correlates with significant activation in the primary auditory cortices and in adjacent compartments of the superior temporal gyrus bilaterally. Processing of normal speech appeared to have a special status, as no frontal activation was observed in this case but was seen in the three other conditions. This difference may point toward a certain automaticity of the linguistic processes used during normal speech comprehension. When considering the three other conditions, we found that these were correlated with activation in both left and right frontal cortices. An increase of activation in the planum polare bilaterally and in the deep portion of the left frontal operculum was found exclusively when syntactic processes were in focus. Thus, the present data may be taken to suggest an involvement of the left frontal and bilateral temporal cortex when processing syntactic information during comprehension.

Adult↗

PubMed2001

Comprehension of reversible relative clauses in specifically language impaired and normally developing Greek children.

This paper aims to investigate the syntactic comprehension of reversible relative clauses in a group of eight Greek children with specific language impairment (SLI) and two control groups of normally developing children matched on chronological and language age, respectively. An experiment using an acting out procedure was undertaken. Group analysis revealed that SLI children's performance is qualitatively different than that of both control groups. Interpreting the data, processes involved in syntactic comprehension are taken into consideration. It is claimed that processing demands impede SLI children's performance due to a deficit in their competence grammar.

Child↗

PubMed2001

Familial handedness and access to words, meaning, and syntax during sentence comprehension.

We compared right-handed familial dextral (FS-) and familial sinistral (FS+) participants who were aged either 10-13 years (children) or 18-23 years (adults). In word probe and associative probe tasks, FS+ adults responded faster than all other groups and FS+ children responded more slowly than all other groups. In the word probe task, only the FS- adults showed a significant effect of the serial position of the target word. We interpret these differences to support an analysis-by-synthesis model of comprehension in which individuals who differ in familial handedness and age emphasize different linguistic representations during comprehension. In general, FS+ individuals focus on words and meaning, while FS- individuals focus on syntactic representations. In FS+ individuals, age-related experiences with language produce a shift in responding from compositional meaning to words and their associations. In FS- individuals, age-related experiences with language produce a shift toward responding based more on detailed syntactic representations, including the serial order of words and possibly the structural roles of clauses.

Adolescent↗

PubMed2002

Comprehensive determinant mapping of the hepatitis C-specific CD8 cell repertoire reveals unpredicted immune hierarchy.

While CD8 cells are thought to play an important role in the control hepatitis C infection, low frequencies of virus-specific cells and high numbers of potential determinants have made it challenging to obtain direct and comprehensive data regarding fine specificity and clonal size of the CD8 cells involved. Most assays suited for measuring CD8 cell frequencies require prior knowledge of immune dominant peptides. While there are excellent algorithms for predicting MHC-peptide binding strength for particular class I alleles, it is unknown how accurate these algorithms are in predicting the actual determinant recognized in an individual coexpressing other class I alleles. We used a high throughput ELISPOT approach to test for responses to every possible 9-mer determinant within the 191 residue hepatitis C core protein in addition to 61 previously defined CD8 cell determinants. The amino acid sequence of each determinant recognized was compared with HLA-binding predictions for the expressed class I alleles. These data show feasibility for and importance of comprehensive direct ex vivo monitoring, an approach which should facilitate design of antiviral immunotherapeutic strategies.

Algorithms↗

PubMed1995

Index, comprehensive microsatellite, and unified linkage maps of human chromosome 14 with cytogenetic tie points and a telomere microsatellite marker.

Three sets of linkage maps (index, comprehensive microsatellite, and unified) have been constructed for human chromosome 14 based on genotypes from the CEPH reference pedigrees. The index maps consist of 18 microsatellite markers, with heterozygosities of at least 68% and intermarker spacing no greater than 11 cM. The sex-average comprehensive microsatellite map is 125 cM in length and includes 115 markers with 54 loci uniquely placed with odds for marker order of at least 1000:1. The sex-average index map length is 121 cM, and the female- and male-specific maps are 143 and 101 cM, respectively. A unified map was also constructed from 147 loci (162 marker systems), which includes 32 RFLP markers in addition to the 115 microsatellites. The sex-average length of the unified map is 128 cM with 69 loci uniquely placed. Our maps are anchored by a microsatellite telomere marker sCAW1 (D14S826), developed from a telomere YAC clone TYAC196, which extends the linkage map to the physical terminus of the long arm of chromosome 14. Furthermore, we have also physically mapped seven of the loci by fluorescence in situ hybridization of cosmid clones or Alu-PCR products amplified from YACs containing the marker sequences. Together with previously established cytogenetic map designations for other loci, our maps display links between genetic markers for 10 of 13 cytogenetic bands of chromosome 14 at the 550 genome band resolution.

Base Sequence↗

PubMed2002

Targeted construction of a high-resolution, integrated, comprehensive, and comparative map for a region specific to bovine chromosome 6 based on radiation hybrid mapping.

To resolve a candidate chromosome region on the middle part of bovine chromosome 6 (BTA6) containing several different quantitative trait locus (QTL) intervals, we constructed a high-resolution, integrated, comprehensive, and comparative map using a 12,000-rad, whole-genome, cattle-hamster radiation hybrid (RH) panel. The RH map includes a total of 71 loci either selected from bovine and comparative maps or targeted directly from a microdissection library specific for the BTA6 region. All loci typed were placed in one linkage group at a lod score threshold of 4.0. The length of the comprehensive RH map, which is the first high-resolution RH map in cattle, spans 2568.8 cR(12,000). The order of markers obtained principally agrees with the order on published bovine genetic maps. Our RH map integrates markers as well as genes and ESTs available from several physical and genetic maps of BTA6 and the orthologous ovine chromosome 6, human chromosome 4, and mouse chromosomes 5/3. Comparative analysis confirms and refines current knowledge about conservation and rearrangements in corresponding chromosomal regions on BTA6. We identified and localized two new breakpoints for intrachromosomal rearrangements between human chromosome 4 and BTA6. This RH map is a powerful tool in all aspects of genetic, physical, transcript, and comparative mapping. Due to its links to the gene-dense maps of human and mouse, it can serve as a prerequisite to identify possible candidate genes for quantitative trait loci localized in the targeted BTA6 region.

Animals↗

PubMed1999

Time course of fMRI-activation in language and spatial networks during sentence comprehension.

Functional neuroimaging previously has been considered to provide inadequate temporal resolution to study changes of brain states as a function of cognitive computations; however, we have obtained evidence of differential amounts of brain activity related to high-level cognition (sentence processing) within 1.5 s of stimulus onset. The study used an event-related paradigm with high-speed echoplanar functional magnetic resonance imaging (fMRI) to trace the time course of the brain activation in the temporal and parietal regions as participants comprehended single sentences describing a spatial configuration. Within the first set of images, on average 1 s from when the participant begins to read a sentence, there was significant activation in a key cortical area involved in language comprehension (the left posterior temporal gyrus) and visuospatial processing (the left and right parietal regions). In all three areas, the amount of activation during sentence comprehension was higher for negative sentences than for their affirmative counterparts, which are linguistically less complex. The effect of negation indicates that the activation in these areas is modulated by the difficulty of the linguistic processing. These results suggest a relatively rapid coactivation in both linguistic and spatial cortical regions to support the integration of information from multiple processing streams.

Adult↗

PubMed2000

A common language network for comprehension and production: a contribution to the definition of language epicenters with PET.

In this paper, we report on a PET activation study designed to assess whether functional neuroimaging would help to uncover essential language areas in normal volunteers and to provide a more accurate definition of their localization. Regional cerebral blood flow was repeatedly monitored in eight right-handed male volunteers, while performing a language comprehension task (listening to factual stories) and a language production task (covert generation of verbs semantically related to heard nouns), using silent resting as a control condition. The conjunction analysis, conducted with SPM, was used to uncover the network of activations common to both task that included three left hemisphere areas, namely (1) the pars opercularis and triangularis of the inferior frontal gyrus, (2) the posterior part of the superior temporal cortex centered around the superior temporal sulcus, extending to the planum temporale posterior part but sparing the supramarginalis and angular gyri, and (3) the most anterior part of the left inferior temporal gyrus at the junction with the anterior fusiform gyrus. The inferior and lateral parts of the right cerebellar cortex were also included in the conjunction network. Each of the three cortical areas, when they are site of lesion or electrical stimulation, elicit impairment in both language comprehension and production and can thus be considered as essential to language. Accordingly, the present results provide conservative anatomofunctional definitions of the Broca, Wernicke, and basal language areas. Interestingly, contralateral homologues of Broca's and Wernicke's areas also lighted up in the conjunction analysis that could be related to the interindividual variability of hemispheric language dominance.

Adult↗

PubMed2002

From perception to sentence comprehension: the convergence of auditory and visual information of language in the left inferior frontal cortex.

We used functional magnetic resonance imaging (fMRI) to characterize cortical activation associated with sentence processing, thereby elucidating where in the brain auditory and visual inputs of words converge during sentence comprehension. Within one scanning session, subjects performed three types of tasks with different linguistic components from perception to sentence comprehension: nonword (N(AV); auditory and visual), phrase (P; either auditory or visual), and sentence (S; either auditory or visual) tasks. In a comparison of the P and N(AV) tasks, the angular and supramarginal gyri showed bilateral activation, whereas the inferior and middle frontal gyri showed left-lateralized activation. A comparison of the S and P tasks, together with a conjunction analysis, revealed a ventral region of the left inferior frontal gyrus (F3t/F3O), which was sentence-processing selective and modality-independent. These results unequivocally demonstrated that the left F3t/F3O is involved in the selection and integration of semantic information that are separable from lexico-semantic processing.

Adult↗

PubMed1988

The comprehensive cohort study: the use of registry data to confirm and extend a randomized trial.

There are distinct advantages to the comprehensive cohort design for randomized clinical trials. The design allows the researcher to systematically compare the trial participants and the trial results with the characteristics and results in the population of eligible patients who were not randomly assigned to treatment. There are some problems with this design. The added costs of enrollment and follow-up for the nonrandomized cohort can add substantially to the cost of a trial. As the CASS example illustrates, careful attention must be given to definition of the treatment groups in the nonrandomized cohort. For the randomized patients, group assignment by "intention to treat" is preferred in most cases. The definition of "intention to treat" in the nonrandomized cohort may be difficult, since the patient may receive recommendations from several sources and, in the case of chronic disease, the decision may be postponed for a long period. This problem is not specific to the comprehensive cohort design, however, and a comparison group of concurrently enrolled and followed patients is almost always preferred over a comparison group found elsewhere.

Clinical Trials as Topic↗

PubMed1994

Formation and resolution of brain edema associated with brain tumors. A comprehensive theoretical model and clinical analysis.

The purpose of this study is to quantify the relative contribution of the mechanisms in the absorption of edema fluid. The convection/diffusion and the comprehensive bulk flow model were applied for the finite element analysis of peritumoral brain edema. For clinical analysis, 90 meningiomas studied by MRI were selected. Serial CT scan and MRI were performed at 0, 2, 4, 6 hours after injection of Iopamidol or Gadpenteic acid respectively. Then the tracer distributions in the edematous brain was analyzed. The tracer movement in the brain is well represented by the convection/diffusion equation. The absence of the preferential fluid flow directing toward the ventricle indicates that a limited role of CSF sink action into the ventricle. From capillary surface area (240 cm2/g brain), capillary hydraulic conductivity (1.8 x 10(-8) ml/cmH2O/cm2/min) and the simulated average tissue pressure of 9.8 mmHg, maximum absorption rate into capillaries was estimated to be 0.003 ml/h/cm3 brain tissue. Considering the limited role of edema fluid clearance into the ventricle, the results indicate a possible role of subarachnoid CSF space for the clearance of edema fluid. The clearance of edema fluid into subarachnoid CSF space should be studied quantitatively. Finally, unification of the convection/diffusion and the comprehensive bulk flow model will provide a more quantitative analysis of edema formation and resolution by using MRI and tracer studies.

Blood-Brain Barrier↗

PubMed1995

Working memory in older subjects: dealing with ongoing and stored information in language comprehension.

The purpose of this experiment was to investigate the role of aging in working memory (WM), or at least the part involved in language comprehension, e.g., a double function of processing the ongoing information and keeping in memory the product of this processing. Young and older subjects were asked to simultaneously detect incongruities in sentences and keep increasing longer series of words (3, 4, or 5) in memory. The difficulty of incongruity detection was manipulated by variation of the number of intervening words (0, 6, or 12) between two critical words. Incongruity detection was assumed to be linked to the processing of information function of working memory. The concurrent mnemonic load consisted of material previously processed, and was assumed to be linked to the storage function of WM. Results showed that an increment in incongruity-detection difficulty led to a greater decrement in accuracy in older than in young subjects, indicating an impairment in the information-processing function. On the other hand, an increment in concurrent mnemonic load led to a slightly smaller decrement in accuracy in older subjects. Furthermore, fewer words from this mnemonic load were recalled in older subjects. It is suggested that older subjects are impaired in coping with both requirements of the task, and tend to sacrifice the storage of information recently processed to devote their resources to the immediate processing component of the task. These results are discussed in relation to their implications for language comprehension.

Adult↗

PubMed1984

Comprehension of nonverbal communication: a reexamination of the social competencies of learning-disabled children.

This study was designed to determine whether learning-disabled (LD) children differed from nondisabled (NLD) children in their ability to comprehend nonverbal communication when potential attentional differences between the groups were controlled. In addition, the relationship between nonverbal comprehension and social competence was assessed. Thirty LD and 30 NLD boys between 9 and 12 years of age were administered a short form of the Profile of Nonverbal Sensitivity (PONS) to assess nonverbal comprehension; social competence measures included teachers' ratings of aggressive and withdrawn behaviors using the Behavior Problem Checklist, and "blind" judges' ratings of performance on a role-play of friendship-making skills. Under attention-incentive conditions, no performance differences between LD and NLD children were found on the PONS; however, LD children were judged to be more withdrawn and less socially skilled. While PONS scores were not related to other social competence measures, they were associated with academic achievement and IQ. Results emphasize the importance of considering the presence of attentional problems in LD children that may interfere with an accurate assessment of their skills.

Achievement↗

PubMed1988

A model for capacity planning of a comprehensive integrated information system for hospitals and clinics.

Appropriate system sizing is essential to ensuring a reasonable computer response time for end users. A model is discussed that describes the type and number of interactions between user terminals and printers and the central processor for a comprehensive, integrated medical information system. The system modeled includes support to inpatient and outpatient order entry and results reporting for clinical services; registration; admission, disposition, and transfer; patient appointing; pharmacy, clinical laboratory, and radiology; medical record management; and electronic messages. Originally developed for use in benchmark testing of comprehensive systems designed for military hospitals and clinics, the model has been generalized to be applicable to other systems and settings. Results are presented for a routine busy day in a 200-bed teaching hospital providing extensive outpatient services, and a large free-standing clinic. The model results can be applied to several facets of system planning, including sizing of the central processor and communications network, determining the optimal number of storage devices and user devices, and fine tuning the user interface.

Ambulatory Care Information Systems↗

PubMed1984

Comprehensive behavioral management of complex tinnitus: a case illustration.

This paper describes a comprehensive program for behavioral management of complex tinnitus. The clinical characteristics and typical treatment of tinnitus are reviewed. Psychosocial sequelae are discussed in terms of their exacerbation of the symptom and their potential as foci of treatment. The management problems of tinnitus are considered analogous to those of chronic pain. A case illustration is provided with a description of the treatment process. The comprehensive behavioral program discussed in the present paper included biofeedback therapy, pain management training, social skills training, assertion training, in vivo exposure to being alone, cognitive treatment of depression, and marital therapy. Outcomes were monitored multidimensionally. Self-report of tinnitus severity decreased after the 6th treatment day and stabilized at a "mild" rating after the 9th day. Skin temperature readings at baseline increased and stabilized after the 8th day, and the patient was able to reliably increase skin temperature on request. Scores on the Beck Depression Inventory and the Willoughby Personality Schedule, and a self-rating of Fear of Being Alone dropped markedly by the end of treatment. Follow-up data at 3 months indicated maintenance of gains.

Assertiveness↗

PubMed1982

Cognitive processes, school achievement, and comprehension of ambiguous sentences.

Previous research has identified three distinct forms of linguistic ambiguity: lexical, surface structural, and deep structural. Cummins and Das (1978) studied these forms of ambiguity in the context of Das, Kirby and Jarman's (1979) model of simultaneous and successive processing, and demonstrated that comprehension of lexical ambiguity depended upon simultaneous processing, while that of surface and deep structural ambiguity depended upon successive processing. The present study investigated the relationship between these cognitive and linguistic processes in a group of older children. The subjects' level of English achievement was also considered. The results showed that comprehension of all three forms of ambiguity was strongly related to level of English achievement, though deep structure ambiguities best descriminated the English achievement groups. Results also showed that perception of all types of ambiguity was related to both simultaneous and successive processing. Subjects with high successive processing scores had an additional advantage in perceiving deep structure ambiguities. These results suggest the need for an elaboration of the Cummins and Das cognitive process model of linguistic processes, demonstrating that a variety of task variables can alter the cognitive processes required in performance of linguistic tasks.

Achievement↗