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Biomedical subjects

E Plante

Publications and source records attributed to E Plante.

32 records · Page 2Linked to original sources
PubMed1993

Language matches: illuminating or confounding? Research note.

The practice of matching younger, language-matched controls, in addition to age-matched controls, is often used in studies of language-disordered children to examine the role of "language level" on performance. However, the interpretation of the relative performance of subjects in studies using such dual control groups is problematic. Conceptual concerns arise with the use of language matches because language is a multidimensional skill that is not reflected equivalently for the language-disordered children and their language-matched controls. Furthermore, matching by language level inevitably introduces an extraneous age effect that confounds interpretation. In addition, erroneous interpretations of null findings can occur when no differences are found between language-disordered and language-matched groups.

Age Factors↗
PubMed1992

Relations among verbal and nonverbal cognitive skills in normal language and specifically language-impaired children.

This study tested the hypothesis that specifically language-impaired (SLI) children have a qualitatively different cognitive system from that of normal language (NL) children. Twenty NL and 20 SLI children between the ages of 4:2 (years:months) and 5:11 were presented with experimental language-learning measures, experimental nonverbal measures, and verbal and nonverbal norm-referenced tests. A confirmatory analysis of the covariance matrix structures of the two subject groups indicated that relations among cognitive skills differed between NL and SLI children. In addition, a planned comparison indicated that the relation between nonverbal rule-induction and novel bound-morpheme learning differed significantly between groups. The findings indicate that a "qualitative-differences" model of specific language impairment better accounts for the co-occurrence of poor verbal and poor nonverbal cognitive skills in SLI children than a "low-normal" model.

Child, Preschool↗
PubMed1991

MRI findings in boys with specific language impairment.

Magnetic resonance imaging scans of specifically language-impaired (SLI) boys were examined to determine whether atypical cerebral findings could be documented in children whose primary deficits were in language skills. Clinical examination of the scans failed to reveal any visually obvious lesions or abnormalities. In contrast, measurement of the scans revealed atypical perisylvian asymmetries in most of these subjects. The distribution of perisylvian asymmetries in SLI subjects was significantly different from the distribution in controls (p less than .01). Measurement of other brain regions revealed that extraperisylvian areas were occasionally deviant in individual SLI subjects; but no one region was consistently deviant across the SLI group. Thus, only atypical perisylvian asymmetries were linked to the language disorder. These neuroanatomical findings suggest that a prenatal alteration of brain development underlies specific language impairment.

Brain Damage, Chronic↗
PubMed1991

MRI findings in the parents and siblings of specifically language-impaired boys.

Four families that include a specifically language-impaired (SLI) boy were studied to test the hypothesis that developmental language disorders are biologically transmittable. A majority of the parents of the SLI boys had experienced communication difficulty (i.e., difficulty with speech, language, or academic skills) as children. Evidence of communication difficulty was paired on an individual basis with neuroanatomical data obtained through quantitative analysis of magnetic resonance imaging scans. Atypical perisylvian asymmetries were documented in a majority of the parents and were frequently associated with a history of communication difficulty. Atypical perisylvian asymmetries and disordered language skills were also documented for siblings of SLI boys. These findings suggest that atypical perisylvian asymmetries reflect a transmittable, biological factor that places some families at risk for language impairment.

Adult↗
PubMed1991

Sources of error in the quantitative analysis of MRI scans.

The increasing use of quantitative analysis of MRI scans in the literature has produced a need to identify potential sources of bias in such analysis procedures. Six sources of bias are demonstrated in this paper. These include bias attributable to partial volume effects, head tilt, plane of view, use of noncontiguous slices, contrast/intensity manipulations, and magnetic inhomogeneities. The magnitude of bias for each source varied according to whether a hemisphere or regions within a hemisphere were measured, with regional effects typically exceeding hemisphere effects.

Bias↗
PubMed1990

Involvement of a phospholipase D in the mechanism of action of granulocyte-macrophage colony-stimulating factor (GM-CSF): priming of human neutrophils in vitro with GM-CSF is associated with accumulation of phosphatidic acid and diradylglycerol.

The generation of diradylglycerol (DRG) and phosphatidic acid (PdtOH) was investigated in neutrophils primed with granulocyte-macrophage colony-stimulating factor (GM-CSF). Mass accumulation of DRG and PdtOH was measured using reversed-phase high performance liquid chromatography and thin layer chromatography, respectively. GM-CSF had no direct effect on the levels of PdtOH and DRG, but it increased PdtOH generation and the late phase of DRG accumulation in human neutrophils stimulated with FMLP. The elevation of the mass of PdtOH peaked approximately 100 s and clearly preceded that of DRG, which peaked at 150 s. The diacylglycerol kinase inhibitor R59022 enhanced the sustained increase in DRG but did not produce a parallel inhibition in PdtOH production. GM-CSF was without effect on the level of inositol 1,4,5-triphosphate [Ins(1,4,5)P3] and did not affect the liberation of Ins(1,4,5)P3 induced by FMLP. These findings exclude the involvement of the PtdIns(4,5)P2-specific phospholipase C/diacylglycerol pathway in the sustained phase of DRG accumulation. The early (30-s) appearance of PdtOH clearly suggests that GM-CSF enhanced FMLP receptor-linked phospholipase D (PLD) generation of PdtOH. PLD was assessed more directly by formation of labeled phosphatidylethanol (PEt) through PLD capacity of catalyzing a trans-phosphatidylation in presence of ethanol. The formation of PEt associated with a concomitant decrease in PdtOH directly demonstrated that the mechanism by which GM-CSF enhances PdtOH production is activation of a PLD active on phosphatidylcholine. This study provides evidence that the mechanism of action of GM-CSF involves upregulation of PLD activity leading to enhanced generation of PdtOH and DRG in FMLP-stimulated neutrophils. These findings may provide the basis for several of the priming effects of GM-CSF.

Chromatography, High Pressure Liquid↗
PubMed1990

Predictors of novel inflection learning by preschool-aged boys.

This study addressed the extent to which performance on selected verbal and nonverbal measures contributes to the prediction of inflection learning. Twenty normal boys between the ages of 4:4 (years:months) and 5:7 were presented with stories designed to teach novel vocabulary and morphological inflections. A multiple regression analysis indicated that the measure of current inflection skills accounted for nearly half of the variance in inflection learning results. In addition, performance on a posttest of vocabulary learning significantly (p less than .05) contributed to the prediction equation. Although closer analysis of the findings indicates that the relation between nonverbal rule learning and inflection learning warrants further investigation, none of the three nonverbal measures was a significant contribution to the prediction equation. The results suggest that inflection learning may be tied more to other language abilities than to nonverbal cognitive skills in normally developing boys.

Child, Preschool↗
PubMed1989

Anatomical correlates of normal and impaired language in a set of dizygotic twins.

This report presents findings for a set of dizygotic twins at age 4 years 9 months. The male was diagnosed as specifically language impaired. For both children, the left-right perisylvian configuration was atypical. Only the male's configuration was symmetrical, a finding in line with autopsy data reported for subjects with "developmental dyslexia" who also may have had a form of language impairment. In addition, the male had an atypical (L greater than R) configuration of the cerebral hemispheres, a finding not seen in his twin, or in a series of volunteers without a history of developmental language impairment. The in utero effects of gonadal hormones that may account for these findings are discussed.

Brain Mapping↗
PubMedDate not supplied

IQ variability in children with SLI: implications for use of cognitive referencing in determining SLI.

The practice of cognitive referencing assumes that IQ scores can be used as a measure of intellectual potential from which language scores may deviate. To test the validity of this assumption the WISC scores of children with specific language impairment were compared over time. The variability of WISC scores from children with SLI from their initial evaluation and from the federally-mandated three year re-evaluation was analyzed. Significant differences in the performance scale scores were found. This indicates that the IQ scores of these children are more properly interpreted as reflecting current abilities rather than potential for language learning. This further calls into question the practice of cognitive referencing as a method of determining the presence of a language impairment, eligibility for services, and the service delivery model for which a child qualifies.

Adolescent↗
PubMedDate not supplied

Right hemisphere contribution to developmental language disorder: Neuroanatomical and behavioral evidence.

UNLABELLED: Developmental language disorder (DLD) is identified by virtue of the verbal deficits that define it. However, numerous studies have also documented nonverbal deficits in this population. This study attempts to explain the co-occurrence of both verbal and nonverbal deficits in this population from a brain-based perspective. Two samples of adults selected for DLD were compared with subjects without such a history on verbal and nonverbal skills in exploratory and confirmatory studies. Subjects also received MRI scans, which were used to determine the relation between left- and right-hemisphere regions hypothesized to relate to the behavioral skills tested. Results revealed replicable differences between groups on both verbal and nonverbal tasks. In addition, a significant association between performance on tests sensitive to facial affect and spatial rotation with the gray matter volume within the right supramarginal gyrus was found in both samples. These results support the hypothesis of a right hemisphere contribution to the profile of DLD. LEARNING OUTCOMES: As a result of this activity, the participant will be able to describe evidence in support of a role for the right hemisphere in DLD.

Adult↗
PubMedDate not supplied

Short-term and working memory differences in language/learning disabled and normal adults.

Fifteen adults who reported a childhood history of speech-language and/or learning disability (L/LD) were tested on two verbal memory tasks. Their performance on sentence repetition and reading span measures was compared with that of a matched control group who reported no childhood history of L/LD. Results indicated statistically significant group performance differences on both short-term and working memory tasks. This suggests that verbal memory difficulties may be a longterm component of L/LD.

Adolescent↗