Biomedical subjects

Elena Plante

Publications and source records attributed to Elena Plante.

At least 19 recordsLinked to original sources

PubMed2007

Object identification and lexical/semantic access in children: a functional magnetic resonance imaging study of word-picture matching.

Theoretical models for lexical access to visual objects have been based mainly on adult data. To investigate the developmental aspects of object recognition and lexical access in children, a large-scale functional MRI (fMRI) study was performed in 283 normal children ages 5-18 using a word-picture matching paradigm in which children would match an aurally presented noun to one of two pictures (line drawings). Using group Independent Component Analysis (ICA), six task-related components were detected, including (a) the posterior superior temporal gyrus bilaterally; (b) the fusiform, inferior temporal, and middle occipital gyri bilaterally; (c) the dorsal aspect of the inferior frontal gyrus bilaterally, the left precuneus, the left superior/middle temporal gyrus, and the anterior cingulate; (d) the right medial fusiform gyrus; (e) a left-lateralized component including the inferior/middle frontal, middle temporal, medial frontal, and angular gyri, as well as the thalamus and the posterior cingulate; and (f) the ventral/anterior aspect of the inferior frontal gyrus bilaterally. Increased activation associated with age was seen in the components (b) and (d) (ventral visual pathway) for object recognition, and (c) and (f) likely associated with semantic maintenance and response selection. Increased activation associated with task performance was seen in components (b) and (d) (ventral visual pathway) while decreased activation associated with task performance was seen in component (f) (ventral/anterior inferior frontal gyrus). The results corroborate the continued development of the ventral visual pathway throughout the developmental period.

Acoustic Stimulation↗

PubMed2006

Age-related connectivity changes in fMRI data from children listening to stories.

The way humans comprehend narrative speech plays an important part in human development and experience. A group of 313 children with ages 5-18 were subjected to a large-scale functional magnetic resonance imaging (fMRI) study in order to investigate the neural correlates of auditory narrative comprehension. The results were analyzed to investigate the age-related brain activity changes involved in the narrative language comprehension circuitry. We found age-related differences in brain activity which may either reflect changes in local neuroplasticity (of the regions involved) in the developing brain or a more global transformation of brain activity related to neuroplasticity. To investigate this issue, Structural Equation Modeling (SEM) was applied to the results obtained from a group independent component analysis (Schmithorst, V.J., Holland, S.K., et al., 2005. Cognitive modules utilized for narrative comprehension in children: a functional magnetic resonance imaging study. NeuroImage) and the age-related differences were examined in terms of changes in path coefficients between brain regions. The group Independent Component Analysis (ICA) had identified five bilateral task-related components comprising the primary auditory cortex, the mid-superior temporal gyrus, the most posterior aspect of the superior temporal gyrus, the hippocampus, the angular gyrus and the medial aspect of the parietal lobule (precuneus/posterior cingulate). Furthermore, a left-lateralized network (sixth component) was also identified comprising the inferior frontal gyrus (including Broca's area), the inferior parietal lobule, and the medial temporal gyrus. The components (brain regions) for the SEM were identified based on the ICA maps and the results are discussed in light of recent neuroimaging studies corroborating the functional segregation of Broca's and Wernicke's areas and the important role played by the right hemisphere in narrative comprehension. The classical Wernicke-Geschwind (WG) model for speech processing is expanded to a two-route model involving a direct route between Broca's and Wernicke's area and an indirect route involving the parietal lobe.

Adolescent↗

PubMed2006

Prosodic processing by children: an fMRI study.

Prosodic information in the speech signal carries information about linguistic structure as well as emotional content. Although children are known to use prosodic information from infancy onward to assist linguistic decoding, the brain correlates of this skill in childhood have not yet been the subject of study. Brain activation associated with processing of linguistic prosody was examined in a study of 284 normally developing children between the ages of 5 and 18 years. Children listened to low-pass filtered sentences and were asked to detect those that matched a target sentence. fMRI scanning revealed multiple regions of activation that predicted behavioral performance, independent of age-related changes in activation. Likewise, age-related changes in task activation were found that were independent of differences in task accuracy. The overall pattern of activation is interpreted in light of task demands and factors that may underlie age-related changes in task performance.

Adolescent↗

PubMed2006

The effects of variation on learning word order rules by adults with and without language-based learning disabilities.

UNLABELLED: Non-adjacent dependencies characterize numerous features of English syntax, including certain verb tense structures and subject-verb agreement. This study utilized an artificial language paradigm to examine the contribution of item variability to the learning of these types of dependencies. Adult subjects with and without language-based learning disabilities listened to strings of three non-words for which the first and third elements had a dependent relationship. In the low variability condition, 12 non-words occurred in the middle position, and in the high variability condition, 24 non-words occurred in this position. Non-disabled adults were able to learn the non-adjacent contingencies and generalize the underlying structure to new strings, but only when variability was high. Adults with language-based learning disabilities did not perform above chance levels under either variability condition. Thus, this group showed poor sensitivity to statistical information in speech input that both infants and non-disabled adults are known to track. LEARNING OUTCOMES: As a result of this activity, the reader will: (1) understand the advantages of using an artificial language to investigate language learning; (2) become familiar with a paradigm for studying the rapid learning of syntactic contingencies; (3) comprehend how the ability to map language structure differs for non-disabled adults and adults with a history of language/learning disability as a function of variability in the input the listener receives.

Adolescent↗

PubMed2006

A longitudinal functional magnetic resonance imaging study of language development in children 5 to 11 years old.

OBJECTIVE: Language skills continue to develop rapidly in children during the school-age years, and the "snapshot" view of the neural substrates of language provided by current neuroimaging studies cannot capture the dynamic changes associated with brain development. The aim of this study was to conduct a 5-year longitudinal investigation of language development using functional magnetic resonance imaging in healthy children. METHODS: Thirty subjects enrolled at ages 5, 6, or 7 were examined annually for 5 years using a 3-Tesla magnetic resonance imaging scanner and a verb generation task. Data analysis was conducted based on a general linear model that was modified to investigate developmental changes whereas minimizing the potential for missing data. RESULTS: With increasing age, there is progressive participation in language processing by the inferior/middle frontal, middle temporal, and angular gyri of the left hemisphere and the lingual and inferior temporal gyri of the right hemisphere and regression of participation of the left posterior insula/extrastriate cortex, left superior frontal and right anterior cingulate gyri, and left thalamus. CONCLUSION: The age-related changes observed in this study provide evidence of increased neuroplasticity of language in this age group and may have implications for further investigations of normal and aberrant language development.

Algorithms↗

PubMed2006

Eligibility criteria for language impairment: is the low end of normal always appropriate?

PURPOSE: The assumption that children with language impairment will receive low scores on standardized tests, and therefore that low scores will accurately identify these children, is examined through a review of data in the manuals of tests that are intended for use in identifying such children. METHOD: Data from 43 commercially available tests of child language were compiled to identify whether evidence exists to support their use in identifying language impairment in children. RESULTS: A review of data concerning the performance of children with impaired language failed to support the assumption that these children will routinely score at the low end of a test's normative distribution. A majority of tests reported that such children scored above 1.5 SD below the mean, and scores were within 1 SD of the mean for more than a quarter (27%) of the tests. The primary evidence needed to support the purpose of identification, test sensitivity and specificity, was available for 9 of the 43 tests, and acceptable accuracy (80% or better) was reported for 5 of these tests. IMPLICATIONS: Specific data supporting the application of "low score" criteria for the identification of language impairment is not supported by the majority of current commercially available tests. However, alternate sources of data (sensitivity and specificity rates) that support accurate identification are available for a subset of the available tests.

Age Factors↗

PubMed2006

The composition of normative groups and diagnostic decision making: shooting ourselves in the foot.

PURPOSE: The normative group of a norm-referenced test is intended to provide a basis for interpreting test scores. However, the composition of the normative group may facilitate or impede different types of diagnostic interpretations. This article considers who should be included in a normative sample and how this decision must be made relative to the purpose for which a test is intended. METHOD: The way in which the composition of the normative sample affects classification accuracy is demonstrated through a test review followed by a simulation study. The test review examined the descriptions of the normative group in a sample of 32 child language tests. The mean performance reported in the test manual for the sample of language impaired children was compared with the sample's norms, which either included or excluded children with language impairment. For the simulation, 2 contrasting normative procedures were modeled. The first procedure included a mixed group of representative cases (language impaired and normal cases). The second procedure excluded the language impaired cases from the norm. RESULTS: Both the data obtained from test manuals and the data simulation based on population characteristics supported our claim that use of mixed normative groups decreases the ability to accurately identify language impairment. Tests that used mixed norms had smaller differences between the normative and language impaired groups in comparison with tests that excluded children with impairment within the normative sample. The simulation demonstrated mixed norms that lowered the group mean and increased the standard deviation, resulting in decreased classification accuracy. CONCLUSIONS: When the purpose of testing is to identify children with impaired language skills, including children with language impairment in the normative sample can reduce identification accuracy.

Child↗

PubMed2006

Factors that influence lexical and semantic fast mapping of young children with specific language impairment.

PURPOSE: This purpose of this study was to investigate the lexical and semantic fast mapping ability of young children with specific language impairment (SLI) and normal language (NL), with a specific emphasis on the influence of phonological factors. METHOD: The study included 46 children (mean age 58 months), half with SLI and half with NL. Children were asked to fast map visual information only, visual-plus-nonlinguistic-auditory information, and visual-plus-linguistic-auditory information. A mixed design was used to compare children across and within groups. RESULTS: Children with SLI performed worse than children with NL overall. The SLI group showed specific deficits in semantic fast mapping when they saw visual information only. This condition may have disrupted encoding because it varied from the expected auditory and visual pattern. The children with SLI also performed poorly when they were asked to map phonotactically infrequent linguistic information and when the difficulty of the task increased. A nonword repetition task was correlated with both semantic and lexical fast mapping. CONCLUSIONS: The findings are discussed in the light of their support for a limited capacity model of processing, as well as the impact of phonology on word learning.

Case-Control Studies↗

PubMed2006

Subcategory learning in normal and language learning-disabled adults: how much information do they need?

PURPOSE: The purpose of this experiment was to determine if nonreferential morphophonological information was sufficient to facilitate the learning of gender subcategories (i.e., masculine vs. feminine) in individuals with normal language (NL) and those with a history of language-based learning disabilities (HLD). METHOD: Thirty-two adults listened for 18 min to a familiarization set of Russian words that included either 1 (single-marked) or 2 (double-marked) morphophonological markers indicating gender. Participants were then tested on their knowledge of both trained and untrained members of each gender subcategory. RESULTS: Testing indicated that morphophonological information is sufficient for lexical subcategory learning in both NL and HLD groups, although the HLD group had lower overall accuracy. The HLD group benefited from double-marking relative to single-marking for subcategory learning. CONCLUSION: The results demonstrated that learning through implicit mechanisms occurred after a relatively brief exposure to the language stimuli. In addition, the weaker overall learning by the HLD group was facilitated when multiple cues to linguistic subcategory were available in the input group members received.

Adult↗

PubMed2005

Sex differences in the activation of language cortex during childhood.

Sex differences have been well documented in the behavioral literature but have occurred inconsistently in the neuroimaging literature. This investigation examined the impact of subject age, language task, and cortical region on the occurrence of sex differences in functional magnetic resonance imaging. Two hundred and five (104 m, 101 f) right handed, monolingual English speaking children between the ages of 5 and 18 years were enrolled in this study. The study used fMRI at 3T to evaluate BOLD signal variation associated with sex, age, and their interaction. Children completed up to four language tasks, which involved listening to stories, prosody processing, single word vocabulary identification, and verb generation. A sex difference for behavioral performance was found for the prosodic processing task only. Brain activation in the classical left hemisphere language areas of the brain and their right homologues were assessed for sex differences. Although left lateralization was present for both frontal and temporal regions for all but the prosody task, no significant sex differences were found for the degree of lateralization. Sex x age interaction effects were found for all but the task involving single word vocabulary. However effect sizes associated with the sex differences were small, which suggests that relatively large sample sizes would be needed to detect these effects reliably.

Adolescent↗

PubMed2005

Cognitive modules utilized for narrative comprehension in children: a functional magnetic resonance imaging study.

The ability to comprehend narratives constitutes an important component of human development and experience. The neural correlates of auditory narrative comprehension in children were investigated in a large-scale functional magnetic resonance imaging (fMRI) study involving 313 subjects ages 5-18. Using group independent component analysis (ICA), bilateral task-related components were found comprising the primary auditory cortex, the mid-superior temporal gyrus, the hippocampus, the angular gyrus, and medial aspect of the parietal lobule (precuneus/posterior cingulate). In addition, a right-lateralized component was found involving the most posterior aspect of the superior temporal gyrus, and a left-lateralized component was found comprising the inferior frontal gyrus (including Broca's area), the inferior parietal lobule, and the medial temporal gyrus. Using a novel data-driven analysis technique, increased task-related activity related to age was found in the components comprising the mid-superior temporal gyrus (Wernicke's area) and the posterior aspect of the superior temporal gyrus, while decreased activity related to age was found in the component comprising the angular gyrus. The results are discussed in light of recent hypotheses involving the functional segregation of Wernicke's area and the specific role of the mid-superior temporal gyrus in speech comprehension.

Adolescent↗

PubMed2005

Auditory-visual speech integration by adults with and without language-learning disabilities.

UNLABELLED: Auditory and auditory-visual (AV) speech perception skills were examined in adults with and without language-learning disabilities (LLD). The AV stimuli consisted of congruent consonant-vowel syllables (auditory and visual syllables matched in terms of syllable being produced) and incongruent McGurk syllables (auditory syllable differed from visual syllable). Although the identification of the auditory and congruent AV syllables was comparable for the two groups, the reaction times to identify all syllables were longer in the LLD compared to the control group. This finding is consistent with previous research demonstrating slower processing in learning disabled individuals. Adults with LLD also provided significantly fewer integration-type or McGurk responses compared with their normal peers when presented with speech tokens representing a mismatch between the auditory and visual signal. These results suggest the poor integration for auditory-visual speech previously documented in children with poor language skills also occurs in adults with LLD. LEARNING OUTCOMES: The reader will be able to (1) describe the McGurk effect; (2) describe group differences (language learning disabled and control adults) in auditory and auditory-visual speech perception of consonant-vowel syllables.

Acoustic Stimulation↗

PubMed2005

Diagnostic accuracy of the structured photographic expressive language test: third edition (SPELT-3).

PURPOSE: This study examined the empirical evidence for using the Structured Photographic Expressive Language Test: Third Edition (SPELT-3; Dawson, Stout, & Eyer, 2003) to diagnose language impairment in preschool children. The SPELT-3 is a revision of the SPELT-II (Werner & Kresheck, 1983), which has been proven in the past to have high levels of discriminant accuracy in identifying preschoolers with language impairment. METHOD: Forty-two 4- and 5-year-old children with a specific language impairment (SLI) and 43 children with typically developing (TD) language abilities were studied to determine the classification accuracy and other aspects of validity for the SPELT-3. RESULTS: Results from both an exploratory and a confirmatory sample indicated 90% sensitivity and 100% specificity when a cutoff standard score of 95 was applied to the data. In addition, use of the SPELT-3 was supported by additional data on convergent and divergent aspects of validity. IMPLICATIONS: The data provide empirical support for the use of the SPELT-3 for the purpose of differentiating between children with normal language and those with impaired language.

Adolescent↗

PubMed2005

A functional magnetic resonance imaging investigation of verbal working memory in adolescents with specific language impairment.

This study used neuroimaging and behavioral techniques to examine the claim that processing capacity limitations underlie specific language impairment (SLI). Functional magnetic resonance imaging (fMRI) was used to investigate verbal working memory in adolescents with SLI and normal language (NL) controls. The experimental task involved a modified listening span measure that included sentence encoding and recognition of final words in prior sets of sentences. The SLI group performed significantly poorer than the NL group for both encoding and recognition and displayed slower reaction times for correct responses on high complexity encoding items. fMRI results revealed that the SLI group exhibited significant hypoactivation during encoding in regions that have been implicated in attentional and memory processes, as well as hypoactivation during recognition in regions associated with language processing. Correlational analyses indicated that adolescents with SLI exhibited different patterns of coordinating activation among brain regions relative to controls for both encoding and recognition, suggesting reliance on a less functional network. These findings are interpreted as supporting the notion that constraints in nonlinguistic systems play a role in SLI.

Adolescent↗

PubMed2004

Memory and executive function in older adults: relationships with temporal and prefrontal gray matter volumes and white matter hyperintensities.

Forty-eight healthy adults aged 65-85 were recruited for structural magnetic resonance scans after an extensive neuropsychological battery that ensured a high degree of variability across the sample in performance on long-term memory tests, and on tests traditionally thought to rely on prefrontal cortex. Gray matter volumes were measured for three gyri in the frontal lobe (superior, middle, inferior), six gyri in the temporal lobe (superior, middle, inferior, fusiform, parahippocampal, and hippocampus), and the occipital lobe. Gray matter volumes declined across the age range evaluated, but with substantial regional variation--greatest in the inferior frontal, superior temporal, and middle temporal gyri but negligible in the occipital lobe. Both memory performance and executive function declined as the number of hyperintense regions in the subcortical white matter increased. Memory performance was also significantly correlated with gray matter volumes of the middle frontal gyrus (MFG), and several regions of temporal neocortex. However, the correlations were all in the negative direction; better memory performance was associated with smaller volumes. Several previous reports of significant negative correlations between gray matter volumes and memory performance are described, so that the possible reasons for this surprising finding are discussed.

Aged↗

PubMed2004

Semantic features in fast-mapping: performance of preschoolers with specific language impairment versus preschoolers with normal language.

This study examined the receptive language skills of young children (4-6 years old) with specific language impairment (SLI). Specifically, the authors looked at their ability to fast-map semantic features of objects and actions and compared it to the performance of age-matched peers with normally developing language (NL). Children completed a computer task during which they were exposed to novel objects and actions with novel names. The children then were asked questions about the semantic features of these novel objects and actions. Overall, the questions about actions were more difficult for children than objects. The children with SLI were able to recognize fewer semantic features than were their peers with NL. They also performed poorly relative to their peers on a lexical label recognition task. These results lend support to the idea that children with SLI have broader difficulties with receptive vocabulary than simply a reduced ability to acquire labels.

Analysis of Variance↗

PubMed2004

Difference in standard scores of adults on the Peabody Picture Vocabulary Test (Revised and Third Edition).

Differences in the standard scores for the Peabody Picture Vocabulary Test-Revised (PPVT-R; L. M. Dunn and L. M. Dunn, 1981) and the PPVT-Third Edition (PPVT-III; Dunn and Dunn, 1997b) are known to exist for children, with typically higher scores occurring on the PPVT-III. However, these tests are administered into adulthood as well, and score equivalence must be evaluated for this age range. Analysis of data from the PPVT-R and PPVT-III tests from 76 adult participants revealed significant score differences. Participants with poor language skills scored significantly higher on the PPVT-III than on the PPVT-R. The control group showed no significant difference between the PPVT-R and PPVT-III scores. The results suggest that the two tests should not be considered interchangeable.

Adolescent↗

PubMed2003

fMRI variability and the localization of languages in the bilingual brain.

The cerebral localization of multiple languages is a topic of active research. This study presents a method for assessing whether partial overlap of active voxels reflects differential language localization, or simply the variability known to occur with multiple runs of the same task in fMRI studies. Two groups of bilingual subjects (early and later learners of L2) performed word fluency and sentence generation tasks in both languages. The degree of separation for regions of activation did not exceed that associated with run-to-run variability for either task or either group. Early bilinguals, however, showed greater total numbers of active voxels than Late bilinguals for both tasks. This effect occurred despite a lack of a behavioral performance differences by the two groups.

Adolescent↗