Biomedical subjects

Judy Reilly

Publications and source records attributed to Judy Reilly.

11 recordsLinked to original sources

PubMed2006

Early environmental factors, ethnicity, and adult cognitive test performance.

This study was conducted to better understand cross-cultural variation in neuropsychological test performance by exploring the relationship between early environmental factors and adult neuropsychological functioning in African Americans (AA) and Caucasians (CA). Cognitive testing data and detailed retrospective early environmental histories were obtained from 100 neurologically healthy adults (75 AA, 25 CA). Results indicate that: (a) consistent with previous research, the two ethnic groups differed significantly on their cognitive test performance; (b) early environmental factors were significantly related to performance on cognitive tests; (c) the two ethnic groups demonstrated slight, but significant, differences in their early environmental histories; but (d) covarying early environmental factors did not substantially reduce the group performance in cognitive test performance. The failure of reported environmental factors to account for more of the ethnic disparity in test performance may have resulted from the inherent weakness of the retrospective assessment method (i.e., lack of precision or objectivity in participants' recollections of their early environments). These results highlight the remaining need for ethnicity specific normative data until cross-cultural variation in neuropsychological test performance is better understood.

Adult↗

PubMed2005

Cognitive development following early brain injury: evidence for neural adaptation.

Over the past few decades a large body of work from developmental neurobiology has shown that mammalian brain development is the product of dynamic and adaptive processes operating within highly constrained, but continually changing, biological and environmental contexts. The recent study of children with prenatal focal brain injury supports this dynamic view of development for humans. Children's injuries often affect substantial portions of one cerebral hemisphere, resulting in damage that would compromise cognitive ability in adults. However, longitudinal behavioral studies of this population have revealed only mild deficits. It is suggested here that children's capacity for adaptation reflects normal developmental processes operating against a backdrop of serious neural perturbation. Data from three behavioral domains--linguistics, spatial cognition and affective development--illustrate this complex profile of change.

Adolescent↗

PubMed2005

A crosslinguistic study of the relationship between grammar and lexical development.

The relationship between grammatical and lexical development was compared in 233 English and 233 Italian children aged between 1;6 and 2;6, matched for age, gender, and vocabulary size on the MacArthur Communicative Development Inventories (CDI). Four different measures of Mean Length of Utterance were applied to the three longest utterances reported by parents, and to corrected/expanded versions representing the 'target' for each utterance. Italians had longer MLUs on most measures, but the ratio of actual to target MLUs did not differ between languages. Age and vocabulary both contributed significant variance to MLU, but the contribution of vocabulary was much larger, suggesting that vocabulary size may provide a better basis for crosslinguistic comparisons of grammatical development. The relationship between MLU and vocabulary size was non-linear in English but linear in Italian, suggesting that grammar 'gets off the ground' earlier in a richly inflected language. A possible mechanism to account for this difference is discussed.

Child Language↗

PubMed2004

Language development in children at risk for language impairment: cross-population comparisons.

At 3 years of age the spontaneous language of 17 typically developing children was compared to two groups of toddlers who were at risk for language delay for very different reasons. One at-risk group, late talkers, appeared normal in all respects except for their delayed language. These 20 children scored at or below the fifteenth percentile for expressive vocabulary on the MacArthur Communicative Development Inventory (Fenson et al., 1993) when originally identified at 20-27 months of age and within the normal range on the Bayley Scales of Infant Development (Bayley, 1969). The other group, 21 children with unilateral focal brain injury, suffered localized damage to their brain prenatally, perinatally, or within the first 6 months of life. Results indicated that both of the at-risk groups were still significantly lower in vocabulary diversity and grammar at 3 years of age. There was also significantly greater variability in the at-risk groups than in the control groups, and in the children with focal brain injury than in the late talkers in both areas. The importance of language comprehension to development in this period was supported by two findings. First, children with focal brain injury had significantly lower scores than late talkers on the Index of Productive Syntax, a test of emerging grammar, and had been lower in comprehension on a standardized test of language comprehension a year earlier. Second, late talkers with delay in comprehension as well as production had significantly lower scores on IPSyn than those with normal comprehension, suggesting that they are at greater risk for continued delay. Qualitative analyses indicated that the at-risk groups produced the same kinds of errors, but that late talkers produced a substantially greater proportion of errors in obligatory contexts than did children with focal brain injury.

Brain Injuries↗

PubMed2004

Mechanisms of verbal memory impairment in four neurodevelopmental disorders.

Profiles of verbal learning and memory performance were compared for typically developing children and for four developmental disorders characterized by different patterns of language functioning: specific language impairment, early focal brain damage, Williams Syndrome, and Down Syndrome. A list-learning task was used that allowed a detailed examination of the process of verbal learning, recall, and recognition (California Verbal Learning Test--Children's Version). Distinct patterns of performance characterized the four disorders. These patterns were consistent with the language deficits typically seen in the disorders, with the exception of a dissociation seen in Williams Syndrome.

Adolescent↗

PubMed2004

The development of morphosyntactic ability in atypical populations: The acquisition of tag questions in children with early focal lesions and children with specific-language impairment.

We examined the development of some features of morphosyntactic ability, specifically the acquisition of auxiliaries and use of agreement marking, along with sentence processing capacity. We used a conceptually simple task called the Tags Question Task, which is a method for evaluating a number of language processes in the production of a commonly used, familiar linguistic device. We compared the performance of children with early focal lesions (N=21), children with specific-language impairment (N=24), and typically developing children (N=24) matched in age and nonverbal ability; additional analyses involved comparisons of children matched on performance level. The data converge to support a "delayed" development of language behavior in our clinical groups, as overall patterns of performance and age-related changes on individual tag features and tag questions were strikingly similar in all three groups across a number of methods of comparison. Implications for theories of the development of brain-language relationships as they pertain to early focal brain damage, specific-language impairment, and the language acquisition process in typically developing children are discussed.

Adolescent↗

PubMed2004

"Frog, where are you?" Narratives in children with specific language impairment, early focal brain injury, and Williams syndrome.

In this cross-population study, we use narratives as a context to investigate language development in children from 4 to 12 years of age from three experimental groups: children with early unilateral focal brain damage (FL; N=52); children with specific language impairment (SLI; N=44); children with Williams syndrome (WMS; N=36), and typically developing controls. We compare the developmental trajectories of these groups in the following domains: morphological errors, use of complex syntax, complexity of narrative structure, and types and frequency of evaluative devices. For the children with early unilateral brain damage, there is initial delay. However, by age 10, they are generally within the normal range of performance for all narrative measures. Interestingly, there are few, if any, side specific differences. Children with SLI, who have no frank neurological damage and show no cognitive impairment demonstrate significantly more delay on all morphosyntactic measures than the FL group. Quantitatively, on morphosyntactic measures, the SLI group clusters with those children with WMS who are moderately retarded. Together these data help us to understand the extent and nature of brain plasticity for language development and those aspects of language and discourse that are dissociable.

Brain Injuries↗

PubMed2002

Cognitive efficiency on a match to sample task decreases at the onset of puberty in children.

Electrocortical evidence indicates that a wave of synaptic proliferation occurs in the frontal lobes around the age of puberty onset. To study its potential influence on cognition, we examined 246 children (10-17 years) and 49 young adults (18-22 years) using a match-to-sample type of task to measure reaction times to assess emotionally related information. Based upon the instruction set, subjects made a yes/no decision about the emotion expressed in a face, a word, or a face/word combination presented tachistoscopically for 100 ms. The faces were images of a single individual with a happy, angry, sad or neutral expression. The words were 'happy,' 'angry,' 'sad,' or 'neutral,' In the combined stimulus condition, subjects were asked to decide if the face and word matched for the same emotion. Results showed that compared to the previous year, reaction times were significantly slower for making a correct decision at 11 and 12 years of age in girls and boys, the approximate ages of puberty onset. The peripubertal rise in reaction time declined slowly over the following 2-3 years and stabilized by 15 years of age. Analyses of the performance of 15-17 year olds revealed significantly longer reaction times in females to process both faces and words compared to males. However, this sex difference in late puberty appeared to be transient since it was not present in 18-22 year olds. Given the match-to-sample nature of the task employed, the puberty related increases in reaction time may reflect a relative inefficiency in frontal circuitry prior to the pruning of excess synaptic contacts.

Adolescent↗

PubMed2002

Homing of purified murine lymphohematopoietic stem cells: a cytokine-induced defect.

This study was designed to establish a direct homing assay using purified lineage-negative Sca-1-positive (Lin(-) Sca(+)) murine bone marrow cells and to evaluate the effects of cytokines on homing. C57BL/6 Lin(-) Sca(+) marrow stem cells were labeled with 5-(and 6)-carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) and then injected by tail vein into untreated C57BL/6 mice. Marrow was harvested at various times after cell infusion and analyzed on a high-speed MoFlo cell sorter for fluorescent positive events, using a large event analysis, with at least 16 million total events analyzed. We have shown that homing of Lin(-) Sca(+) cells plateaus by 1 h, and at 3 h post-infusion is linear between 50,000 and 1,000,000 infused cells. This forms a base for a homing assay in which 250,000 CFDA-SE labeled Lin(-) Sca(+) marrow cells are infused and then recovered from marrow 3 h later, followed by a large-event fluorescence-activated cell sorting (FACS) analysis. We found that 7.45-9.32% of infused cells homed and that homing of stem cells cultured for 48 h in interleukin-3 (IL-3), IL-6, IL-11, and steel factor cultured cells was defective when compared to noncultured cells. Exposure of marrow stem cells to IL-3, IL-6, IL-11, and steel factor induces a stem cell homing defect, which probably underlies the engraftment defect previously characterized under these conditions.

Animals↗

PubMed2002

Engraftment of post 5-fluorouracil murine marrow into minimally myeloablated (100 cGy) murine hosts.

Minimal myeloablative approaches are now being widely applied in the treatment of different hematological malignancies. One hundred cGy whole-body irradiation is a stem-cell-toxic, relatively non-myelotoxic treatment that allows for relatively high levels of donor chimerism. 5-Fluorouracil (5-FU) treatment leads to a relative concentration of high proliferative potential-colony-forming cell (HPP-CFC) and is an approach that has been used to induce in vivo progenitor/stem cell cycling to facilitate retroviral integration in gene therapy approaches. We have now evaluated the capacity of marrow harvested 1, 2, 6, or 12 days after 5-FU treatment (150 mg/kg) to engraft in 100 cGy-treated female BALB/c mice. Engraftment was assessed at 3, 10, and 24 weeks. A rapid induction of an engraftment defect occurred 1 day post 5-FU and persisted through day 6 with a recovery by day 12. To evaluate cell cycle status of normal and 5-FU-treated marrow cells, male donors received hydroxyurea (900 mg/kg i.v.) or phosphate-buffered saline (PBS), 2 h prior to marrow harvest and transplantation into submyeloablated female recipients. Engraftment levels were similar for hydroxyurea-treated mice and controls. Thus, these studies show transiently defective engraftment of 5-FU-treated marrow into submyeloablated hosts, which may be related to the cell cycle status of the stem cells.

Animals↗

PubMed2002

The MacArthur Communicative Development Inventory: Normative Data for American Sign Language.

To This is a 1 test per thousand learn more about normal language development in deaf children, we have developed the MacArthur Communicative Development Inventory for American Sign Language (ASL-CDI), a parent report that measures early sign production. The ASL-CDI is an inventory of sign glosses organized into semantic categories targeted to assess sign language skills in children ages 8 to 36 months. The ASL-CDI uses a recognition format in which parents check off signs that their child produces. The form has demonstrated excellent reliability and validity. To date, normative data have been collected from 69 deaf children with deaf parents who are learning sign language as a first language. We discuss the development of the ASl-CDI and preliminary cross-sectional and longitudinal findings from this early data collection with particular focus on parallels with spoken language acquisition. We also discuss the acquisition of first signs, negation, wh-questions, and fingerspelling with developmental patterns provided based on age, as well as vocabulary size.

Journal Article↗