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Catherine Lord

Publications and source records attributed to Catherine Lord.

32 records · Page 2Linked to original sources
PubMed2005

Stress hormones and human memory function across the lifespan.

In this paper, we summarize the data obtained in our laboratory showing the effects of glucocorticoids on human cognitive function in older adults, young adults and children. We first present data obtained in the aged human population which showed that long-term exposure to high endogenous levels of glucocorticoids is associated with both memory impairments and a 14% smaller volume of the hippocampus. We then report on studies showing that in older adults with moderate levels of glucocorticoids, memory performance can be acutely modulated by pharmacological manipulations of glucocorticoids. In young adults, we present data obtained in our laboratory showing that cognitive processing sustained by the frontal lobes is also sensitive to acute increases of glucocorticoids. We also summarize studies showing that just as in older adults, memory performance in young adults can be acutely modulated by pharmacological manipulations of glucocorticoids. We then present a study in which we showed a differential involvement of adrenergic and glucocorticoid hormones for short- and long-term memory of neutral and emotional information. In the last section of the paper, we present data obtained in a population of young children and teenagers from low and high socioeconomic status (SES), where we showed that children from low SES present significantly higher levels of basal cortisol when compared to children from high SES. We then present new data obtained in this population showing that children and teenagers from low and high SES do not process the plausibility of positive and negative attributes in the same way. Children from low SES tended to process positive and negative attributes on a more negative note than children from high SES, and this type of processing was significantly related to basal cortisol at age 10, 12 and 14. Altogether, the results of these studies show that both bottom-up (effects of glucocorticoids on cognitive function), and top-down (effects of cognitive processing on glucocorticoid secretion) effects exist in the human population.

Adolescent↗
PubMed2005

Early regression in social communication in autism spectrum disorders: a CPEA Study.

In a multisite study of 351 children with autism spectrum disorders, 21 children with developmental delays, and 31 children with typical development, this study used caregiver interviews (i.e., the Autism Diagnostic Interview-Revised) at the time of entry into other research projects and follow-up telephone interviews designed for this project to describe the children's early acquisition and loss of social-communication milestones. Children who had used words spontaneously and meaningfully and then stopped talking were described by their caregivers as showing more gestures, greater participation in social games, and better receptive language before the loss and fewer of these skills after the loss than other children with autism spectrum disorders. A significant minority of children with autism without word loss showed a very similar pattern of loss of social-communication skills, a pattern not observed in the children with developmental delays or typical development.

Age Factors↗
PubMed2004

Early indicators of autism spectrum disorders in the second year of life.

Three groups of 18 children were selected for this study, one group with autism spectrum disorders (ASD), one group with developmental delays in which ASD was ruled out (DD), and one group with typical development (TD), from a pool of 3026 children who were screened with the Communication and Symbolic Behavior Scales Developmental Profile (CSBS DP, Wetherby & Prizant. 2002) Infant-Toddler Checklist under 24 months of age. The CSBS DP Behavior Sample was videotaped on selected children as a second-level evaluation during the second year of life. The Infant-Toddler Checklist had a sensitivity and specificity of 88.9% for this sample of children. Significant group differences were found on the Infant-Toddler Checklist and the Behavior Sample, however, these differences did not distinguish children with ASD and DD with high accuracy. The videotapes of the Behavior Sample were reanalyzed to identify red flags of ASD. Nine red flags differentiated children in the ASD group from both the DD and TD groups and four red flags differentiated children in the ASD Group from the TD group but not the DD group. These 13 red flags were found to discriminate the three groups with a correct classification rate of 94.4%.

Age Factors↗
PubMed2004

Subject selection and characterization in clinical trials in children with autism.

The goal of psychopharmacologic research in autism is to provide guidance to clinicians and families on the risks and benefits of specific interventions. Careful subject selection and subject characterization in clinical trials are necessary for replication, to inform clinicians about the sample, and to elucidate the type of patients who might benefit from the treatment. At minimum, subject characterization includes demographic information, diagnosis (autism, Asperger's syndrome, or pervasive developmental disorder-not otherwise specified), intellectual functioning, adaptive functioning, symptom severity, general behavioral profile, health status, pertinent clinical laboratory measures, height, weight, current treatments, and educational placements. Subject selection, sample size, and choice of the primary outcome measure are closely interrelated and linked to the study hypothesis. The magnitude of expected improvement on the primary outcome measure, which can be expressed by effect size, has direct implications for sample size. Large sample sizes are required to detect small effect sizes. To facilitate interpretation of study results, research reports should provide descriptive characteristics of the sample as well as the mean change and standard deviation on the primary outcome measure data to permit calculation of the effect size.

Autistic Disorder↗
PubMed2004

Autism and pervasive developmental disorders.

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the 'broader phenotype' remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed. Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.

Autistic Disorder↗
PubMed2004

Outcome classification of preschool children with autism spectrum disorders using MRI brain measures.

OBJECTIVE: To test the hypothesis that a combination of magnetic resonance imaging (MRI) brain measures obtained during early childhood distinguish children with autism spectrum disorders (ASD) from typically developing children and is associated with functional outcome. METHOD: Quantitative MRI technology was used to measure gray and white matter volumes (cerebrum and cerebellum), total brain volume, and the area of the cerebellar vermis in 52 boys with a provisional diagnosis of autism (aged 1.9-5.2 years) and 15 typically developing young children (aged 1.7-5.2 years). Diagnostic confirmation and cognitive outcome data were obtained after the children reached 5 years of age. RESULTS: A discriminant function analysis of the MRI brain measures correctly classified 95.8% of the ASD cases and 92.3% of the control cases. This set of variables also correctly classified 85% of the ASD cases as lower functioning and 68% of the ASD cases as higher functioning. CONCLUSIONS: These results indicate that variability in cerebellar and cerebral size is correlated with diagnostic and functional outcome in very young children with ASD.

Analysis of Variance↗
PubMed2004

Regression and word loss in autistic spectrum disorders.

BACKGROUND: For many years, researchers and clinicians have described parent reports of an unusual developmental phenomenon in a substantial minority of children with Autistic Spectrum Disorders (ASD), the acquisition and then loss of communication skills during the second year of life. METHODS: As part of a longitudinal study of 110 children referred for assessments of possible autism at age 2 years or younger, 21 developmentally delayed children and 33 typically developing controls, 19 children were described by their parents at age 2 as having gained and lost spontaneous, meaningful words, and 12 children as having a history of less specific loss of imitated words or nonword vocalizations. A battery of diagnostic and cognitive tasks was administered to all children at study entrance, at ages 3 (for the referral children only) and 4 or 5 (for referral and developmentally delayed children). RESULTS: Results indicated that the acquisition of a small number of spontaneous words used meaningfully and consistently followed by loss of all words, often associated with other social changes, was unique to children diagnosed at 5 years with ASD. Few differences, besides those that defined the pattern of word loss, emerged between children with ASD with and without word loss. Loss of less specific, nonword vocalizations was associated with cognitive delay, with or without autism. CONCLUSIONS: Word loss is a reliably identifiable phenomenon in early childhood that appears to be unique, but not universal to, ASD. Histories and outcome of children with word loss were not in keeping with a sudden change from normal to abnormal functioning, but did suggest that this type of loss in the second year of life may be a useful 'red flag' for ASD in a significant minority of cases.

Autistic Disorder↗
PubMed2004

Effects of self-esteem on age-related changes in cognition and the regulation of the hypothalamic-pituitary-adrenal axis.

Epidemiological studies have demonstrated the effects of self-esteem on global health and life expectancy in normal aging. Endocrinological studies in humans have demonstrated the effects of self-esteem on basal regulation and reactivity of the hypothalamic-pituitary adrenal (HPA) axis. To investigate the effects of differences in self-esteem on age-related changes in cognitive performance and HPA regulation, we investigated 20 healthy elderly subjects (age range 60-84, mean age 69.8 y). We assessed salivary cortisol levels together with neuropsychological assessment, and psychological assessment for self-esteem and locus of control. Across the study sample, age was significantly associated with reductions in cognitive performance and changes in basal cortisol regulation. Self-esteem appeared independent of age. Defining two groups of subjects with high and low self-esteem, age-related changes in cognitive and endocrinological variables became more prominent in the low self-esteem group, whereas age no longer had a significant impact on the variables in the high self-esteem group. These data suggest an effect of self-esteem on cognitive decline with aging. It further suggests an effect on age-related endocrine changes in humans. These results are discussed with regard to potential mechanisms by which the reported association between self-esteem and aging could be mediated.

Aged↗
PubMed2003

The symptoms of autism spectrum disorders in adolescence and adulthood.

This article describes the symptoms of autism spectrum disorders (ASD) manifested by 405 individuals between the ages of 10 and 53 years, all of whom had an ASD diagnosis. Data were collected using the Autism Diagnostic Interview-Revised (ADI-R) to assess the pattern of autism symptoms in adolescence and adulthood. Findings include that although virtually all sample members met the criteria for Autistic Disorder earlier in their childhood, just over half (54.8%) would have met autism criteria if current scores were used to complete the diagnostic algorithm; that adolescents were more likely to improve in the Reciprocal Social Interaction domain than the adults, whereas the adults were more likely to improve in the Restricted, Repetitive Behaviors and Interests domain, and there were no differences in severity of symptoms between cohorts in the Communication domain; and that individual symptoms showed unique trajectories, with greatest symptom abatement between lifetime and current ADI-R ratings for speaking in at least three-word phrases and the least symptom improvement for having friendships. Findings were interpreted in the context of life course development, reformulations of diagnostic criteria, and changing service contexts for individuals with autism spectrum disorders.

Adolescent↗
PubMed2002

Transmission disequilibrium studies of the serotonin 5-HT2A receptor gene (HTR2A) in autism.

Hyperserotonemia in autism is one of the longest-standing biochemical findings in a psychiatric disorder. This well-replicated finding and subsequent studies of platelet serotonin receptors in autism indicate that the serotonin 2A receptor gene (HTR2A) on chromosome 13q is a primary candidate gene in autism. Converging data from recent genome screens also implicates the genomic region containing HTR2A. Based on these lines of evidence, the transmission/disequilibrium test (TDT) was used to assess transmission disequilibrium between autism and haplotypes of three polymorphisms, including the promoter -1438 G/A single nucleotide polymorphism (SNP) in perfect linkage disequilibrium with the 102 T/C SNP in previous studies, a newly identified SNP in intron 1 near exon 2, and the SNP responsible for the His452Tyr amino acid change in exon 3. Because expression studies have shown HTR2A to be polymorphically imprinted in the brain, secondary analyses were split into maternal and paternal transmissions. No evidence was found for unequal transmission of haplotypes; however, power analysis reveals low power to detect a parent-of-origin effect in this sample size.

Alleles↗
PubMed2002

Mutation screening and transmission disequilibrium study of ATP10C in autism.

Autism is a complex genetic disorder. Chromosome 15 is of particular interest in this disorder, because of previous reports of individuals with autism with chromosomal abnormalities in the 15q11-q13 region. Transmission disequilibrium between polymorphisms in this region and autism has been also been reported in some, but not all studies. Recently, a novel maternally expressed gene, ATP10C, was characterized and mapped to the chromosome 15q11-q13 region, 200 kb distal to UBE3A. It encodes a putative aminophospholipid translocase likely to be involved in the asymmetric distribution of proteins in the cell membrane. Preferential maternal expression has been demonstrated in fibroblasts and brain. Because of its physical location and imprinting pattern, ATP10C was considered to be a candidate gene for chromosome 15-associated autism. In an effort to find the genes responsible for autism in this chromosomal region, 1.5 kb of the 5' flanking region, as well as the coding and splicing regions of ATP10C, were screened for sequence variants. Several polymorphic markers including five nonsynonymous SNPs were identified. To investigate transmission disequilibrium between ATP10C and autism, a family-based association study was conducted for 14 markers in 115 autism trios. No significant transmission disequilibrium was found, suggesting ATP10C is unlikely to contribute strongly to susceptibility to autism in these families. However, due to limited power to detect genes of modest effect, the possible functional role of the nonsynonymous SNPs and the functional implications of the SNPs identified from 5' flanking region and intron 2 splicing region may be evaluated in further studies.

Adenosine Triphosphatases↗
PubMed2002

Volumetry of temporopolar, perirhinal, entorhinal and parahippocampal cortex from high-resolution MR images: considering the variability of the collateral sulcus.

Researchers in clinical and basic neuroscience frequently target structures of the human medial temporal lobe (MTL) for volumetric analysis with magnetic resonance imaging (MRI). In neurodegenerative diseases, a precise volumetric analysis of MTL structures can assist in differential diagnosis and can be used in guiding early treatment. Also, in functional neuroimaging, exact localization is crucial for the correct interpretation of focal MTL activations with respect to specific memory functions. In presently available protocols, precise and consistent volumetric analysis of MTL structures is compromised in numerous ways. Most importantly, in order to cover all structures of the MTL, the researcher is presently forced to combine independently developed segmentation protocols for different structures from different laboratories. This approach limits anatomical precision because these protocols are based on different anatomical guidelines and descriptions that cannot easily be integrated. The segmentation approach presented in this paper was designed to address this issue by presenting segmentation guidelines for all major structures of the parahippocampal gyrus (PHG). It was developed directly to complement a volumetric protocol for hippocampus and amygdala (Pruessner et al., 2000, Cereb Cortex 10:433-442), thus allowing volumetric assessment of all major MTL structures in an integrated and consistent manner. Furthermore, it takes into consideration the neuroanatomical appearance of the collateral sulcus by presenting a method to correct the volumes of the surrounding cortices for the variability of this sulcus. The protocol was validated using MR images of 40 healthy normal control subjects (20 men and 20 women, age range 18-42 years). Intra- and interrater coefficients are presented, together with mean values for the volumes of all PHG structures, correlations with age and sex, and tests for hemispheric differences.

Adult↗
PubMed2002

Cognitive profiles and social-communicative functioning in children with autism spectrum disorder.

BACKGROUND: Whether there is an unusual degree of unevenness in the cognitive abilities of children with autism spectrum disorder (ASD) and whether different cognitive profiles among children with ASD might index etiologically significant subgroups are questions of continued debate in autism research. METHOD: The Differential Ability Scales (DAS) and the Autism Diagnostic Observation Schedule (ADOS) were used to examine profiles of verbal and nonverbal abilities and their relationship to autistic symptomatology in 120 relatively high-functioning children with ADI-confirmed diagnoses of autism. RESULTS: Discrepancies between verbal and nonverbal ability scores occurred at a significantly higher rate than in the DAS normative sample (30%) in both a younger group of 73 children (56%) with a mean age of 5;5 and an older group of 47 children (62%) with a mean age of 8;11. Discrepancies were mainly in favor of nonverbal ability in the younger group, but occurred equally in favor of verbal and nonverbal abilities in the older group. Comparison of the two age groups suggested a growing dissociation between verbal and nonverbal (and particularly visual processing) skills with age. In the older group, children with discrepantly higher nonverbal abilities demonstrated significantly greater impairment in social functioning, as measured on the ADOS, independent of absolute level of verbal and overall ability. CONCLUSIONS: These findings demonstrate a high rate of uneven cognitive development in children with ASD. Indications of a dissociation between verbal and visual-perceptual skills among the older children, and the specific association of discrepantly high nonverbal skills with increased social symptoms suggest that the nonverbal > verbal profile may index an etiologically significant subtype of autism.

Adolescent↗