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Biomedical subjects

Katherine A Loveland

Publications and source records attributed to Katherine A Loveland.

14 recordsLinked to original sources
PubMed2007

Improving the reliability of autism diagnoses: examining the utility of adaptive behavior.

The classification agreement of the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) was examined in 129 children and adolescents (aged 7-18 years) who were evaluated for autism. Participants received a diagnosis of autism or non-autism based on the ADI-R. Linear discriminant analysis revealed adequate concordance between the ADI-R and ADOS, with 75% of the participants being correctly classified using the ADOS. Classification accuracy significantly improved to 84% when a measure of adaptive functioning (i.e., the Vineland Adaptive Behavior Scales) was included in the analysis. The findings suggest that when clinicians obtain discrepant information on the ADI-R and ADOS, assessment of an individual's adaptive functioning may reduce diagnostic errors.

Adaptation, Psychological↗
PubMed2006

A comparison of behavioral and emotional functioning in children and adolescents with Autistic Disorder and PDD-NOS.

Behavioral symptomatology was compared in 26 children and adolescents with Autistic Disorder ("autism") and 25 children and adolescents with Pervasive Developmental Disorder, Not Otherwise Specified ("PDD-NOS"). Relative to individuals with PDD-NOS, those with autism had more symptoms of depression, social withdrawal, atypical behavior, and immature social skills--and fewer family problems. These differences remained even when group differences in intellectual ability were statistically controlled. No group differences emerged in somatization, anxiety, or hyperactivity. Findings suggest that although both groups demonstrate considerable evidence of behavioral and emotional problems, those with autism are at particularly high risk for comorbid behavioral and emotional disabilities.

Adaptation, Psychological↗
PubMed2005

The orbitofrontal-amygdala circuit and self-regulation of social-emotional behavior in autism.

Individuals with an autistic spectrum disorder are impaired not only in understanding others' mental states, but also in self-regulation of social-emotional behavior. Therefore, a model of the brain in autism must encompass not only those brain systems that subserve social-cognitive and emotional functioning, but also those that subserve the self-regulation of behavior in response to a changing social environment. We present evidence to support the hypothesis that developmental dysfunction of the orbitofrontal-amygdala circuit of the brain is a critical factor in the development of autism and that some of the characteristic deficits of persons with autism in socio-emotional cognition and behavioral self-regulation are related to early dysfunction of different components of this circuit. A secondary hypothesis posits that the degree of intellectual impairment present in individuals with autism is directly related to the integrity of the dorsolateral prefrontal-hippocampal circuit of the brain. Together, these hypotheses have the potential to help explain the neurodevelopmental basis of some of the primary manifestations of autism as well as the heterogeneity of outcomes.

Amygdala↗
PubMed2005

Index finger movement imitation by human neonates: motivation, learning, and left-hand preference.

Imitation of a fine motor movement, index finger protrusion, was examined in 39 neonates using an ethologically based objective coding system. Results confirmed that imitation of finger movements exists, and infants demonstrated "learning" as imitation developed through an incomplete imitation stage. Neonatal imitation was more frequently left-handed, an early sign of laterality in motivation to be investigated further. The existence of index finger imitation in human neonates indicates that volitional control of individuated finger movements develops much earlier than previously thought. The differential increase of index finger protrusion movements during the imitation periods suggests that this behavior is not an automatic response triggered by general arousal but instead is a true indicator of purposeful neonatal imitation.

Analysis of Variance↗
PubMed2005

Aging in adults with intellectual disabilities.

A cross-sequential design was used to examine changes related to aging in adults with and without Down syndrome (ns = 55 and 75, respectively). Adults received yearly neuropsychological and medical evaluations. Support for precocious aging in adults with Down syndrome was evident only on a test of verbal fluency, with weaker support obtained on a test of fine-motor skills. Cross-sectional age differences for all adults were obtained on tests of memory and community living skills. General intellectual level, gender, and psychiatric status were consistently related to performance, indicating the need to examine such mediating variables in studies on aging.

Activities of Daily Living↗
PubMed2005

Role of orientation in perception of emotions.

Our study examined whether perception of novel emotions, as with perception of novel objects, elicits a cardiac orientation reaction. Using a habituation-dishabituation paradigm, data from 11 adult subjects showed that orientation to both novel emotions and novel objects elicited a heart-rate deceleration. Results suggest that the orientation reaction may be an integral part of perception of emotion. Perception of emotions, therefore, is a complex, multistep process that includes an early orientation reaction.

Adult↗
PubMed2004

Effects of methylphenidate treatment in children with mental retardation and ADHD: individual variation in medication response.

OBJECTIVE: Individual variation in cognitive and behavioral response to methylphenidate (MPH) was investigated in children with mental retardation and attention-deficit/hyperactivity disorder. METHOD: Twenty-four children (mean age 10.9 years, SD = 2.4) participated in a placebo-controlled, double-blind, crossover trial with 0.15-, 0.30-, and 0.60-mg/kg b.i.d. doses of MPH. Parent and teacher behavioral ratings, as well as cognitive task performance, were assessed at each dose. RESULTS: Relative to placebo, most children with attention-deficit/hyperactivity disorder and mental retardation showed some degree of behavioral and cognitive improvement with MPH treatment. However, fewer of these children made substantial gains (>30% improvement, relative to placebo) with MPH treatment. At the highest dose, 55% of the children showed substantial behavioral gains and 46% made substantial gains in cognitive task performance. However, there was substantial independence between changes in behavior and changes in cognitive performance. CONCLUSIONS: At the 0.60-mg/kg MPH dose, more children showed substantial cognitive and behavioral gains than those who showed substantial declines in a ratio of more than 5:1. However, it may be prudent to assess cognitive change as well as behavioral effects because improvements in the former do not necessarily forecast improvements in the latter in children with attention-deficit/hyperactivity disorder and mental retardation.

Attention Deficit Disorder with Hyperactivity↗
PubMed2004

Treatment effects of methylphenidate on cognitive functioning in children with mental retardation and ADHD.

OBJECTIVE: Cognitive effects of stimulant medication were investigated in children with mental retardation (MR) and attention-deficit/hyperactivity disorder (ADHD). METHOD: Performance on tasks tapping sustained attention, visual and auditory selective attention, inhibition, and immediate memory was assessed for 24 children (mean age 10.9 years) during a placebo-controlled, double-blind, crossover treatment trial with 0.15, 0.30, and 0.60 mg/kg b.i.d. dosages of methylphenidate (MPH). RESULTS: Successively higher MPH doses were associated with consistent gains in cognitive task performance, with optimal performance noted at the highest dose. Analysis of dose-response curves revealed significant linear components of trend on measures tapping sustained attention, visual selective attention, auditory selective attention, as well as two tasks tapping inhibition/impulsivity: delay of gratification and match-to-sample. No evidence of a curvilinear dose-response relationship emerged for any measure. CONCLUSIONS: Inattention and disinhibition/impulsivity decline with MPH treatment in children with ADHD/MR, and consistent with the Multimodal Treatment Study of ADHD, higher MPH doses are most effective. These findings also suggest that cognitive testing, together with behavioral and medical assessment, can be an effective tool in assessing stimulant response in children with ADHD/MR.

Analysis of Variance↗
PubMed2003

Sex-related ERP differences in deviance detection.

The effect of sex on neural mechanisms of auditory mismatch detection was examined using dense sensor array (128 channel) event-related potential recordings (ERPs). ERPs of 32 right-handed subjects (16 males) were recorded to frequent (85%, 880 Hz) and infrequent (15%, 1480 Hz) tones. There were no sex differences in mismatch negativity (80-180 ms), however, the fronto-central P2 (180-260 ms) was less positive in males (F=12.56, P<0.005) and the N2 (260-340 ms) was more negative in males (F=6.28, P<0.05). The increased negativity in males spanning the P2 and N2 may index a top-down process of attention bias towards novelty. This result supports the hypothesis of an adaptive, sexually dimorphic processing of novel events in humans.

Acoustic Stimulation↗
PubMed2003

Treatment effects of methylphenidate on behavioral adjustment in children with mental retardation and ADHD.

OBJECTIVE: The effects of stimulant medication treatment were investigated in children with mental retardation (MR) and attention-deficit/hyperactivity disorder (ADHD). METHOD: Parent and teacher behavioral ratings and reports of side effects were obtained for children (N = 24, mean age = 10.9 years, SD = 2.4) during a placebo-controlled, double-blind, crossover treatment trial with 0.15 mg/kg, 0.30 mg/kg, and 0.60 mg/kg b.i.d. dosages of methylphenidate. RESULTS: The most significant improvements occurred at the 0.60 mg/kg methylphenidate dose for teacher ratings of inattention (p =.024), hyperactivity (p <.001), aggression (p <.001), and asocial behavior (p =.009). No significant improvements, relative to placebo, occurred at the 0.15 mg/kg dosage. Of interest, nearly all significant medication-related behavioral improvements were detected by teachers. However, parents were sensitive raters of side effects, noting more sleeping problems and loss of appetite at the 0.60 mg/kg dose compared with placebo. CONCLUSIONS: These results suggest that symptoms of ADHD can be treated successfully in children with ADHD/MR, and consistent with MTA study results, higher doses were most effective. Furthermore, these improvements were not accompanied by increases in symptoms such as staring, social withdrawal, or anxiety.

Attention Deficit Disorder with Hyperactivity↗
PubMed2002

Quantifying practice effects in longitudinal research with the WISC-R and WAIS-R: a study of children and adolescents with hemophilia and male siblings without hemophilia.

OBJECTIVE: To quantify practice effects associated with annual administrations of WISC-R and WAIS-R in children and adolescents with and without hemophilia. METHODS: Participants were young men (age: 7-19; 80 with hemophilia, 30 siblings) enrolled in the Hemophilia Growth and Development Study. Participants with hemophilia completed age-appropriate Wechsler scales at baseline and at four annual follow-ups; the siblings, at baseline and one 2-year follow-up. Regression analyses were used to quantify average changes in scores, adjusting for variables related to test performance. RESULTS: Consecutive annual evaluations were free of significant practice effects for 4 years with the Verbal Scale and for 2 years with the Performance Scale. VIQ decreased, and PIQ increased over time. Baseline VIQ was related to changes in VIQ; baseline PIQ and number of test-specific retests were related to changes in PIQ. CONCLUSIONS: The findings support use of Wechsler scales for annual evaluations to monitor cognitive development in children and adolescents.

Adolescent↗
PubMedDate not supplied

Hemophilia Growth and Development Study: caregiver report of youth and family adjustment to HIV disease and immunologic compromise.

OBJECTIVE: To assess differences in caregiver report of youth and family psychosocial adjustment associated with HIV infection and greater immune compromise in youths with hemophilia. METHODS: Caregivers of 162 boys with hemophilia 8 to 20 years old completed three youth and family questionnaires (Personality Inventory for Children, Revised [PIC-R]; Questionnaire on Resources and Stress [QRS]; Family Environment Scale). RESULTS: Caregivers of HIV positive (HIV+) youths reported greater health concerns, social withdrawal (PIC-R), physical and adaptive limitations associated with illness (QRS) in their sons, and more pessimism about their sons' future and negative attitudes about parenting (QRS). Caregivers of HIV+ youths with greater immune compromise reported greater concerns about their sons' health and greater pessimism about their futures, as well as lower levels of family integration and more limited family opportunities. CONCLUSIONS: Results suggest caregivers perceive psychosocial problems in HIV+ youths with hemophilia and their families; some problems are specifically associated with greater immune compromise.

Adaptation, Psychological↗
PubMedDate not supplied

Accentuated Virchow-Robin spaces in the centrum semiovale in children with autistic disorder.

OBJECTIVE: The purpose of this study was to assess the incidence of abnormal Virchow-Robin (VR) spaces in children and adolescents with an autistic disorder (AD). An increased incidence of enlarged VR spaces in children has been reported in several developmental disorders. METHODS: Sixteen children and adolescents (13 male, 3 female; mean age = 143.5 months; mean IQ = 95.1) with an AD, verified by use of standardized procedures (Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule-Revised), received cranial magnetic resonance (MR) imaging. Sixteen children and adolescents (13 male, 3 female; mean age = 160.7 months; mean IQ = 111.6) without AD, as determined using the same procedures, were scanned as a comparison group. The MR scans were performed using a 1.5-T scanner. Two T1-weighted spoiled GRASS sequences (0.7-mm coronal thin-slice, 0-mm gap; 1.5-mm sagittal, 0-mm gap) and a complementary T2-weighted fast spin echo sequence (1.5-mm, 0-mm gap) were obtained. A neuroradiologist and a neurobiologist without clinical information determined the incidence of normal, accentuated, and/or dilated VR spaces. RESULTS: Seven of 16 subjects with AD (approximately 44%) had dilated VR spaces in the centrum semiovale. No grossly abnormal spaces were present in the control subjects. CONCLUSION: Unusually large VR spaces are seen in at most 22% to 27% of MR scans in children with tension headaches and other psychiatric disorders, suggesting that the incidence of spaces of this type is greater in AD than in other abnormal populations. The origin and significance of this phenomenon remain unknown.

Adolescent↗