The delineation of subspecies is important in the evaluation and protection of biodiversity. Subspecies delineation is hampered by inconsistently applied criteria and a lack of agreement and shifting standards on how a subspecies should be defined. The Australian endemic Yellow Chat () is split into three subspecies (.
View Article and Find Full Text PDFObjective: This retrospective study examined treatment adherence in Cognitive Processing Therapy (CPT) for combat-related posttraumatic stress disorder (PTSD) in Veterans of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) with and without history of mild traumatic brain injury (mTBI).
Method: Medical record review of consecutive referrals to an outpatient PTSD clinic identified veterans diagnosed with combat-related PTSD who began treatment with CPT. The sample (N = 136) was grouped according to positive (n = 44) and negative (n = 92) mTBI history.
For over 50 years, cognitive psychologists and neuropsychologists have relied almost exclusively on a method for computing semantic clustering on list-learning tasks (recall-based formula) that was derived from an outdated assumption about how learning occurs. A new procedure for computing semantic clustering (list-based formula) was developed for the CVLT-II to correct the shortcomings of the traditional method. In the present study we compared the clinical utility of the traditional recall-based method versus the new list-based method using results from the original CVLT administered to 87 patients with Alzheimer's disease and 86 matched normal control participants.
View Article and Find Full Text PDFObjective: Traumatic brain injury (TBI) is a risk associated with military duty, and residual effects from TBI may adversely affect a service member's ability to complete duties. It is, therefore, important to identify factors associated with a change in job status following TBI in an active military population. On the basis of previous research, we predicted that apolipoprotein E (APOE) genotype may be 1 factor.
View Article and Find Full Text PDFThe objective of the study is to investigate the longitudinal effects of the Houston Child Advocates, Inc., program on children's outcomes. The treatment group consisted of children in the court system that were assigned Child Advocates volunteers, and the comparison children were chosen randomly from a similar population of children.
View Article and Find Full Text PDFObjective: The association between the APOE epsilon4 allele and depression was investigated in a retrospective study of 323 AD patients.
Methods: Patients were divided into demographically comparable groups based on the presence or absence of depression.
Results: Results showed that the frequency of APOE epsilon4 allele was significantly higher in the depressed vs non-depressed AD patients (72% and 58%, respectively), and an interaction revealed that women possessing the APOE epsilon4 allele were almost four times more likely to be depressed than those without the epsilon4 allele.
Background/aims: Because of conflicting findings across studies, we sought to better determine the relationship between apolipoprotein E (APOE) genotype, hippocampal volume, and cognitive performance in nondemented older adults.
Methods: Two groups ofolder adults, as determined by their APOE epsilon4 allele status, received structural MRI and comprehensive neuropsychological testing on two occasions separated on average by 17 months.
Results: Cross-sectional comparisons by APOE group revealed no differences in hippocampal volumes, although longitudinal percent reduction in hippocampal volume was significantly greater for those possessing the APOE epsilon4 allele.
J Neurol Neurosurg Psychiatry
October 2007
Objective: Although research has implicated the apolipoprotein E (APOE) epsilon-4 genotype as having a negative effect on neuropsychological outcomes following traumatic brain injury (TBI), the potentially negative role of the epsilon4 allele on TBI outcomes has recently been challenged. In light of this debate, the present study served to examine the role of APOE genotype on neuropsychological outcomes approximately 1 month following mild to moderate TBI in a military population. Because of the well documented role of the APOE-epsilon4 allele in increasing the risk of Alzheimer's disease, we predicted that persons with the APOE-epsilon4 genotype would display relatively greater deficits in cognition than their non-epsilon4 counterparts.
View Article and Find Full Text PDFNeuropsychol Dev Cogn B Aging Neuropsychol Cogn
September 2006
Demonstrations of memory changes in those at risk for Alzheimer's disease by the presence of the APOE e4 allele have been inconsistent to date. The present study went beyond traditional analyses of central tendency (i.e.
View Article and Find Full Text PDFRecent studies have reported cognitive asymmetries in patients with Alzheimer's disease (AD) and in individuals with apolipoprotein E epsilon4 (APOE epsilon4) genotype who are in the preclinical phase of AD. This increased frequpncy of cognitive asymmetry, typically defined as a significant discrepancy (in either direction) between verbal and spatial abilities, often occurs despite an absence of differences on traditional measures of central tendency (i.e.
View Article and Find Full Text PDFPrevious studies of episodic memory report a greater extent of blood-oxygenation-level-dependent (BOLD) response in non-demented older adults with the apolipoprotein E epsilon-4 (APOE epsilon4) allele than in those without the allele. We conducted a functional MRI study to investigate whether APOE genotype is related to brain response to verbal paired-associate encoding and consolidation, particularly in the right hemisphere, among non-demented older adults. Structurally segmented volumes and BOLD response were measured in 13 non-epsilon4 and 12 epsilon4 subjects.
View Article and Find Full Text PDFPrevious studies have identified cognitive asymmetries in elderly people at increased risk for Alzheimer's disease (AD) by comparing standardized neuropsychological tests of verbal and spatial abilities in both preclinical AD and apolipoprotein epsilon4+ elderly groups. This prospective study investigated cognitive asymmetries within a single test by comparing cognitively intact elderly (with and without the epsilon4+ allele) on a learning and memory measure that uses global and local visuospatial stimuli. Both groups demonstrated comparable overall learning and recall.
View Article and Find Full Text PDFBackground: Functional magnetic resonance imaging plays a promising role in the preclinical characterization of Alzheimer disease (AD) for use in early diagnosis and in preventive drug trials.
Objective: To determine whether functional magnetic resonance imaging can reliably distinguish risk groups for AD among cognitively normal middle-aged adults.
Design: Cross-sectional case-control study.
This prospective study of nondemented older adults at genetic risk for AD and other types of dementia (i.e., APOE e4 allele) utilized a new Stroop test that includes a dual executive-function condition requiring both response inhibition and cognitive switching.
View Article and Find Full Text PDFObjective: To determine whether APOE genotype influences brain response and whether nonverbal stimuli generate findings comparable with those of previous studies that used verbal stimuli. The relationship between APOE genotype and blood oxygenation level dependent (BOLD) brain response was examined during a picture-encoding task in nondemented older adults.
Methods: Twenty nondemented participants with normal episodic memory function were divided into two groups based on the presence (n = 10) or absence (n = 10) of the APOE epsilon4 allele.
The profiles of neuropsychological deficits associated with Alzheimer's disease (AD) in Young-Old (M age and 70) and Very-Old (M age > 80) patients were compared, along with possible modifying effects of apolipoprotein E (APOE) genotype on these profiles. A comprehensive battery of neuropsychological tests was administered to the two AD patient groups (Young-Old: n = 33; Very-Old: n = 48) and their respective age-matched normal control (NC) groups who remained free of dementia on follow-up examinations over a 1 to 10 year period (Young-Old: n = 43; Very-Old: n = 36). AD and NC groups did not differ in education levels or gender distributions.
View Article and Find Full Text PDFA phase 1, randomized, double-blind, placebo-controlled, dose escalation study of the purine derivative, AIT-082 (Neotrofin, NeoTherapeutics) was conducted in mild Alzheimer's disease (AD) patients to evaluate multiple-dose safety, tolerability, and pharmacokinetics. Possible short-term effects of AIT-082 on cognition and memory were preliminarily investigated. AIT-082 is currently being developed as a potential treatment for Alzheimer's disease and other neurological disorders.
View Article and Find Full Text PDFThe loss of color vision secondary to central nervous system disease (achromatopsia) is thought to preclude visual imagery of colors. We report a patient with achromatopsia, secondary to bilateral temporo-occipital infarcts inclusive of the lingual and fusiform gyri, with preserved color imagery. Our findings, in conjunction with previous cases in the literature, are consistent with a single neural network for color processing in which a disconnection of internal activation from stored color representations produces impaired color imagery with preserved color perception, whereas a disconnection of visual input to these representations produces achromatopsia with preserved color imagery.
View Article and Find Full Text PDFWe investigated the effects of faking bad on the Wisconsin Card Sorting Test, comparing the performance of simulating malingerers (M; n = 24) to controls (C; n = 21), closed head-injured patients (CHI, n = 70), and patients with mixed CNS pathology other than CHI alone (CNS; n = 89). Stepwise discriminant functions achieved good accuracy (91-96%), sensitivity (58-100%), and specificity (92-100%) in differentiating simulating malingerers from these groups. The Categories score was a consistent significant independent discriminating variable.
View Article and Find Full Text PDFAccording to the traditional model of language organization, repetition deficits arise following damage to the arcuate fasciculus of the dominant hemisphere (conduction aphasia). Conduction aphasia may result from lesions that spare the arcuate fasciculus. However, these patients have atypical language organization.
View Article and Find Full Text PDFArch Clin Neuropsychol
November 1993
We tested the hypothesis that malingering is distinguished by poorer performance on recognition relative to recall tasks by evaluating the ability of discriminant functions to distinguish between 89 subjects simulating malingering and 44 subjects with a history of closed head injury (CHI) on the Wechsler Memory Scale - Revised (WMS-R). Functions with good accuracy in discriminating between simulated malingerers and controls in prior studies did not have adequate specificity when applied to the CHI group. A newly derived discriminant function achieved overall classification accuracy of 79% for the malingering versus CHI groups on cross-validation, with 79% sensitivity (true positives for malingering) and 80% specificity (true negatives for closed head injured).
View Article and Find Full Text PDFCleft Palate Craniofac J
March 1993
The study models of a group of adult Sri Lankan patients with clefts of the secondary palate were investigated. Tooth-size and arch-dimension comparisons were made with a comparable control group. Significant differences were found between the cleft and control groups in tooth sizes, chord lengths, and arch widths.
View Article and Find Full Text PDFJ Clin Psychol
January 1993
We evaluated five potential indicators of malingering on the Rey Memory Test (RMT), Hebb's Recurring Digits (HRD), the Wechsler Memory Scale-Revised (WMS-R), the Complex Figure Test (CFT), and the Auditory Verbal Learning Test (AVLT). Fifty-seven subjects were assigned randomly to either a control group or a simulated malingering group. Two indicators-discriminant functions derived from the WMS-R and from the CFT/AVLT-achieved classification accuracy of 88% and 86%, respectively, without misidentifying controls as malingerers.
View Article and Find Full Text PDFIonic concentrations of potassium, sodium, and chloride were determined in osteocytes of the rat calvarium. The values were determined by fluorescent microscopy of both intra- and extracellular concentrations. Following the baseline determination, the calvaria were placed in tension by retraction of a microelectrode manipulator, and the fluorescence of the cells were measured again.
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