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Midlife measurements of white matter microstructure predict subsequent regional white matter atrophy in healthy adults
Human Brain Mapping, in press
Abstract
... [read more]
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Calorie restriction attenuates astrogliosis but not amyloid plaque load in aged rhesus macaques: a preliminary quantitative imaging study
Brain Research, In press
Abstract
While moderate calorie restriction (CR) in the absence of malnutrition has been consistently shown to have a systemic, beneficial effect against aging in several animals models, its effect on the brain microstructure in a non-human primate model remains to be studied using post-mortem histopathologic techniques. In the present study, we investigated differences in expression levels of glial fibrillary acid protein (GFAP) and β-amyloid plaque load in the hippocampus and the adjacent cortical areas of 7 Control (ad libitum)-fed and 6 CR male rhesus macaques using immunostaining methods... [read more]
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Interleukin-8 and interleukin-10, brain volume and microstructure, and the influence of calorie restriction in old rhesus macaques
AGE, in press
Abstract
Higher systemic levels of the proinflammatory cytokine interleukin-6 (IL-6) were found to be associated with lower gray matter volume and tissue density in old rhesus macaques. This association between IL-6, and these brain indices were attenuated by long-term 30 % calorie restriction (CR)... [read more]
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Cerebral blood flow is diminished in asymptomatic middle-aged adults with maternal history of Alzheimer’s disease
Cerebral Cortex. In Press, Nov 2012
Abstract
Cerebral blood flow (CBF) provides an indication of the metabolic status of the cortex and may have utility in understanding preclinical brain changes in persons at risk for Alzheimer’s disease (AD) and related diseases. In this study, we investigated CBF in 327 well-characterized adults including patients with AD (n=28), patients with amnestic mild cognitive impairment (aMCI, n=23), older cognitively-normal adults (OCN, n=24), and asymptomatic middle-aged adults (n=252) with and without family history (FH) of AD... [read more]
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Low cerebral blood flow is associated with lower memory function in metabolic syndrome.
Obesity. Accepted Article Nov, 2012
Abstract
Background: Metabolic syndrome (MetS)—a cluster of cardiovascular risk factors—is linked with cognitive decline and dementia. However, the brain changes underlying this link are presently unknown... [read more]
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Neural correlates of behavioral variation in healthy adults’ antisaccade performance
Psychophysiology 2013 (In Press)
Abstract
Cognitive control is required for correct antisaccade performance. High antisaccade error rates characterize certain psychiatric disorders, but can be highly variable, even among healthy groups... [read more]
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Q-MKL: Matrix-induced Regularization in Multi-Kernel Learning with Applications to Neuroimaging
NIPS 2012
Abstract
Multiple Kernel Learning (MKL) generalizes SVMs to the setting where one simultaneously trains a linear classifier and chooses an optimal combination of given base kernels. Model complexity is typ- ically controlled using various norm regularizations on the base kernel mixing coefficients... [read more]
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White matter microstructural integrity and executive function in Parkinson’s disease
in press; Journal of the International Neuropsychological Society
Abstract
... [read more]
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Wavelet based multi-scale shape features on arbitrary surfaces for cortical thickness discrimination
NIPS (In Press)
Abstract
Hypothesis testing on signals defined on surfaces (such as the cortical surface) is a fundamental component of a variety of studies in Neuroscience. The goal here is to identify regions that exhibit changes as a function of the clinical condition under study... [read more]
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Brain volumetric and microstructural correlates of executive and motor performance in aged rhesus monkeys
Frontiers in Neuroscience, 4:31; Nov 2012
Abstract
The aged rhesus macaque exhibits brain atrophy and behavioral deficits similar to normal aging in humans. Here we studied the association between cognitive and motor performance and anatomic and microstructural brain integrity measured with 3T magnetic resonance imaging in aged monkeys... [read more]
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Insulin resistance, brain atrophy, and cognitive performance in late middle-aged adults
Diabetes Care, in press
Abstract
Objective: Insulin resistance dysregulates glucose uptake and other functions in brain areas affected by Alzheimer’s disease. Insulin resistance may play a role in Alzheimer’s disease etiopathogenesis... [read more]
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Evidence from cluster analysis for differentiation of antisaccade performance groups based on speed/accuracy trade-offs
International Journal of Psychophysiology 2012;85(2):274-277.
Abstract
Anti and pro-saccade performance in single or mixed contexts was explored in a large sample of young adults (n=281). ANOVAs were first conducted to evaluate trial type, context and gender effects... [read more]
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Longitudinal diffusion tensor imaging and neuropsychological correlates in traumatic brain injury patients
Frontiers in Humans Neuroscience, 2012, Vol 6; 160
Abstract
Traumatic brain injury often involves focal cortical injury and white matter (WM) damage that can be measured shortly after injury. Additionally, slowly evolving WM change can be observed but there is a paucity of research on the duration and spatial pattern of long-term changes several years post-injury... [read more]
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Longitudinal volumetric changes following traumatic brain injury: A tensor based morphometry study
Journal of the International Neuropsychological Society
Abstract
After traumatic injury the brain undergoes a prolonged period of degenerative change that is paradoxically accompanied by cognitive recovery. The spatiotemporal pattern of atrophy and the specific relationships of atrophy to cognitive changes are ill understood... [read more]
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Current status and future perspectives of magnetic resonance high-field imaging: a summary
Neuroimaging Clinics of North America 2012;22(2):373-397.
Abstract
There are several magnetic resonance (MR) imaging techniques that benefit from high-field MR imaging. This article describes a range of novel techniques that are currently being used clinically or will be used in the future for clinical purposes as they gain popularity... [read more]
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Head size may modify the impact of white matter lesions on dementia
Neurobiology of Aging 2012 Jul;33(7):1186-93
Abstract
We aimed to examine whether total intracranial volume (TICV), a marker of premorbid brain size, modified the impact of the apolipoprotein E (apoE) e4 phenotype and ischemic white matter lesions (WMLs) on odds for dementia. The study comprised a population-based sample of 104 demented and 135 nondemented 85-year-olds, and included physical and neuropsychiatric examinations, and head computerized tomography (CT)... [read more]
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Practice-related changes in neural activation patterns investigated via wavelet-based clustering analysis
Human Brain Mapping 2012; doi:10.1002/hbm.22066.
Abstract
Objectives: To evaluate brain activation using functional magnetic resonance imaging (fMRI) and specifically, activation changes across time associated with practice-related cognitive control during eye movement tasks. Experimental design: Participants were engaged in antisaccade performance (generating a glance away from a cue) while fMR images were acquired during two separate test sessions: (1) at pre-test before any exposure to the task and (2) at post-test, after 1 week of daily practice on antisaccades, prosaccades (glancing toward a target), or fixation (maintaining gaze on a target)... [read more]
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A generalized form of context-dependent psychophysiological interactions (gPPI): A comparison to standard approaches
NeuroImage, 2012 Jul 16;61(4):1277-1286
Abstract
Functional MRI (fMRI) allows one to study task-related regional responses and task-dependent connectivity analysis using psychophysiological interaction (PPI) methods. The latter affords the additional opportunity to understand how brain regions interact in a task-dependent manner... [read more]
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Family history of Alzheimer disease predicts hippocampal atrophy in healthy middle-aged adults
Neurology, 2012 May 29;78(22):1769-76
Abstract
Objective: To evaluate the longitudinal influence of family history (FH) of Alzheimer disease (AD) and apolipoprotein E4 (APOE4) on brain atrophy and cognitive decline over 4 years among asymptomatic middle-aged individuals. Methods: Participants were cognitively-healthy adults with (FH+,n=60) and without (FH-,n=48) FH of AD (mean age at baseline=54 years) enrolled in the Wisconsin Registry for Alzheimer's Prevention... [read more]
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Calorie restriction reduces the influence of glucoregulatory dysfunction on regional brain volume in aged rhesus monkeys
Diabetes, 2012 May;61(5):1036-42
Abstract
Insulin signaling dysregulation is related to neural atrophy in hippocampus and other areas affected by neurovascular and neurodegenerative disorders. It is not known if long-term calorie restriction (CR) can ameliorate this relationship through improved insulin signaling, or if such an effect might influence task learning and performance... [read more]
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Medial Prefrontal Functional Connectivity - Relation to Memory Self-appraisal Accuracy in Older Adults with and without Memory Disorders
Neuropsychologia, 2012 Apr;50(5):603-11
Abstract
It is tentatively estimated that 25% of people with early Alzheimer's disease (AD) show impaired awareness of disease-related changes in their own cognition. Research examining both normative self-awareness and altered awareness resulting from brain disease or injury points to the central role of the medial prefrontal cortex (MPFC) in generating accurate self-appraisals... [read more]
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MKL-based sample enrichment and customized outcomes enable smaller AD clinical trials
Lecture Notes in Artificial Intelligence (LNAI), in press
Abstract
Recently, the field of neuroimaging analysis has seen a large number of studies which use machine learning methods to make predictions about the progression of Alzheimer's Disease (AD) in mildly demented subjects. Among these, Multi-Kernel Learning (MKL) has emerged as a powerful tool for systematically aggregating diverse data views, and several groups have shown that MKL is uniquely suited to combining different imaging modalities into a single learned model... [read more]
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CSF T-Tau/Aβ(42) Predicts White Matter Microstructure in Healthy Adults at Risk for Alzheimer's Disease
PLoS One. 2012; 7(6)
Abstract
Cerebrospinal fluid (CSF) biomarkers T-Tau and Aβ(42) are linked with Alzheimer's disease (AD), yet little is known about the relationship between CSF biomarkers and structural brain alteration in healthy adults. In this study we examined the extent to which AD biomarkers measured in CSF predict brain microstructure indexed by diffusion tensor imaging (DTI) and volume indexed by T1-weighted imaging... [read more]
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The Effects of Ramipril in Individuals at Risk for Alzheimer's Disease: Results of a Pilot Clinical Trial
J Alzheimers Dis
Abstract
... [read more]
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Effects of Atorvastatin on Cerebral Blood Flow in Middle-Aged Adults at Risk for Alzheimer's Disease: A Pilot Study
Current Alzheimer research, in press
Abstract
Background/Aims: Hypercholesterolemia in midlife increases risk for Alzheimer's disease (AD) and contributes to cerebrovascular dysregulation - an early finding in preclinical AD pathology. Statins improve vascular reactivity, but it is unknown if they increase regional cerebral blood flow (CBF) in individuals at risk for AD... [read more]
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Capacity-speed relationships in prefrontal cortex
PLoS ONE 2011;6(11):e27504.
Abstract
Working memory (WM) capacity and WM processing speed are simple cognitive measures that underlie human performance in complex processes such as reasoning and language comprehension. These cognitive measures have shown to be interrelated in behavioral studies, yet the neural mechanism behind this interdependence has not been elucidated... [read more]
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Topology based Kernels with Application to Inference Problems in Alzheimer’s disease
IEEE Transaction on Medical Imaging. 2011 Oct;30(10):1760-70
Abstract
Alzheimer’s disease (AD) research has recently witnessed a great deal of activity focused on developing new statistical learning tools for automated inference using imaging data. The workhorse for many of these techniques is the Support Vector Machine (SVM) framework (or more generally kernel based methods)... [read more]
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Rate of 6-[18F]fluoro-L-dopa uptake decline in striatal subregions in Parkinson’s disease
Movement Disorders; March, 2011, 26(4): 614-20.
Abstract
Using both a volume of interest (VOI) and whole brain voxel-wise approach, we compared rates of decline of 6-L-[18F]-fluorodopa (FDOPA) positron emission tomography (PET) uptake ipsilateral (IL) and contralateral (CL) to the initially symptomatic limbs over 4.5 years in 26 subjects with Parkinson’s disease (PD) and 11 controls. The VOI approach used six subregions: Head/body of caudate nucleus, whole putamen, and posterior putamen... [read more]
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Predictive Markers for AD in a Multi-Modality Framework: An Analysis of MCI Progression in the ADNI Population
NeuroImage 2011 Mar 15;55(2):574-89. Epub 2010 Dec 10
Abstract
Alzheimer's Disease (AD) and other neurodegenerative diseases affect over 20 million people worldwide, and this number is projected to significantly increase in the coming decades. Proposed imaging-based markers have shown steadily improving levels of sensitivity/specificity in classifying individual subjects as AD or normal... [read more]
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The Effect of TOMM40 Poly-T length on Gray Matter Volume and Cognition in Middle-Aged Persons with APOE ε3/ε3 Genotype
Alzheimers and Dementia 7, 456-465
Abstract
Objective: Apolipoprotein E (APOE) genotypes are associated with variable risk of developing late onset Alzheimer’s disease (LOAD), with APOE ε4 having higher risk. A variable poly-T length polymorphism at rs10524523, within intron 6 of the TOMM40 gene has been shown to influence age of onset in LOAD, with very long poly-T length associated with earlier disease onset, and short poly-T length associated with later onset... [read more]
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A within-subject comparison of 6-[18F]Fluoro-m-tyrosine and 6-[18F]Fluoro-L-dopa in Parkinson’s disease
Movement Disorders (in press)
Abstract
Background: Progression of Parkinson’s disease (PD) clinical symptoms is imperfectly correlated with positron emission tomography biomarkers for dopamine biosynthetic pathways. The radiopharmaceutical 6-[18F]Fluoro-m-tyrosine is not a substrate for catechol-O-methyltransferase, and therefore has a more favorable uptake to background ratio than 6-[18F]Fluoro-L-dopa... [read more]
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Effects of Hypoperfusion in Alzheimer's Disease
Advances in Alzheimer's Disease, Handbook of Imaging the Alzheimer Brain. 2011;2:253-63.
Abstract
The role of hypoperfusion in Alzheimer's disease (AD) is a vital component to understanding the pathogenesis of this disease. Disrupted perfusion is not only evident throughout disease manifestation, it is also demonstrated during the pre-clinical phase of AD (i.e., mild cognitive impairment) as well as in cognitively healthy persons at high-risk for developing AD due to family history or genetic factors... [read more]
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A longitudinal study of motor performance and striatal [18F]fluorodopa uptake in Parkinson's disease
Brain Imaging and Behavior (in press)
Abstract
Although [18F]fluoro-L-dopa [FDOPA] positron emission tomography (PET) has been used as a surrogate outcome measure in Parkinson’s disease therapeutic trials, this biomarker has not been proven to reflect clinical status longitudinally. We completed a retrospective analysis of relationships between computerized sampling of motor performance, FDOPA PET, and clinical outcome scales, repeated over 4 years, in 26 Parkinson’s disease (PD) patients and 11 healthy controls... [read more]
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Effects of Hypoperfusion in Alzheimer's Disease
J Alzheimers Dis. 2011;26 Suppl 3:123-33
Abstract
The role of hypoperfusion in Alzheimer's disease (AD) is a vital component to understanding the pathogenesis of this disease. Disrupted perfusion is not only evident throughout disease manifestation, it is also demonstrated during the pre-clinical phase of AD (i.e., mild cognitive impairment) as well as in cognitively healthy persons at high-risk for developing AD due to family history or genetic factors... [read more]
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Functional Magnetic Resonance Imaging of Swallowing: From Neurophysiology to Neuroplasticity
Head Neck. 2011 Oct;33 Suppl 1:S14-20.
Abstract
Swallowing is a complex neurogenic sensorimotor process involving all levels of the neuraxis and a vast number of muscles and anatomic structures. Disruption of any of these anatomic or functional components can lead to swallowing disorders (also known as dysphagia)... [read more]
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Swallowing Intentional off-state in aging and Alzheimer’s Disease: A preliminary study
Journal of Alzheimer’s Disease (epub ahead of print Jun 7, 2011)
Abstract
... [read more]
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Calorie restriction reduces psychological stress reactivity and its association with brain volume and microstructure in aged rhesus monkeys
Psychoneuroendocrinology, In Press
Abstract
Background: Heightened stress reactivity is associated with hippocampal atrophy, age-related cognitive deficits, and increased risk for Alzheimer’s disease. This temperament predisposition may aggravate age-associated brain pathology or be reflective of it... [read more]
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Mapping the structural brain changes in Alzheimer's disease: the independent contribution of two imaging modalities
Abstract
The macrostructural atrophy of Alzheimer's disease (AD) has been fully described. Current literature reports that also microstructural alterations occur in AD since the early stages... [read more]
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NSAIDs may protect against age-related brain atrophy
Front Aging Neurosci. 2010 Sep 3;2. pii: 35.
Abstract
The use of non-steroidal anti-inflammatory drugs (NSAIDs) in humans is associated with brain differences including decreased number of activated microglia. In animals, NSAIDs are associated with reduced microglia, decreased amyloid burden, and neuronal preservation... [read more]
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White matter is altered with parental family history of Alzheimer’s disease
Alzheimers Dement. 2010 Sep;6(5):394-403. Epub 2010 Aug 14.
Abstract
Background: Brain alterations in structure and function have been identified in people with risk factors for sporadic type Alzheimer’s disease (AD), suggesting that alterations can be detected decades before AD diagnosis. While the effect of Apolipoprotein E (ApoE) ε4 on the brain is well studied, less is known about the effect of family history of AD... [read more]
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Homocysteine, neural atrophy, and the effect of caloric restriction in rhesus monkeys
Neurobiol Aging. epub August 2010. In Press.
Abstract
Higher serum homocysteine (Hcy) levels in humans are associated with vascular pathology and greater risk for dementia, as well as lower global and regional volumes in frontal lobe and hippocampus. Calorie restriction (CR) in rhesus monkeys (Macaca mulatta) may confer neural protection against age- or Hcy-related vascular pathology... [read more]
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Low HDL cholesterol is associated with lower gray matter volume in cognitively healthy adults
Frontiers in Aging Neuroscience (2010). July 15, 2
Abstract
Dyslipidemia is common in adults and contributes to high rates of cardiovascular disease and may be linked to subsequent neurodegenerative and neurovascular diseases. This study examined whether lower brain volumes and cognition associated with dyslipidemia could be observed in cognitively healthy adults, and whether apolipoprotein E (APOE) genotype or family history of Alzheimer's disease (FHAD) alters this effect... [read more]
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Age-related changes in neural volume and microstructure associated with interleukin-6 are ameliorated by a calorie-restricted diet in old rhesus monkeys
Neuroimage. 2010 Jul 1;51(3):987-94. Epub 2010 Mar 15.
Abstract
Systemic levels of proinflammatory cytokines such as interleukin-6 (IL-6) increase in old age and may contribute to neural atrophy in humans. We investigated IL-6 associations with age in T1-weighted segments and microstructural diffusion indices using MRI in aged rhesus monkeys (Macaca mulatta)... [read more]
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Effects of aging and calorie restriction on white matter in rhesus macaques.
Neurobiol Aging. Epub ahead of print: 2010 Jun 10
Abstract
Rhesus macaques on a calorie restricted diet (CR) develop less age-related disease, have virtually no indication of diabetes, are protected against sarcopenia, and potentially live longer. Beneficial effects of caloric restriction likely include reductions in age-related inflammation and oxidative damage... [read more]
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A Calorie-Restricted Diet Decreases Brain Iron Accumulation and Preserves Motor Performance in Old Rhesus Monkeys
Journal of Neuroscience. 2010, 30(23):7940-7947
Abstract
Caloric restriction (CR) reduces the pathological effects of aging and extends the lifespan in many species, including nonhuman primates, although the effect on the brain is less well characterized. We used two common indicators of aging, motor performance speed and brain iron deposition measured in vivo using MRI, to determine the potential effect of CR on elderly rhesus macaques eating restricted (n = 24; 13 males, 11 females) and standard diets (n = 17; 8 males, 9 females)... [read more]
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White Matter in Aging and Cognition: A Cross-sectional Study of Microstructure in Adults Aged Eighteen to Eighty-Three
Dev Neuropsychol. 2010 May;35(3):257-77.
Abstract
Structural brain change and concomitant cognitive decline are the seemingly unavoidable escorts of aging. Despite accumulating studies detailing the effects of age on the brain and cognition, the relationship between white matter features and cognitive function in aging have only recently received attention and remain incompletely understood... [read more]
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Developing a national strategy to prevent dementia: Leon Thal Symposium 2009
Alzheimers Dement, Mar;6(2):89-97
Abstract
Among the major impediments to the design of clinical trials for the prevention of Alzheimer's disease (AD), the most critical is the lack of validated biomarkers, assessment tools, and algorithms that would facilitate identification of asymptomatic individuals with elevated risk who might be recruited as study volunteers. Thus, the Leon Thal Symposium 2009 (LTS'09), on October 27-28, 2009 in Las Vegas, Nevada, was convened to explore strategies to surmount the barriers in designing a multisite, comparative study to evaluate and validate various approaches for detecting and selecting asymptomatic people at risk for cognitive disorders/dementia... [read more]
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Rhesus Macaque Brain Morphometry: A Methodological Comparison of Voxel-Wise Approaches
Methods. 2010 Mar;50(3):157-65
Abstract
Voxel-based morphometry studies have become increasingly common in human neuroimaging over the past several years; however, few studies have utilized this method to study morphometry changes in non-human primates. Here we describe the application of voxel-wise morphometry methods to the rhesus macaque (Macaca mulatta) using the 112RM-SL template and priors (McLaren et al... [read more]
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Reliability and Precision of Pseudo-continuous Arterial Spin Labeling Perfusion MRI on 3.0 T and Comparison with 15O-water PET in Elderly Subjects at Risk for Alzheimer’s Disease
NMR in Biomedicine. 2010 Apr;23(3):286-93.
Abstract
Arterial spin labeling (ASL) offers MRI measurement of cerebral blood flow (CBF) in vivo, and may offer clinical diagnostic utility in populations such as those with early Alzheimer’s Disease (AD). In the current study, we investigated the reliability and precision of a pseudo-continuous ASL (pcASL) sequence that was performed two or three times within one hour on eight young normal control subjects, and 14 elderly subjects including 11 with normal cognition, 1 with AD and 2 with Mild Cognitive Impairment (MCI)... [read more]
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Microstructural diffusion changes are independent of macrostructural volume loss in moderate to severe Alzheimer’s disease
J Alzheimers Dis. 2010;19(3):963-76.
Abstract
Although it is established that Alzheimer’s disease (AD) leads to cerebral macrostructural atrophy, microstructural diffusion changes have also been observed, but it is not yet known whether these changes offer unique information about the disease pathology. Thus, a multi-modal imaging study was conducted to determine the independent contribution of each modality in moderate to severe AD... [read more]
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Awareness of memory abilities in community-dwelling older adults with suspected dementia and mild cognitive impairment
Dement Geriatr Cogn Disord. 2010;30(1):83-92
Abstract
AIMS: To examine awareness of memory abilities by groups (healthy control, suspected dementia/mild cognitive impairment, MCI, and diagnosed dementia/MCI), and to describe group differences in the relationship between awareness and cognitive performance in a community sample. METHODS: In a cross-sectional design, 183 subjects were evaluated in a community setting and categorized into 3 groups based on their cognitive performance and reported medical history. Awareness of memory abilities was quantified using a published anosognosia ratio (AR) comparing the estimated to the objective memory performance by subjects... [read more]
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Midlife predictors of Alzheimer's disease
Maturitas. Epub ahead of print, 2009 Dec 29.
Abstract
Factors contributing to increased risk for Alzheimer's disease (AD) include age, sex, genes, and family history of AD. Several risk factors for AD are endogenous; however, accumulating evidence implicates modifiable risk factors in the pathogenesis of AD... [read more]
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Caloric Restriction Delays Disease Onset and Mortality in Rhesus Monkeys
Science 10 July 2009: Vol. 325. no. 5937, pp. 201 - 204 DOI: 10.1126/science.1173635
Abstract
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research... [read more]
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Spatially augmented LPboosting for AD classification with evaluations on the ADNI dataset
Neuroimage. 2009 May 27.
Abstract
Structural and functional brain images are playing an important role in helping us understand the changes associated with neurological disorders such as Alzheimer's disease (AD). Recent efforts have now started investigating their utility for diagnosis purposes... [read more]
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Anti-inflammatory drugs reduce age-related decreases in brain volume in cognitively normal older adults
Neurobiol Aging. 2009 Apr 20. [Epub ahead of print]
Abstract
Previous studies have indicated a decreased risk for developing Alzheimer's disease in anti-inflammatory (AI) drug users. Yet few studies have determined whether AI drug use provides a protective effect against normal age-related changes in the brains of older adults... [read more]
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Posterior Cingulate and Lateral Parietal Gray Matter Volume in Older Adults with Depressive Symptoms
Brain Imaging Behav. 2009 Sep;3(3):233-239. Epub 2009 Apr 15.
Abstract
Depressive symptoms occurring late in life are an important risk factor for Alzheimer’s disease. The latest research finds that onset of depressive symptoms in late life may herald the development of AD, not only for aMCI patients, but also for cognitively-normal older adults... [read more]
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A population-average MRI-based atlas collection of the rhesus macaque
Neuroimage. 2009 Mar 1;45(1):52-9. Epub 2008 Nov 14.
Abstract
Magnetic resonance imaging (MRI) studies of non-human primates are becoming increasingly common; however, the well-developed voxel-based methodologies used in human studies are not readily applied to non-human primates. In the present study, we create a population-average MRI-based atlas collection for the rhesus macaque (Macaca mulatta) that can be used with common brain mapping packages such as SPM or FSL... [read more]
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Neurophysiology of swallowing: effects of age and bolus type
Neuroimage. 2009 Feb 1;44(3):982-91. Epub 2008 Oct 28.
Abstract
This study examined age-related changes in swallowing from an integrated biomechanical and functional imaging perspective in order to more comprehensively characterize changes in swallowing associated with age. We examined swallowing-related fMRI brain activity and videoflouroscopic biomechanics of three bolus types (saliva, water and barium) in 12 young and 11 older adults... [read more]
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The influence of parental history of Alzheimer's disease and apolipoprotein E epsilon4 on the BOLD signal during recognition memory
Brain. 2009 Feb;132(Pt 2):383-91. Epub 2008 Oct 1.
Abstract
First-degree family history (FH) of sporadic Alzheimer's disease and the apolipoprotein E epsilon4 allele (APOE4) are risk factors for Alzheimer's disease that may affect brain function prior to onset of clinical symptoms. In this functional MRI (fMRI) study, we used an episodic recognition task that required discrimination of previously viewed (PV) and novel (NV) faces to examine differences in blood oxygen level dependent (BOLD) signal due to risk factors in 74 middle-aged cognitively normal individuals... [read more]
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A preliminary study of the safety, feasibility and cognitive efficacy of soy isoflavone supplements in older men and women
Age Ageing. 2009 Jan;38(1):86-93. Epub 2008 Dec 2.
Abstract
BACKGROUND: a small number of reports exist on the cognitive effects of soy isoflavones, the findings from which are mixed. Isoflavone efficacy is dependent upon conversion of glycosides contained in soy foods and supplements to the biologically active aglycons... [read more]
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Longitudinal changes in patients with traumatic brain injury assessed with diffusion-tensor and volumetric imaging
Neuroimage. 2008 Aug 15;42(2):503-14. Epub 2008 May 7.
Abstract
Traumatic brain injury (TBI) is associated with brain volume loss, but there is little information on the regional gray matter (GM) and white matter (WM) changes that contribute to overall loss. Since axonal injury is a common occurrence in TBI, imaging methods that are sensitive to WM damage such as diffusion-tensor imaging (DTI) may be useful for characterizing microstructural brain injury contributing to regional WM loss in TBI... [read more]
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Effect of parental family history of Alzheimer's disease on serial position profiles
Alzheimers Dement. 2008 Jul;4(4):285-90.
Abstract
BACKGROUND: An exaggerated recency effect (ie, disproportionate recall of last-presented items) has been consistently observed in the word list learning of patients with Alzheimer's disease (AD). Our study sought to determine whether there were similar alterations in serial position learning among asymptomatic persons at risk for AD as a result of parental family history... [read more]
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Atorvastatin Therapy is Associated with Greater and Faster Cerebral Hemodynamic Response
Brain Imaging and Behavior. vol. 2, no. 2, pp. 94-104. June, 2008.
Abstract
Hypercholesterolemia in midlife increases the risk of subsequent cognitive decline, neurovascular disease, and Alzheimer’s disease (AD), and statin use is associated with reduced prevalence of these outcomes. While statins improve vasoreactivity in peripheral arteries and large cerebral arteries, little is known about the effects of statins on cerebral hemodynamic responses and cognition in healthy asymptomatic adults... [read more]
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Magnetic resonance imaging characterization of brain structure and function in mild cognitive impairment: a review
J Am Geriatr Soc. 2008 May;56(5):920-34. Epub 2008 Apr 9.
Abstract
Given the predicted increase in prevalence of Alzheimer's disease (AD) in the coming decades, early detection and intervention in persons with the predementia condition known as mild cognitive impairment (MCI) is of paramount importance. Recent years have seen remarkable advances in the application of neuroimaging and other biomarkers to the study of MCI... [read more]
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Hippocampal volume change in the Alzheimer Disease Cholesterol-Lowering Treatment trial
Cleve Clin J Med. 2008 Mar;75 Suppl 2:S87-93.
Abstract
Numerous clinical studies suggest a link between elevated cholesterol and increased risk of Alzheimer disease (AD), and the preponderance of data suggests that statin therapy may reduce the risk of AD later in life. The first clinical investigation of statin therapy in patients with AD, the AD Cholesterol-Lowering Treatment (ADCLT) trial, found that atorvastatin 80 mg/day was associated with improvements relative to placebo on some, but not all, cognitive measures after 6 months and 1 year of therapy... [read more]
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Effects of simvastatin on cerebrospinal fluid biomarkers and cognition in middle-aged adults at risk for Alzheimer's disease
J Alzheimers Dis. 2008 Mar;13(2):187-97.
Abstract
BACKGROUND: Statins reduce amyloid-beta (Abeta) levels in the brain and cerebrospinal fluid (CSF) in animals and may thereby favorably alter the pathobiology of AD. It is unclear if statins modify Abeta metabolism or improve cognition in asymptomatic middle-aged adults at increased risk for AD... [read more]
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Associative learning over trials activates the hippocampus in healthy elderly but not mild cognitive impairment
Neuropsychol Dev Cogn B Aging Neuropsychol Cogn. 2008 Mar;15(2):129-45.
Abstract
The ability to form associations between choice alternatives and their contingent outcomes is an important aspect of learning that may be sensitive to hippocampal dysfunction in memory disorders of aging such as amnestic mild cognitive impairment (MCIa), or early Alzheimer disease. In this preliminary study we examined brain activation using functional magnetic resonance imaging (fMRI) in 12 healthy elderly participants and nine patients with MCIa during an associative learning task... [read more]
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fMRI activation during episodic encoding and metacognitive appraisal across the lifespan: risk factors for Alzheimer's disease
Neuropsychologia. 2008;46(6):1667-78. Epub 2007 Dec 17.
Abstract
In the present study, we used fMRI to examine the influence of age on two other known risk factors for Alzheimer's disease (AD), APOE genotype and parental history of AD (FH status), during episodic encoding (ENC) and metacognitive self-appraisal (SA) paradigms. These paradigms have previously been shown to evoke activity from brain regions that are implicated in AD... [read more]
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Brain mapping in cognitive disorders: a multidisciplinary approach to learning the tools and applications of functional neuroimaging
BMC Med Educ. 2007 Oct 22;7:39.
Abstract
BACKGROUND: With rapid advances in functional imaging methods, human studies that feature functional neuroimaging techniques are increasing exponentially and have opened a vast arena of new possibilities for understanding brain function and improving the care of patients with cognitive disorders in the clinical setting. There is a growing need for medical centers to offer clinically relevant functional neuroimaging courses that emphasize the multifaceted and multidisciplinary nature of this field... [read more]
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Effect of Alzheimer disease risk on brain function during self-appraisal in healthy middle-aged adults
Arch Gen Psychiatry. 2007 Oct;64(10):1163-71.
Abstract
CONTEXT: Asymptomatic middle-aged adult children of patients with Alzheimer disease (AD) recently were found to exhibit functional magnetic resonance imaging (fMRI) deficits in the mesial temporal lobe during an encoding task. Whether this effect will be observed on other fMRI tasks is yet unknown... [read more]
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Anosognosia in mild cognitive impairment: Relationship to activation of cortical midline structures involved in self-appraisal
J Int Neuropsychol Soc. 2007 May;13(3):450-61.
Abstract
Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer's disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI... [read more]
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Longitudinal changes in global brain volume between 79 and 409 days after traumatic brain injury: relationship with duration of coma
J Neurotrauma. 2007 May;24(5):766-71.
Abstract
Neuropathological and experimental animal studies indicate that traumatic brain injury (TBI) results in long-term, neurodegenerative changes. Structural image evaluation using normalization of atrophy (SIENA) offers an automated analysis of the subtle changes in percent brain volume change (%BVC) associated with TBI... [read more]
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The Relationship Between Gray Matter Morphometry and Neuropsychological Performance in a Large Sample of Cognitively Healthy Adults.
Brain Imaging Behav. 2007;1(1-2):3-10.
Abstract
Voxel-based morphometry (VBM) was used to examine the relationship between gray matter (GM) volume and performance on two commonly used clinical neuropsychological measures of frontal lobe or executive function, the Trail Making Test part B (TrailsB) and the Controlled Oral Word Association Test (COWAT) in 221 cognitively healthy adults between the ages of 18 and 84. We hypothesized that these measures would be associated with GM volume in the dorsolateral frontal lobes... [read more]
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Relevance to self: A brief review and framework of neural systems underlying appraisal
Neurosci Biobehav Rev. 2007;31(4):585-96.
Abstract
We argue that many similar findings observed in cognitive, affective, and social neuroimaging research may compose larger processes central to generating self-relevance. In support of this, recent findings from these research domains were reviewed to identify common systemic activation patterns... [read more]
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Caffeine attenuates practice effects in word stem completion as measured by fMRI BOLD signal
Hum Brain Mapp. 2007;28(7):654-62.
Abstract
Caffeine ingestion results in increased brain cell metabolism (Nehlig et al. [1992] Brain Res Brain Res Rev 17:139-170) and decreased cerebral blood flow (Field et al... [read more]
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Hormone effects on fMRI and cognitive measures of encoding: importance of hormone preparation
Neurology. 2006 Dec 12;67(11):2039-41.
Abstract
We compared fMRI and cognitive data from nine hormone therapy (HT)-naive women with data from women exposed to either opposed conjugated equine estrogens (CEE) (n = 10) or opposed estradiol (n = 4). Exposure to either form of HT was associated with healthier fMRI response; however, CEE-exposed women exhibited poorer memory performance than either HT-naive or estradiol-exposed subjects... [read more]
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Neural correlates of self-evaluative accuracy after traumatic brain injury
Neuropsychologia. 2006;44(5):762-73. Epub 2005 Sep 8.
Abstract
Individuals who have sustained a traumatic brain injury (TBI) often exhibit an array of cognitive deficits, yet perhaps most maladaptive of these sequelae is the frequent occurrence of reduced insight into one's own condition. In such cases, TBI individuals may overestimate their post-injury level of socio-cognitive functioning, leading to disparities between how they perceive themselves and what others observe... [read more]
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Network analysis of single-subject fMRI during a finger opposition task
Neuroimage. 2006 Aug 1;32(1):325-32. Epub 2006 Jun 2.
Abstract
The analysis of functional magnetic resonance imaging (fMRI) data has typically relied on univariate methods to identify areas of brain activity related to cognitive and behavioral task performance. We investigated the ability of multivariate network analysis using a modified form of principal component analysis, the Scaled Subprofile Model (SSM), applied to single-subject fMRI data to identify patterns of interactions among brain regions over time during an anatomically well-characterized simple motor task... [read more]
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Relationship of cognitive measures and gray and white matter in Alzheimer's disease
J Alzheimers Dis. 2006 Aug;9(3):253-60.
Abstract
OBJECTIVE: To examine the relationship between commonly used screening cognitive measures with gray and white matter integrity in patients with mild to moderate AD. BACKGROUND: New neuroimaging techniques, such as voxel-based morphometry (VBM), make it possible to study the relationship between structural brain integrity and cognitive functioning in AD... [read more]
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Computational models of the hippocampal region: implications for prediction of risk for Alzheimer's disease in non-demented elderly
Curr Alzheimer Res. 2006 Jul;3(3):247-57.
Abstract
We have pursued an interdisciplinary research program to develop novel behavioral assessment tools for evaluating specific memory impairments following damage to the medial temporal lobe, including the hippocampus and associated structures that show pathology early in the course of Alzheimer's disease (AD). Our approach uses computational models to identify the functional consequences of hippocampal-region damage, leading to testable predictions in both rodents and humans... [read more]
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The influence of Alzheimer disease family history and apolipoprotein E epsilon4 on mesial temporal lobe activation
J Neurosci. 2006 May 31;26(22):6069-76.
Abstract
First-degree family history of sporadic Alzheimer disease (AD) and the apolipoprotein E epsilon4 (APOE4) are risk factors for developing AD. Although the role of APOE4 in AD pathogenesis has been well studied, family history remains a rarely studied and poorly understood risk factor... [read more]
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Self-appraisal decisions evoke dissociated dorsal-ventral aMPFC networks
Neuroimage. 2006 Apr 15;30(3):1050-8. Epub 2005 Dec 2.
Abstract
The anterior medial prefrontal cortex (aMPFC) is consistently active during personally salient decisions, yet the differential contributory processes of this region along the dorsal-ventral axis are less understood. Using a self-appraisal decision-making task and functional magnetic resonance imaging, we demonstrated task-dependent connectivity of ventral aMPFC with amygdala, insula, and nucleus accumbens, and dorsal aMPFC connectivity with dorsolateral PFC and bilateral hippocampus... [read more]
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Application of Brodmann's area templates for ROI selection in white matter tractography studies
Neuroimage. 2006 Feb 1;29(3):868-78. Epub 2005 Oct 21.
Abstract
Brodmann's areas are part of the common vernacular used by neuroscientists to indicate specific location of brain activity in functional brain imaging studies. Here, we have employed a template based on the Brodmann's areas as a means of compartmentalizing underlying white matter pathways... [read more]
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Task-dependent posterior cingulate activation in mild cognitive impairment
Neuroimage. 2006 Jan 15;29(2):485-92. Epub 2005 Aug 15.
Abstract
Neuroimaging research has demonstrated that the posterior cingulate cortex (PCC) is functionally compromised in individuals diagnosed with amnestic mild cognitive impairment (MCI), a major risk factor for the development of Alzheimer's disease (AD). In functional MRI studies with healthy participants, this same region is active during self-appraisal (requiring retrieval of semantic knowledge about the self) as well as episodic recognition of previously learned information... [read more]
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Reduced hippocampal activation during episodic encoding in middle-aged individuals at genetic risk of Alzheimer's disease: a cross-sectional study
BMC Med. 2006 Jan 13;4:1.
Abstract
BACKGROUND: The presence of the apolipoprotein E (APOE) epsilon4 allele is a major risk factor for the development of Alzheimer's disease (AD), and has been associated with metabolic brain changes several years before the onset of typical AD symptoms. Functional MRI (fMRI) is a brain imaging technique that has been used to demonstrate hippocampal activation during measurement of episodic encoding, but the effect of the epsilon4 allele on hippocampal activation has not been firmly established... [read more]
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Structural MRI discriminates individuals with Mild Cognitive Impairment from age-matched controls: A combined neuropsychological and voxel based morphometry study.
Alzheimers Dement. 2006;2(4):296-302.
Abstract
BACKGROUND: Several previous studies have reported that amnestic mild cognitive impairment (aMCI), a significant risk factor for Alzheimer's disease (AD), is associated with greater atrophy in the medial temporal lobe (MTL) and posterior cingulate gyrus (PCG). METHOD: In the present study, we examined the cross-sectional accuracy (i.e., the sensitivity and specificity) of voxel-based morphometry (VBM) in discriminating individuals with MCI (n =15) from healthy age-matched controls (n =15)... [read more]
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The effect of body mass index on global brain volume in middle-aged adults: a cross sectional study
BMC Neurol. 2005 Dec 2;5:23.
Abstract
BACKGROUND: Obesity causes or exacerbates a host of medical conditions, including cardiovascular, pulmonary, and endocrine diseases. Recently obesity in elderly women was associated with greater risk of dementia, white matter ischemic changes, and greater brain atrophy... [read more]
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The cerebral response during subjective choice with and without self-reference
J Cogn Neurosci. 2005 Dec;17(12):1897-906.
Abstract
The anterior medial prefrontal (AMPFC) and retrosplenial (RSC) cortices are active during self-referential decision-making tasks such as when participants appraise traits and abilities, or current affect. Other appraisal tasks requiring an evaluative decision or mental representation, such as theory of mind and perspective-taking tasks, also involve these regions... [read more]
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Functional MRI neuroanatomic correlates of the Hooper Visual Organization Test
J Int Neuropsychol Soc. 2004 Nov;10(7):939-47.
Abstract
The Hooper Visual Organization Test (VOT), a commonly applied neuropsychological test of visual spatial ability, is used for assessing patients with suspected right hemisphere, or parietal lobe involvement. A controversy has developed over whether the inferences of this test metric can be assumed to involve global, lateralized, or regional functionality... [read more]
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Voxel-based morphometry of unilateral temporal lobe epilepsy reveals abnormalities in cerebral white matter
Neuroimage. 2004 Sep;23(1):167-74.
Abstract
Voxel-based morphometric (VBM) investigations of temporal lobe epilepsy have focused on the presence and distribution of gray matter abnormalities. VBM studies to date have identified the expected abnormalities in hippocampus and extrahippocampal temporal lobe, as well as more diffuse abnormalities in the thalamus, cerebellum, and extratemporal neocortical areas... [read more]
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Metacognitive evaluation, self-relevance, and the right prefrontal cortex
Neuroimage. 2004 Jun;22(2):941-7.
Abstract
The capability to foster metacognitive evaluations (MEs) of oneself and others represents a major component of conscious awareness. Separate emerging lines of brain activation research examining ME have converged on the medial prefrontal cortex as a common finding... [read more]
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Hippocampal adaptation to face repetition in healthy elderly and mild cognitive impairment
Neuropsychologia. 2004;42(7):980-9.
Abstract
We examined the dynamic process of encoding novel repeating faces using functional MRI (fMRI) in non-demented elderly volunteers with and without diagnosed memory problems. We hypothesized that adaptation (repetition dependent reduction in activity) would occur in the mesial temporal lobe (MTL), and that this would be associated with cognitive status... [read more]
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Functional MRI and Wada determination of language lateralization: a case of crossed dominance
Epilepsia. 2004 Jan;45(1):85-9.
Abstract
The Wada test has historically been the conventional procedure for determining language lateralization before neurosurgery. However, functional magnetic resonance imaging (fMRI) offers a less invasive alternative to the Wada procedure... [read more]
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Apolipoprotein E epsilon 4 affects new learning in cognitively normal individuals at risk for Alzheimer's disease
Neurobiol Aging. 2003 Nov;24(7):947-52.
Abstract
The Apolipoprotein E (APOE) epsilon 4 allele is an important risk factor for Alzheimer's disease (AD). Given the interest in early identification of at-risk individuals, we examined memory decline as a function of APOE status and age in cognitively intact participants aged 48-77 years old (yo)... [read more]
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Neural correlates of self-reflection
Brain, Vol. 125, No. 8, 1808-1814, August 2002
Abstract
The capacity to reflect on one’s sense of self is an important component of self-awareness. In this paper, we investigate some of the neurocognitive processes underlying reflection on the self using functional MRI... [read more]
