Overview
The behavioral measures have focused on reaction time, with the goal of distinguishing age-related changes in specific cognitive abilities from more general effects arising from a slowing in elementary perceptual processes. The cognitive abilities of interest include selective attention as measured in visual search tasks, semantic and episodic memory retrieval, and executive control processes.
The behavioral measures are necessary to define the cognitive abilities of interest, and the neuroimaging techniques help define the functional neuroanatomy of those abilities. The PET and fMRI measures provide information regarding neural activity during cognitive performance. DTI is a recently developed technique that images the structural integrity of white matter. The white matter tracts of the brain provide critical pathways linking the gray matter regions, and thus this work will complement the studies using PET and fMRI that focus on gray matter activation.
A current focus of the research program is the functional connectivity among regions, not only during cognitive task performance but also during rest. These latter measures, referred to as intrinsic functional connectivity, are beginning to show promise as an index of overall brain functional efficiency, which can be assessed without the implementation of a specific cognitive task. From DTI, information can be obtained regarding how anatomical connectivity constrains intrinsic functional connectivity. It will be important to determine the relative influence of white matter pathway integrity, intrinsic functional connectivity, and task-related functional connectivity, as mediators of age-related differences in behavioral measures of cognitive performance.
Ultimately, the research program can help link age-related changes in cognitive performance to changes in the structure and function of specific neural systems. The results also have implications for clinical translation, in terms of the identification of neural biomarkers for the diagnosis of neural pathology and targeting rehabilitation procedures.
Current Appointments & Affiliations
Professor Emeritus in Psychiatry and Behavioral Sciences
·
2025 - Present
Psychiatry & Behavioral Sciences, Behavioral Medicine & Neurosciences,
Psychiatry & Behavioral Sciences
Chair of the Scientific Review Committee in the Center for Brain Imaging and Analysis
·
2013 - Present
Duke-UNC Brain Imaging and Analysis Center,
Institutes and Centers
Member of the Center for Cognitive Neuroscience
·
2009 - Present
Center for Cognitive Neuroscience,
Duke Institute for Brain Sciences
Faculty Network Member of the Duke Institute for Brain Sciences
·
2011 - Present
Duke Institute for Brain Sciences,
University Institutes and Centers
Recent Publications
Regulating Negative Autobiographical Memories: An fMRI Investigation of Reappraisal and Distraction in Middle-aged and Older Adults.
Journal Article J Cogn Neurosci · February 1, 2026 Cognitive reappraisal and attentional distraction constitute two core strategies for regulating emotions. Prior studies have largely focused on young adults regulating simple laboratory stimuli, with few direct comparisons of brain regions that differentia ... Full text Open Access Link to item CiteImaging iron in the brain: solving the puzzle of brain iron, systemic iron, cerebral blood flow, and cognition.
Journal Article Eur Radiol · January 23, 2026 Full text Open Access Link to item CiteHigher spatial resolution diffusion-weighted imaging improves characterization of white matter disconnection in Alzheimer's disease.
Journal Article Imaging Neurosci (Camb) · 2026 In addition to the accumulation of neuropathologies (i.e., amyloid beta, neurofibrillary tangles), Alzheimer's disease (AD) is associated with the degradation of white matter (WM) structural pathways that connect distributed brain regions. However, previou ... Full text Open Access Link to item CiteRecent Grants
High resolution diffusion imaging of brain connectivity in healthy aging and Alzheimer's disease
FellowshipPrincipal Investigator · Awarded by National Institute on Aging · 2024 - 2025Neuroimaging of Visual Attention in Aging
ResearchPrincipal Investigator · Awarded by National Institutes of Health · 2011 - 2025Neurobehavioral Mechanisms of Emotion Regulation in Depression across the Adult Lifespan
ResearchCo Investigator · Awarded by National Institutes of Health · 2017 - 2024View All Grants
Education
University of California, Davis ·
1977
Ph.D.
University of Victoria (Canada) ·
1974
M.A.
University of California, Davis ·
1972
B.A.