Jason Steffener, Ph.D.
The Taub Institute for Research on Alzheimer's Disease and the Aging Brain
630 West 168th St, P&S 16
New York, NY 10032
Multi-modal neuroimaging into the underpinnings of age-related neural changes.
Currently, many approaches (functional or structural neuroimaging, behavioral or neuropsychological testing) to aging research are performed independently thus diminishing their impact on understanding the over all effects of normal aging on the brain. My current research integrates measures of neural activity (functional activations) and underlying brain structure (cerebral blood flow and brain tissue volume) to study their influences on the relationship between advancing age and decreased performance on cognitive tests.
Investigating the Spatial and Temporal Hemodynamics of the fMRI BOLD Signal
In this research multiple imaging modalities are used to investigate the hemodynamic response to neuronal stimulation. The measured response to a stimulus is the result of a complex interplay between neuronal activity and blood flow with BOLD fMRI only capturing changes in blood oxygen levels. Through the use of other imaging modalities, such as structural and flow images, the BOLD fMRI response is investigated to capture a better understanding of the actual neuronal response to stimuli. This work also investigates factors that cause variability in the hemodynamic responses, such as spatial location, age or disease progression. The temporal dynamics of hemodynamics are investigated through the application of adaptive filters that track signal changes over time.
Steffener J, Tabert, M.H., Reuben, A., Stern, Y. Investigating hemodynamic response variability at the group level using basis functions. NeuroImage. In-press
Steffener J, Brickman, A. M., Rakitin, B. C., Gazes, Y., Stern, Y. The impact of brain structure on age-related changes in functional network activity during a working memory task. Brain, Imaging and Behavior. 2009 3(2):142-153
Tabert MH, Steffener J, Albers, M., Michaels, M., Kern, D., Brown, T., and Devanand, D.P. Validation and optimization of statistical approaches for modeling odorant-induced fMRI signal changes in olfactory-related brain areas, Neuroimage. 2007 Feb 15;34(4):1375-90.
Software for basis set analyses discussed in the paper:
"Investigating hemodynamic response variability at the group level using basis functions"