Publications
You can look up publications by PI (see left column) or view recent publication summaries from various groups below.
Recent publications from various brain imaging groups
Alexander
"Computation of Diffusion Function Measures in q-Space Using Magnetic Resonance Hybrid Diffusion Imaging" (Wu et al, June 08, IEEE Transactions on Medical Imaging). The distribution of water diffusion in biological tissues may be estimated by a 3-D Fourier transform (FT) of diffusion-weighted measurements in -space. In this study, methods for estimating diffusion spectrum measures (the zero-displacement probability, the mean-squared displacement, and the orientation distribution function) directly from the -space signals are described. These methods were evaluated using both computer simulations and hybrid diffusion imaging (HYDI) measurements on a human brain.
Christian
"PET measurement of changes in D2/D3 dopamine receptor binding in a
nonhuman primate during chronic deep brain stimulation
of the bed nucleus of the stria terminalis" (Vandehey et al., January 09, Journal of Neuroscience Methods). PET imaging is a powerful tool for measuring physiological changes in the brain during deep brain stimulation (DBS). In this work, we acquired five PET scans using a highly selective D2/D3 dopamine antagonist, 18F-fallypride, to track changes in dopamine receptor availability, as measured by the distribution volume ratio (DVR), through the course of DBS in the bed nucleus of the stria terminalis (BNST) in a nonhuman primate.
Chung
"Encoding cortical surface by spherical harmonics" (Chung et al., October 08, Statistica Sinica).
We present a radically different asymmetry analysis technique that
utilizes a novel weighted spherical harmonic representation of
cortical surfaces. The weighted spherical harmonic representation is a
surface smoothing technique given explicitly as a weighted linear
combination of spherical harmonics. The new representation avoids the
traditional image flipping method.
"Tensor-based cortical surface morphometry via weighted spherical harmonic representation" (Chung et al., August 08, IEEE Transactions on Medical Imaging). We present a new tensor-based morphometric framework that quantifies cortical shape variations using a local area element. The local area element is computed from the Riemannian metric tensors, which are obtained from the smooth functional parametrization of a cortical mesh. For the smooth parametrization, we have developed a novel weighted spherical harmonic (SPHARM) representation, which generalizes the traditional SPHARM as a special case.
Davidson
"Dynamic variation in pleasure in children predicts nonlinear change in lateral frontal brain electrical activity" (Light et al., March 2009 Developmental Psychology). Individual variation in the experience and expression of pleasure may relate to differential patterns of lateral frontal activity. Brain electrical measures have been used to study the asymmetric involvement of lateral frontal cortex in positive emotion, but the excellent time resolution of these measures has not been used to capture second-by-second changes in ongoing emotion until now. Children who expressed increasing amounts of pleasure during the task exhibited increasing left lateral frontal activity during the task, whereas children who expressed contentment exhibited increasing right/decreasing left activity. These findings indicate that task-dependent changes in pleasure relate to dynamic, nonlinear changes in lateral frontal activity as the task unfolds.
Nitschke
"Uncertainty during anticipation modulates neural responses to aversion in human insula and amygdala" (Sarinopoulos et al., August 09, Cerebral Cortex). Uncertainty about potential negative future outcomes can cause great stress and is a central feature of anxiety disorders. In this fMRI study, we found that uncertainty during anticipation resulted in greater responses to aversive pictures in the insula and amygdala, key regions in responding to aversion. Anticipatory activity in the anterior cingulate cortex (ACC) predicted these modulated insula and amgydala responses. In addition, ACC and insula activity predicted biased post-scan estimates of the relationship between uncertain cues and aversive pictures.
"Anticipatory activation in the amygdala and anterior cingulate in generalized anxiety disorder and prediction of treatment response" (Nitschke et al., 2009, American Journal of Psychiatry). The anticipation of adverse outcomes, or worry, is a cardinal symptom of generalized anxiety disorder. Prior work with healthy subjects has shown that anticipating aversive events recruits a network of brain regions, including the amygdala and anterior cingulate cortex. This study tested whether patients with generalized anxiety disorder have alterations in anticipatory amygdala function and whether anticipatory activity in the anterior cingulate cortex predicts treatment response.