Daniel S. Reich

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Diffusion tensor imaging (DTI) is an exciting new MRI modality that can reveal detailed anatomy of the white matter. DTI also allows us to approximate the 3D trajectories of major white matter bundles. By combining the identified tract coordinates with various types of MR parameter maps, such as T2 and diffusion properties, we can perform tract-specific(More)
How do neurons in the primary visual cortex (V1) encode the contrast of a visual stimulus? In this paper, the information that V1 responses convey about the contrast of static visual stimuli is explicitly calculated. These responses often contain several easily distinguished temporal components, which will be called latency, transient, tonic, and off.(More)
We report that neuronal spike trains can exhibit high, stimulus-dependent temporal precision even while the trial-to-trial response variability, measured in several traditional ways, remains substantially independent of the stimulus. We show that retinal ganglion cells and neurons in the lateral geniculate nucleus (LGN) of cats in vivo display both these(More)
Inflammation, demyelination, gliosis and axonal degeneration are pathological hallmarks of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis. Axonal damage is thought to contribute to irreversible damage and functional impairment, but is difficult to quantify. Conventional MRI has been used to assess the inflammatory and demyelinating(More)
We describe a new fully automatic method for the segmentation of brain images that contain multiple sclerosis white matter lesions. Multichannel magnetic resonance images are used to delineate multiple sclerosis lesions while segmenting the brain into its major structures. The method is an atlas-based segmentation technique employing a topological atlas as(More)
We examine the responses of single neurons and pairs of neurons, simultaneously recorded with a single tetrode in the primary visual cortex of the anesthetized macaque monkey, to transient presentations of stationary gratings of varying spatial phase. Such simultaneously recorded neurons tended to have similar tuning to the phase of the grating. To(More)
We develop fast fitting methods for generalized functional linear models. The functional predictor is projected onto a large number of smooth eigenvectors and the coefficient function is estimated using penalized spline regression; confidence intervals based on the mixed model framework are obtained. Our method can be applied to many functional data designs(More)
We estimate the rates at which neurons in the primary visual cortex (V1) of anesthetized macaque monkeys transmit stimulus-related information in response to three types of visual stimulus. The stimuli-randomly modulated checkerboard patterns, stationary sinusoidal gratings, and drifting sinusoidal gratings-have very different spatiotemporal structures. We(More)
Diffusion tensor imaging (DTI) and immunohistochemistry were used to examine axon injury in the rat spinal cord after unilateral L(2)-L(4) dorsal root axotomy at multiple time points (from 16 h to 30 d after surgery). Three days after axotomy, DTI revealed a lesion in the ipsilateral dorsal column extending from the lumbar to the cervical cord. The lesion(More)