ABSTRACT Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high fields, we demonstrate in vivo images of brain microvasculature

demonstrate improved spatial resolution and accelerated acquisition for multislice fast spinecho brain imaging and 3D contrast enhanced angiography.

The finite mixture (FM) model is the most commonly used model for statistical segmentation of brain magnetic resonance (MR) images because of its simple mathematical form and the piecewise constant nature of ideal brain MR images. However, being a histogram-based model, the FM has an intrinsic

email rwcoxmcwedu A package of computer programs for analysis and visualization of threedimensional human brain functional magnetic resonance imaging FMRI results is described The software can color overlay neural activation maps onto higher resolution anatomical scans Slices in each cardinal

MOTOR and visual cortices of normal volunteers were activated by transcranial magnetic stimulation. The electrical brain activity resulting from the brief electromagnetic pulse was recorded with high-resolution electroencephalography (HR-EEG) and located using inversion algorithms. The stimulation

fMRI was used to study human brain activity during Pavlovian fear conditioning. Subjects were exposed to lights that either signaled painful electrical stimulation (CS‡), or that did not serve as a warning signal (CS). Unique patterns of activation developed within anterior cingulate and visual

FUNCTIONAL magnetic resonance imaging was used to assess inter-subject variability in the cortical representation of language comprehension processes. Moderately fluent French–English bilinguals were scanned while they listened to stories in their first language (L1 = French) or in a second

USING positron emission tomography, we studied changes in the regional cerebral blood ¯ow (rCBF) associated with cross modality (auditory to visual) and within modality visual priming in a word stem completion task. Compared to baseline completion performance and to within modality visual priming, cross modality priming was associated with increased rCBF in prefrontal cortex and decreased rCBF in the left angular gyrus. The results con®rm and complement trends observed in a previous study concerning visual to auditory cross modality priming, and suggest that distinct cortical mechanisms may mediate within- and cross modality priming on the stem completion task. The ®ndings are consistent with the neuropsychological data concerning auditory to visual cross modality priming, and indicate involvement of aspects of explicit retrieval and lexical processes in cross modality priming.

neuroreport

, requiring little or no manual intervention. Automated routines for unfolding and flattening the cortical surface are described in a companion paper. These procedures allow for the routine use of cortical surface-based analysis and visualization methods in functional brain imaging.