Mechanisms of hemispheric lateralization: A replication study.

It has been shown, using functional magnetic resonance imaging (fMRI), that hemispheric lateralization of brain activity depends on the requirements of the cognitive task performed during the processing of a sensory stimulus rather than on the intrinsic characteristics of that stimulus [Stephan et al., 2003, Science 301 (5631): 384-6]. Task-dependent increase in the coupling of the anterior cingulate cortex (ACC), a region involved in cognitive control, and brain areas in the left prefrontal and right parietal cortex, respectively, regions involved in task execution, was proposed as the mechanism underlying this task-dependency of hemispheric lateralization.

Fractional anisotropy in the posterior limb of the internal capsule and prognosis in amyotrophic lateral sclerosis.

Objective: To explore the value of diffusion tensor imaging applied to those specific cerebral white matter tracts consistently involved pathologically in amyotrophic lateral sclerosis as a source of prognostic biomarkers.

Design: Baseline clinical assessment and 3-T diffusion tensor imaging, repeated after approximately 6 months.Tract-based spatial statistics were used to assess voxel wise correlations of just the baseline diffusion tensor imaging indices with the progression rate (change in disability score/time interval) within the corticospinal tract and corpus callosum.