Technical advances in Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) have provided researchers with the opportunity to study functional and metabolic changes of the central nervous system (CNS) in both normal individuals and individuals with neurological diseases in response to sensory, motor or cognitive stimulation. New MRI and MRS techniques specifically designed for Functional Magnetic Resonance Imaging (fMRI) and Magnetic Resonance Spectroscopic Imaging of the CNS will be evaluated at 1.5 and/or at 4.0 Tesla on normal volunteers and in patients with CNS pathology.