Cognitive aging is a major source of disability in an increasingly aging population. The paucity of effective treatments for cognitive aging disorders, and most importantly in Alzheimer's disease instigates a need for further research into novel therapeutic possibilities. Alzheimer's disease is the most common neurodegenerative disorder and its prevalence steeply increases. Glutamate-mediated excitotoxicity in neuropsychiatric disorders and in particular in Alzheimer's disease has been shown to cause significant cerebral damage. Early effective therapeutic intervention in Alzheimer's disease is critical in order to prevent or at least retard neuropathological progression that will lead to widespread irreversible neuronal loss and significant cognitive dysfunction. Riluzole, a glutamate modulator agent that is a proven safe medication and has not yet been used in cognitive aging disorders, will be tested in mild Alzheimer's disease patients. Cognitive functional changes along with two established in vivo biomarkers, namely, Magnetic Resonance Spectroscopy (MRS) and Fluorodeoxyglucose (18F) positron emission tomography (FDG-PET) will be evaluated.