The central nervous system (CNS), (i.e., the spinal cord, and the cortical and subcortical areas of the brain), processes different kinds of sensory information through highly organized neuronal structures that function as specific information-processing areas in the brain in a modular fashion. For instance, the visual, olfactory, motion, and somatic areas are well-defined functional structures, specialized in processing specific types of sensory stimuli, whereas the association areas are able to deal with multiple pre-analyzed sensations, which are received from these other areas through a close interchange with the limbic system. In this way, memory and association areas match the inputting information with stored responses, mainly through the interplay of impulses between the cortical and the limbic system. Therefore, the CNS is a complex system of interlinked structures that requires intercommunication among distant neurons...