WHY USE LINEAR SYSTEMS ANALYSIS?
The neural masses in the central numerical region can be conceived empirically as occupying a few mm2 of cortical surface, or a few mm3 of nuclear volume in the brain stem or spinal cord. They have three properties of particular interest in the present context. First, the output of a neural mass is often accessible to measurement as a holistic event, such as a compound action potential of a nerve trunk, a field of potential in the volume of the mass owing to the extracellular spread and summation of dendritic current, or some derivative event such as the strength of a muscle contraction. For neural masses in the brain the electrical field potentials may be the single most valuable source of information about their dynamic properties, because they manifest the weighted instantaneous sum of extracellular potentials generated by large numbers of neurons. The problems of determining the locations, distributions, and active states of neurons in the masses generating such fields have been di
