When considering a broken neck or a cut spinal cord, location of neurons and their ultimate destinations are fundamental. If the spinal cord is cut, the entire body does not become non-functional, but, as a result of the Law of Physical Continuity, certain actions of the body are affected and certain actions that tend to coincide may no longer do so. For example, if the spinal cord is cut right before the brain, then sensory neurons receive external information and transmit it to the spinal cord, but the transmission of the signal may not be continued to the brain because of the cut of interneurons that pass the signal to other interneurons and motor neurons in the brain. Therefore, although there may be an output from the body, it is in conjunction with neurons associated with the spinal cord, and not the brain. The reverse situation is also plausible, in which the brain receives input that requires an output from the body, and yet it cannot occur because if the interruption of the connection. Furthermore, the nervous sytem is a distributed system in which complete behaviors are often the result of the entire nervous system coordinating a single output that may involve many aspects of the body. This implies that a cut in the spinal cord may cause certain human behaviors to be partial or incomplete, such as when one may be able to scream in fear, but unable to run, indicating a seemingly incomplete action.
One of the implications of having a nervous system dependent on the localization of neurons and a distributed system is that, in the case of a neck injury, not all human function is damaged. Furthermore, the locations and functions of particular neurons becomes more accesible to the researcher. By determining which actions and behaviors are seemingly incomplete, one can determine some of the locations of certain neurons, and the realtionship that these neurons have to the body. A problem arises, however, being that neurons may affect one another even though they may not be directly linked. Because of the actions of one particular neuron, located in the brain, for example, another neuron associated with the spinal cord may act differently depending on whether or not it receives a signal, or whether or not a neuron associated with it receives a signal, and so forth. Therefore, determining the location and function of certain neurons may not be as simple as it appears.
Accurate and sophisticated summary of the situation. Yes, both distributed system and one in which elements differ and location of each is important. Important both for understanding system, and for interpreting observations on it. PG