The fact that a person with a broken neck does not say "Ouch" or feel when their toe is pinched, but pulls away their foot, indicates that there are certain behaviors that are totally independent of the brain and the I-function box in the brain. More specifically, it indicates that some behaviors, besides dreaming, do not involve consciousness or free will. In addition, this demonstrates how the behaviors are highly dependent on communication between the different "boxes" of the nervous system. This high dependence on communication accounts for the large number of interneurons. The mechanism by which a person with a broken neck, and any person for that matter, pulls away their foot when stimulated can be easily accounted for by simply looking at it as the communication of neurons. An input (pinching) to the toe causes the sensory neurons of the toe to send a signal to the motor neurons in the ventral horn of the grey matter. The motor neuron, transmits the signal to the muscle which ultimately makes the person contract their foot. In the case of the person with a broken neck a signal sent at the spinal cord by the sensory neuron does not reach the brain because the connection between the two is severed. My questions is, how does this signal in a normal person get translated into the person saying "Ouch" and feeling the pain? Put more broadly how does an input impulse(signal) translate into a behavior? Not just any simple behavior, but one which causes a person to connect the word "Ouch" with pain and then proceed to make the vocal cords move to say it. It seems to me that there are three types of behaviors that the case of a person with a broken neck brings about: one which is independent of the brain, one which is dependent of the peripheral nervous system, and one which is dependent on both. Now, what seems interesting to me is to see
Yes, we'll want to put things back together again. But you've understood the main point: the problem is understanding how the parts interrelate. Careful, though, about two things. First, the sensory to motor transformation in the isolated spinal cord is nowhere near as simple as you describe it, there are lots of interneurons involved. And two: we don't, for reasons discussed in class, know whether what the spinal cord does involves consciousness and free will or not. In fact, we'll use some of what the spinal cord can do by itself to try and develop a clearer understanding of what is meant by those terms. PG