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            Late in Thursday’s discussion we arrived at the conclusion that an isolated nervous system does indeed generate outputs. I have had somewhat of a hard time internalizing this notion that an isolated nervous system may operate independently of the normal inputs that we experience all day long. This conclusion has implications on end of life care for patients sustaining serious brain trauma, or patients in a “vegetative state.”

            This discussion begs the question, what does it mean to generate outputs? If we as humans generate outputs, does that mean we are living? Is the generation of output the key criteria for humanness? As humans, we internalize, process, react, and produce. But it appears that is not all that is involved. Previously I would suggest that someone in a “vegetative state” is not truly alive, in the human sense of the word. It seems possible that the nervous system may be “alive” independent of its normal surroundings, if it is independently generating outputs in an isolated environment. If it is possible for a nervous system to independently generate product regardless of external surroundings, is it possible to ever call someone dead? Purely because they fail to respond to any external stimulus, do we really have any way of knowing that they are not continuing to function independent of sensory input?

            Perhaps “being alive” is a human-defined condition wherein you input, process, and react according to your nervous system networking (recall the lines connecting the nodes). For example, if someone is defibrillated, (shocked, as in when their heart stops), and they respond to this stimulus by output (specifically returning to normal cardiac rhythm), then we call them alive. But if they fail to respond, we call them dead. It would appear that humans may have the ability to generate impulses internally, (as in the latest nervous system model we discussed), although they must have the ability to respond to inputs.

            Initially this seems satisfactory to me. But returning to the cricket model makes me challenge my proposition. If the cricket hears a song and doesn’t move, it’s because she has input the signal and the pathway has not led to the same output that it sometimes does. If she does nothing, isn’t that an output in itself? Doing nothing is a response. If we poke a corpse, is it possible that their nervous system is choosing a pathway of no response?

            So how is our “being alive” status tied to our nervous system? If a response is neither necessary nor sufficient to determine if we are indeed alive, how can we determine if we are alive? I have no idea on this one. Stepping outside of immediate selves, is it possible to determine if someone else is alive? If we cannot make judgments on the state of someone’s nervous system based on their ability to input, react, or output, can we truly ever determine if someone is alive? I have no answer to this question, but as we go forward with our exploration of the nervous system, I want to be able to define the limits of when a nervous system fails to operate and we could consider it "dead."