We have spent the past two weeks discussing the brain= behavior principle. The model of the nervous system introduced to us this past week further develops the brain = behavior principle and introduces neurons as an extension to the brain = behavior principle. Therefore, it would seem that neurons make up the brain and are behavior (neurons= brain= behavior). If this is the case, questions of autonomy and the validity of neural passivity come to mind and toy with the brain = behavior principle that I thought I felt comfortable with just one week ago. To begin I will define the nervous system (NS) and with respect to it, explain the neuron.
The nervous system (NS) can be thought of as a box. Within this box there are a number of internal boxes all of which give outputs and receive inputs. Some of the boxes interconnect and some do not. And each box is autonomous. Box A may connect to Box B, C, D or 1000 different boxes at any point in time. A direct correlation between two specific boxes does not exist. NS therefore consists of as many as 1012 input and output boxes which are cells, and more specifically neurons. No two neurons are identical, and thereby no two individuals have exactly the same brain and behavior. Dendrites serve as the source of input for neurons and axons conversely carry output from one neuron to the next. The site of this association of the dendrite of one neuron with the axon of another is called the synapse. The brain therefore is nothing more than 1012 communicating neurons that pass messages to one another autonomously.
It would follow therefore that since neurons are the smallest boxes within the multitude of boxes within the nervouse system, that the brain is defined by this system of neurons, and that neurons, or more specifically the interaction between them, are behavior. As the neurons talk to each other at the synapse, behavior occurs. Lack of interaction between neurons results perhaps in the lack of behavior. The correlation seems to be direct. Thereby, I am extrapolating that neurons (or the communication that exists between them) is brain and thereby is behavior.
Again, a week ago, this brain= behavior principle seemed more clear, or easily to accept. With the addition of neurons in this grander scheme of behavior, more questions are posed. The example of a person breaking their neck and not receiving a painful input would imply that there was no connection between the neck and the spinal cord. This implies the lack of neural interaction. What if however the breaking of the neck triggered interaction with a different neuron that (directly or indirectly) gave the output of no pain. The brain = behavior principle brings me to question whether boxes or neurons exist that produce a seemingly non-response response. Also, the autonomy of neurons contradicts what man has grown to accept: a stimulus- response action. It is difficult to grasp that me slamming the door on my hand won't necessarily prompt a pain output, given the autonomy of neurons. And also, how does learned behavior that seems to be programmed within us fit into this theory. For example, in the case of going to the bathroom. Will neurons autonomously signal different neurons that will keep me from going to the bathroom when I need to? And at what points do my neurons send the messages or "decide" that I need to go to the bathroom? What is my brain thinking? How are the neurons deciding when to talk? These are questions that remain with respect to the brain= behavior principle, perhaps the neurons= brain = behavior principle.
Sounds to me like you've taken the first two weeks VERY seriously ... and come to some very reasonable concerns as a result. Interesting that some of your colleagues are made MORE comfortable by having lots of littlest boxes, and you are less so. Indeed, we will have to account for what SOME behaviors ARE pretty predictable ... and also for what makes neurons "decide" to do what they do. They don't, needless to say, "decide" whether you are ... going to be bathroom or not, certainly not as individual neurons. But maybe the collective effect of what each neuron does decide is ... ? We'll see. PG Sounds to me like you've taken the first two weeks VERY seriously ... and come to some very reasonable concerns as a result. Interesting that some of your colleagues are made MORE comfortable by having lots of littlest boxes, and you are less so. Indeed, we will have to account for what SOME behaviors ARE pretty predictable ... and also for what makes neurons "decide" to do what they do. They don't, needless to say, "decide" whether you are ... going to be bathroom or not, certainly not as individual neurons. But maybe the collective effect of what each neuron does decide is ... ? We'll see. PG