On Sat, Oct 8, 2011 at 10:48 AM, Craig Weinberg <whatsons...@gmail.com> wrote: > On Oct 7, 7:10 pm, Stathis Papaioannou <stath...@gmail.com> wrote: >> On Sat, Oct 8, 2011 at 7:06 AM, Craig Weinberg <whatsons...@gmail.com> wrote: >> >> If a motor neuron involved in voluntary activity fires where you would >> >> not predict it would fire given its internal state and the inputs then it >> >> is *by definition* acting contrary to physical law. >> >> > Every firing of motor neurons involved in voluntarily activity fires >> > where you would not predict, given that the internal state provides no >> > prediction and that the inputs are determined by the subject and >> > therefore unknowable to anyone outside of the subject. >> >> The internal state of the neuron determines its sensitivity to inputs. >> The internal state is complex but it includes things such as the >> membrane potential, the intracellular ion concentrations, the number, >> type and location of ion channels, to what extent the synaptic >> vesicles have filled with neurotransmitter, and multiple other >> factors. The inputs consist of every environmental factor that might >> potentially affect the neuron such as the extracellular ionic >> concentrations, pH, temperature, synaptic connections, concentration >> of neurotransmitter in the synapse, concentration of enzymes which >> break down neurotransmitter and so on. > > Not one of those things determines whether or not a given neuron > associated with voluntary action will fire. It is the same thing as > talking about the drive shaft, CV boot, transmission, fuel line, spark > plugs, and paint job as determining when and where an automobile goes. > It's the same as saying that the TV remote control uses you to change > the channel instead of the other way around.
Of course all the parts of the car determine how it will move! You can predict exactly what the car will do if you know how it works and you have the inputs. A model of the car, such as a car racing computer game, does not include the driver and the whole universe, as you seem to think, just the car. >> If the neuron fires where >> consideration of these factors would lead to a prediction that it >> should not fire then that is by definition the neuron acting contrary >> to physical law. > > There is no such thing as a factor which leads to a prediction of when > efferent nerves will fire. Even if you say that the subject is just > regions of the brain, it is still those regions, those tissues and > neurons which *decide* to fire as a first cause - without any > deterministic precursor that could ever be predicted with any degree > of accuracy without access to the private subjective content of the > decision process. Seeing a nerve fire doesn't tell you when it's going > to fire again, just as seeing a car make a left turn doesn't tell you > what direction it's going to turn after that. So a neuron fires in those regions of the brain associated with subjectivity where the biochemistry suggests it would not fire. Ligand-activated ion channels open without any ligand present, or perhaps an action potential propagates down the axon without any change in ion concentrations. That is what I call "contrary to physical laws". You don't agree, so you must have some other idea of what a neuron would have to do to qualify as firing contrary to physical laws. What is it? -- Stathis Papaioannou -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
