Neuroscientists don’t know much about the brain, but we do know, at least, a little bit…
Our nervous system (and by “us” I mean animals in general) can be compartmentalized into separate units by function and/or structure. Categorizing by structure is done by basically looking at samples and marking off areas that appear to be separate (frontal lobe, pons, ganglia, axon terminal button, etc). Categorizing by function mostly comes from knowledge acquired by lesion studies (cut/damage/insult ‘this’ what happens now?), or through fMRI studies (can’t lesion a human eh? ); this is how we know that the V1 has Orientation and Ocular dominance columns that process angled visual line stimuli and gives ocular preference (to name an example). So, generally what we learn is that certain localized areas take care of certain functions (damage the visual cortex and subject has some loss of sight).
To ground this thread a bit, I’d like to draw some thick lines of what we know and where it happens. a) If by ‘mind’ you mean a localization of intellect, understanding, etc (shady concepts themselves, but lets not get into that here), it’s widely agreed that this takes place in the prefrontal cortex. b) I’d also like to point out that the peripheral nervous system (all areas of the nervous system outside of the brain and spinal cord) merely serves to detect/sense and transmit signals I)from our sensors to the CNS (afferent neuronal pathway) or II)transmit signals from our CNS to our muscles or glands. That’s it.
The OP mentioned that “muscle memory is real” but what is muscle memory? What is memory? Truthfully, what we know about memory is pretty spotty.
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[li]It’s useful to think of memory as “experience influences behaviour”, but we have many different working models for this concept (sensory, short/long-term, etc). [/li][li]We ultimately know that (for our muscles to work) our brain must first send a signal to them. We know it must start at some region(s) in the prefrontal cortex and end in the terminal button of a motor neuron; but what happens in between? Also, every time we do a simple task (like grab a cup of coffee) we need a great amount of muscles to simply lift it; how do we activate all of them without thought. Also, when we grab the cup, we don’t crush it, or send it past our mouths and through our teeth; we’re not only sending signals to our muscles, but we are then receiving signals from our sensors and adjusting accordingly. All done without conscious effort. What is happening between our head and our hand?[/li][li]What you called “muscle memory” is normally termed procedural memory, it’s basically that complex tasks (grabbing coffee, tying our laces), repeatedly done, are unconsciously learned and eventually preformed effortlessly. This is a form of memory too.[/li][li]Tying it all together. We know that there are structures in the brain that control for elements in complex motor tasks. If you damage your cerebellum you will have trouble maneuvering that coffee directly to your mouth by any of these ways[[/li][QUOTE]
loss of coordination of motor movement (asynergia), 2) the inability to judge distance and when to stop (dysmetria), 3) the inability to perform rapid alternating movements (adiadochokinesia), 4) movement tremors (intention tremor), 5) staggering, wide based walking (ataxic gait), 6) tendency toward falling, 7) weak muscles (hypotonia), 8) slurred speech (ataxic dysarthria), and 9) abnormal eye movements (nystagmus).
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](Cerebellum | CNS Traumatic Brain Injury Rehabilitation)also, (thanks to Donald Hebb) we know that neurons that transmit signals repeatedly become easier to excite, they transfer signals quicker, and the neural pathways that they invoke become stronger. So it makes sense that a task, that is repeatedly done, is done effortlessly because its motor-neural pathway has strengthened.[/ul]
Also I would like to point out that stimulation of a motor neuron will not cause a subject to report that the action was conscious and deliberate. Theoretically speaking, one would need to stimulate the areas highest up the neural pathway to get the subject to report this (possibly key areas of the prefrontal cortex).
Eric Kandel (after escaping the Nazis as a child) literally spent his life writing the book on the neural basis of memory and learning of Aplysia (a simple sea slug) and won a Nobel prize for his life long contributions. His work was covered in my classes and I was able to catch this interview with him on CBC radio a year ago. Fascinating story, fascinating guy.
One could consider the leg as part of the mind, if one wants to. The loss of a leg then becomes the loss of some sensory stimulus. All in all, a rather minor part of a mind. For someone born without legs, it would effect one’s mind and it’s perception of the world to some degree, just as a lack of eyesight or hearing would. But in terms of the unique aspects of the human mind, this would mean little, and still has nothing to do with the concept of free will.
I think what the OP is somewhat misremembering are the classic experiments by Benjamin Libet from the early eighties according to which a readiness potential indicating an impending action builds up before a conscious decision to perform that action is made. At least those are the experiments usually pointed to in these discussions…
I think you’re misunderstanding the point of it. Whether the external stimulation was done in the arm or in the brain, the point was that the impulses that resulted in the movement were already in place before the person had awareness of it, and his brain retrofitted the movement with his conscious decision to move it.
And to that person, this sequence of events was indistinguishable from any other event when he considers the options and makes a choice, so at least in this case, there was no “free will” but there was the perception of free will.
Sure, it doesn’t prove that in some cases you don’t actually have free will, but it provides an explanation for why we can have that perception when we know (at least in this case) that we really don’t. The fact is that to a neuroscientist, the concept of free will does not even make sense, but we humans have this perception that we have it, and this experiment shows how this can happen.
And I have heard people say this disproves free will - although this is not true. The conscious mind is simply a relatively small portion of the total human being; but being a small portion doesn’t make it nonexistent or mean that we’re deceiving ourselves. The totality of even a single thought is vastly more complicated than the conscious portion fo the mind can conceive of, and may involve numerous arrays of memory neurons, emotional triggers, complex instincts, risk factoring, and successfully does all the above when no single factor has a clear valuation. The conscious surely simplifies more than it hypothetically ought and often doesn’t note how deeply our emotions affect our judgement, but it does so because we have better things to do than sit around all day thinking through decisions.
But then, the anti-free-will group knew I’d say that.
Edit: I also agree with the concept that the total human being makes up the mind, although in a different fashion than its material weighting. The brain is definitely more important, but remove a man’s arms and legs and you have diminished him. Remove or damage facial neurons to make it harder for him to notice emotions, and you’ve diminished him more. Cause deliberate brain damage and (in addtion to being Mengele Jr.) you’ve diminished even a lot. Kill him and you’ve taken away everything he is and could be.
); this is how we know that the V1 has Orientation and Ocular dominance columns that process angled visual line stimuli and gives ocular preference (to name an example). So, generally what we learn is that certain localized areas take care of certain functions (damage the visual cortex and subject has some loss of sight).
