Life

[Touring Mars]

The universe itself could be infinite, but it could be that everything after a certain distance from the centre of the universe is simply empty, and therefore life wouldn't necessarily be infinite...

A slight problem with that - from all available evidence, there is no centre of the Universe.

 

[CMvan46]

Well Famine you would fall over if an infant only had the leg strength to support themselves and the stepping reflex but it's not being believed that this is the first step in how we learn to walk and that there a couple of rate limiting factors:

-Skeletal muscle development to produce leg strength to support the upright state
-Neural development to coordinate walking and to balance

Oh and another thing I hadn't realized with primitive reflexes. There is a grasping (Palmer) reflex where when a baby's palm is touched they should be grabbing or trying to grab whatever is touching it. Kind of funny when you see people who think their baby is holding there hand when really it's just a reflex.
The body really is an amazing thing. There are literally thousands of things happening in your body every second even if your just standing still.

 

[Danoff]

Please read up on "motor learning" (better known as "muscle memory"). It's nothing to do with muscles having memory, but with intensive training through repetition that results in permanent (or near-permanent) change in the physiology of the motor cortex (spinal motor circuit control), basal ganglia (action selection) and cerebellum (fine action control). The prefrontal cortex - the part of the brain "that thinks" (specifically the planning, decision-making and personality part) - isn't involved in muscle memory.


Walking is a terrific example. We aren't born knowing how to walk, but we learn how to do it and can eventually manage to accomplish it - standing up is quite a balancing act and walking really is just a series of controlled falls - without having to put any effort into thinking about it. By repetition you effect a permanent change in the basal ganglia (which selects actions for you without conscious control), cerebellum (which governs the precision of those actions) and motor cortex (which drives the muscles). Ever heard the phrase "It's like riding a bike - you never forget how"? That's muscle memory.

I did not. I'm postulating that you can affect your unconscious decisions by conditioning your mind beforehand. If you give it any thought, it actually has to be true - otherwise you could never influence your own behavior in any situation, and yet we know that we can. Military personnel, for example, can influence their actions/decisions/choices/movements in hostile life-or-death think-fast situations simply by training for months ahead of time.

Famine explained it better than I did, and my point is a bit more general. But it is basically my point.

I think you can also condition yourself for other more-intellectual responses. Military personnel can teach themselves to do a lot of unnatural things. Things like jumping out of a plane, not running away from an explosion, even throwing themselves on a grenade.

The final decision to act in each of those situations may be subconscious, even pre-determined by our brain. But that doesn't mean that the brain wasn't intentionally conditioned to respond in exactly that way in those circumstances. So the notion that we're a machine without "free will" is fairly silly, and does not follow from research that indicates that the final decision to act is made before the conscious brain realizes it. You exercise your free will in the years, months, and days prior to the moment.

 

[Dapper]

• The cortex is the outermost layer of brain cells. Thinking and voluntary movements begin in the cortex.
http://www.webmd.com/brain/picture-of-the-brain

The stress causes blood and oxygen to flow to your torso. Only a limited amount gets to the frontal cortex, which deals with your rational thought. Instead, you use muscle memory, repeating tasks from a drill.

This is in no way possible. Any amount of muscle memory still requires full brain functioning, this bomb guy says there isn't enough blood in his brain to work properly. Like I already said before, if there isn't enough oxygen to think, there isn't enough to operate muscles.

Not to mention what the bomb guy says about the body's response to stress is all wrong.
http://www.fi.edu/learn/brain/stress.html

 

[Famine]

• The cortex is the outermost layer of brain cells. Thinking and voluntary movements begin in the cortex.
http://www.webmd.com/brain/picture-of-the-brain

Would that not lend itself to a following conclusion that reflex movements don't begin in the cortex and are independent of the part of the brain that deals with thinking and decision-making?

This is in no way possible. Any amount of muscle memory still requires full brain functioning

You need a fully functioning brain - you don't use a lot of muscle memory if you're heavily brain damaged and in a wheelchair - but the part of your brain responsible for making decisions is not involved:

Please read up on "motor learning" (better known as "muscle memory"). It's nothing to do with muscles having memory, but with intensive training through repetition that results in permanent (or near-permanent) change in the physiology of the motor cortex (spinal motor circuit control), basal ganglia (action selection) and cerebellum (fine action control). The prefrontal cortex - the part of the brain "that thinks" (specifically the planning, decision-making and personality part) - isn't involved in muscle memory.

When you're first learning to ride a bike - or drive a car - you're thinking quite hard about how to do it and making lots of conscious choices and decisions. When you've learned to ride a bike - or drive a car - you're thinking only about where you're going and how to get there. The actual riding or driving is largely governed by the basal ganglia - muscle memory.

 

[homeforsummer]

This is in no way possible. Any amount of muscle memory still requires full brain functioning, this bomb guy says there isn't enough blood in his brain to work properly. Like I already said before, if there isn't enough oxygen to think, there isn't enough to operate muscles.

Not to mention what the bomb guy says about the body's response to stress is all wrong.

I'm sorry, but this is a guy who diffuses bombs for a living. I suspect he knows what he's talking about. He knows how his body acts in that situation. And I see nothing in that link you posted to suggest that he's just making stuff up.

Once again: You can accept that I've provided evidence to prove that you can train your body to act independently of thought in stressful situations (with an account from someone who makes his extremely dangerous living because he's able to do exactly that), or you can continue with the same line of argument that's going absolutely nowhere.

 

[Dapper]

Would that not lend itself to a following conclusion that reflex movements don't begin in the cortex and are independent of the part of the brain that deals with thinking and decision-making?

Maybe, but initiation of a muscle memory exercise is started voluntarily, kind of like one thinks about riding a bike before actually riding one, or starts to disarm a bomb (which involves little to no muscle memory). But the basal ganglia is where motor function happens, it just starts in the cortex.

When you're first learning to ride a bike - or drive a car - you're thinking quite hard about how to do it and making lots of conscious choices and decisions. When you've learned to ride a bike - or drive a car - you're thinking only about where you're going and how to get there. The actual riding or driving is largely governed by the basal ganglia - muscle memory.

Forgetting the fact that someone thinks to start an activity such as disarming a bomb (but this is realized within the brain before one is aware), do you think the part of the brain that is right next to the frontal lobe/cortex (the basal ganglia) receives a more than negligible amount of blood supply compared to the cortex during these times of stress that apparently cause a lack of blood flow to the brain?