Human brain growth - few questions

[maciekqqq]

I'am interested in human brain growth and have some doubts.

 

Suppose there are two identical persons. The first person in teenage years (14-20) diligently studied maths and physics, and the other person didn't.

1. What are the differences in their brains structure?

2. If second person would start learn maths and physics in adult years (>23), is she able to fill the gap and develop her brain to the same state?

3. Does adult human brain creates new synapses while learning, escpecially mathematics, physics and logic? I thought that their level falls from 4th year of age.

4. (If answer at question 3 is "yes") In adult ages the myelining process is finished, so won't new synapses have myelin sheath?

[Ringer]

1.) There isn't a specific difference to be pinpointed that would be meaningful.

2.) Their learning and knowledge could develop to the same level, but there isn't enough known about the specifics of neuronal development to know about the to say any brain could ever be completely identical. There are far to many neurons to believe they could be identical though.

3.) Yes, you always create more synapses through dendritic development.

4.) The bodies of axons are what is myelinated, it stops before the synapse. Also, most developing synapses are mainly done through dendrites forming connections with existing axons.

[PhDwannabe]

I'll echo much of what Ringer had to say, with minor additions:

1. Yeah, structural differences are going to be tough to spot. Differences in activity, less so.

2. Indeed, getting to the "same state" is a tough idea to handle. In general, the answer is what you think it is: almost all learning is less efficient in adulthood than it was in early childhood (for language, motor acquisition) or adolescence (for most other academic things).

3. You present a false dichotomy, because you're right on both counts. Yes, learning generates new synapses, as well as alters the activity of existing synapses. Look up "long-term potentiation" if you want to find out a bit about one of the basic neurophysiological mechanisms of learning. It is also true that synapses fall away constantly after early childhood, in the same way that many neurons are dying--this is called "pruning." It does not mean that new ones cannot be created, even though the net total is generally a loss.

4. Ringer is correct, (though, your term "body" is not maximally clear, but I do see what you're talking about). Better to just say that it is the axon itself is myelinated--the axon is itself the long, stringlike projection. A synapse is like a shadow--it sort of doesn't exist, really, it's just a space. IIRC: Myelin, however, is continually produced, as it wears out and is recycled and replaced by oligodendrocytes, which are constantly generating new myelin projections to grab onto nearby axons.

[maciekqqq]

Thanks for answers.

 

In general, the answer is what you think it is: almost all learning is less efficient in adulthood than it was in early childhood (for language, motor acquisition) or adolescence (for most other academic things).

What is it caused by?

[PhDwannabe]

PhDwannabe, on 27 October 2011 - 12:47 PM, said:

 

In general, the answer is what you think it is: almost all learning is less efficient in adulthood than it was in early childhood (for language, motor acquisition) or adolescence (for most other academic things).

What is it caused by?

 

You mean, why is it this way? It is that way because it is that way--the brain is set up to acquire information with great rapidity in childhood. We could talk about all of the evolutionary, distal causes for that, which are somewhat well-known. But as for the proximal, mechanical causes, well, that's something any neuroscientist would step over grandma to figure out. Take language acquisition: through a neurocognitive process called "fast mapping" (it's actually just one major hypothesis of how things work), toddlers acquire dozens (some people say hundreds) of new words or concepts daily, sometimes with just a single or double exposure. It's absolutely astounding. If we knew exactly how it worked, we might be able to go a long way towards replicating it, and your high school French class would take about a week to finish. Simple answer: we don't know how it works. Couple of Nobel Prizes in store for the folks who figure it out.

[maciekqqq]

2. Indeed, getting to the "same state" is a tough idea to handle. In general, the answer is what you think it is: almost all learning is less efficient in adulthood than it was in early childhood (for language, motor

acquisition) or adolescence (for most other academic things).

You mean "learning" as new synapses creation process?

Do you think that intensive learning of mathematics, logic, etc. in adulthood can increase efficiency of learning process to the level of adolescence?

[PhDwannabe]

You mean "learning" as new synapses creation process?

Do you think that intensive learning of mathematics, logic, etc. in adulthood can increase efficiency of learning process to the level of adolescence?

1. Yes.

2. I have no data on which to answer, but I lean towards "no, not quite."

[Ringer]

Yeah, I couldn't remember what to call the axon between the terminal and hillock, so I just said body and hoped my meaning would get across.