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Adult Brains More Flexible Than Previously Thought
stemceller passed us a link to the official site for Johns Hopkins, which is reporting on some research into cognition. Generally, doctors have understood our best learning to be done at a young age, when the brain has a 'robust flexibility'. As we get older, our brain cells become 'hard-wired' along certain paths and don't move much - if at all. Or, at least, that was the understanding. Research headed by the hospital's Dr. Linden has taken advantage of 'two-photon microscopy', a new technique, to get a new picture inside a mouse's head. "They examined neurons that extend fibers (called axons) to send signals to a brain region called the cerebellum, which helps coordinate movements and sensory information. Like a growing tree, these axons have a primary trunk that runs upward and several smaller branches that sprout out to the sides. But while the main trunk was firmly connected to other target neurons in the cerebellum, stationary as adult axons are generally thought to be, 'the side branches swayed like kite tails in the wind,' says Linden. Over the course of a few hours, individual side branches would elongate, retract and morph in a highly dynamic fashion. These side branches also failed to make conventional connections, or synapses, with adjacent neurons. Furthermore, when a drug was given that produced strong electrical currents in the axons, the motion of the side branches stalled.'"
They just normally prefer not to do so.
I had to fight them for a long time to use it, but now even my parents (in their 60s) suffer from internet withdrawal if they go without for a few days.
Damn kids! Get off my lawn!
There's a branch of neural net studies that focuses on a technique called entropic topography. Essentially, it involves random evolution of just the fringes of a digital neural net. That is, much as this John-Hopkins study has found, a rigid core is kept. It is only the neural subnets branching off that undergo synthesis and morphing.
While there are various deterministic algorithms that are used to evolve neural nets, it's only recently that we've begun seeing randomness used. This has an added benefit of bringing in unexpected mutations, which really don't happen with the deterministic algorithms.
Some advances from the study of Lei topographies have also lead to breakthroughs recently, where some of the more complex, yet deterministic, algorithms have had entropic terms introduced in order to bring in an element of randomness. These neural nets are probably the closest to the human brain, as they introduce the random mutation that is so prevalent within the human species, while also following the constraints of this new-found core neural path.
Here's another article on the same topic.
This is kind of what I'd expect, actually. Even if an adult mind was completely plastic, as people learn of the type of experiences that will come to them, they're going to quickly learn to categorize them, and which kinds of categories tend to work with more and more experiences.
It's like as a programmer learns of which coding constructs work for which situations... they learn it becomes more important to worry about understandability rather than speed, and to code with clear structures they can pick up later if and when they need to clean up misunderstandings later. The default practice becomes a sort of robust defensive form, that requires the fewest changes over the widest plausible set of needs - while still doing the job of completely enumerating the problem set needed.
I'd expect that even with minds unhindered by age, the same sort of defensive practices programmers pick up would have analogues in most other realms of experience that mankind goes through. That would then, be easily confused with a mind unable to rapidly change, because such wide change is then rarely observed.
That said - there are more concrete bits of evidence that complicate things - such as rates of new language adoption between adults and children... but again, there's also evidence that some adults can still pick up new languages rapidly. Perhaps those same defensive practices act as a 'language censor' to 'wasting time with confusing sentence structure' - or perhaps there really is some factor of truth to the hardware limitations of an aging brain. Hard to know for sure until we get the computational nuerobiology tools in place to be able to strictly test such things... I'm really happy to see the progress so far though.
Ryan Fenton
I's true. After reading the article I had my old dog learn new tricks.
I hate this view that some how results of tests on animals don't apply to humans at all. It's simply not true, almost every major medical advance has been tested or researched on animals like mice first. the simple fact is mammals bodies all work in very similar ways.
Having worked in a lab (disclaimer: not as a scientist) I learned that there are loads and loads of promising treatments for cancer and such that work great in mice, and never translate beyond. Even a casual glance at immunology from a layman's perspective reveals your statement to be utter bullshit; there are many, many diseases and afflictions that are species specific, sometimes highly so.
Anyway...it is entirely plausible that this ability to re-purpose brain cells is a plus for mice in survival/adaptation, where they have very little brain capacity at their disposal. We have loads at our disposal, and tend to build a lot of generally useful knowledge..ie, we build tools, literally or figuratively, and apply those 'real' tools or knowledge/skill 'tools'. Mice do not do either. We're more "general purpose", so maybe we don't *need* the ability to re-learn, since our learned skills are so broadly applicable in a survival sense.
Please help metamoderate.
Or maybe young people are smart enough not to clog up their brains with information that can be more easily and accurately recorded elsewhere. If all our fancy devices somehow stopped working, there would definitely be a period of confusion, but people would adapt. They'd go back to using their memories (or pen and paper.)
Technology isn't conflicting with our brain's evolution; it's extending and enhancing it. One less phone number to remember is who knows how many neurons that don't have to waste time storing and retrieving it. You might question whether young people are using this freed memory space to good use (for the love of all that's holy, I do NOT care about who won the latest reality show or what celebrities do in their spare time), but I think that it's a mistake to view this phenomenon as a fault.
That is actually an important observation that often goes unexplained. The fact is, mice are genetically very close to humans, but they reproduce quickly, are cheap, and their genetics and physiology are very well understood. That makes them a great animal to experiment on.
At the cellular level, most mammals are very, very similar to each other. In fact, we know so little about neurology in the first place, any understanding we can draw from mice helps us understand the basics of the vertebrate nervous system.
Most importantly, we cannot breed and sacrifice humans for the purpose of experimentation. The best we can do is use animals and hope that they are close enough (usually they are, by the way).
- Demosthenes
cynicsreport.com
Why is this article tagged with 'ronpaul' and 'ronpaulisanazi'? I thought this was slashdot, not digg. Why don't we just tag the article with 'omgiphonejailbreak' and '10waystoimproveyourwebsite' while we're at it?
Even a casual glance at immunology from a layman's perspective reveals your statement to be utter bullshit; there are many, many diseases and afflictions that are species specific, sometimes highly so.
He stated that it's "not true" that animal tests don't apply to humans at all (true), that almost every major medical advance has been tested or researched on animals like mice first (true, at least since the mid-twentieth century), and that mammal bodies work in very similar ways (true).
What you said is also true--that despite the huge similarities there are also significant differences--but that doesn't make his statement "bullshit"... perhaps merely "incomplete."
I support your point in general, especially because brains is obviously one of the organs in which humans differ the most, but I don't think that gives you the right to call a bunch of essentially truthful statements "bullshit."
That kind of conclusion is totally unwarranted. To begin with, the mice were not 70 years old. No, don't laugh! Either mouse neurons age as fast as the mice themselves do, which implies that (the processes in) their neurons differ fundamentally from ours, or these neurons age the way we do, but then they were studying two year old neurons, which I thought used to be considered pretty young.
Second, the observation that learning and memorizing becomes more difficult with age is pretty solid. If our neurons maintain their plasticity, these people should explain how a plastic brain stops learning.
Concluding: the observations are probably true, the conclusions were just made to draw attention and get more funding (aging is a big topic for funds these days). Such is the sad state of science.
PS I hold a post-doc in neurocognition.
And this is also one reason why it may be good for a person to change job now and then to not grow stale in one environment. It may be good to not change too often but if the job stops to develop a person it will result in that the person having the job will get bound to the job and unable to accept changes or the person will change job.
It's important for people to take on challenges now and then - even if failing it's a learning experience. If failing all the time - it's just meaning that this person is attempting things that always are too hard or that that particular person hasn't the ability to know his/her own limits.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
I've got a knife, you've got a brain... let's study this on your brain. ;-)
Must I understand that you don't have a brain? ;-)
You just got troll'd!