<p>Tokenadult: I really found a lot of the criticisms in the articles tangential. Esperanto is not meant to save endangered languages (that’s a separate endeavour), and I dont’ see what’s so evil about having synonyms – that seems a very natural part of the natural language process. In so far as having an international auxiliary language, the main obstacle to its goals naturally is increasing the number of speakers. </p>
<p>
</p>
<p>Mmm, but is the language acquisition device (as Chomsky has called it) in those neurons?</p>
<p>The most perplexing part of the human brain is that it’s so difficult to pin down consciousness, language processing (though we do have Broca’s and Wernicke’s areas, those seem like “add-ons” to our main language faculties) and even where long-term memories are stored (after they get “moved out” of the hippocampus). There isn’t one specialised area for procedural memory, which might make sense because if the areas that store procedural memory seem to be scattered throughout the brain, they may be quickly activated for each “body part” the procedural memory is intended for. What sort of neurological processes would be involved in language acquisition, especially as fluency is concerned? Would it be mostly procedural learning, or memory linked to consciousness and personality? There is good evidence of the former (amnesiacs still remember how to speak) but at the same time language is strongly tied to cognition.</p>
<p>Furthermore, many aspects of learning may not be involved in just the neurons, but the glial cells that were previously thought to be just involved in support. Anyhow, the brain does pruning all the time. Sometimes in fact it may be used for efficiency – if brain matter there is storing nothing, then it is removed or moved around. The neurons that die (or get signals to kill themselves by apoptosis, or create eat-me signals) often are the ones that are unused. It’s sort of a form of natural selection. Adults have neural stem cells too, and at least 50% of neural stem cells die before they ever make it to their intended spot, and if they are not quickly linked to the existing “framework” that is another chance for them to die. </p>
<p>I just really have a hard time seeing that the pruning mechanism necessarily equates to pruning of learning ability. Furthermore, if I actively try to “learn like a child,” I find that my learning attempts become far more successful. Taken together with the fact that it’s so hard to set down even a rough approximation of the critical window period, I’m not really sure if losing neurons has much to do with it. It sounds alarming (“we’re losing brain matter?!”), but you can also remove entire portions of the brain with little damage. </p>
<p>Take for example a girl who was prone to violent epileptic fits (I am unable to recall her name so you can look her up on Google Scholar – maybe you’ve known her case too) – it was found that an entire hemisphere of her brain was faulty (I forgot what the exact disorder was), but anyway, the remarkable thing was they could remove that problematic hemisphere, have her recover from surgery and her personality did not change at all! Her intelligence (bright, inquisitive and bubbly when she wasn’t in a fit) was not affected! This seems to tell me that having more brain matter is useless, even a liability, if it remains unorganised or diseased. I suspect the pruning is not unlike removing an entire diseased hemisphere of a brain, where learning ability may not even be impacted significantly.</p>
<p>The paper you cited details a phenomenon that is well-known – babies originally babble in all sounds of the human language, then they start babbling only in the sounds of their parents. But taken together with other studies in language acquisition, I think one has to be careful before concluding that this means that babies are “locking in” sounds. One thing is true, and it’s that children are incredibly perceptive to language – babies can perceive sounds that they do not know yet how to produce ([the</a> Fis phenomenon](<a href=“http://en.wikipedia.org/wiki/Fis_phenomenon]the”>Fis phenomenon - Wikipedia)). As you get older, you become less perceptive. But is it because you lose neurons, or is it because something else happens – a change in your sensory filters, perhaps? For one, we do not became immediately enchanted when a new toy dangles in our faces, and what I suspect is that the older we get, the more likely we shut some stimuli out. But this doesn’t make things impossible – you just have to consciously become meticulous and attentive when learning a language. </p>
<p>Anyway BedHead, both of us share similar recommendations I think – that you should teach children foreign languages at a young age. I’m just disputing critical window theory because it’s my hypothesis (given the linguistic data I’ve come across) that all adults can learn foreign languages to native fluency; they only don’t because of various interfering factors. The “language acquisition device” can be reactivated. We should also remember that the brain as a whole imposes a very taxing energy drain on the body – not a big deal in the modern age, but it would have been a big deal before agriculture. The reason why the device would be “turned off” I think, is not so much as due to neuron-pruning, but to manage mental resources. Remember, at a young age children have less things to think about, so using their brains to acquire language would be a good use of mental resources. But subconsciously and automatically analysing every word might consume more attention that it might be worth … at least in the days before globalisation.</p>