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12

There is a huge body of literature on axon growth cone guidance which will give you some insights into how the biology works. Unfortunately, incorporating it all into a model is probably going to make it unwieldy unless your express purpose is to model the physiology, which doesn't seem like the case. Here are some references: Hong K, Nishiyama M. ...


6

For the dentate gyrus, which is probably more closely analogous to a feedforward hidden layer in a memory network, here are some answers: Axon and dendrite connectivity is essentially local and can probably be assumed to be initially random within that local region. That is, a neuron integrating into the DG at the midpoint (along the long hippocampal ...


6

Another reason for reduced plasticity in adults is that learning something different in the presence of an existing knowledge structure is more difficult than learning from a "blank slate". In a sense, you get interference from the known language (for example). One person who has developed this argument computationally is Jay McClelland in the context of ...


6

Although LTP might be necessary for brain plasticity, I would doubt that it is also sufficient. There is quite a lot of literature about homeostatic plasticity (for a review, see Turrigiano & Nelson, 2004) and synaptic scaling (for another review, see Turrigiano, 2008) which seem to be necessary to keep LTP working in the long run. References ...


4

Assuming you're getting at a related idea to your other recent question (Does a more ergonomic and user friendly interface/device make the human brain work less?), I wouldn't worry about user friendliness causing mental atrophy by precluding the need for thought. Thought continues well beyond matters of control to matters of application and optimization. ...


4

In adult mouse cortex, synaptic spines can last anywhere from days to months. I'm not sure that any such work has been done on human Broca's area, but keep in mind that many synapses are experience dependent. One study found that fear conditioning and fear extinction lead, respectively, to synapse formation and elimination. So the lifetime of a synapse ...


4

One great example of such plasticity is the ability of early-blind people to utilize their V1 area to read Braille: Functional relevance of cross-modal plasticity in blind humans (Cohen et al., 1997) Excerpt from the abstract: We conclude that blindness from an early age can cause the visual cortex to be recruited to a role in somatosensory ...


4

Yes, the visual cortex is plastic, even in adults: We measured adaptation in the responses of populations of cat V1 neurons to stimulus ensembles with markedly different statistics of stimulus orientation. We found that adaptation served two homeostatic goals. First, it maintained equality in the time-averaged responses across the population. ...


3

The concept of mental rotation was introduced by Shepard & Metzler (1971). The 3D assemblages of cubes were part of their original experiment. Vandenburg and Kuse (1978) later developed a paper-and-pencil test based on this prior experiment, named the Vandenberg and Kuse’s Mental Rotation Test (VMRT). The study which Bavelier most likely refers to is ...


2

Consider that elimination of such a phenomena is not ideal. It's been proposed that actual neuronal networks exist under the tension of synchronous decoupling. http://www.sciencedirect.com/science/article/pii/S0896627308001281 To answer your question though, you probably should consider that reciprocal connections might not be between two individual ...


2

The truth is, we don't fully know. There are likely a number of factors. One of them seems to be the Brain Derived Neurotrophic Factor (BDNF). This molecule seems to be involved with maintaining and encouraging neuron growth. In Rats with a transgenically accelerated rise in BDNF levels, the critical period began earlier, and finished earlier as well (Huang ...


1

What you mean is that you want teenage existentialist angst to last for life? The neuroplasticity of younger children comes at a cost, which is not really knowing ones place in the world, because the world model you are building is constantly changing. Getting a world model broadly settled then enables you to move on in life and do more. If we retained the ...



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