[zug_zug]

Really? It seems obvious to me.

During the learning stage we want input from every variable so that we are sure that we don't omit a variable that turns out to be essential for the calculation. However in any calculation a human does 99.9999% of variables are irrelevant (e.g. what day of the week it is, am I sleepy, etc), so of course the brain wouldn't use resources to keep connections that aren't relevant to a given function. Imagine what a liability it would be if we have had excessive direct connections from our visual processing system to the piece of our brain that controls heartrate.

[idiotsecant]

We can convince ourselves of a lot of things that 'seem obvious'. The pesky thing is that sometimes those obvious facts have the temerity to be untrue. That's why we try to understand systems instead of believing obvious things.

[xpuente]

As far as I know, pruning is related to age. At birth, we have a massive number of silent synapses. As we grow older, those that remain unused (i.e., inactive) tend to disappear. This process involves a delicate mechanism, including components of the immune system.

The unfortunate reality is that no one truly understands how memory works. Many theories are floating around, but the fundamental components remain elusive. One thing is certain: it is quite different from backpropagation. Thankfully, our brains do not suffer from catastrophic forgetting.