A stab in the dark

To what extent do we understand brain’s activity during sleep?

I’ll give you a little timeline that covers not only sleep, but learning itself. It was in 1893 when Ramón y Cajal, a Spanish scientist, proposed that plasticity was the way we learn. Plasticity means that the brain’s neurons reshape their connections. It’s important to know that neurons are constantly changing their connections. Even with elderly adults, that’s still happening. It’s a common belief that we can only learn, and our brain only changes, when we are kids. That’s actually not true. We are changing our brain connections all the time. Our neuron connections or our synapses change when we learn new things.

Then, in 1924, it was [John] Jenkins and [Karl] Dallenbach who found that, while we sleep, we reinforce whatever we learned that day. So, if you learn something during the day, let’s say, a new language, that night your brain will recall everything you learned that day. That will reinforce the new connections that you created.

Is this reinforced via dreams, or does it happen unconsciously?

It is