It was probably more about sleep deprivation, chronic stress, and immediate reprioritization in your life, more than anything. It's hard to focus on learning new tasks when you're tired, and you're forced to confront a million new things at home.

The study just said that, in small areas of the brain, gray matter was reduced, and they theorized that this specialization helped a new mother recognize her infant and its needs. Nothing to do with math and physics.

I don't know much about the reality of 'baby brain', but in the study under discussion the researchers tested cognitive skills like memory, verbal skills, and working memory, and there was no significant change over time. It looks like the after-pregnancy tests were given late enough that kids were probably sleeping through the night (or at least in 5-6 hr chunks).

From conversations I've had with several mothers, it's not just sleep deprivation, there's a fog that someone else here called "baby brain".

This article suggests a physical reason why that is so, as well.

I have to say I don't think the article supports that at all. The study looks at a 2-year stretch and the changes in all but the hippocampus are still there at 2 years. Even friends who have reported "baby brain" don't claim it lasts 2 years, and synaptic pruning is not correlated with feeling foggy in any other study (and there have been a bunch!).

Did it revert, and after what time if yes?

For me, yes, but it took YEARS.

My kids are now teenagers, and I feel sharper than ever, but those baby years were a blur.