A note for Lesson no. 1, "You Have One Brain (Not Three)," in Lisa Feldman Barrett.
Some context from page 14 is:
The outermost layer, part of the cerebral cortex, is said to be uniquely human and the source of rational thought; it’s known as the neocortex (“new cortex”).
The cerebral cortex is a sheet of neurons arranged in layers:
The sheet covers the cortex:
Here you can see the cingulate cortex and the so-called neocortex: