The trine model of the human brain first introduced by MacLean — seeing the human brain as evolved in three main waves, the first of which has created a reptilian complex at the core, the second a paleo-mammal limbic system and lastly the recent structures of the neo-cortex — is now considered anatomically obsolete and Damasio's work has clearly shown the most "primitive" structures to be vital to superior cognition.
How much of this layered conception, made of levels, ancient and recent, primitive or cognitively superior, with interactions flowing in both senses (top-down or bottom-up), still survives in the debate?