This is a potentially controversial issue, since there is no consensus yet on the evolution of the brain, beyond a very coarse-grained chronology. Broadly speaking, neocortical areas are new, hence the term “neo-cortex”. But among cortical areas, there is still some disagreement about which areas emerged most recently in primates.
Based on what we know about development in the womb, along with structural findings, my labmates, who are neuroanatomists, suggest that the “eulaminate” areas — the ones that have sharply defined layers — may be the most recent, evolutionarily, compared to the “agranular” and “dysgranular” cortices, which have less sharply defined layers. These less sharply defined areas are also labeled as “limbic”.
This post, which mostly provides useful citations, was originally written as an answer to the following Quora question:
Is ADHD one of the only psychiatric conditions that can be diagnosed objectively?
My research is on cognitive-emotional interaction, so I suppose I am qualified to answer this question. 🙂
But my answer cannot be the answer, since there is actually no consensus among scientists concerning the definition of emotions.
[Illustration of grief from Charles Darwin’s book The Expression of the Emotions in Man and Animals.]
Dopamine is not the feel good molecule or the basis of pleasure. The idea that any molecule considered in isolation could be the basis of a subjective experience is basically nonsense.
For people who can’t really reason through this idea, there is plenty of experimental evidence showing the complexity of each and every “celebrity” neurochemical — dopamine, serotonin, oxytocin, and so on.
I was asked this question on Quora:
Can you explain to a layman what neuroplasticity entails?
Neuroplasticity is the umbrella term for all of the brain’s mechanisms for learning and memory.
Since the average layperson already knows about learning and memory, I’m not sure whether there are any interesting implications.
Unless of course you are surprised that the brain is involved in learning and memory. Then the implications are vast. 🙂
This answer was written in response to the following Quora question:
New research has found no neurogenesis in human adults, could this mean there is none or could it mean that neural stem cells are undetectable with the used techniques? What are your thoughts on this?
It’s good that you’re thinking of such things, since that is exactly what researchers themselves have to do, and what reviewers do. In order to show that the method works, there have to be adequate controls as part of the experiment.
And this is in fact the case. The paper would not have been published without controls.