Reply to comment

Reading your response made me wonder how recently human primates have evolved to have such a large and complex neocortex...I didn't find an answer to this question (and would love if somebody could contribute information about it) but I found an interesting article talking about some of the unique properties and functions of the neocortex in mammals.

When brains expand: Mind and the evolution of cortex.

I couldn't get the full text but part of the abstract is interesting:

"the mammalian neocortex is unique: its relationship to the rest of the nervous system is unusually plastic, allowing great changes in cortical organization to occur in relatively short periods of evolution. The fact that even advanced abilities like self-recognition have arisen in species from different mammalian orders suggests that expansion of the neocortex quite naturally generates new levels of cognitive sophistication. Our cognitive and behavioural sophistication may, therefore, be attributable to these intrinsic mechanisms' ability to generate complex interarchies when the neocortex reaches a sufficient size."

Thus one additional part of the picture is the ability of the mammalian neocortext to evolve quickly, likely leading to greater cognitive sophistication.

I also found another article attesting to a tie between neocortical functions and socioemotional capacities of humans and other primates for such things as communication of emotions to others and within groups, complex facial communication, empathy, and self-conscious emotions. These functions allow such species to respond adaptively to their social environments and ensure their reproductive survival.

TI: Emotional communication in primates: Implications for neurobiology. AU: Parr,-Lisa-A; Waller,-Bridget-M; Fugate,-Jennifer SO: Current-Opinion-in-Neurobiology. Vol 15(6) Dec 2005, 716-720.

(I saved it in Haverford storage in a folder called "neurobiology and behavior")

The article cites a theory by Dunbar positing "a relationship between large brain size and complex societies among Homonoids." Thus several people in the forum were possibly correct in attributing many evolved social abilities to the neocortex according to the theory (such as increased ability to cultivate large numbers of personal relationships as facilitated by better cognitive processing speed and memory for social information).

Interestingly, none of this evidence presents information about neocortical functions that exist only in humans. If anyone has anything to say about that I'd be really interested to hear it.