Monkey Broca, Wernicke?

[cc at cds-web.net]

Strictly speaking, present-day monkeys are not "pre-human primates".
They are the evolutionary descendants of a common ancestor with  
humans, as indeed are we.
This type of short-hand can be seriously misleading.

cheers,
chris



Quoting Tom Givon <tgivon at uoregon.edu>:

>
> Neuroscience advances somewhat fitfully. For every announced new
> discovery,  there is sooner or later (more often sooner) a finding
> pointing in another direction. This is because of the complexity &
> distributiveness of most higher cognitive system. Another instasnce, I
> suppose, of the three blind men describing the elephant. So first, we
> need to be cautious about evaluating 'radical new discoveries',
> particularly about language (which is the most complex & distributive
> capacity supported by the brain).
>
> More to the point, the function-specific regions ("modules") of the
> cortex  ('periphery') are all  mamalian evolutionary projections from
> the *limbic-thalamic sub-cortex*. This is true of vision, audition,
> motor control, somatic-sensory areas, attention, episodic & semantic
> memories, etc. And for most of those 'higher' cortical capacities, the
> limbic-thalamic areas remain part of the functional system--in a a
> *distributive network* (see e.g. M-M. Mesulam's  "Principles of
> Behavioral & Cognitive Neurology", 2nd edition,  Oxford U. Press, 2000
> as a major source on this. But there is a vast  lit. on the subject).
>
> Thus, because so many of the cognitive capacities that support human
> language are  the outgrowth of (functionally amenable) pre-linguistic
> capacities, the limbic-thalamic areas are implicated in almost all
> brain-activity related to language processing. And the pre-human
> primate brain is so close to ours in its general architecture, there's
> no reason to assume that the same core-periphery relation doesn't apply
> there.
>
> So if at one time research implicates a cortical area ('periphery')
> and at another a sub-cortical one ('core') in executing the same
> function, be it linguistic or pre-linguistic, it is because* both* are
> implicated. Keep on truckin'.  TG
>
> =======================
>
> Mark P. Line wrote:
>
>> jess tauber wrote:
>>
>>> Study hints language skills came early in
>>> primates-http://news.yahoo.com/s/nm/20060725/sc_nm/science_language_dc
>>>
>>> I remember being told that lower primates only utilize lower (limbic)
>>> brain centers for vocal communication. So what does all this mean??
>>>
>>
>> I think this study is important precisely because it had been hypothesized
>> that monkey vocalization does not involve the cortex. This rather
>> seriously overgeneralized hypothesis came about because experiments
>> (starting in the 1970's, I think) showed that vocalization was elicited by
>> limbic but not by cortical stimulation.
>>
>> Apart from the obvious ramifications for our understanding of the
>> phylogeny of primate communication, the study also suggests that the
>> reason for those stimulation results in monkeys may be due to limbic
>> control of vocalization even if there is cortical involvement in the
>> actual behavior: limbic stimulation causes vocalization because it
>> provides the control stimulus, while cortical stimulation does nothing
>> because the limbic signal is absent. Note that monkeys don't want to
>> vocalize willy-nilly except for good reason (since there might be an
>> undetected predator within earshot), and that there would be solid
>> inhibitory pathways preventing vocalization if only Broca is stimulated
>> without the limbic input.
>>
>> Humans will have evolved past this limbic control -- most communication is
>> consciously intended and neocortically controlled. (There's an obvious
>> joke about throwbacks at a recent coffee klatsch.)
>>
>> I'm surprised that no such study was done before now and that the
>> limbic-only hypothesis for monkey vocalization remained unfalsified until
>> now, but I guess I'll take their word for it.
>>
>> -- Mark
>>
>> Mark P. Line
>> Polymathix
>> San Antonio, TX
>>