Monkey Broca, Wernicke?

[jess tauber]

In a completely speculative vein, I wonder whether differences in stimulability between monkey and human cortical versus limbic areas (re vocal communication) are due to stereotypicality/innateness in the responses elicited. Our more linguistically oriented  vocalizations are largely learned and often highly context dependent- would this not be far less likely to be the case for most of the limbically motivated vocalizations, both in man and monkey? Is it not also true that monkey and ape brains are to some extent both less lateralized and interconnected via corpus callosum etc.? AND also true that limbically motivated vocalizations in humans, given our lateralization, are more likely to be organized via the RIGHT hemisphere statistically? One might also notice that my thoughts here exhibit perhaps less interconnection than they should before committing them to the electronic sea. :-)  Now I have heard it said (though not remembering where from...) that ape lateralization is the reverse of ours statistically. Any of you heard that as well?

IF so then a) the cortical areas in monkey being compared to the corresponding homologous human ones should be on the opposite side of the head. It would also be interesting to know whether cortical versus limbic stimulation of the human right hemispheric Broca/Wernicke area homologues elicits the same responses as those done on the left side. b)   Even for the right hemisphere some vocalizations are linguistic (epithets, for instance), while others are more purely continuum-type interjections (the ones that are hard to write in a consistent form), perhaps also ideophones (still linguistic but outside lexicon proper for many students), pragmatic modulation of intonation, etc. Is there a cortex versus lower center hierarchy for these different forms (hmmm)??

Parallel, but opposite symmetry, evolution isn't all that uncommon in biology. Our reptilian ancestors (with apologies to those of you reading many might still consider reptilian in demeanor...) had TWO bilateral aortas and vena cavas (my Latin is failing me here). This symmetry was broken in birds and mammals respectively- but birds made the opposite choice. Thus their hearts are oriented opposite to ours. Brain lateralization may have had similar choice in anlagen/raw materials.

Functionalists, more than other species of linguist, should be painfully aware that comparisons can be forced when categories are not so clearly identical, have fuzzy boundaries, etc. Symmetry is an issue that needs to be addressed- the recent discussion about 'time reversal' showed us that- keeping in mind that symmetry breaking can create differences leading to somewhat false homology. One last point- why is it I write so much better than I speak in public?- aaaarrrrgh!

Jess Tauber