Here's my first attempts with Photobucket, to give you guys a road map. Can't know where you're going unless you have a map.
First map gives you the lobes of the cerebral cortex (in colors) and the cerebellum (really a balance-related piece of the brainstem with an attitude complex ... taking on all kinds of higher-order functions related to actions, motor reactions and balance)
Here's another way of looking at things ... all the names and labels aren't important right now ... just another roadmap with different markers on it.
Okay ... now that we have the "Michelin Guide" to the higher-order CNS ... let's go for a trip.
The new research appears in the Proceedings of the National Academy of Sciences, or PNAS for short. This is the house journal of the august body of mainly American scientists that inducts a few new members a year, usually as old ones die off. There is a vulgar joke about the abbreviation for this journal and the traditionally predominantly male composition of the National Academy, but thankfully, this joke is becoming less and less relevant as the years pass.
Anyway, the research in the article was not done by Academy members, but was reviewed and recommended by one of them. If you're interested in the affiliations of the authors, the reviewer or just want to take a look at the original, go to your local library and use the computer to look up "Shapiro et al., Cortical signatures of noun and verb production," in the January 23rd Advance Publication Section of PNAS. I can't give my hyperlink, as it uses my library's license ... and that's a no-no, apparently.
Shapiro and his colleagues asked themselves, "What goes on in the brain when we read a phrase and a word is meant to be a noun? What about when it's a verb?" As the authors note, linguists have long understood that even preschoolers can tell you whether a word is meant to convey a thing (noun) or an action (verb). Chomsky makes a great deal of hay out of this. So Shapiro and his boss, Alfonso Caramazza, both psychologists, figured that if the linguists were right that this is hardwired, we should be able to look at the discrete activity in the brain that encodes verbs and nouns.
The group gave subjects stimulus phrases that introduced the concept of interest, like think/thought. Then they presented cue words and asked the subjects to produce the correct word that expressed the concept of interest with that cue. So if the stimulus was "one idea," and the cue was "he ...," a correct response from the subject would be "he thinks" or "he thought." If the stimulus was "one idea," and the cue was "many ... ," then the correct response could be "many thoughts." The researchers also threw in pseudowords, like "zib" or "wug," to which the subjects would have to form phrases with cues; "he ..." could be answered with "he zibs" if the stimulus was "they zib," and "many ..." could be answered with "many wugs" if the stimulus was "I wugged" (note that even pseudoword stimuli phrases could use the concepts as verbs, whereas the correct cued response could be to use the concept-word as a noun).
Using fMRI, discussed in the last diary, the researchers looked at the activity when subjects produced verbs based on the cue phrase word and compared it to when they produced nouns based on the cue phrase word. They also looked at some other issues that we won't go into here, but which I can try to field questions about if you're really interested.
It took longer for subjects to provide answers in the form of verbs than in the form of nouns. The processing involved with nouns took significantly less time, and this was the first hint that the words are not processed in the same way (the language pathways are not entirely identical for the two basic types of words).
Nouns, whether pseudowords or actual English nouns, preferentially activated a region in the inferior temporal lobe in the left hemisphere, called the left fusiform gyrus. On our maps, that's the "lower" part of the temporal lobes (it appears to border the cerebellum and the brainstem, but it isn't actually contiguous with either one). As my wife would say, "Okay ... big deal."
However, the fascinating thing about this region is that this is where visual information about the features of THINGS like houses and toilet brushes and faces is discretely processed. Visual information first comes into the cerebral cortex in the part of the map labelled OCCIPITAL, but activity related to more and more complex features is sent "forward" through neurons in the visual association areas and "down" into the temporal lobe. In other words, when you see a dog, neurons in the temporal lobe assemble the features and this is generally agreed to help you recognize a dog. Most neuroscientists would not say that there is a "dog neuron" somewhere in the middle or inferior temporal lobe, or even a single neuron that encodes your dog Spot (if you consider how many neurons you lose after one beer, you can see the disadvantage of such a highly specific neuronal network), but there is probably a network that when it is synchronously active leads to the recognition of dogs or the differentiation of Spot from other dogs. And the region where that network would appear to be is also the region that gets particularly active when you read the phrase "my dog" or say the phrase "his dog."
There were a variety of regions that were active when verbs were produced by subjects (again, whether English or gibberish used as a verb), but only two were preferentially activated in all the experimental conditions used. One was the prefrontal cortex, which can be simply thought of as a higher-order region that links broader goals or cues with motor plans and the other is the superior parietal cortex (the piece of the pinkish region closest to the red strip labelled sensorimotor area). The posterior parietal cortex (the whole pinkish region, and part of the yellow labelled as temporal as well) also receives visual inputs from the occipital cortex. It is sensitive to object motion and location, and less sensitive to size and overall form of objects. But it is highly activated when subjects want to DO SOMETHING relative to the observed object, like reach for it or grab it. In fact, posterior parietal cortex not only receives a lot of information from occipital cortex, but has dense connections with frontal cortical neurons related to motor plans and somatosensory neurons (anterior parietal, that red strip) that provide tactile information as the hand or other body part hits objects and manipulates them. So, just as the part of the cortex that "lights up" specially for nouns also helps to recognize things, the parts of the cortex that "light up" specially for verbs helps to PERFORM ACTIONS.
It reminds me a little of a poster I saw when I was about nine years old.
"To Do is To Be" - Plato
"To Be is To Do" - Descartes
"Do Be Do Be Do" - Sinatra
As we read or speak, we are conveying stimuli to our cortex (or those of other individuals) that correspond with object or action recognition. The visual stimuli or auditory stimuli take the place of the objects or actions ... they are cortically equivalent. Shared concepts of things are what we call nouns. Shared concepts for action plans are what we call verbs. And the stimuli can even be nonsense, and receive particular cortical processing by the surrounding linguistic context. "I Tarzan, You Jane" is immediately picked up as pidgin by an English speaker above the age of 5, because the context is giving false signals about the key words that are usually used as proper nouns (names). The same would be true of "One think" but not "One thought" or "One thinks" (although the processing of the second example is different from that of the third).
Therefore, when we read, "Take up Arms, my fellow citizens, the time has come to Filibuster Alito," a series of concepts and contexts are conveyed and processed in rapid order. We prepare (metaphorically) to take up a weapon conjured up by our imagination (specific to the individual, no doubt), which provides its own context to the rest of the idea. We perceive the group of citizens, using different circuitry than we did for the first three words. Here, we do not prepare to do, but focus instead to whom I am referring. Do we belong to this group? Not if we are trolling from RedState (or maybe we do). The next part involves both circuits, to recognize the abstract object of "time" and its abstract action of arrival. We can almost see it catching up to us where we are standing. Then we perform the same process again, that we will perform "Filibustering" on Alito. Now, you realize that we will not storm the Capitol and Filibuster the nominee ourselves, as that will get us dragged off the floor. But in preparing to Filibuster, we make the plans that we will convey in writing or on the phone to our Representatives in the Senate.\
And this is an area where Chomsky and many linguists seem to be correct. Although the relationship between the individual words (gibberish or English) has to be worked out in our formative years, linking "dog" with dogs and "petting" with stroking fur gently, the brain appears to innately zero in on context and parcels out the association making to the Action-Frontal-Parietal network or the Object-Temporal network. The question becomes, "When does that begin?" and will require working with spoken language among preschoolers.
But the sword cannot create such nuanced associations in the brain. It can create fear or anger or even annoyance, but without words on a proclamation or yelled into the air, the sword is largely meaningless to our brains. Do you mean yield? En Garde? This can be yours for just fifty dollars? It is up to the word to clarify the communication. How much more can be accomplished between overgrown monkey brains with language than with crude threat? A great deal more, especially when given rich context and specifics.
Until next time, here's hoping you've gleaned some of my intentions.