The researchers found that a network comprising the basal ganglia was activated for the timing of regular sounds, whereas a network in the cerebellum was found to be activated for the timing of irregular sound sequences.The basal ganglia are involved in such things as voluntary motor control, procedural learning relating to routine behaviors or habits, eye movements, and modulates cognitive and emotional functions. With the exception of the emotional functions, each of these are timing functions.
The cerebellum is involved in the coordination, precision, and accurate timing of motor control, with attention and language, and in regulating fear and pleasure. Again, with the exception of the emotional functions, each of these are timing functions.
The rhythms of rhythmic poetry and prose, it seems, invoke different parts of the brain. Interestingly, the part of the brain involved in language is that which is used for irregular sounds sequences. We speak in prose. Yet note some of the other things listed. The cerebellum is also involved in fear and pleasure regulation. We have horror novels, but where are the horror poems? The closest might be Poe's "The Raven," but then one does not feel so much horror when reading the poem as a certain creepiness, sadness, or haunting feeling. I will also note that much literary prose we read is in the form of novels -- a genre that requires our attention. These may not be unrelated, then.
But let us look at the relation between rhythmic verse and the functions of the basal ganglia. Regular rhythms are very much like routine behaviors -- the same rhythm, like a habit, recurs. The fact that cognitive and emotional functions are also modulated in the basal ganglia might also suggest that rhythmic poetry could contribute to the modulation of into our emotions and cogntiive abilities. Or at least influence it, for better or worse? Regular rhythms at the very least seem to be very persuasive -- both emotionally and cognitively. Might this be the very reason for that? Consider the fact, too, that rituals are a kind of "procedural learning relating to routine behaviors or habits," allowing for the perpetuation of cultural norms, including ethical beliefs. This suggests a close relationship between ritual and poetry beyond the mere use of poetry in rituals.
Of course, rarely are poems purely and perfectly rhythmic. There are variations in just how stressed or unstressed a syllable is. And some syllables can change based on its neighbors. This creates a level of irregularity on top of the regularity. Those poems which can accomplish this, then, are likely to tap into both parts of the brain simultaneously. Another way a poet might be able to accomplish this is to mix up the regularity of the rhythms in the lines. Many ancient Greek poems did this. where regular line rhythms are used, but a variety are mixed together. A poem with, say, the following rhythm:
U//U/U/U/with each quatrain repeated might be able to do both simultaneously, since the brain is detecting both regularity and irregularity.
What other insights might we be able to gain from this? What uses might one be able to put this in regards to versification?