Imagine a critic scanning a text for what TS Eliot called the "objective correlative," famously described as
...a set of objects, a situation, a chain of events which shall be the formula of that particular emotion; such that when the external facts, which must terminate in sensory experience, are given, the emotion is immediately evoked....Similarly, literary neuroscientists would look for the effect, not the cause--examining the brain, not the text. Davis explains:
With the help of my colleague in English language Victorina Gonzalez-Diaz, as well as the scientists, I designed a set of stimuli—40 examples of Shakespeare's functional shift. At this very early and rather primitive stage, we could not give our student-subjects undiluted lines of Shakespeare because too much in the brain would light up in too many places: that is one of the definitions of what Shakespeare-language does. So, the stimuli we created were simply to do with the noun-to-verb or verb-to-noun shift-words themselves, with more ordinary language around them. It is not Shakespeare taken neat; it is just based on Shakespeare, with water....Davis's excitement at the results is as measurable as the N400 effect:
So far we have just carried out the EEG stage of experimentation under Dr Thierry at Bangor. EEG works as follows in its graph-like measurements. When the brain senses a semantic violation, it automatically registers what is called an N400 effect, a negative wave modulation 400 milliseconds after the onset of the critical word that disrupts the meaning of a sentence. The N400 amplitude is small when little semantic integration effort is needed (e.g., to integrate the word "eat" in the sentence, "The pizza was too hot to eat"), and large when the critical word is unexpected and therefore difficult to integrate (e.g., "The pizza was too hot to sing").
But when the brain senses a syntactic violation there is a P600 effect, a parietal modulation peaking approximately 600 milliseconds after the onset of the word that upsets syntactic integrity. Thus, when a word violates the grammatical structure of a sentence (e.g., "The pizza was too hot to mouth"), a positive going wave is systematically observed.
This, then, is a chance to map something of what Shakespeare does to mind at the level of brain, to catch the flash of lightning that makes for thinking. For my guess, more broadly, remains this: that Shakespeare's syntax, its shifts and movements, can lock into the existing pathways of the brain and actually move and change them—away from old and aging mental habits and easy long-established sequences.To switch poet/critics, this is something akin to Wordsworth's "flash upon that inward eye," magnetically measured.