Longing for a world both near and far (Books - The Emigrants by W.S. Sebald)

The force of the praise for W.G. Sebald from  the likes of Susan Sontag, A.S. Byatt, Richard Eder, Cynthia Ozick, Michael Dirda in The New Yorker, The New York Times, TLS and elsewhere, make it pretty near impossible to come to his work unswayed.  I felt less like I dove into a new narrative world with anticipation in reading Sebald's The Emigrants (New Directions, 1997, Trans. Michael Hulse) and more like I had been invited to an exhibit of fine porcelain at a small museum.  I mustn't run, I mustn't touch, but I may walk through the hallowed rooms, look, and breathlessly admire. Whatever the use of literary criticism, or even book jacket blurbs, I don't imagine that that was the intention of these writers.  Whatever I came to like about The Emigrants on my own, was come to slowly, after I was able to drop the obligation I felt to search for evidence of his genius yet, it was worth the effort.

Keeper of the cabinet of human curiosities (Books - Hallucinations by Oliver Sacks)

Now nearly 80, neurologist, writer, and keeper of the cabinet of human curiosities - Oliver Sacks - has written his 12th book.  This one is on activations of the perceptual systems that are produced by internal rather than external stimulation or Hallucinations (Knopf, 2012).  They run the gamut.  You can smell them, hear them, see them, and feel them.  They can have their origin in disease processes, chemicals, injury to the nervous system, or sensory deprivation.  They can take the form of geometric patterns, religious conviction, snatches of music, or little people (Lilliputian hallucinations).  I too have seen a patient with this last form of hallucination.  Her's were holding their heads in their hands (detached from their necks), but it didn't seem to cramp their style any.  I think that the term is probably my favorite in neurology.

I have always admired Sacks's writing about his patients because I feel that I am reading about people rather than cases.  I am a great admirer of Sacks's early books like An Anthropologist on Mars and The Man Who Mistook His Wife for a Hat, both are less continuous narratives than Hallucinations or Sacks's recent Musicophilia and The Mind's Eye.  Rather than thematic in nature, these earlier books are simply collections of essays on human beings whose strange neurologic cases make them fascinating, but who otherwise have little or no relation to each other.  I found some of the material included in Hallucinations had to stretch to be subsumed under the book's theme.  While I found most of the material interesting, an episodically constructed book might have been a more natural and satisfying form.

On more than one occasion in this book (and his last, The Mind's Eye) Sacks becomes his own subject. In this case, he writes frankly of his experimentation with hallucinogenic drugs, a piece that appeared in The New Yorker last year, and of a serious hiking accident during which Sacks says that a voice commanded him to keep going. 

I am always impressed by the historical sources Sacks cites.  They immediately make me want to visit the library.  Jackson's original papers on epilepsy and aphasias, are cited in Hallucinations.  Perhaps this is not as enticing to the average lay-reader, but for a neuroscientist, these are the golden oldies. Jacksonian seizures were named for John Hughlings Jackson.

Hallucinations makes colorfully clear that the mechanisms in the brain that eventuate patients' perceptions in the absence of external stimulation can be diverse.  The light patterns that are experienced in the aura prior to migraine might be thought of as electrical disturbances like a wave passing across the visual parts of the brain.  Whereas the hallucinations reported around near death experiences such as a floating above one's own body may occur due to stimulation of the right angular gyrus, one of several brain regions implicated in a circuit that according to Sacks mediates body image and vestibular sensations.  The vision of a dark tunnel with light at the end may be the result of decreased circulation to the retina, which narrows the visual fields.

The most remarkable of the cases Sacks writes of in Hallucinations was that of an 86-year-old English man who already had glaucoma and macular generation, but when a stroke compromises his right occipital lobe he loses vision completely in his left visual field.  What is most interesting is that he is not aware of his loss

...his brain appears to fill in the missing parts.  Interestingly, though, his visual hallucination/filling in always seem to be context-sensitive or consistent.  In other words, if he is walking in a rural setting, he can be aware of bushes and trees or distant building in his left visual field, which when he turns to engage his right side, he discovers are not really there.  The hallucination do, however, seem to be filled in seamlessly with his ordinary vision.  If he is at his kitchen bench, he "sees" the entire bench, even to the extent of perceiving a certain bowl or plate within the left side of his vision - but which on turning disappear, because they were never really there.  Yet he definitely sees a whole bench, with no clear separation between parts composed of hallucination and true perception.

The human brain is a remarkable country and it is always enjoyable to travel there with Oliver Sacks as your guide.

Now you see it. Now you see it. Now you don't

Now you see it. Now you see it. Now you don't. No, I'm not stuttering. That sentence more accurately describes what happens when the visual cortex pays attention to sudden changes in the environment, according to Dr. Susana Martinez-Conde of the Barrow Neurological Institute in Phoenix. After the sudden disappearance of an object, an after-image of it lingers behind for a very short time, but just long enough that the brain is distracted, and that distraction provides the cover for the magician's manipulation which the human eye is unlikely to see. Benedict Carey's article in today's Science Times is about a paper in Nature Reviews Neuroscience written by two neuroscientists and a magician, that explores how the magician exploits the compensatory strategies our brains have evolved to overcome the limits of our perceptive and attentional systems.

...the brain focuses conscious attention on one thing at a time [not everyone agrees with this], at the expense of others, regardless of where the eyes are pointing. In imaging studies, neuroscientists have found evidence that the brain suppresses activity in surround visual areas when concentrating on a specific task. Thus preoccupied, the brain may not consciously register actions witnessed by the eyes.

Perception is my research area, and performing on stage is my former life but my very first work when in my teens was as a magician. I had a business doing shows for kids' birthday parties and the like. Perhaps I really have come full circle. There are six film clips in the supplementary section of the Nature Review Neuroscience article of magicians doing various tricks that illustrate the phenomena discussed in the article. Enjoy the show.