The Phi Effect and a Quarrel about Consciousness

In my recent blog post on rereading Thoreau’s Walden I described how “bubbles of light” danced around the pages of my book as I sat reading under a tree, and also how some of these circles of light seemed to jump from one spot to another. The technical name for this visual “jumping” effect is the Phi phenomenon, and it’s an illusion that is crucial to our ability to process “motion pictures.”   As it happens, this effect has also been discussed by two very different thinkers seeking to explore the nature of consciousness: the philosopher Daniel Dennett and the psychologist Merlin Donald.  Donald describes the phenomenon as follows in his excellent book A Mind So Rare: the Evolution of Human Consciousness:

The simplest demonstration of Phi is to alternate two light sources spaced a few feet apart: on-off-on-off., etc.  At a certain speed of alteration the viewer no longer sees two lights turning on and off but instead reports seeing a single light moving back and forth.  The observer’s brain has unconsciously resolved the alternating images into a single moving picture.

So in my case the light passing through the leaves of the tree above me was dispersed onto the page of my book, producing many circles of light, and these circles moved around on the page, or appeared and disappeared, as a result of the breeze fluttering the leaves.  Apparently the “speed of alteration” was at certain times, and in certain spots on my page,  just right for producing the Phi illusion, so that I began to see a single light jumping back and forth.

Now, what does any of this have to do with consciousness?  That question brings us to Daniel Dennett’s brilliant and provocative book Consciousness Explained, which has sometimes been dubbed by his detractors Consciousness Explained Away, because of Dennett’s relentless determination to do away with our “illusions” about consciousness.  For Dennett, the Phi phenomenon is interesting because it is yet another example of the mind tricking itself.  And the big trick he wants us to see through is our belief that “consciousness” is more powerful, and more prevalent, than it really is.  His argument is detailed, complicated, and lengthy, so I can’t do justice to it here, but it has been quite important to my thinking about mind, and about all the ways our behaviors and decisions are influenced by factors and processes that are, in fact, inaccessible to conscious awareness.  But in A Mind So Rare, Donald takes up a serious quarrel with Dennett, whom he labels both a Minimalist and a Hardliner because of his habit of “downgrading consciousness to the status of epiphenomenon.” In Donald’s view, the Hardliners substitute for consciousness “a computational netherworld deep under the surface of the mind, [so that] old-fashioned consciousness simply slips away from our grasp, fading into the mist.”  I may not have made it entirely clear yet how exactly Dennett and Donald get from the Phi phenomenon to an argument about consciousness, but the debate involves the question of how much importance we should give to illusions like the Phi effect when we try to evaluate our capacity for conscious awareness.  Since I don’t want this to get too long, I think I’ll go a little deeper into this question in another post. For now, I’ll just say that things get especially interesting when you consider the phenomenon of Color Phi, which you can experience here.

 

 

Reading Thoreau (Again)

Thoreau Portrait Restored

Henry David Thoreau’s Walden (free ebook at The Literature Project), is among the rather small number of books that has become lodged in my consciousness, inescapable and integral, an element of my very being.  The fact that it has been years since I’ve read it all the way through has no effect on this primacy of place.  Nevertheless, the time has come to read it again.  This feels, on the one hand, like deciding to visit an old friend, a boon companion from the past with whom the connection is still strong; but, on the other hand, if this re-encounter is to be genuine, if it is to have real meaning, then I will inevitably be disturbed, provoked.  Walden is above all a provocative book, intended to shake us out of complacency, to force us to question things we are used to taking for granted.  To read it again, really to read it, will mean not just to call up old memories but to stir new thoughts and feelings, to test Thoreau’s conclusions against my own values.  As Thoreau writes, to be a philosopher, as he would ask us all to be, is not just to have “subtle thoughts,” but “so to love wisdom as to live according to its dictates, a life of simplicity, independence, magnanimity, and trust.”  And as Thoreau well knew, these are easier words to write than to live.  So, I have some work ahead of me, but there is also immense pleasure in store as well, since Thoreau’s wit is sharp and his prose both finely crafted and exuberant, among the best ever written in English, or, shall we say American (in the large-spirited rather than narrow sense of that word).

And, in fact, my rereading has already begun, launched last week while we were visiting Cape Cod, the subject of another of Thoreau’s books (his chapter on “The Well-Fleet Oysterman” is a particular favorite of mine).  I didn’t get far before I picked up my journal and began to write:

Sitting here this morning on the deck, under a tree, reading Walden, the white page dappled with sunlight, breezes sighing through the leaves.  My page is dotted with circles of light, and I peer at the words through these circles as they dance in time to the breathy puffs of air fluttering the leaves.  The light comes through the shifting gaps between the leaves above me, but why the regularity of circles, these swaying and bobbing bubbles of light?  This must be some trick of vision, some preference of eye and brain.  If the breeze blows hard enough the circles burst and the familiar shadowed contours of oak leaves flutter and twist on the page until the heavens calm and the bubbles alight once more.  Some of these bubbles form not circles but ovals and some flash on and off or leap from one spot to another.  Some clump and cluster to make flowers of light drifting left and right, up and down.  Some go fluid, watery, and some overlap into grayish opacities that seem to pulse, so that I have the sense of new life forming, taking shape under some vast microscope.  Through the lens of which I would appear how?

Sometimes we turn to books for a sort of escape, a retreat into fantasy and adventure, and that can be great fun, but some books attune us more sharply to the world, to the present moment, which has a way of expanding almost infinitely when we give it the right sort of attention.  As Thoreau writes, he strove during his time at Walden pond “to stand at the meeting of two eternities, the past and future, which is precisely the present moment; to toe that line.”

Walden Frontispiece

My Pocket Universe

cropped-milky-way-earth-location 

My Pocket Universe is a blog about, well, anything and everything that seems worth writing about, but it will certainly deal with books and music and movies, and also nature (of which we are a part!).  The concept “pocket universe” comes from physics and refers to the idea that the universe might be full of pockets of space that are each governed by their own physical laws, but I mean it loosely, just to refer to my little corner, or pocket, of the universe.  I do, though, like the physics-y suggestion that this little pocket of space might not follow exactly the same rules as the rest of the universe.  One of the reasons the act of writing is so powerful is that you can, with very little in the way of technology, create your own world, maybe even your own “pocket universe.”  With this blog, I want to create a writing space that allows me to notice things I might not otherwise notice, and to explore ideas that might merely dissipate into the ether, jostled about and dissolved by the hurly-burly of daily life.   Since reading, for me, is not far behind breathing as a necessity of life, I imagine I will write fairly often about literature, and about all sorts of books covering a wide range of subjects.  I am interested in history and philosophy, in music and movies, and in science and technology, among other things.  Within the field of science, I have a special interest in neuroscience and cognitive science, and I have done some thinking and writing on the question of how research from those fields can be applied to literary study and to the teaching of writing.  But that is already the subject of a book project, and I don’t intend to make it the primary focus of this blog.  One great work of literature that is very much on my my mind these days is Henry David Thoreau’s Walden (free ebook at The Literature Project), so I wouldn’t be too surprised if I find myself writing about that before long.  And I started off the summer by reading Richard Powers’ fascinating and important new novel The Overstory (public library), so I will probably have something to say about that as well.  Watch this space!

(The Wikipedia article on pocket universes is pretty weak, so you might have better luck with this article instead.  You will probably also come across one or two if you watch a few episodes of Dr. Who!)