The Clarity, or Not, of Visual Experience
Most people (not everyone!) will say there is some experiential difference between the center of their visual field and the periphery. The center is clear, precise, sharply detailed -- something like that -- and the periphery is hazy, imprecise, lacking detail.
If you agree with this (and if you don't, I'd be interested to hear), I want you to think about the following question: How large is that center of clarity? If you're comfortable with degrees of arc, you might think of it in those terms. Otherwise, think about, say, how much of your desktop you can see in precise detail in a single moment. Consider also, how stable the region of clarity is, approximately how much shifting there is of things from the clear center to the unclear periphery and vice versa. Is it a constant flux, say, or pretty stable over stretches of several seconds?
Humor me, if you will, and formulate in your mind an explicit answer to these questions before reading on.
Dan Dennett suggests the following experiment. Randomly take a card from a deck of playing cards and hold it at arm's length off to one side, just beyond your field of view. Holding your gaze fixed on a single point in front of you, slowly rotate the card toward the center of your field of view (keeping it at arm's length). How close to the center do you have to bring the card before you can determine its suit, its color, its value?
Most people are surprised at the results of this little experiment (so Dennett reports, and so I've found, too). You have to bring it really close! Go try it! If a playing card isn't handy, try a book cover with a picture on it. I've also posted a playing card here, if that might help (image from here).
In doing this exercise, you're doing something pretty unusual (unless you've been a subject in a lot of vision science experiments!) -- you've been attending to, or thinking about, your experience of parts of your visual field not quite at the center of fixation. It's a little tricky, but you can try doing this as your eyes move around more naturally. For example, you might decide to attend to your visual experience of one particular object (maybe the top left part of the banner at the top of your screen, or the Jack to the right), allowing your eyes to move around so that you're looking all around it but never directly at it. How well do you see it?
So here's the question: Has your opinion about your visual experience changed as a result of this little exercise? And if so, how?
I have a little bit of a wager, you might say, with a colleague of mine about this.