MaCro Philosophy

The Unreliability of Naive Introspection

Another shorter post. I present a classic experiment and show a nice example of the lack of precision in our peripheral vision. This lack of precision seems at odds with standard introspective reports which often claim a uniformly clear visual field. I argue that this doesn't show that we are commonly mistaken about the contents of consciousness, but just that the contents contain generally include high-level predictions of the world. As with last week's post about the refrigerator light illusion, this draws heavily on Eric Schwitzgebel's work specifically the section on "Our Poor Knowledge of Our Own Conscious Experience".

How accurate is your knowledge of your perceptual ability?

There is a classic experiment in this literature that is fun to try. If you don't have a pack of cards handy, get someone else to hand you a card-shaped object that you couldn't guess the details of. Here is Eric Schwitzgebel talking about it:

Draw a card from a normal deck without looking at it. Keeping your eyes fixed on some point in front of you, hold the card at arm’s length just beyond your field of view. Without moving your eyes [this part is harder than it sounds, it helps to fixate on a specific point], slowly rotate the card toward the center of your visual field. How close to the center must you bring it before you can determine the color of the card, its suit, and its value? Most people are quite surprised at the result of this little experiment. They substantially overestimate their visual acuity outside the central, foveal region. When they can’t make out whether it’s a Jack or a Queen, though the card is nearly (but only nearly) dead center, they laugh, they’re astounded, dismayed. You have to bring it really close. [Schwitzgebel: The unreliability of Naive Introspection pp254-255]

I don't think the right conclusion is that we are normally wrong about the content of our conscious experience containing more detail in the periphery than it actually does. I think it makes more sense to think of that detail as a part of our everyday experience, formed from our predictions of what is there (and what will be filled in with a simple eye movement or turn of the head). It's the strong constraint of no eye movement and an unpredictable stimulus in the above experiment that causes the startling result.

A real-life Illustration

This clip is a perfect example of confidence in our peripheral vision.

If you look closely, you'll see that the player never looks down directly. He also, unfortunately, happens to trap the ball just over the round, ball coloured, ball shaped penalty spot (most obvious in the second part of the clip where he clearly tries to kick the penalty spot). Due to the penalty spot, his peripheral vision probably contained the same information that it would if the ball was actually there, a round ball-sized white blob.

It makes more sense to me to say that his conscious experience is of a ball (what he believes he is seeing due to high-level predictions), than of an indeterminate white blob (the information he has when only considering his low-level visual system). Conscious experience is based on our high-level expectations, which are formed out of (but don't entirely consist of) low-level information. In the card experiment, there is no way to make a good high-level prediction so we (perhaps for the first time) notice the inaccuracy of peripheral vision by itself.