A Scene on a Very Small Stage
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world, though what it sees is very different from the world as it appears to
us. The fairyfly’s compound eye consists of 20 to 30 independent units called
ommatidia, each with its own photoreceptor cells and lens. It delivers to the
insect a mosaic image, which to us would look like the low-frequency photo
of Abraham Lincoln depicted below.
Unlike us, the insect does not perceive this as a low-resolution, boxy image:
For one thing, the informativeness of the image is greatly enhanced by exploiting motion and the ever-changing overlap of light and dark regions while in
flight. What the insect sees is consistent with its overall experience of the environment, and presents to the insect precisely what it needs to see in order to
find nourishment and mates, and to evade predators.
As just noted, how the fairyfly sees the world is vastly different from the way
we do. The purpose of vision in any living organism is to enable it to see the
world in a form in which it may efficiently (and almost instantaneously) size up
the current situation and produce an action program. The visual representation
of scenes in an organism is so designed by nature that it closely matches the
available response patterns, thereby leading rapidly to appropriate action.
Excess information would be confusing and maladaptive. Thus, how a creature
pictures the world is very specific to its lifestyle.
The fairyfly has what biologists call an inner world-model which represents
the world to be a certain way. Every animate being needs such an inner model
as a frame of reference in order to make sense of what it perceives, and to make
correct decisions about how to act. Undoubtedly the fairyfly’s world-model is
extremely simple—and since it interprets what it sees in the light of its worldmodel, the world as the fairyfly sees it is simple. Its visual world must have the
same elegant simplicity and economy as its body structure.
9
world, though what it sees is very different from the world as it appears to
us. The fairyfly’s compound eye consists of 20 to 30 independent units called
ommatidia, each with its own photoreceptor cells and lens. It delivers to the
insect a mosaic image, which to us would look like the low-frequency photo
of Abraham Lincoln depicted below.
Unlike us, the insect does not perceive this as a low-resolution, boxy image:
For one thing, the informativeness of the image is greatly enhanced by exploiting motion and the ever-changing overlap of light and dark regions while in
flight. What the insect sees is consistent with its overall experience of the environment, and presents to the insect precisely what it needs to see in order to
find nourishment and mates, and to evade predators.
As just noted, how the fairyfly sees the world is vastly different from the way
we do. The purpose of vision in any living organism is to enable it to see the
world in a form in which it may efficiently (and almost instantaneously) size up
the current situation and produce an action program. The visual representation
of scenes in an organism is so designed by nature that it closely matches the
available response patterns, thereby leading rapidly to appropriate action.
Excess information would be confusing and maladaptive. Thus, how a creature
pictures the world is very specific to its lifestyle.
The fairyfly has what biologists call an inner world-model which represents
the world to be a certain way. Every animate being needs such an inner model
as a frame of reference in order to make sense of what it perceives, and to make
correct decisions about how to act. Undoubtedly the fairyfly’s world-model is
extremely simple—and since it interprets what it sees in the light of its worldmodel, the world as the fairyfly sees it is simple. Its visual world must have the
same elegant simplicity and economy as its body structure.