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2 The Visual World
ultimately it is we—the family of all living creatures—who bestow form on
objects, bequeath colors to them, and populate the world with the myriad patterns only we discern. If there were an innocent eye, what it perceived would
be very disappointing.
A Necessary Deception
When you explore your surroundings with your eyes, what appears to you
is a detailed and comprehensive picture of specific objects laid out in space.
Your visual brain has done such an exhaustive job of analyzing the optic array
that the important objects before you have been found, identified and correctly
situated in space. The Gestalt picture you see is actually in your mind’s eye: You
have no access to the raw pattern of dark, light and colored patches projected
onto your retina: That display would have no meaning or value to you at all,
and for that reason the visual system was designed by evolution to shield you
from the clutter, and reveal to you only the fully processed image.
The image, or representation that you see appears to you realistically laid
out in space. The correct spatial distribution of objects is obviously of the
most extreme importance to all living creatures. A preeminent portion of the
visual computation carried out by the brain is devoted to the task of coding the
positions of objects relative to one another and to you. Thanks to this coded
information, your inner picture of a scene meticulously displays its overall
geometry.
This extensive computational work is located in your brain, and in a sense
so is the picture you see, since it is experienced in your mind. Yet what you see
is presented to you as being in the external world, and the objects you see are
clearly displayed to you at varying distances from you, laid out in surrounding
space. This is an illusion: It is a necessary deception built into your brain by
nature. How would animals cope in their habitat if they felt themselves having
pictures in their heads? It is obviously necessary for them to project what they
see onto the outside world.
This property of projecting our visual constructions onto the world is ubiquitous, and is called distal attribution. It is no different with hearing: Most
animals are able to localize the source of a sound, and consider the sound to
come from where it’s heard. Moreover, it is unusual for us to say “I hear a
sound”: More commonly we say “I hear the baby crying” or “I hear a dog
barking”. When the sound reaches our awareness, it is already interpreted, just
as the optical array is.
2 The Visual World
ultimately it is we—the family of all living creatures—who bestow form on
objects, bequeath colors to them, and populate the world with the myriad patterns only we discern. If there were an innocent eye, what it perceived would
be very disappointing.
A Necessary Deception
When you explore your surroundings with your eyes, what appears to you
is a detailed and comprehensive picture of specific objects laid out in space.
Your visual brain has done such an exhaustive job of analyzing the optic array
that the important objects before you have been found, identified and correctly
situated in space. The Gestalt picture you see is actually in your mind’s eye: You
have no access to the raw pattern of dark, light and colored patches projected
onto your retina: That display would have no meaning or value to you at all,
and for that reason the visual system was designed by evolution to shield you
from the clutter, and reveal to you only the fully processed image.
The image, or representation that you see appears to you realistically laid
out in space. The correct spatial distribution of objects is obviously of the
most extreme importance to all living creatures. A preeminent portion of the
visual computation carried out by the brain is devoted to the task of coding the
positions of objects relative to one another and to you. Thanks to this coded
information, your inner picture of a scene meticulously displays its overall
geometry.
This extensive computational work is located in your brain, and in a sense
so is the picture you see, since it is experienced in your mind. Yet what you see
is presented to you as being in the external world, and the objects you see are
clearly displayed to you at varying distances from you, laid out in surrounding
space. This is an illusion: It is a necessary deception built into your brain by
nature. How would animals cope in their habitat if they felt themselves having
pictures in their heads? It is obviously necessary for them to project what they
see onto the outside world.
This property of projecting our visual constructions onto the world is ubiquitous, and is called distal attribution. It is no different with hearing: Most
animals are able to localize the source of a sound, and consider the sound to
come from where it’s heard. Moreover, it is unusual for us to say “I hear a
sound”: More commonly we say “I hear the baby crying” or “I hear a dog
barking”. When the sound reaches our awareness, it is already interpreted, just
as the optical array is.