Illusory Contours:
In cells are 18, the cells responded as if the edges were real.
The important element is the line ends/corners on the opposite side of the stimuli. If they
are aligned in a row, they are likely to mark an object boundary. Because they are frequently
produced by interposition of objects, that is when an object is partially occludes others.
Task 6:
Space Perception and Binocular Vision
Wolfe, Chapter 6
§ Given the curved, two-dimensional images on the retina of each eye, how does the brain
reconstruct our rich three- dimensional world?
§ How does the brain combine different cues to depth?
§ How does three-dimensional vision develop?
The problem that the visual system needs to solve is how to construct a three-dimensional world
based on the inverted images on the retina of each eye.
The retinal area occupied by an object gets smaller as the object moves farther away from the eyeball.
To be more precise, as a general rule our visual experience is a reconstruction of the world based on
two distorted inputs: the two distinct retinal images.
, • The real image has to be re-constructed in the retina
the two retinal images always differ. They differ because your two eyeballs (and their two retinas)
are in slightly different places in your head
Why do we have 2 eyes?
Humans, with frontal eyes, still see more of the world with two eyes than with one. Our visual field is
limited to about 190 degrees from left to right, 110 degrees of which is covered by both eyes
,binocular visual fields give predator animals such as humans a better chance to spot small, fast-
moving objects in front of them that might provide dinner.
binocular visual fields give predator animals such as humans a better chance to spot small, fast-
moving objects in front of them that might provide dinner.
Binocular = two eyes
probability summation The increased detection probability based on the statistical advantage of having two (or
more) detectors rather than one.
• Meaning we have 2 detectors looking at the same object, so the probability of
missing the object decreases
binocular summation The combina- tion (or “summation”) of signals from both eyes in ways that make perfor-
mance on many tasks better than with either eye alone.
• we will do better at many tasks with two eyes than with just one
binocular disparity—the differences between the two retinal images of the same world.
stereopsis The ability to use binocular disparity as a cue to depth.
monocular depth cue A depth cue that is available even when the world is viewed with one eye alone.
binocular depth cue A depth cue that relies on information from both eyes. Stereopsis is the primary example in
humans, but convergence and the ability of two eyes to see more of an object than one eye sees are also bin-ocular
depth cues.
Monocular Cues to Three-Dimensional Space:
, • even with one eye, you can perceive the depth in this scene.
On the basis of the retinal images and an implicit understanding of physics and geometry, we collect
cues that provide hints about the likely structure of the space in front of us and the disposition of
objects in that space.
We use cues to perceive depth in two dimensional images. What cues does the visual system use
to infer depth relations?
In cells are 18, the cells responded as if the edges were real.
The important element is the line ends/corners on the opposite side of the stimuli. If they
are aligned in a row, they are likely to mark an object boundary. Because they are frequently
produced by interposition of objects, that is when an object is partially occludes others.
Task 6:
Space Perception and Binocular Vision
Wolfe, Chapter 6
§ Given the curved, two-dimensional images on the retina of each eye, how does the brain
reconstruct our rich three- dimensional world?
§ How does the brain combine different cues to depth?
§ How does three-dimensional vision develop?
The problem that the visual system needs to solve is how to construct a three-dimensional world
based on the inverted images on the retina of each eye.
The retinal area occupied by an object gets smaller as the object moves farther away from the eyeball.
To be more precise, as a general rule our visual experience is a reconstruction of the world based on
two distorted inputs: the two distinct retinal images.
, • The real image has to be re-constructed in the retina
the two retinal images always differ. They differ because your two eyeballs (and their two retinas)
are in slightly different places in your head
Why do we have 2 eyes?
Humans, with frontal eyes, still see more of the world with two eyes than with one. Our visual field is
limited to about 190 degrees from left to right, 110 degrees of which is covered by both eyes
,binocular visual fields give predator animals such as humans a better chance to spot small, fast-
moving objects in front of them that might provide dinner.
binocular visual fields give predator animals such as humans a better chance to spot small, fast-
moving objects in front of them that might provide dinner.
Binocular = two eyes
probability summation The increased detection probability based on the statistical advantage of having two (or
more) detectors rather than one.
• Meaning we have 2 detectors looking at the same object, so the probability of
missing the object decreases
binocular summation The combina- tion (or “summation”) of signals from both eyes in ways that make perfor-
mance on many tasks better than with either eye alone.
• we will do better at many tasks with two eyes than with just one
binocular disparity—the differences between the two retinal images of the same world.
stereopsis The ability to use binocular disparity as a cue to depth.
monocular depth cue A depth cue that is available even when the world is viewed with one eye alone.
binocular depth cue A depth cue that relies on information from both eyes. Stereopsis is the primary example in
humans, but convergence and the ability of two eyes to see more of an object than one eye sees are also bin-ocular
depth cues.
Monocular Cues to Three-Dimensional Space:
, • even with one eye, you can perceive the depth in this scene.
On the basis of the retinal images and an implicit understanding of physics and geometry, we collect
cues that provide hints about the likely structure of the space in front of us and the disposition of
objects in that space.
We use cues to perceive depth in two dimensional images. What cues does the visual system use
to infer depth relations?
