Midterm 1: Chapter 10 Flashcards by Cai Ramnarine

Focuses on identifying information in the retinal image that is correlated with depth.

Cue approach to depth perception

How well did you know this?

Not at all

Perfectly

monocular depth cue where one object in front of another

Occlusion

How well did you know this?

Not at all

Perfectly

Cues based on our ability to sense the position of our eyes and the tension in our eye muscles.

Oculomotor

How well did you know this?

Not at all

Perfectly

Cues based on the visual info available within one eye.

Monocular

How well did you know this?

Not at all

Perfectly

Cues that depend on visual info within both eyes.

Binocular

How well did you know this?

Not at all

Perfectly

How are oculomotor cues created?

convergence and accommodation

How well did you know this?

Not at all

Perfectly

The inward movement of the eyes that occurs when we look at nearby objects

Convergence

How well did you know this?

Not at all

Perfectly

The change in the shape of the lens that occurs when we focus on objects at various distances.

Accommodation

How well did you know this?

Not at all

Perfectly

At what distance are convergence and accommodation most useful?

when an object is close; they are useful up to a distance of about arm’s length.

How well did you know this?

Not at all

Perfectly

A type of cue that uses accommodation, pictorial cues, and movement cues?

Monocular

How well did you know this?

Not at all

Perfectly

sources of depth info that can be depicted in a picture (2-D).

Pictorial cues

How well did you know this?

Not at all

Perfectly

Sources of depth info created by movement.

Movement-based cues

How well did you know this?

Not at all

Perfectly

Types of Monocular Cues

Pictorial: occlusion, relative height, familiar and relative size, perspective convergence, perspective, texture gradient, shadows
Motion-produced: motion parallax, deletion, and accretion.

How well did you know this?

Not at all

Perfectly

Occurs when one object hides or partially hides another from view. The partially hidden object is seen as being farther away.

Occlusion

How well did you know this?

Not at all

Perfectly

The height in the photo’s frame corresponds to the height in our field of view, and objects that are higher in the field of view are usually farther away.

Relative Height

How well did you know this?

Not at all

Perfectly

Objects with their bases closer to the horizon are usually seen as being more distant.

Relative Height

How well did you know this?

Not at all

Perfectly

When we judge distance based on our prior knowledge of the sizes of objects.

Familiar Size

How well did you know this?

Not at all

Perfectly

When two objects are known to be of equal physical size, the one that is farther away will take up less of your field of view than the one that is closer.

Relative Size

How well did you know this?

Not at all

Perfectly

Parallel lines appear to meet at a single point in the distance, also known as the vanishing point. This further enhances the perception of depth through the cue of relative size.

Perspective Convergence

How well did you know this?

Not at all

Perfectly

This occurs because the farther away objects is, the more air and particles we have to look through so that distant objects appear less sharp than nearer objects and sometimes have a slight blue tint

Atmospheric Perspective

How well did you know this?

Not at all

Perfectly

Why do farther objects look bluer?

Scattered light gives the sky its blue tint and is scattered between us and the object we are looking at.

How well did you know this?

Not at all

Perfectly

elements are seen as being spaced more closely being perceived as farther.

Texture Gradient

How well did you know this?

Not at all

Perfectly

Decreases in light intensity are caused by the blockage of light, can provide info regarding the locations of objects. It also enhances the three-dimensionality of objects.

Shadows

How well did you know this?

Not at all

Perfectly

As we move, nearby objects appear to glide rapidly past us, but more distant objects appear to move more slowly

Motion Parallax

How well did you know this?

Not at all

Perfectly

How do animals use motion parallax?

before jumping out toward an object such as prey, locusts move their body from side to side to create a movement of its head to generate motion parallax signals that indicate the distance of their target.

Some things become covered, and others become uncovered.

Deletion and Accretion

When is relative height most useful?

When objects are on a flat plane and we can see where they touch the ground.

When are shadows most useful?

if the scene is illuminated at an angle.

When is familial size most helpful?

If we have prior knowledge of the object's size.

What monocular cues work best at a close distance?

accommodation and convergence

What monocular cues work best at medium distances?

motion parallax, deletion, accretion.

What monocular cue works at all distances?

Occlusion

depth perception created by input from both eyes.

Stereoscopic Depth Perception

What monocular cues work best at long distances?

atmospheric perspective, relative height, and texture gradient.

Misalignment of the eyes: the visual system suppresses vision in one of the eyes to avoid double vision.

Strabismus

The difference in the images on the left and right retinals: is the basis of stereoscopic vision.

Binocular Disparity

3-D movies add _____________ to create the effects.

Stereoscopic Depth Perception

Points on the retina that would overlap if the eyes were superimposed on each other

Corresponding retinal points

A line or surface containing all those points in space whose images fall on corresponding points of the retinas of the two eyes

Horopter

The images of objects that are not on the horopter fall on what?

non-corresponding points

The degree to which an image deviates from falling on corresponding points

Absolute Disparity

The amount of absolute disparity; the angle between the corresponding point on the right eye for the left-eye image of the object and the actual location of the image on the right eye.

Angle of Disparity

The pattern of disparity where the left eye sees an object to the right of the observer's fixation and the right eyes sees the same object to the left of the fixation point

Crossed Disparity

When does crossed disparity occur?

Whenever an object is closer to the observer than where the observer is looking

The pattern of disparity where the left eye sees an object to the left of the observer's fixation point and the right eyes sees that same object to the right of the fixation point.

Uncrossed Disparity

When does uncrossed disparity occur?

Whenever an object is behind the horopter.

The angle of disparity is ___________ for objects at greater distances from the horopter.

Greater

Difference in depth between two objects in space when there are multiple depth planes in an image. Related to how we judge the distance between two objects.

Relative Disparity

The impression of depth that results from information provided by binocular disparity.

Stereopsis

A 3D image pops out from what appears to be a sheet of random dots. The dots are arranged in repeating pattern, with slight differences in each repetition. Each eye sees a slightly different pattern because of the different angles between the page and each eye. Your brain tries to overlap the two patterns, and creates the virtual 3D object.

Random dot stereogram

How the visual system determines which object's image in one eye matches the same object's image in the other eye.

The Correspondence Problem

Uses two lenses to focus the left image on the left eye and the right image on the right eye.

Stereoscope

Why do people think the random dot stereogram is a problem?

the switching their gaze back and forth between 2 pictures and comparing small areas of the pictures one after another.

Neurons in the visual cortex that respond to the difference in images between the two eyes.

Disparity selective cells

A plot that shows how neurons respond to different stimulus disparities. The shape of the curve is determined by the relationship between the receptive fields of the left and right eye.

Disparity tuning curve

What are frontal eyes and what type of animals have them?

They result in overlapping fields of view, can use disparity to perceive depth. Monkeys, cats, and humans.

What are lateral eyes and what type of animals have them?

They have much less overlap and can use disparity only in the small area of overlap to perceive depth.

How is motion parallax important for bugs?

it's their method of judging distance, and they use it in a number of different ways.

Sonar works by sending out pulses of sound and using info contained in the echoes of this sound to determine the location of objects.

Echolocation

The observer's task on each trial was to adjust the diameter of the comparison circle in the left corridor to match his or her perception of the sizes of the various test circles presented in the right corridor.

Holway and Boring Experiment

The angle of an object relative to the observer's eye; tells how large the object will be on the back of the eye.

Visual angle

In the Holway and Boring Experiment, how did they eliminate binocular disparity?

by having the observer view test circles with one eye.

In the Holway and Boring Experiment, how did they eliminate motion parallax?

had the observer view test circles through a peephole.

In the Holway and Boring Experiment, how did they eliminate shadows and reflections?

By adding drapes to the hallway.

What does the Holway and Boring Experiment indicate?

Size estimation is based on the actual size of objects when there is good depth info, but that size estimation is strongly influenced by the object's visual angle when depth info is eliminated.

Perception of an object's size is relatively constant even when we view the object from different distances

Size Constancy

The process of perceiving the size of an object in relation to how far away it is

Size-distance scaling

The farther away an afterimage appears, the larger it will seem.

Emmert's law

What is one source of info for size perception?

Relative Size

Where two alternating scenes appear similar even though there are differences between them.

Change blindness

A theory that explains the Müller-Lyer illusion as a result of the visual system misinterpreting the distance of lines from the observer

Misapplied Size Consistency scaling

Illusion where the right vertical line appears to be longer than the left vertical line, even though they are both exactly the same length.

The Muller-Lyer Illusion

In the Muller-Lyer Illusion, why do the lines seem to be different sizes?

the arrows on the right line make this line look like part of the inside corner of a room, and the arrows on the other (left) line look like a part of a corner viewed from the outside.

States that our perception of line length depends on two cues: 1) the actual length of the vertical lines and 2) the overall length of the figure.

Conflicting Cues Theory

Illusion where the animals are the same size and have the same visual angle, but the one on top appears longer.

The Ponzo Illusion

In the Ponzo Illusion, why does the top animal appear bigger?

The depth info provided by the converging railroad tracks makes the top animal appear farther away.

Illusion that causes two people of equal size appear very different in size. The construction of the room causes the person on the right to have a much smaller visual angles than the person on the left.

The Ames Room

Illusion of when the moon is on the horizon, it appears much larger than when it is high in the sky.

Moon Illusion

In the moon Illusion, why is the moon perceived to be bigger on the horizon?

The apparent distance theory: The moon on the horizon appears more distant because it is viewed across the filled space of the terrain, which contains depth info.

How does the moon appear when it is in the sky?

It appears less distant because it is viewed through empty space, which contains little depth info.

Another theory of the moon Illusion that proposed that the high-in-the-sky moon appears smaller because the large expanse of sky surrounding it makes it appear smaller by comparison.

Angular Size Contrast Theory

What is one requirement for the operation of binocular disparity?

Eyes must be able to binocularly fixate so that the two eyes are both looking directly at the object and the two foveas are directed to exactly the same place.