Depth Perception

Depth Perception

Ability to perceive distance and three-dimensionality.

Monocular Depth Cues

Aspects of a scene that yield information about depth when viewed with only one eye

Binocular Depth Cues

Cues of depth perception that arise from the use of two eyes

Oculomotor Cues

Depth cues related to feeling of muscle tension based on eye movement and position

Accommodation

The process by which the eye's lens changes shape to focus near or far objects on the retina

Convergence

Inward movement of eyes when focusing on nearby objects.

Binocular Disparity

The difference in the retinal images of the two eyes that provides information about depth.

Stereoscopic Vision

Combination of two retinal images to give a three-dimensional perceptual experience. Result of binocular disparity.

Pictorial Cues

Monocular depth cues derived from static images or scenes.

Occlusion

When one object partially hides another, indicating depth.

Shadows or Shading

A pictorial monocular depth cue that indicates how close or far away objects are from their background and provides cues for the perception of 3D objects.

Relative Size

Objects of a known size with a smaller retinal image are perceived to be further away

Relative Height

Objects higher in our field of vision are perceived as farther away.

Texture Gradients

Distant parts of a uniform surface appear smaller and denser, or spaced more closely together, indicating depth

Atmospheric Perspective

Distant objects appear less sharp due to more air particles between the object and the observer

Linear Perspective

Parallel lines converge in the distance, indicating depth.

Motion Parallax

Depth perception provided when the movement of close objects across the visual field appears faster than objects that are farther away

Size Constancy

The perception of an object as the same size regardless of the distance from which it is viewed

Visual Angles

Size of the image projected by an object onto the retina measured in degrees. Dependant on distance from the observer.

What is the Size-Distance Scaling Equation?

S = K (R X D)

What does S represent in the Size-Distance Scaling Equation?

Perceived size

Who conceived the Size-Distance Scaling Equation in 1966?

Gregory

Moon Illusion

A visual illusion involving the misperception that the moon is larger when it is on the horizon than when it is directly overhead.

Apparent-Distance Theory

An explanation of the moon illusion that is based on the idea that the horizon moon, which is viewed across the filled space of the terrain, should appear farther away than the zenith moon, which is viewed through the empty space of the sky. This theory states that because the horizon and zenith moons have the same visual angle but are perceived to be at different distances, the farther appearing horizon moon should appear larger.

Müller-Lyer Illusion

Illusion of line length that is distorted by inward-turning or outward-turning corners on the ends of the lines, causing lines of equal length to appear to be different

Stereopsis

Depth perception from binocular disparity.

What was the setup of the Holway and Boring Experiment?

Observers sat at an intersection of two hallways and saw a luminous test circle in one hallway and a luminous comparison circle in the other hallway.

What was the task in the Holway and Boring Experiment?

The task was to adjust the diameter of the comparison circle to match the subjects' perception of sizes of various test circles present in the other hallway.

What did the Holway and Boring Experiment reveal about size estimation?

The experiment indicated that size estimation is based on actual sizes of objects when there's good depth information, and that size estimation is strongly influenced by an object's visual angle when depth information is eliminated.

What does D represent in the Size-Distance Scaling Equation?

Perceived distance

What does R represent in the Size-Distance Scaling Equation?

Retinal image or visual angle