depth/ size, distance and motion

At what age can babies begin to perceive depth?

from around 6 months

How is a 3D perception formed if the retinal image is 2D?

The brain uses various cues (monocular, binocular, etc.) to interpret depth.

what do monocular cues

one eye only

What is interposition?

When one object blocks another, it's perceived as being closer.

What does relative size tell us about depth?

Smaller objects are perceived as being farther away

What is linear perspective?

Greater distance causes lines to converge (e.g., railway tracks).

What is texture gradient?

As distance increases, texture becomes less distinct and more uniform

How does height in the visual field affect perception?

Objects higher in the field appear farther away (if below horizon).

How does shading affect depth perception?

Shadows help us perceive the form and position of objects.

What is atmospheric perspective?

Distant objects appear less clear due to particles in the air

What is accommodation in depth perception?

Eye muscles change lens shape based on object distance (curved = close, flat = far).

What is motion parallax?

Closer objects move faster across our vision than distant ones.

What is the kinetic depth effect?

Objects in motion reveal their 3D structure.

What is convergence?

Eyes rotate inward to focus on closer objects; more convergence = closer.

What is binocular disparity (display)?

The nearer the object, the more different the images on each retina.

What happens if depth cues are removed?

Illusions like the Ames Room can occur.

Why do we perceive motion?

• To perceive depth

• To perceive objects

• To orient attention

• To navigate

What is real movement?

An object moves, retinal image shifts, or observer moves

What is stroboscopic movement?

Two quick images shown in succession appear as one moving object (e.g., video).

What is induced movement?

Motion is perceived due to surrounding objects moving.

What is the autokinetic effect?

In darkness, a static light appears to move.

What is the motion aftereffect?

After staring at moving objects (e.g., waterfall), still objects appear to move.

What is illusory movement?

Perception of movement when none actually exists.