Perception and Lightness Constancy Lecture Notes

These flashcards cover key concepts from the lecture on perception, focusing on lightness constancy, color perception, and related visual phenomena.

What is lightness?

Lightness is how we perceive light, including light on dark surfaces and how it appears to the human eye.

What is lightness constancy?

Lightness constancy refers to the stable perception of lightness or darkness of an object despite changes in lighting conditions.

What does color constancy refer to?

Color constancy is how the brain perceives the color of an object as stable even when the lighting changes.

What is the Mach bent card effect?

The Mach bent card effect is an illusion where a flat card appears bent due to shading, demonstrating how our visual system perceives gradients and shadows.

How does lateral inhibition work?

Lateral inhibition is the process by which neurons reduce the activity of neighboring neurons, enhancing contrast in color perception.

What is the simultaneous lightness contrast (SLC) effect?

The SLC effect is an illusion in which two gray squares of the same shade appear different due to different colored backgrounds.

How can lateral inhibition explain SLC?

Lateral inhibition can explain SLC because it demonstrates how neurons processing light backgrounds inhibit the perception of gray squares, making one appear darker against its background.

What is illumination?

Illumination is the amount of light that falls on a surface from a light source.

What is reflectance?

Reflectance is the amount of light that comes off a surface.

What is luminance?

Luminance is the amount of light that leaves a surface and enters the eye.

What is the Gelb effect?

The Gelb effect is the phenomenon where the appearance of lightness is influenced by surrounding contexts.

What is the Kardos effect?

The Kardos effect is an illusion in which a white object appears black when partially covered by shadow.

What is David Ingle's contribution to color constancy?

David Ingle conducted experiments to show that colors can be identified independently under various illumination conditions.

What is the Barlow and Hill account of motion aftereffects (MAE's)?

Barlow and Hill proposed that prolonged movement in one direction fatigues cells detecting that motion, causing an imbalance in motion perception.

What are the five cues to distance?

The five cues to distance are linear perspective, occlusion, size, texture, and height.

What is the moon illusion?

The moon illusion is the perception that the moon appears larger when closer to the horizon than when it is high in the sky.

What is the corollary discharge theory?

The corollary discharge theory explains how the brain processes sensory information and movement by sending motor commands to sensory areas.

What are rods and cones?

Rods are photoreceptors in the retina that function in low light, while cones provide color vision.

What is synesthesia?

Synesthesia is a condition where stimulation of one sensory pathway leads to automatic experiences in another, such as seeing colors when hearing sounds.

What does percept-percept coupling mean?

Percept-percept coupling is when one perception influences another even when stimuli remain the same.

What is figure ground segregation?

Figure ground segregation is the visual system's process of distinguishing an object from its background.