AP Psych: Sensation and Perception (The Eye)

Sensation

Process where special receptors in sense organs activate from environmental input.

Transduction

Converting outside stimuli, like light, into electrochemical messages for the brain.

Weber's Law

The smallest detectable difference between two stimuli is a constant proportion.

Absolute Threshold

The lowest level of stimulation consciously detectable 50 percent of the time.

Signal Detection Theory

Predicts how and when a faint stimulus is detected amid background noise.

Sensory Adaptation

Sensory receptor cells become less responsive to a constant, unchanging stimulus.

Habituation

The brain decreases attention or response to a constant, unchanging stimulus.

Brightness

Psychological property of light determined by the wave's amplitude.

Hue

Color perceived, determined by the wavelength of light.

Cornea

Clear surface of the eye that protects it and focuses most light.

Visual Accommodation

The change in lens thickness as the eye focuses on near or far objects.

Myopia

Nearsightedness where distant objects appear blurry because light focuses in front of the retina.

Hyperopia

Farsightedness where close-up objects appear blurry because light focuses behind the retina.

Rods

Photoreceptors in the eye periphery that detect shapes and movement in dim light.

Cones

Photoreceptors located in the fovea that process color and fine detail.

Blind Spot

Area in the retina where the optic nerve exits, lacking photoreceptors.

Trichromatic Theory

Color vision theory proposing three types of cones: red, green, and blue.

Opponent-Process Theory

Color vision theory proposing three pairs of opposing color channels.

Afterimages

Visual sensations that persist after the original stimulus is removed.

Monochromatism

Rare total color blindness possessing only one or zero cone types.

Prosopagnosia

Neurological disorder impairing the ability to recognize familiar faces.

Blindsight

Ability to respond to visual stimuli without conscious perception due to visual cortex damage.