AP Psychology: Vision: Light & Eye Structures + Hearing (Audition)

Wavelength

The distance between two peaks of a light wave. Different wavelengths produce different colors. Example: Shorter visible wavelengths appear blue, while longer ones appear red.

Hue

The color we perceive based on the wavelength of light. Example: Red, blue, or green.

Intensity

The amount of energy in a light wave, which affects how bright the light appears (determined through altitude). Example: A bright flashlight has greater intensity than a dim one.

Cornea

The clear outer covering of the eye that protects it and bends incoming light.

Pupil

The opening in the center of the eye that allows light to enter.

Iris

The colored part of the eye that controls the size of the pupil.

Role: adjusts to allow light to enter

Lens

The (transparent) structure behind the pupil that focuses light onto the retina.

Retina

Inner surface of the eye that processes visual stimuli using neurons

The light-sensitive layer at the back of the eye containing rods and cones.

(inner surface of the eye that processes visual stimuli using neurons)

Accommodation

The process of the lens changing shape to focus on objects at different distances. Example: finger moving towards eyes

Rods

Retinal receptors that help us see in dim light and detect movement. They do not detect color– sensitive only to the brightness of light

Cones

Retinal receptors responsible for color vision and sharp detail, especially in bright light.

- most near the fovea – central focal point in the retina

Optic nerve

The nerve that carries visual information from the retina to the brain.

Blind spot

The area of the retina where the optic nerve exits, creating a spot with no rods or cones.

Fovea

The small central area of the retina with the highest concentration of cones, responsible for sharp central vision.

Audition

The sense of hearing.

Frequency

The number of wave cycles that pass a point each second, measured in hertz (Hz). It determines the pitch of a sound. Example: A high-frequency sound has a higher pitch.

Pitch

How high or low a sound seems to us. Example: A whistle has a higher pitch than a drum.

Middle ear

The part of the ear containing three tiny bones that amplify sound vibrations.

Cochlea

A fluid-filled, spiral-shaped structure in the inner ear that converts sound vibrations into neural signals.

Inner ear

The part of the ear containing the cochlea and structures involved in hearing and balance.

Sensorineural hearing loss

Hearing loss caused by damage to the cochlea's hair cells or the auditory nerve.

Conduction hearing loss

Hearing loss caused by problems transferring sound vibrations through the outer or middle ear.

Cochlear implant

An electronic device that helps people with certain types of severe hearing loss by directly stimulating the auditory nerve.

Place theory

The theory that different areas of the cochlea respond to different sound frequencies. Example: High-pitched sounds activate areas near the beginning of the cochlea.

Frequency theory

The theory that the rate of neural impulses matches the frequency of a sound, helping the brain identify pitch.