Sensation and Perception - DR. YANGA'S COLLEGES, INC. School of Psychology

A comprehensive set of vocabulary flashcards covering sensation, perception, anatomy of the eye and ear, color theories, depth cues, perceptual constancies, and notable visual illusions.

Sensation

The process of detecting and responding to sensory stimuli from the environment.

Perception

The brain's interpretation of sensory information to form meaningful experiences.

Transduction

The conversion of outside stimuli into neural activity.

Absolute threshold

Minimum stimulus energy required for detection 50% of the time.

Just noticeable difference (JND)

Smallest amount of change in a stimulus detectable 50% of the time.

Weber's law

The JND is a constant proportion of the original stimulus.

Habituation

Decrease in response to a repeated stimulus as the brain learns it is not important.

Sensory adaptation

Reduction in sensitivity of sensory receptors to a constant stimulus.

Cornea

Transparent front part of the eye that helps focus light.

Iris

Colored part of the eye that regulates pupil size.

Pupil

Black opening in the iris that controls light entry.

Lens

Transparent structure behind the iris that focuses light; changes shape for near/far vision.

Retina

Light-sensitive layer containing rods and cones that transduces light into neural signals.

Rods

Photoreceptors active in low light and peripheral vision.

Cones

Photoreceptors for color and detail, concentrated in the fovea.

Fovea centralis

Central retina region with high cone density for sharp vision.

Optic disc (blind spot)

Where the optic nerve exits the eye; lacks photoreceptors.

Optic nerve

Transmits visual information from retina to brain.

Sclera

White, protective outer layer of the eye.

Choroid

Vascular layer behind the retina supplying blood.

Aqueous humor

Clear fluid in the anterior chamber providing nutrients and maintaining pressure.

Dark adaptation

Increased sensitivity to low light after exposure to bright light.

Light adaptation

Adjustment to bright light after darkness; decreased sensitivity.

Trichromatic theory

Three types of cones (blue, green, red) detect color; brain combines signals.

Opponent-process theory

Color processed in opposing pairs (red-green, blue-yellow); explains afterimages.

Pinna

Visible part of the outer ear that collects sound and helps locate direction.

Auditory canal

Ear canal channeling sound to the eardrum and protecting middle ear.

Tympanic membrane

Eardrum; vibrates in response to sound.

Malleus

Hammer; first ossicle; transmits vibrations from eardrum to incus.

Incus

Anvil; second ossicle; transmits vibrations from malleus to stapes.

Stapes

Stirrup; third ossicle; transmits vibrations to the inner ear; smallest bone.

Cochlea

Spiral, fluid-filled structure with hair cells for hearing.

Hair cells

Sensory cells in the cochlea that transduce vibrations into neural signals.

Auditory nerve

Transmits electrical signals from the cochlea to the brain.

Vestibular nerve

Nerve involved in balance.

Semicircular canals

Inner-ear structures important for balance and head movement sensing.

Eustachian tube

Tube that Equalizes air pressure between middle ear and throat.

Place theory

Pitch is determined by the location along the basilar membrane that is stimulated.

Frequency theory

Pitch is encoded by the rate of firing of auditory nerve fibers.

Volley principle

Groups of neurons fire together to achieve higher-frequency pitch encoding.

Gustation

The sense of taste.

Sweet

Taste associated with sugars; indicates energy-rich nutrients.

Sour

Taste associated with acids.

Salty

Taste associated with salts; related to electrolyte balance.

Bitter

Taste often indicating potentially toxic substances.

Umami

Savory taste associated with glutamates and nucleotides.

Monocular cues

Depth cues available with one eye.

Binocular cues

Depth cues requiring two eyes.

Size constancy

Perceiving an object as the same size despite changes in distance.

Shape constancy

Perceiving an object as having a constant shape despite retinal changes.

Brightness constancy

Perceiving constant brightness despite changes in lighting.

Figure-ground

Perceiving figures as distinct from the background.

Proximity

Grouping nearby objects as related.

Similarity

Grouping by shared features such as shape, color, or size.

Closure

Filling in gaps to perceive complete shapes.

Continuity

Perceiving smooth, continuous lines and patterns.

Depth perception

Ability to perceive the world in three dimensions.

Linear perspective

Parallel lines appear to converge at a vanishing point.

Relative size

Perceiving smaller images as farther away when expected size is known.

Overlap

Partial obscuring of one object by another to indicate depth.

Aerial perspective

Hazy appearance of distant objects increasing perceived distance.

Texture gradient

Textured surfaces appear finer with distance.

Motion parallax

Nearby objects move faster than distant ones as we move.

Convergence

Eye muscles rotate to focus on a single object; greater for closer objects.

Hermann grid illusion

Optical illusion of faint gray spots at intersections due to edge processing.

Muller-Lyer illusion

Illusion where line length appears different due to arrow-like ends.

Illusion of motion (Rotating Snakes)

Perceived motion in a static image due to visual processing of luminance/color.