#05 Sensation and Perception (AP Psych) Post 2025

Sensation

The process by which sensory receptors and the nervous system receive and represent stimulus energy.

Transduction

The conversion of physical stimulus energy into neural impulses.

Sensory Receptors

Specialized cells that detect stimulus energy.

Absolute Threshold

The minimum stimulus intensity needed to detect a stimulus 50 percent of the time.

Difference Threshold

The minimum difference between two stimuli required for detection.

Weber's Law

The principle that the difference threshold is a constant proportion of the original stimulus.

Sensory Adaptation

The diminished sensitivity to a constant stimulus over time.

Sensory Interaction

The principle that one sense can influence another.

Synesthesia

A condition in which stimulation of one sensory pathway leads to experiences in another.

Light Energy

The physical stimulus for vision.

Wavelength

The distance between light waves that determines color.

Hue

The dimension of color determined by wavelength.

Intensity

The amount of energy in a light wave that determines brightness.

Cornea

The transparent outer surface that bends incoming light.

Pupil

The adjustable opening in the center of the eye.

Iris

The colored muscle that controls pupil size.

Lens

A transparent structure that focuses light onto the retina.

Accommodation

The process by which the lens changes shape to focus images.

Retina

The light-sensitive layer at the back of the eye.

Rods

Retinal receptors that detect black, white, and gray and are sensitive to dim light.

Cones

Retinal receptors that detect color and fine detail.

Fovea

The central point of the retina with the highest concentration of cones.

Optic Nerve

The nerve that carries visual information to the brain.

Blind Spot

The point where the optic nerve exits the retina, lacking receptors.

Trichromatic Theory

The theory that color vision is based on three types of cones.

Opponent-Process Theory

The theory that color vision is based on opposing color pairs.

Afterimages

Visual sensations that occur after a stimulus is removed.

Dichromatism

Color vision deficiency involving two functioning cone types.

Monochromatism

Color vision deficiency involving only one or no functioning cone types.

Prosopagnosia

A disorder characterized by difficulty recognizing faces.

Blindsight

The ability to respond to visual stimuli without conscious awareness.

Pitch

A sound's perceived highness or lowness.

Frequency

The number of sound wave cycles per second.

Amplitude

The height of sound waves determining loudness.

Loudness

The perceived volume of a sound.

Place Theory

The theory that pitch perception depends on where sound waves stimulate the cochlea.

Frequency Theory

The theory that pitch is determined by the rate of neural firing.

Volley Theory

The theory that groups of neurons fire in rapid succession to encode pitch.

Cochlea

A fluid-filled structure in the inner ear that converts sound waves to neural signals.

Sound Localization

The ability to determine the origin of a sound.

Conduction Deafness

Hearing loss caused by damage to the outer or middle ear.

Sensorineural Deafness

Hearing loss caused by damage to the inner ear or auditory nerve.

Olfaction

The sense of smell.

Smell Receptors

Chemical receptors that detect airborne molecules.

Olfactory Bulb

The brain structure that processes smell information.

Pheromones

Chemical signals that influence behavior or physiology.

Gustation

The sense of taste.

Taste Receptors

Chemical receptors on the tongue that detect taste.

Sweet

A taste quality signaling energy-rich foods.

Salty

A taste quality signaling essential minerals.

Sour

A taste quality signaling acidity.

Bitter

A taste quality signaling potential toxins.

Umami

A savory taste quality signaling proteins.

Oleogustus

A taste quality signaling fats.

Supertasters

Individuals with heightened taste sensitivity.

Medium Tasters

Individuals with average taste sensitivity.

Non-Tasters

Individuals with reduced taste sensitivity.

Thermoreceptors

Sensory receptors that detect temperature.

Gate-Control Theory of Pain

The theory that pain signals can be blocked by competing sensory input.

Phantom Limb Sensations

Pain or sensations felt in a missing limb.

Vestibular Sense

The sense of balance and spatial orientation.

Semicircular Canals

Structures in the inner ear that detect rotational movement.

Kinesthesis

The sense of body position and movement.

Perception

The process of organizing and interpreting sensory information.

Bottom-Up Processing

Perception that begins with sensory input.

Top-Down Processing

Perception influenced by expectations and prior knowledge.

Schemas

Mental frameworks that organize information.

Perceptual Set

A readiness to perceive stimuli in a particular way.

Context

The environment in which perception occurs.

Gestalt Psychology

An approach emphasizing perception of whole patterns.

Closure

The tendency to fill in missing information.

Figure-Ground

The organization of visual information into objects and backgrounds.

Proximity

The tendency to group nearby objects.

Similarity

The tendency to group similar objects.

Selective Attention

The ability to focus on specific stimuli.

Cocktail Party Effect

The ability to focus on one conversation amid many.

Inattentional Blindness

Failure to notice visible stimuli when attention is elsewhere.

Change Blindness

Failure to detect changes in visual scenes.

Retinal Disparity

A binocular cue based on differences between the eyes' images.

Convergence

A binocular cue based on eye muscle tension.

Relative Clarity

A monocular cue in which hazy objects appear farther away.

Relative Size

A monocular cue where smaller images are perceived as farther away.

Texture Gradient

A monocular cue where detail decreases with distance.

Linear Perspective

A monocular cue where parallel lines appear to converge.

Interposition

A monocular cue where one object blocks another.

Perceptual Constancy

The tendency to perceive objects as stable despite changes.

Apparent Movement

The perception of motion when none exists.