The technical name for the sense of balance, or equilibrium.

The distance from one wave peak to another.

The smallest possible strength of a stimulus that can be detected half the time.

The theory that pain is a product of both physiological and psychological factors that cause spinal gates to open and relay patterns of intense stimulation to the brain, which perceives them as pain.

Technical name for the sense of taste.

The scientific investigation of claims of paranormal phenomena and abilities.

Information processing that emphasizes the importance of the sensory receptors in detecting the basic features of a stimulus in the process of recognizing a whole pattern; analysis that moves from the parts to the whole; also called data-driven processing.

The unpleasant sensation of physical discomfort or suffering that can occur in varying degrees of intensity.

Specialized cells unique to each sense organ that respond to a particular form of sensory stimulation.

The rate of vibration, or the number of sound waves per second.

The coiled, fluid-filled inner-ear structure that contains the basilar membrane and hair cells.

The part of the ear that collects sound waves; consists of the pinna, the ear canal, and the eardrum.

The perceptual experience of different wavelengths of light, involving hue, saturation (purity), and brightness (intensity).

The view that the basilar membrane vibrates at the same frequency as the sound wave.

The thick nerve that exits from the back of the eye and carries visual information to the visual cortex in the brain.

The perception of an object as maintaining the same size despite changing images on the retina.

A famous visual illusion involving the misperception of the identical length of two lines, one with arrows pointed inward, one with arrows pointed outward.

A thin, light-sensitive membrane, located at the back of the eye, that contains the sensory receptors for vision.

A visual illusion involving the misperception that the moon is larger when it is on the horizon than when it is directly overhead.

Gestalt principle stating that a perception is automatically separated into the figure, which clearly stands out, from its less distinct background, the ground.

A tightly stretched membrane at the end of the ear canal that vibrates when hit by sound waves.

Chemical signals released by an animal that communicate information and affect the behavior of other animals of the same species.

In the retina, the specialized neurons that connect the rods and cones with the ganglion cells.

The intensity or amount of energy of a wave, reflected in the height of the wave; the amplitude of a sound wave determines a sound’s loudness.

The tendency to perceive objects, especially familiar objects, as constant and unchanging despite changes in sensory input.

The process by which the lens changes shape to focus incoming light so that it falls on the retina.

The relative highness or lowness of a sound, determined by the frequency of a sound wave.

The technical name for the sense of location and position of body parts in relation to one another.

The long, thin, blunt sensory receptors of the eye that are highly sensitive to light, but not to color, and that are primarily responsible for peripheral vision and night vision.

The process of detecting a physical stimulus, such as light, sound, heat, or pressure.

The part of the ear where sound is transduced into neural impulses; consists of the cochlea and semicircular canals.

A visual experience that occurs after the original source of stimulation is no longer present.

The unit of measurement for loudness.

Sensory receptors, located in the muscles and joints, that provide information about body position and movement.

The process of integrating, organizing, and interpreting sensations.

The membrane within the cochlea of the ear that contains the hair cells.

The point in the brain where the optic nerve fibers from each eye meet and partly cross over to the opposite side of the brain.

The property of wavelengths of light known as color; different wavelengths correspond to our subjective experience of different colors.

Technical name for the sense of smell.

The process by which a form of physical energy is converted into a coded neural signal that can be processed by the nervous system.

In the retina, the specialized neurons that connect to the bipolar cells; the bundled axons of the ganglion cells form the optic nerve.

The specialized sensory receptors for taste that are located on the tongue and inside the mouth and throat.

Technique that involves using auditory or visual feedback to learn to exert voluntary control over involuntary body functions, such as heart rate, blood pressure, blood flow, and muscle tension.

The misperception of the true characteristics of an object or an image.

The technical term for the sense of hearing.

The theory that the sensation of color results because cones in the retina are especially sensitive to red light (long wavelengths), green light (medium wavelengths), or blue light (short wavelengths).

The perception of a familiar object as maintaining the same shape regardless of the image produced on the retina.

The hair-like sensory receptors for sound, which are embedded in the basilar membrane of the cochlea.

The enlarged ending of the olfactory cortex at the front of the brain where the sensation of smell is registered.

Traditional Chinese medical procedure involving the insertion and manipulation of fine needles into specific locations on the body to alleviate pain and treat illness; modern acupuncture sometimes involves sending electrical current through the needles rather than manipulating them.

The part of the ear that amplifies sound waves; consists of three small bones: the hammer, the anvil, and the stirrup.

The perceived intensity of a color, which corresponds to the amplitude of the light wave.

The smallest possible difference between two stimuli that can be detected half the time; also called just noticeable difference.

Distance or depth cues that can be processed by either eye alone.

Area of the retina without rods or cones, where the optic nerve exits the back of the eye.

The opening in the middle of the iris that changes size to let in different amounts of light.

School of psychology that maintained sensations are actively processed according to consistent perceptual rules, producing meaningful whole perceptions, or gestalts.

The detection of stimuli that are below the threshold of conscious awareness; nonconscious perception.

The property of color that corresponds to the purity of the light wave.

The theory that color vision is the product of opposing pairs of color receptors: red–green, blue–yellow, and black–white; when one member of a color pair is stimulated, the other member is inhibited.

A small area in the center of the retina, composed entirely of cones, where visual information is most sharply focused.

A neurotransmitter that is involved in the transmission of pain messages to the brain.

The finding that repeated exposure to a stimulus increases a person’s preference for that stimulus.

The use of visual cues to perceive the distance or three-dimensional characteristics of objects.

One of several inherited forms of color deficiency or weakness in which an individual cannot distinguish between certain colors.

A clear membrane covering the visible part of the eye that helps gather and direct incoming light.

Perception of information by some means other than through the normal processes of sensation.

The tendency to perceive objects or situations from a particular frame of reference.

The intensity (or amplitude) of a sound wave, measured in decibels.

The distinctive quality of a sound, determined by the complexity of the sound wave.

Distance or depth cues that require the use of both eyes.

The point at which the optic nerve leaves the eye, producing a small gap in the field of vision.

Specialized sensory receptors for pain that are found in the skin, muscles, and internal organs.

The decline in sensitivity to a constant stimulus.

The view that different frequencies cause larger vibrations at different locations along the basilar membrane.

The short, thick, pointed sensory receptors of the eye that detect color and are responsible for color vision and visual acuity.

The perception of a familiar object as being the same color under different light conditions.

A principle of sensation that holds that the size of the just noticeable difference will vary depending on its relation to the strength of the original stimulus.

The colored part of the eye, which is the muscle that controls the size of the pupil.

Information processing that emphasizes the importance of the observer’s knowledge, expectations, and other cognitive processes in arriving at meaningful perceptions; analysis that moves from the whole to the parts; also called conceptually driven processing.

A transparent structure, located behind the pupil, that actively focuses, or bends, light as it enters the eye.