psych s&p

Absolute threshold

The minimum stimulation needed to detect a stimulus 50% of the time.

Accommodation

The eye's lens changes shape to focus light from objects at different distances onto the retina.

Afterimages

Visual sensations that remain after looking at a stimulus, often appearing in complementary colors.

Amplitude

The height or intensity of a wave; greater sound-wave amplitude generally produces louder sounds.

Apparent movement

The illusion of movement created when stationary images or lights appear rapidly in sequence.

Attention

The process of focusing awareness on particular stimuli.

Auditory canal

The passage that carries sound waves from the outer ear to the eardrum.

Basilar membrane

A membrane inside the cochlea that vibrates in response to sound and stimulates auditory hair cells.

Binocular depth cues

Depth cues that require both eyes, including retinal disparity and convergence.

Blindsight

The ability to respond to visual stimuli without consciously seeing them, often due to damage to the visual cortex.

Blind spot

The area where the optic nerve exits the retina; it contains no rods or cones.

Bottom-up processing

Processing that begins with sensory information and builds toward perception.

Change blindness

The failure to notice a change in the visual environment.

Closure

The Gestalt principle of mentally filling in missing parts of an image to perceive a complete object.

Cochlea

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

Cocktail party effect

The ability to focus on one conversation while filtering out background conversations, while sometimes noticing personally important information.

Color blindness

A condition involving difficulty distinguishing certain colors because of missing or malfunctioning cone photoreceptors.

Conduction deafness

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

Cones (blue, green, red)

Color-sensitive retinal photoreceptors that respond most strongly to short (blue), medium (green), or long (red) wavelengths of light.

Convergence

A binocular depth cue in which the eyes turn inward more when focusing on nearby objects.

Cornea

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

Dichromatism

A type of color vision in which a person has two functioning types of cone photoreceptors instead of three.

Eardrum

A thin membrane that vibrates when sound waves strike it and transfers vibrations to the middle-ear bones.

Farsightedness (hyperopia)

A vision condition in which nearby objects may appear blurry because light focuses behind the retina.

Figure and ground

The Gestalt principle of separating a visual scene into a main object (figure) and its background (ground).

Fovea

The central area of the retina with the greatest concentration of cones, providing the sharpest central vision.

Frequency theory

The theory that pitch is coded by the rate of auditory nerve firing; it helps explain low-pitch perception.

Ganglion cells

Retinal neurons that send visual information toward the brain through the optic nerve.

Gate control theory

The theory that a neurological mechanism in the spinal cord can increase or decrease the transmission of pain signals to the brain.

Gestalt psychology

An approach to psychology emphasizing that people perceive organized wholes rather than just separate parts.

Gustation

The sense of taste.

Inattentional blindness

The failure to notice a visible object because attention is focused elsewhere.

Interposition

A monocular depth cue in which an object that blocks another object is perceived as closer.

Just-noticeable difference (JND)

The smallest difference between two stimuli that can be detected 50% of the time.

Kinesthesis

The sense of the position and movement of individual body parts.

Lens

The transparent structure inside the eye that changes shape to focus light onto the retina.

Linear perspective

A monocular depth cue in which parallel lines appear to meet as they extend into the distance.

Loudness

The perceived intensity of a sound, influenced mainly by sound-wave amplitude.

Medium tasters

People whose sensitivity to certain bitter-tasting compounds falls between that of supertasters and nontasters.

Monochromatism

A rare form of color vision in which a person has little or no ability to distinguish colors.

Monocular depth cues

Depth cues that can be perceived using only one eye, such as relative size and linear perspective.

Nearsightedness (myopia)

A vision condition in which distant objects appear blurry because light focuses in front of the retina.

Nontasters

People who experience relatively little bitterness from certain compounds compared with supertasters.

Olfactory system

The sensory system responsible for detecting and processing smells.

Opponent-process theory

The theory that color vision uses opposing pairs: red-green, blue-yellow, and black-white.

Ossicle bones

The three tiny middle-ear bones (malleus, incus, and stapes) that transmit and amplify sound vibrations.

Perceptual set

A mental predisposition to perceive something in a particular way based on expectations, experience, or context.

Phantom limb

The sensation that an amputated or missing limb is still present.

Pheromones

Chemical signals released by an organism that can influence other members of the same species.

Photoreceptors

Light-sensitive cells in the retina (rods and cones) that convert light into neural signals.

Pitch

How high or low a sound seems; it is closely related to sound frequency.

Pitch perception

The brain's interpretation of sound frequency as differences in how high or low a sound seems.

Place theory

The theory that pitch depends on where the basilar membrane vibrates most strongly; it helps explain high-pitch perception.

Prosopagnosia

Face blindness; difficulty recognizing familiar faces despite otherwise adequate vision.

Proximity

The Gestalt principle that objects close together are perceived as belonging to the same group.

Relative clarity

A monocular depth cue in which clearer objects are perceived as closer than hazier objects.

Relative size

A monocular depth cue in which, assuming objects are similar in actual size, the object with the smaller retinal image is perceived as farther away.

Retina

The light-sensitive layer at the back of the eye that contains rods, cones, and other neurons.

Retinal disparity

The difference between the images received by the two eyes; the brain uses this difference to judge depth.

Rods

Retinal photoreceptors that work well in dim light and support peripheral vision but do not detect color.

Schema

A mental framework that organizes information and helps interpret experiences.

Selective attention

The process of focusing on one stimulus while ignoring competing stimuli.

Semicircular canals

Three fluid-filled structures in the inner ear that detect rotational head movements and help maintain balance.

Sensation

The process by which sensory receptors detect physical stimuli and send information to the nervous system.

Sensorineural deafness

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

Sensory adaptation

A decrease in sensitivity to an unchanging stimulus over time.

Sensory interaction

The principle that one sense can influence another, such as smell affecting the perception of flavor.

Similarity

The Gestalt principle that objects sharing characteristics, such as color or shape, are perceived as belonging together.

Sound localization

The ability to determine the direction or location a sound comes from.

Supertasters

People who experience especially intense tastes from certain bitter compounds and have heightened taste sensitivity.

Sweet, sour, salty, bitter, umami, oleogustus

The six commonly discussed taste qualities: sweet (often sugars), sour (acids), salty (salts), bitter (many bitter compounds), umami (savory taste associated with glutamate), and oleogustus (the taste associated with certain fatty acids).

Synesthesia

A condition in which stimulation of one sensory pathway automatically produces an additional experience, such as seeing colors when hearing sounds.

Taste receptors

Specialized receptor cells, mainly in taste buds, that detect chemicals in food and help identify taste qualities.

Thalamus

A brain structure that relays most sensory information to the cerebral cortex; smell is a major exception in its initial processing.

Top-down processing

Processing guided by prior knowledge, expectations, experiences, and context.

Transduction

The conversion of physical stimulus energy into neural signals.

Trichromatic theory

The theory that color vision begins with three types of cones sensitive to short, medium, and long wavelengths of light.

Vestibular sense

The sense of balance and head movement, supported by structures in the inner ear.

Visual/optic nerve

The bundle of retinal ganglion-cell axons that carries visual information from the eye toward the brain.

Volley theory

The theory that groups of auditory neurons alternate their firing to represent frequencies too high for a single neuron to follow.

Volume method (hearing)

A method of measuring hearing sensitivity by finding the quietest sounds a person can hear at different frequencies.

Warm/cold receptors

Sensory receptors in the skin that respond to warmth and cold.

Wavelength

The distance between corresponding points on consecutive waves; visible-light wavelength helps determine perceived color.

Weber's law

The principle that the just-noticeable difference is a constant proportion of the original stimulus intensity.