AP Psychology Unit 1B Vocabulary

Flashcards covering key terms and definitions for AP Psychology Unit 1B (Sensation and Perception).

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception

The process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful.

Prosopagnosia

Also known as face blindness.

Top-Down Processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Bottom-up Processing

Information processing that begins with the sensory receptors and works up to the brain's integration of sensory information.

Transduction

Conversion of one form of energy into another. In sensation, the transforming of physical energy, such as sights, sounds, and smells, into neural impulses the brain can interpret.

Absolute Threshold

The minimum stimulus energy needed to detect a particular stimulus $50$ percent of the time.

Difference Threshold

The minimum difference between two stimuli required for detection $50$ percent of the time.

Just Noticeable Difference

The experience of the difference threshold wherein one can barely detect the differences between stimuli.

Weber's Law

The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation.

Lens

The transparent structure behind the pupil that changes shape to help focus images on the retina.

Accommodation

The process by which the eye's lens changes shape to focus images of near or far objects on the retina.

Nearsightedness

If the lens focuses the image on a point in front of the retina, you see near objects clearly but not distant objects.

Farsightedness

If the lens focusing light past the retina, you see distant objects clearly but not near ones.

Retina

The light-sensitive back inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

Rods

Retinal receptors that detect black, white, and gray, and are sensitive to movement and are necessary for peripheral and twilight vision.

Cones

Retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. They detect fine detail and give rise to color sensations.

Fovea

The central focal point in the retina, around which the eye's cones cluster.

Visual (Optic) Nerve

The nerve that carries neural impulses from the eye to the brain.

Blind Spot

The point at which the optic nerve leaves the eye, creating a spot with no receptor cells.

Trichromatic Theory

The theory that the retina contains three different types of color receptors - one most sensitive to red, one to green, one to blue - which, when stimulated in combination, can produce the perception of any color.

Dichromatism

Color vision of two, rather than three, sets of cones.

Monochromatism

Color vision of one, rather than three, sets of cones.

Opponent-Process Theory

The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision.

Afterimage

Lingering perception of color in the opposite opponent color.

Ganglion Cells

Retinal cells that are activated by certain rods or cones to produce electrochemical impulses into the brain.

Blindsight

A condition in which a person can respond to a visual stimulus without consciously experiencing it.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next.

Amplitude

The height of the wave.

Conduction Deafness

A less common form of hearing loss, caused by damage to the mechanical system that conducts sound waves to the cochlea.

Sensorineural Deafness

The most common form of hearing loss, caused by damage to the cochlea's receptor cells or to the auditory nerve.

Place Theory

In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

Frequency Theory

In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.

Volley Theory

In hearing, if a sound is above $1000$ waves per second, neural cells can alternate firing.

Sound Localization

Sound waves strike one ear sooner and more intensely than the other, giving an indication of the source of the sound.

Phantom Limb Sensation

A sensory experience where a person feels that a missing limb is still present.

Gate Control Theory

The theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers, and is closed by activity in larger fibers or by information coming from the brain.

Gustation

Our sense of taste.

Olfaction

Our sense of smell.

Pheromones

Chemical signals that are released by an individual and received by other members of the same species, causing a specific behavioral or developmental response.

Vestibular Sense

Our balance sense; our sense of body movement and position that enables balance.

Semicircular Canals

Fluid-filled tubes located in the inner ear monitors head and body movements in order to balance the body.

Kinesthesis

Our movement sense, our system for sensing the position and movement of individual body parts.

Sensory Interaction

The principle that one sense may influence another, as when the smell of food influences its taste.

Synesthesia

A phenomenon where the stimulation of one sense (such as hearing sound) triggers an experience of another (such as seeing color).

Selective Attention

Focusing conscious awareness on a particular stimulus.

Cocktail Party Effect

Focusing attention on one stimulus, such as a conversation, and filtering out other stimuli, such as the background noise.

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere.

Change Blindness

Failing to notice changes in the environment.

Perceptual Sets

A mental predisposition to perceive one thing and not another.

Schemas

A concept or framework that organizes and interprets information.

Gestalt Psychology

An organized whole, our tendency to integrate pieces of information into meaningful wholes.

Figure/Ground

The organization of the visual field into objects that stand out from their surroundings.

Proximity

A Gestalt principle of grouping that states that we group nearby figures together.

Similarity

A Gestalt principle stating that we group objects based on how similar they are to each other.

Closure

A Gestalt principle stating that we fill in the gaps to create a complete whole object.

Binocular Depth Cues

A depth cue that depends on the use of two eyes.

Monocular Depth Cues

A depth cue available to either eye alone.

Retinal Disparity

A binocular depth cue, by comparing the two different images in the two eyes, the brain computes distance.

Convergence

A binocular depth cue to nearby objects' distance, enabled by the brain combining retinal images.

Relative Clarity

A monocular depth cue where we perceive objects that appear sharper and clearer as being closer, while objects that appear hazy or blurry are perceived as being further away.

Relative Size

A monocular depth cue where if we assume two objects are similar in size, most people perceive the one that casts the smaller retinal image as farther away.

Texture Gradient

A monocular depth cue regarding the progressively finer appearance of textures and surface grains of objects as the viewer moves away from them.

Linear Perspective

A monocular depth cue where parallel lines appear to meet in the distance.

Interposition

A monocular depth cue, if one object partially blocks our view of another, we perceive it as closer.

Apparent Movement

Movement can be visually perceived even when objects are not actually moving.

Perceptual Constancy

Perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change.