Unit 4 AP Psych vocab

Sensation

Sensation

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

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-up processing

analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.

Top-down processing

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

Selective attention

The focusing of conscious awareness on a particular stimulus.

Inattentional blindness

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

Change blindness

Failing to notice changes in the environment.

Psychophysics

The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Absolute threshold

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

Signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness

Subliminal

Below one’s absolute threshold for conscious awareness.

Priming

The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response

Difference threshold

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

Weber’s law

The principle that, to be perceived as different, two stimuli must differ by a constant percentage.

Sensory adaptation

Diminished sensitivity as a consequence of constant stimulation

Transduction

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

Wavelength

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

Hue

The dimension of color that is determined by the wavelength if light.

Intensity

The amount of every in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude.

Pupil

The adjustable opening in the center of the eye through which light enters.

Iris

A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

Lens

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

Retina

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

Accommodation

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

Rods

Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond

Cones

Retinal receptor cells that are concentrated near the center of the retina and that functions in daylight or in well lit conditions. Detects fine detail and gives rise to color sensations

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 _____ because no receptor cells are located there.

Fovea

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

Feature detectors

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

Parallel processing

The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision. Contrasts with the step by step processing of most computers and of conscious problem solving.

Young-Helmholtz trichromatic theory

The theory that the retina contains three different 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.

Opponent-process theory

The theory that opposing retinal processes enable color vison.

Audition

The sense or act of hearing

Frequency

The number of complete wavelengths that pass a point in a given time.

Pitch

A tone’s experienced highness or lowness; depends on frequency

Middle ear

The chamber between the eardrum and cochlea containing three tiny bones that concentrate the vibrations of the eardrum on the cochlea’s oval window.

Cochlea

A coiled, bony, fluid filled tube in the inner ear through which sound waves trigger nerve impulses.

Inner ear

The innermost part of the ear, containing the cochlea, semicircle canals, and vestibular sacs.

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 travelling up the auditory nerve matches the ______ of a tone, thus enabling us to sense its pitch.

Conduction hearing loss

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

Sensorineural hearing loss

Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness

Cochlear implant

A device for converting sound into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Kinesthesis

The system for sensing the position and movement of individual body parts

Vestibular sense

The sense of body movement and position, including the sense of balance

Gate-control theory

The theory that the spinal cord contains a neurological ____ that blocks pain signals or allows them to pass on to the brain. The ____ 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.

Sensory interaction

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

Gestalt

An organized whole.

Figure-ground

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

Grouping

The perceptual tendency to organize stimuli into coherent groups.

Depth perception

The ability to see objects in three dimension although the images that strike the retina are two dimensional; allows us to judge distance

Visual cliff

A laboratory device for testing depth perception in infants and young animals

Binocular cues

Depth cues, such as retinal disparity, that depends on the use of two eyes.

Retinal disparity

A binocular cue for perceiving depth; by comparing images from the retinas in the two eyes, the brain computes distance-the greater the disparity between the two objects, the close the object.

Monocular cues

Depth cues, such as interposition and linear perspective, available to either eye alone.

Phi phenomenon

An illusion of movement created when two or more adjacent lights blink on and off in quick succession

Perceptual constancy

Perceiving objects as unchanging even as illumination and retinal images change.

Color constancy

Perceiving familiar objects as having consistent color, even if changing illumination alters the wave-lengths reflected by the object.

Perceptual adaption

In vision, the ability to adjust to an artificially displaced or even inverted visual field.

Perceptual set

A mental predisposition to perceive one thing and not another

Extrasensory perception

The controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition

Parapsychology

The study of paranormal phenomena, including ESP and psychokinesis