AP Psychology Unit 3

Sensation

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

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Perception

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

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Bottom-up processing

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

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Top-down processing

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

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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; a form of *inattentional blindness*.

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.

Psychophysics

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

Absolute threshold (studied by Gustav Fechner)

the lowest intensity at which a stimulus can be detected.

Signal detection theory

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a theory predicting how and when we detect the presence of a faint stimulus *(signal)* amid background stimulation *(noise)*. Assumes there is no single absolute threshold. 

Subliminal

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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 (Just noticeable difference)

the smallest amount by which two sensory stimuli can differ in order for an individual to perceive them as different.

Weber's law (Ernst Weber)

the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus

Sensory adaptation

diminished sensitivity as a consequence of constant stimulation.

Perceptual set

a mental predisposition to perceive one thing and not another.

Extrasensory perception (ESP)

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.

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 of light; what we know as the color names *blue, green,* and so forth.

Intensity

the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Determined by 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 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

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

Rods

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retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and night vision, when cones don’t respond.

Cones

retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions, detect fine detail and give 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, and no receptor cells are located there.

Fovea

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

Feature detectors (Studied by David Hubel & Torsten Wiesl)

nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement.

Parallel processing

our ability to deal with multiple stimuli simultaneously.

Young-Helmholtz trichromatic (three -color) 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.

Opponent- process theory

one member of the color pair suppresses the other color. For example, we do see yellowish-greens and reddish-yellows, but we never see reddish-green or yellowish-blue color hues.

Gestalt

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

Figure-ground

the organization of the visual field into objects (the *figures*) that stand out from their surroundings (the *ground*)

Grouping

the perceptual tendency to organize stimuli into coherent groups.

Depth perception

the ability to see the three-dimensional objects and the spatial layout of objects relative to one another. It allows us to judge distance

Visual cliff

a laboratory device for testing depth perception in infants and young animals.

Binocular cues

information taken in by our 2 eyes and then processed by our brain in order for us to perceive depth or distance

Retinal disparity

a binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance

Monocular cues

a visual cue for depth perception that only requires one eye.

Perceptual constancy

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

Phi phenomenon

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

Color constancy

perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.

Perceptual adaptation

the ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field.

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Audition

the sense or act of hearing.

Frequency

the number of complete wavelengths that pass a point in a given time

Pitch

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a tone’s experienced highness or lowness; depends on frequency.

Middle ear

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the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.

cochlea

a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses.

Inner ear

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

Sensorineural hearing loss

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hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; the most common form of hearing loss, also called *nerve deafness.*

Conduction hearing loss

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

Cochlear implant

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Place theory

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the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated.

Frequency/ Temporal theory

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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.

Gate-control theory

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the theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain.

Kinesthesia

our movement sense—our system for sensing the position and movement of individual body arts.

Vestibular sense

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

Sensory interaction

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

Embodied cognition

the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments.

Cocktail party effect

the ability to focus one's attention a particular stimulus while filtering out a range of other stimuli

Choice blindness

Refers to ways in which people are blind to their own choices and preferences

Context effects

the same stimulus can evoke different perceptions in different contexts

Telepathy

mind to mind communication

Clairvoyance

perceiving remote events that are happening currently, such as a house on fire in another state

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Precognition

perceiving future events, such as an unexpected death in the next month

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Psychokinesis

ability to move objects with one's mind

Cornea

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the eye’s clear, protective outer layer, covering the pupil and iris.

Proximity

when objects appear close to one another we tend to perceive them as a group

Continuity

We perceive a pattern to be continuous, our eyes follow one object and perceive it to lead to the next one, creating a smooth path and pattern from different aspects of a picture.

Closure

the tendency to complete figures that are incomplete

Stroboscopic movement

a series of still images in rapid succession appears to be continuously moving (movie-like)

Relative Height

a monocular cue for perceiving depth; objects higher in our field of vision are perceived as farther away

Relative motion

a monocular cue where as the observer moves forward, the objects that appear to him/her to move backwards faster are closer than apparently slower-moving objects

Relative size

a monocular cue for perceiving depth; the smaller the image the farther it is farther away

Interposition

if one object partially blocks our view of another, we perceive it as closer

Linear perspective

A monocular cue for perceiving depth; the more parallel lines converge, the greater their perceived distance.

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Light and shadow

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shading produces a sense of depth consistent with our assumption that light comes from above

Brightness constancy & Shape/Size constancy

We perceive objects to have the same descriptions even if the lighting or size changes. Like you would still recognize a banana if you only saw the black shadow

Relative luminance

amount of light an object reflects relative to surroundings

Basilar membrane

A structure that runs the length of the cochlea in the inner ear and holds the auditory receptors, called hair cells.

Volley principle

individual fibers in an auditory nerve respond to one or another stimulus in a rapid succession of rhythmic sound stimuli

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Umami

taste for monosodium glutamate

Olfaction

sense of smell

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Semicircular canals/Vestibular sac

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Both respond to gravity to encode information about the head's orientation 

Synesthesia

describing one kind of sensation in terms of another ("a loud color", "a sweet sound")

Gustation

sense of taste

Psychophysics

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

Ganglion

cells in the retina that receive visual information from the photoreceptors via the bipolar cells, and pass the information on to the brain.

bipolar cells

Provide the main pathway from photo receptors tp ganglion cells

Nueral Impulse

converts light to electrical impulses

Hammer

A tiny bone that passes vibrations/ sound waves from the eardrum to the anvil. Also increases efficiency

Stirrup

A tiny U shaped bone that passes vibrations from the anvil to the cochlea.

auditory canal

the area that sound waves pass through to reach the eardrum

locating sounds

Because we have two ears, sounds that reach one ear faster than the other causes us to localize sounds

decibel

Measurement for Sound