psych sensation and perception test

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sensation

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

sensory receptors

sensory nerve endings that respond to stimuli

perception

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

bottom-up processing

information processing 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 perceptions drawing on our experience and expectations

transduction

conversion of one form of energy into another (ex: for senstion, the transforming of physical energy into neural impulses the 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

the minimum stimulus energy needed to detect a particular stimulus 50% of the time

signal detection theory

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 and that detection depends partly on a person’s experience, expectations, etc

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 2 stimuli required for detection 50% of the time: aka “just noticeable difference”

weber’s law

the principle that, to be percieved as different, 2 stimuli must differ by a constant minimum percentage

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

wavelength

the distance from the peak of one light wave or sound wave to the peak of the next (ex: short gamma rays and long pulses)

hue

the dimension of color that is determined by the wavelength of light, what we know as the color names

intensity

amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. intensity is determined by the wave’s amplitude

cornea

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

pupil

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

iris

ring of muscle tissue that forms the colored portions 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 back 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 images of near or far objects on the retina

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement. rods are necessary for peripheral and twilight 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. cones 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, creating a “blind” spot because no receptor cells are located there

fovea

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

young-helmholtz trichromatic (3 color) theory

theory that the retina contains 3 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

theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. for example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

feature detectors

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

parallel processing

processing multiple aspects of a stimulus or problem simultaneously

audition

the sense or act of hearing

frequency

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

pitch

tone’s experienced highness or lowness; depends on frequency

middle ear

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

cochlea

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

inner ear

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

sensorineural hearing loss

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

conduction hearing loss

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

cochlear implant

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

place theory

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

frequence 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

gate-control theory

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

olfaction

our sense of smell; pheremones

gustation

our sense of taste; taste receptors:

• sweet

• sour

• salty

• bitter

• umami

• oleogustus

supertasters: heightened sensitivity (especially to bitterness), mediumtasters: average sensitivity, and nontasters: low sensitivity with possibly no perception of bitterness

kinesthesis

our movement sense; our system for sensing the position and movement of individual body parts

vestibular sense

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

sensory interaction

the principle that one sense can 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 judgements

selective attention

focusing 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

perceptual set

a mental predisposition to percieve one thing and not another

gestalt

an organized whole rather than separate parts. gestalt psychologists emphasized our tendency to integrate pieces of information onto meaningful wholes

• closure: fill in gaps to perceive a complete object

• figure and ground: perceiving objects (figure) as distinct from background (ground)

• proximity: objects close together are grouped

• similarity: group similar elements together into a single, unified group based on shared characteristics

figure-ground

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

grouping

the perceptual tendency to organize stimuli into coherent groups

depth perception

ability to see objects in 3 dimensions, although the images that strike the retina are 2-dimensional; allows us to judge distance

visual cliff

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

binocular cue

a depth cue, such as retinal disparity, that depends on the use of 2 eyes

• retinal disparity: slight difference in images from each eye to depth

• convergence: eyes turn inward to focus on a nearby object, and the brain uses the degree of inward rotation to judge its distance

convergence

a cue to nearby objects’ distance, enables by the brain combining retinal images

retinal disparity

binocular cue for perceiving depth. by comparing retinal images from 2 eyes, the brain computes distance—the greater the disparity (difference) between the 2 images, the closer the object

monocular cue

depth cue, such as interposition or linear perspective, available to either eye alone

• relative clarity: closer objects appear sharper and more detailed, while objects farther away appear hazier and blurry

• relative size: smaller objects appear farther

• texture gradient: textures appear finer, more detailed, and less dense up close, becoming smoother, less detailed, and more compressed as they recede into the distance

• linear perspective: parallel lines appear to converge in distance

• interposition: closer objects block distant ones (overlapping)

stroboscopic movement

an illusion of continuous movement experienced when viewing a rapid series of slightly varying still images

phi phenomenon

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

autokinetic effect

the illusory movement of a still spot of light in a dark room

perceptual constancy

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

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 ,

necker cube

ambiguous line drawing that can be seen in multiple ways

moon illusion

psychological phenomenon where the moon appears larger when near the horizon and smaller when high in the sky, even though its angular size remains the same

mcgurk effect

auditory illusion where the brain perceives a different sound when visual and auditory speech stimuli don't match

synesthesia

perceptual phenomenon where stimulating one sense automatically and involuntarily triggers a response in another sense

volley theory of audition

the ear perceives sound frequencies higher than a single neuron can individually fire

phantom limb sensation

perception of feeling a limb that has been amputated or is missing

nociceptors

specialized sensory neurons that detect and transmit pain signals to the central nervous system