unit 4 Flashcards
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 perceptions drawing 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
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.
change blindness
failing to notice changes in the environment
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 (signal) amid background stimulation (noise). Assumes that 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. We experience the difference threshold as a just noticeable difference (or jnd)
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
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. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission
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 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 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 function in daylight or in well - lit conditions. The 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.
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 (serial) processing of most computers and of conscious problem solving
young Helmholtz (three-color) 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 (red-green, yellow-blue, 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
gestalt
an organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.
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 objects in three dimensions 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 depend 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 (difference) between the two images, the closer 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 (having consistent shapes, size, brightness, and color) even as illumination and retinal images change
color constancy
perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.
perceptual adaptation
in vision, the ability to adjust to an artificially displaced or even inverted visual field
audition
the sense or act of hearing
frequency
the number of complete wavelengths that pass a point in a given time (for example, per second)
pitch
a tone’s experienced highness or lowness; depends on frequency.
middle ear
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
hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness
conduction hearing loss
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
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.
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 fi-bers or by information coming from the brain
kinesthesia
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.
sensory interaction
the principle that one sense may influence an-other, as when the smell of food influences its taste.
embodied cognition
in psychological science, the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments.
gustav fechner
german scientist who studied our awareness of faint stimuli and labeled them absolute thresholds
Ernst Weber
founder of experimental psychology
david hubel
studies on the organization and functioning of the brain
torsten wiesel
made discoveries concerning info processing in the visual system
