Chapter 6- Sensation and Perception Flashcards
sensation
the process by which our sensory receptors and nervous system recieve and represent stimulus energies from our environment
perception
the process by which our brain organizes and interprets sensory information
enables 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
starts at ur sensory receptors + works up to higher levels of processing
top down processing
information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations
What are the three steps that are basic to all of our senses?
- recieving sensory stimulation (often using specialized receptor cells)
- transform that stimulation into neural impulses
- deliver the neural info to our brain
Transduction
conversion of one form of energy into another. In sensation, the tranforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
like a translation of physical energy into brain’s electroch. language
Pyschophysics
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 praticular stimulus 50 percent of the time
the edge of our awareness of faint stimuli
Gustav Fechner
studied absolute threshold
signal detection theory
a theory predicting how and when we detect the presence of a faint stimulus
predicts when we will detect weak signals
subliminal
below one’s absolute threshold for conscious awareness
stimuli you cannot consciously detect 50 percent of the time
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time. We experiece the difference threshold as a just noticeable difference
the detectable difference increases with the size of the stimulus
Ex. music going from 40-45 decibles is detectable, but music changing from 100-105 decibles is most likely not able to be detected
Weber’s Law
the principle that, to be percieved as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)
priming
the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
perceptual set
a set of mental tendencies and assumptions that affects, top-down, what we hear, taste, feel, and see
a mental predisposition to perceive one thing and not another
Campbell, 1986
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 gamma rays to the long pulses of radio transmission
the distance from one wave peak to the next
hue
the dimension of color that is determined by the wavelength of the light; what we know as the color names blue, green,and so forth
the color we experience
intensity
the amount of energy in a light wave or sound wave, which influences what we percieve as brightness or loudness. Intensity is determined by the wave’s amplitude.
the amount of energy the wave contains, influences brightness
Amplitude
height of a wavelength, determine’s their intensity
great amplitude (height)= bright colors; small amplitude= dull colors
frequency
the number of complete wavelengths that can pass a point in a given time
shorter wavelength=high frequency= bluish colors… longer wavelength=low frequency=reddish colors
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
multilayered tissue on the eyeball’s sensitive inner surface
accommodation
the process by which the eye’s lens changes shape to focus near or far objects on the retina
process where the lens changes its curvature and thickness
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 (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
the theory that opposing retinal process (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.
Color processing stages
- The retina’s red-, green-, and blue-sensitive cones respond in varying degrees to different color stimuli, as the Young-Hemholtz trichromatic theory suggested
- The cones’ responses are then processed by opponent-process cells, as Hering’s opponent-process theory proposed.
feature detectors
nerve cells in the brain’s visual cortex that respond to specific features od the stimulus, such as shape, angle, or movement
nerve cells in the occipital lobe’s visual cortex that respond to a scene’s specific features
parallel processing
processing many aspects of a stimulus or problem simultaneously
doing many things at once
gesalt
an organized whole. Gesalt psychologists emphasized our tendency to integrate pieces of info into meaningful wholes
in perception, the whole may exceed the sum of its parts
figure-ground
the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Ex. vase and faces allusion
grouping
the perceptual tendency to organize stimuli into coherent groups
the percieved whole often differs from the sum of its’ parts
proximity, continuity, closure
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
babies and baby animals refuse to lean over a visual cliff
binocular cue
a depth cue, such as retinal disparity, that depends on the use of two eyes
retinal disparity
a binocular cue for perceiving depth. by comparing retinal images from the two eyes, the brain computes distance–the greater the disparity (difference) between two images,
monocular cue
a depth cue, such as interposition or linear perspective, available to either eye alone
ex. relative height, relative size, relative motion, linear perspective, interposition
phi phenomenon
an illusion of movement created when two or more adjacent lights blink on and off in quick succession (like a moving arrow)
perceptual constancy
percieving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change
regardless of the viewing angle, distance, and illumination, we can identify people and things in less time than it takes to take a breath
perceptual adaptation
the ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field
audition
the sense or act of hearing
pitch
a tone’s experienced highness or lowness; depends on frequency
short wavelength=high frequency, long wavelength=low frequency, great amplitude=loud sounds, small amplitude=quiet sounds
middle ear
the chamber betwen the eardrum and cochlea containing three tiny bones–hammer (malleus), anvil (incus), and stirrup (stapes)– 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 vesibular sacs
sonsorineural hearing loss
the most common form of hearing loss, caused by damage to the cochlea’s receptor cells or to the auditory nerve; 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
cause of loudness
number of activated hair cells
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, aka temporal coding
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
hypnosis
a social interaction in which one person (the hypnotist) suggests to another person (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur
dissociation
a split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others
posthypnotic suggestion
a suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized, used by some clinicians to help control undesired symptoms and behaviors
gustation
our sense of taste
olfaction
our sense of smell
kinestesia
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
extrasensory perception (ESP)
the controversial claim that perception can occur appart from sensory input; includes telepathy , clairvoyance, and precognition
