Ch3. Perception and Sensation Flashcards
Sensation
stimulation of sensory receptors and the transmission for sensory info to nervous system. Automatic
Perception
process by which sensations are organized into an inner representation of world. Not automatic
Absolute threshold
minimum amount of energy to produce sensation. Based on 50% of people being able to detect stimulus
Difference threshold
minimal difference in intensity required between 2 sources of energy so that they will be perceived as being different (white paints; sugar in coffee)
Just noticeable difference
minimum amount by which a source must be increase or decreased so that a difference in intensity will be perceived
Signal-detection theory
the view that the perception of sensory stimuli involve the interaction of physical, biological, and physical factors. How hot or cold. How loud or quiet
Sensitization
become more sensitive to stimuli
Desensitization
become less sensitive to stimuli
Transduction
changing one form of energy to another, occur in sensory organs, eyes, ears, hair cells, taste buds, receptor sites, joints, muscles
Feature detectors
neurons in the sensory cortex that fires in response to specific features of sensory info
Vision
dominant sense, more work done on this sense than any other
Light
we are only stimulated by electromagnetic energy in visible light
Cornea
transparent, protects eyes, begins bending light waves
Iris
muscle surrounding pupil allows varying amount of light to enter
Pupil
black opening where light enters the eye, sensitive to light and emotions
Light passes through the _____, then _____, muscle changes shape of _____ to focus image on ______
pupil, lens, lens, retina
Cataracts
Cloudy lens, lens yellow as we age and lose ability to accommodate
Image is focused on retina, inner surface of eye that contains photoreceptors
rods and cones
rods
light and dark
cones
RGB
Chemical changes are transmitted to ______ and ______ cells
bipolar, ganglion
Image on retina is ______, and unfocused
upside down
Macula
central area of retina, essential for vision
Macular degeneration
cause of blindness
Fovea
small area within macular composed of cones; visual acuity greatest in this area
Blind spot
where the optic nerve leaves the eye (no rods or cones)
Dark adaptation
after a period in darkness, we see better, better in young people
trichromatic theory
based on cones, combining RGB lights could create any color in spectrum
Opponent-processed theory
ganglion cells overstimulated and then briefly inhibited
Trichromats
sensitive to red-green blue-yellow- dark-light
Monochromats
light and dark
Dichromats
red and green or yellow and blue
Red-green color blindness
a genetic disorder is the most common after normal trichromatic vision (1 in 13 males)
Visual perception
Process by which we make sense of sensory impressions. Studied early in 200th century by gestalt psychologists
Law of proximity
stimulus elements that are closed together tend to be perceived as a group
Law of similarity
similar stimuli tend to be grouped, this tendency can even dominate grouping due to proximity
Law of closure
stimuli tend to be grouped into complete figures
Law of good continuation
stimuli tend to be grouped as to minimize change or discontinuity
Stroboscopic motion
illusion in which perception of motion is generated by series of stationary images that are presented in rapid succession. Flip books, motion pictures
Top-down processing
see what you expect to see
Bottom-up processing
organizing the bits and pieces of information until aware of the pattern
Binocular cues
cues that require both eyes to perceive depth
Convergence
based on tension of muscles in eyes as they focus on an object coming closer (cross eyes)
Retinal disparity
the difference in the images cast by on each retina as objects move closer and further away.
Monocular cues
create an illusion of depth. Only perceived by one eye
Type of monocular perspective cues
Linear perspectives
shadowing
texture
gradient
motion parallax
overlapping
relative size
clearness
Size constancy
object is perceived as same size even if retina changes
Color constancy
perceive objects as same color even lighting conditions change its appearance
Brightness constancy
perceiving an object as just as bright although intensity of light has changed
Shape constancy
tendency to perceive and object as same shape although retinal image changes as it rotates
Outer ear
Pinna, auditory canal, eardrum, (tympanic membrane)
Middle ear
3 bones known as ossicles: Hammer, anvil, stirrup. Amplify sound.
Inner ear
Cochlea, oval window, auditory nerve, semicircular canals.
Stirrup
attached to oval window. Works in conjunction with round window that balance pleasure
Oval window
transmit vibrations to cochlea
Cochlea
the spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations
Pitch theory
receptor sites lined up along basilar membrane
Frequency theory
lower pitches must be matched to frequency
Deafness
conductive (older), sensorineural deafness
Smell
contributes to flavor, detects odors, info from nostril goes to brain via olfactory nerves
Taste
samples molecules of substance
Taste buds
taste cells, warn us of bad foods before swallowed
Basic senses
sweet, sour, bitter, salty, umami
Touch
constant pressure, intermittent pressure
Temperature
receptors for warmth and cold beneath skin
Pain
Chronic or acute,
Second pain
longer lasting, not localized, more unpleasant, involves slower c fibers. Chronic
Acupuncture
stimulates nerves that reach hypothalamus and cause release of endorphins
Gate theory
nervous system can handle only so much info at a time. Dull throbbing pain uses slower nerves. Scratching, rubbing, ice, stimulate faster nerves cause “bottleneck” at spinal cord
Phantom limb pain
affects 2-3% with amputated limbs. May be due to activation of neurons in stump. Those who have it – reorganization of motor and somatosensory cortex
Kinesthesis sense
informs about position and motion of body. Joints, tendons, muscles
Vestibular sense
provides brain with info as to whether we are physically upright
Parapsychology
the study of ESP and other psi phenomena or events that seem to defy accepted scientific laws
Extra Sensory Perception
clairvoyance, telepathy, precognition
Clairvoyance (remote viewing)
the ability to perceive events or gain information in ways that appear unaffected by distance or normal barriers.
Telepathy
extrasensory perception of another’s thoughts. Cards or the ganzfeld procedure are used in the lab to test.
Precognition
ability to perceive or accurately predict future events. Precognition may take the form of prophetic dreams that foretell the future. New research is done using computers.
Psychokinesis
the ability to exert influence over inanimate objects by willpower (mind over matter)
Synesthesia
stimulation of one sensory system involuntarily leads a person to experience an additional sensory response in a different sensory system. Taste colors, hear orange juice, etc
Subliminal perception
perception of messages about which we have no awareness
