Psychology Ch. 6

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Psychology Ch. 6
2013-10-05 14:36:36

Sensation and perception
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  1. prosopagnosia
    face blindness
  2. sensation
    the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
  3. perception
    the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events
  4. bottom-up processing
    analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
  5. top-down processing
    the information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations
  6. psychophysics
    • the study of relationships btween the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
    • *"You are physically psycho to stimuli when you experience them"
  7. absolute threshold
    the minimum stimulation needed to detect a particular stimulus (light, sound, pressure, taste or odor) 50% of the time
  8. subliminal
    below one's absolute threshold for conscious awareness
  9. priming
    the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or reponse
  10. difference threshold
    the minimum difference btwn two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference (jnd)
  11. Webers law
    the principle that, to be perceived as different, two stimuli must differ by a constant minimum % (rather than a constant amount)
  12. sensory adaption
    diminished sensitivity as a consequence of constant stimulation
  13. masking stimulus
    interrupts the brain's processing before conscious perception
  14. Because sometimes we feel what we do not know and cannot describe...
    Much of our information processing occurs automatically, out of sight, off the radar screen of our conscious mind
  15. For the average person to perceive differences...
    • two lights must differ in intensity by 8%
    • two objects must differ in weight by 2%
    • two tones must differ in frequency by only 0.3%
  16. We perceive the world not exactly as it is...
    but as it is useful for us to perceive it
  17. 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
  18. 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
  19. 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
  20. Two physical characteristics of light which help determine our sensory experience
    Wavelength, and intensity
  21. frequency
    • the number of complete wavelengths that can pass a point in a given time, depends on wavelength
    • shorter the wavelength, the figher the frequency
  22. amplitude
    • the height from peak to trough
    • in vision, it determines the intensity of colors
    • In hearing, it applies to the strength of sound waves, which determines the loudness
  23. cornea
    • what light passes through to enter the eye
    • protects the eye and bends light to provide focus
  24. retina
    • a multilayered tissue on the eyeball's light sensitive inner surface.
    • contains receptor rods and cones plus layers of neurons that begin the processing of visual information
  25. accommodation
    a process by which the lens focuses the rays by changing it's curvature
  26. path of a light-energy particle into your eye
    • first it would make its way through the retina's outer layer of cells to it's buried receptor cells, rods and cones
    • there, you would see the light energy trigger chemical changes which spark a neural impulse, activating bipolar cells
    • bipolar cells would then activate the ganglion cells
    • from there, following the path of the ganglion cells axons which form optic nerve which carries info to brain
  27. rods
    • retinal receptors that detect black, white, and gray
    • necessary for peripheral and twilight vision, when cones don't respond
    • don't have a "hotline" to brain, share bipolar cells w other rods, sending combined messages
  28. cones
    • retinal receptor cells 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
    • Many have their own "hotline" to the brain; bipolar cells which help relay a cones individual message to the visual cortex
  29. optic nerve
    the nerve that carries neural impulses from the eye to the brain (where the thalamus will receive and distribute the info)
  30. blind spot
    the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
  31. fovea
    the central focal pint in the retina, around which the eye's cones cluster
  32. How does the brain receive and process visual information?
    • After processing by retina's nearly 130 million rods and cons, info travels to bipolar cells, then to ganglion cells & through their axons which make up the optic nerve, to the brain. 
    • Any given retinal area relays info to corresponding location in visual cortex, in occipital lobe.
  33. feature detctors
    nerve cells in the brain that respond to specific features of a stimulus, such as shape, angle, or movement
  34. parallel processing
    • doing many things at once
    • the processing of many aspects of a problem simultaneously;
    • the brain's natural mode of information processing form many functions, including vision.
    • Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving.
  35. blindsight
    a localized area of blindness in part of the field of vision
  36. Young-Helmholtz trichromatic (three-color) theory
    the theory that the retina contains three different color receptors -- one most sensitive to red, one to green, and one to blue -- which, when stimulated in combination, can produce the perception of any color
  37. Explain why people with color-deficient vision are not actually "colorblind"
    • They simply lack functioning red- or green- sensitive cones, or sometimes both. 
    • Their vision is either monochromatic (one color) or dichromatic (two color) instead of trichromatic (3 color), making it impossible to distinguish red and green.
    • Dogs also lack receptors for red
  38. monochromatic
    ONE color
  39. dichromatic
    two color
  40. opponent-process theory
    • By Hering, 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
  41. The physical characterstic of light that determines the color we experience, such as blue and green, is..
  42. The mystery of color vision:
    • Color processing occurs in two stages:
    • The retina's cones for red, green, and blue respond in varying degrees to different color stimuli (as in Young-Helmholtz theory)
    • The cones' signals are then processed by the nervous system's opponent-process cells, en route to the visual cortex
  43. audition
    • the sense of hearing
    • highly adaptive
  44. pitch
    • a tone's experienced highness or lowness; depends on frequency
    • Short waves have high frequency and high pitch
    • Long waves have low frequency and low pitch
  45. How sound is measured
    • in decibels
    • The absolute threshold for hearing arbitrarily defined as zero decibels. 
    • Every 10 decibels correspond to tenfold increase in sound intensity
    • Normal conversation is 60 decibels/ a whisper is 20 decibels
  46. middle ear
    the chamber btwn the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup which make up a piston) that concentrate the vibrations of the eardrum on the cochlea's oval window
  47. cochlea
    a coiled,snail-shaped, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
  48. inner ear
    the innermost part of the ear, containing the cochlea, semicircular canals, and vestivular sacs
  49. How the ear transforms sound energy into neural messages
    • First, outer ear channels sound waves though auditory canal to eardrum (tiny membrane which vibrates w/ the waves)
    • Next, the middle ear transmits the eardrum's vibrations through bones to oval window (the cochlea's membrane) jostling the fluid in the tubes.
    • This motion ripples in the basilar membrane, bending the hair cells which triggers impulses from adjacent nerve cells, whose axons converge to form auditory nerve, which sends neural messages (via thalamus) to temporal lobe's auditory cortex
  50. What accounts for most hearing loss?
    damage to hair cells
  51. how does the brain interpret loudness
    from the number of activated hair cells
  52. kinesthesis
    • the system for sensing the position and movement of individual body parts
    • Enabled by important sensors in joints, tendons, bones, and ears, as well as skin
  53. vestibular sense
    • the sense of body movement and position, including the sense of balance
    • The semicircular canals, which look like 3D pretzel, and the vestibular sacs, which connect the canals with the cochlea, contain fluid that moves when your head rotates or tilts
  54. The basic four skun sensations
    • pressure, warmth, cold, and pain
    • Only pressure has identifiable receptors
  55. nociceptors
    sensory receptors that detect hurtful temps, pressure or chemicals
  56. 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
  57. tinnitus
    • a ringing the the ears sensation 
    • associated with the phantom sounds people with hearing loss often experience as the sound of silence
  58. How do we edit our memories of pain
    • people tend to over look pains duration. Their memory snapshots instead record two factors:
    • 1- people tend to record pain's peak moment, which leads them to recall variable pain, with peaks as worse
    • 2 - they register how much pain the felt at the end
  59. 5 basic taste sensations
    • sweet, sour, salty, bitter, and umami (the savory meaty taste, MSG)
  60. The survival functions of basic tastes
    • Sweet ~ energy source
    • Salty ~ Sodium essential to physiological processes
    • Sour ~ Potentially toxic acid
    • Bitter ~ potential poisons
    • Umami ~ Proteins to grow and repair tissue
  61. reproduction of taste receptors
    • reproduces every week or two
    • however, as you grow older, the number of taste buds decreases, as does taste sensitivity
    • smoking and alcohol use accelerate these declines
    • Those who lose their sense of taste report food tastes like "straw" and is hard to swallow
  62. anosmia
    unable to smell
  63. sensory interaction
    • the principle that one sense may influence another, as when smell of food influences it's taste
    • smell + texture + taste = flavor
  64. McGurk effect
    • the idea that we may perceive a third syllable when we see a speaker saying one syllable while we hear another
    • Ex: Seeing the mouth movements for ga while hearing ba, we may perceive da
  65. gestalt
    • an organized whole
    • gestalt psychologist empasized our tendency to integrate pieces of information into meaningful wholes
    • German for "whole" or "form"
  66. figure-ground
    the organization of the visual field into objects (the figures that stand out from their surroundings (the ground)
  67. grouping
    the perceptual tendency to organize stimuli into coherent groups
  68. Our minds rules for grouping
    • Proximity ~we group nearby figures together
    • Similarity ~ we group similar figures together
    • Continuity ~ we perceive smooth, continuous patters rather than discontinuous ones.
    • Connectedness ~ (two dots & line in book) because they are uniform and linked, we perceive each set as a single unit
    • Closure ~ We fill in gaps to create a complet, whole object
  69. depth perception
    the ability to see objects in 3 dimensions although the images that strike the retina are 2-dimensional; allows us to judge distance
  70. visual cliff
    a lab device for testing depth perception in infants and young animals
  71. binocular cues
    depth cues, such as retinal disparity, that depend on the use of two eyes
  72. 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
  73. monocular cues
    depth cues, such as interposition and linear perspective, available to either eye alone
  74. horizontal - vertical illusion
    our perceiving vertical dimensions as longer than identical horizontal dimensions
  75. relative height illusion
    a monocular cue: we perceive objects higher in our field ov vision as farther away.
  76. Relative size
    A monocular cue: If we assume two objects are similar in size, most people perceive the one that casts the smaller retinal image as further away
  77. Interposition
    A monocular cue: If one object partially blocks our view of another, we perceive it as closer.
  78. Linear perspective
    A monocular cue: parallel lines appear to converge w distance. The more they converge, the greater their perceived distance
  79. Light and shadow
    • a monocular cue: nearby objects reflect more light to our eyes. Thus, given two identical objects, the dimmer one seems farther away.
    • Shading, too, produces a sense of depth consistent with our assumption that light comes from above.
  80. Relative motion
    A monocular cue: as we move, objects that are actually stable may appear to move.
  81. perceptual constancy
    perceiving objects as unchanging (having consistent shapes, size, lightness, and color) even as illumination and retinal images change
  82. shape constancy
    we can perceive the form of familiar objects as constant even while our retinal image of it changes
  83. size constancy
    we can perceive objects as having a constant size, even while our distance from them varies
  84. lightness constancy
    also called brightness constancy; we perceive an object as having a constant lightness even while it's illumination varies
  85. relative luminance
    the amount of light an object reflects relative to it's surroundings
  86. color constancy
    perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object
  87. perceptual adaptation
    in vision, the ability to adjust to an artificially displaced or even inverted visual field
  88. perceptual set
    a mental predisposition to perceive one thing and not another
  89. Context can
    • guide our perception of lightness and color; also shapes perception in other ways.
    • Ex: the 2 monsters in the textbook pic
  90. extrasensory perception
    ESP; the contoversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition
  91. telepathy
    mind-to-mind communication; one person sending thoughts to another person or perceiving another's thoughts
  92. clairvoyance
    perceiving remote events, such as sensing that a friends house is on fire
  93. precognition
    perceiving future events
  94. psychokinesis
    mind over matter... such as levitating a table or influencing a roll of a die
  95. parapsychology
    the study of paranormal phenomena, including ESP and psychokinesis