Module 5

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Module 5

• Sensation

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THREE DEFINITONS

• Eyes, ears, nose, skin, and tongue are complex,
  miniaturized, living sense organs that
  automatically gather information about your
  environment
• Transduction
• Process in which a sense organ changes, or
  transforms, physical energy into electrical
  signals that become neural impulses, which may be
  sent to the brain for processing
• Adaptation
• The decreasing response of the sense organs as
  theyre exposed to a continuous level of
  stimulation

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THREE DEFINITONS (CONTD)

• Sensation versus perception
• Relatively ____________ bits of information that
  result when the brain processes electrical
  signals that come from the sense organs
• Perceptions
• ______________ sensory experiences that result
  after the brain combines hundreds of sensations

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Cocktail-party phenomenon

• The cocktail party effect ________________________
  __________________________________________________
  __________________________________________________
  ____________________________________
• ____________________.

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Energy v. Chemical senses

• Energy Senses

• Chemical Senses

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Vision

• Our most dominating sense.

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(No Transcript)
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EYE VISION (CONTD)

• Structure and function
• Eyes perform two separate processes
• first ___________________________________________
  _____________________________________
• second __________________________________________
  __________________________________________________
  _______________________
• Process called transduction

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Phase Two Getting the light in the eye
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EYE VISION (CONTD)

• Retina
• Three layers of cells
• back layer contains two kinds of photoreceptors
  that begin the process of transduction
• change light waves into electrical signals
• _________________________________
• __________________________________of the retina
  called the fovea

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EYE VISION (CONTD)

• Rods
• Photoreceptor that contain a single chemical,
  called __________________________
• Activated by ___________ amounts of light
• Very light sensitive
• Allow us to see in ___________ light
• See only _______________________________

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EYE VISION (CONTD)

• Cones
• Photoreceptors that contain three chemicals
  called _____________
• Activated in ____________________
• Allow us to see _______________________
• Cones are wired individually to neighboring cells
• Allow us to see __________________

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Transduction Continued

• Order is Rods/Cones to Bipolar to Ganglion to
  Optic Nerve.
• Sends info to thalamus- area called lateral
  geniculate nucleus (LGN).
• Then sent to cerebral cortexes.
• Where the optic nerves cross is called the optic
  chiasm.

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EYE VISION (CONTD)

• Making colors from wavelengths
• Sunlight is called white light because it
  contains all the light waves
• White light passes through a prism separates
  light waves that vary in length
• Visual system transforms light waves of various
  lengths into millions of different colors
• Shorter wavelengths of violet, blue, green
• Longer wavelengths of yellow, orange, and red
• An apple is seen as red because reflection of
  longer light waves that brain interprets as red

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EYE VISION (CONTD)
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Trichromatic Theory

• Three types of cones
• Red
• Blue
• Green
• These three types of cones can make millions of
  combinations of colors.
• Does not explain afterimages or color blindness
  well.

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Opponent-Process theory

• The sensory receptors come in pairs.
• Red/Green
• Yellow/Blue
• Black/White
• If one color is stimulated, the other is
  inhibited.

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Hearing
Our auditory sense
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The Ear
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EAR AUDITION

• Stimulus
• Sound waves
• ____________________(audition)
• ripples of different sizes sound waves travel
  through space with varying heights and frequency
• Height
• distance from the _____________ of a sound wave
  amplitude
• Frequency
• _______________________________________

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EAR AUDITION (CONTD)

• Loudness
• Subjective experience of a sounds intensity
• Brain calculates loudness from specific physical
  energy ______________________________
• Pitch
• Subjective experience of a sound being high or
  low
• Brain calculates from specific physical stimuli
• _______________________________________
• __________________(how many sound waves in a
  second)

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EAR AUDITION (CONTD)

• Measuring sound waves
• Decibel ______________________________
• Threshold for hearing
• 0 decibels (no sound)
• 140 decibels (pain and permanent hearing loss)

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EAR AUDITION (CONTD)
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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Outer ear
• consists of three structures
• ___________________________
• ___________________________
• ___________________________

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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Outer ear
• external ear
• oval-shaped structure that protrudes from the
  side of the head
• function
• __________________________________________________
  __________________________________________________
  __________________________________________________
  ______________________

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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Outer ear
• auditory canal
• __________________________________________________
  __________________________________________________
  __________________________________________________
  __

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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Outer ear
• tympanic membrane
• taut, thin structure commonly called the eardrum
• sound waves strike the tympanic membrane and
  cause it to vibrate

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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Middle ear
• bony cavity sealed at each end by membranes that
  are connected by three tiny bones called ossicles
• hammer, anvil, and stirrup
• hammer is attached to the back of the tympanic
  membrane
• anvil receives vibrations from the hammer
• stirrup makes the connection to the oval window
  (end membrane)

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EAR AUDITION (CONTD)

• Outer, middle, and inner ear
• Inner ear
• contains two structures sealed by bone
• cochlea __________________________
• vestibular system _______________________

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EAR AUDITION (CONTD)

• Cochlea
• Bony coiled exterior that resembles a snails
  shell
• Contains receptors for hearing
• Function is transduction
• Transforms vibrations into nerve impulses sent to
  the brain for processing into auditory
  information

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EAR AUDITION (CONTD)
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EAR AUDITION (CONTD)

• Auditory cues
• Direction of sound
• determined by brain calculates slight difference
  in time it takes sound waves to reach the two
  ears
• Calculating pitch
• frequency theory
• applies only to low-pitched sounds
• Rate that nerve impulses reach the brain
  determines how low a sounds pitch is
• place theory
• brain determines medium-to-higher-pitched sounds
  from the place on the basilar membrane where
  maximum vibration occurs

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EAR AUDITION (CONTD)

• Auditory cues
• Calculating loudness
• brain calculates loudness primarily from the
  frequency or rate of how fast or how slow nerve
  impulses arrive from the auditory nerve

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Vestibular Sense

• __________________________________________________
  __________________________.
• ___________________.
• __________________________________________________
  _____________________________________________.

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VESTIBULAR SYSTEM BALANCE (CONTD)

• Motion sickness (sensory mismatch between
  information from the vestibular system)
• symptoms feelings of discomfort, nausea, and
  dizziness in a moving vehicle
• head bouncing, but distant objects look fairly
  steady
• Menieres disease (malfunction of the
  semicircular canals of the vestibular system)
• symptoms dizziness, nausea, vomiting, spinning,
  and piercing buzzing sounds
• Vertigo (malfunction of the semicircular canals
  of the vestibular system)
• symptoms dizziness and nausea

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CHEMICAL SENSES

• Taste
• Chemical sense because the stimuli are various
  chemicals
• Tongue
• Surface of the tongue
• Taste buds

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CHEMICAL SENSES (CONTD)

• Tongue
• Five basic tastes
• ________________________
• ________________________
• ________________________
• ________________________
• ________________________

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CHEMICAL SENSES (CONTD)

• Taste buds
• Produce nerve impulses that reach areas of the
  brains parietal lobe
• Brain transforms impulses into sensations of
  taste
• Flavor
• __________________________________________

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Taste

• We have bumps on our tongue called papillae.
• Taste buds are located on the papillae (they are
  actually all over the mouth).
• Sweet, salty, sour bitter, umami.

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CHEMICAL SENSES (CONTD)

• Smell, or olfaction
• Steps for olfaction
• stimulus
• olfactory cells
• sensation and memories
• functions of olfaction

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CHEMICAL SENSES (CONTD)
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CHEMICAL SENSES (CONTD)

• Smell, or olfaction
• Stimulus
• _____________________________________
• __________________________________________________
  __________________________________________________
  ____________________
• examples skunk spray, perfumes, warm brownies
  not glass or steel

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CHEMICAL SENSES (CONTD)

• Smell, or olfaction
• Olfactory cells
• receptors for smell located in a one-inch-square
  patch of tissue in the uppermost part of the
  nasal passages
• olfactory cells are covered in mucus that
  dissolves volatile molecules and stimulates the
  cells
• the cells trigger nerve impulses that travel to
  the brain, which interprets the impulses as
  different smells

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CHEMICAL SENSES (CONTD)

• Smell, or olfaction
• Sensations and memories
• _____________________________________________
• _____________________________________________
• __________________________________________________
  __________________________________________
• _____________________________________________
• __________________________________________________
  __________________________________________________
  ____________________

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CHEMICAL SENSES (CONTD)

• Smell, or olfaction
• Functions of olfaction
• one function _____________________________
• second function _________________________________
  _______________________________________________
• third function __________________________________
  ______________________________________________

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CHEMICAL SENSES (CONTD)
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TOUCH

• Touch
• Includes pressure, temperature, and pain
• Beneath the outer layer of skin are a half-dozen
  miniature sensors that are receptors for the
  sense of touch
• Change mechanical pressure or temperature
  variations into nerve impulses that are sent to
  the brain for processing

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TOUCH (CONTD)
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TOUCH (CONTD)

• Receptors in the skin
• Skin
• Hair receptors
• Free nerve endings
• Pacinian corpuscle

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TOUCH (CONTD)

• Skin
• Outermost layer
• Thin film of dead cells containing no receptors
• Just below are first receptors, which look like
  groups of thread-like extensions
• Middle and fatty layer
• Variety of receptors with different shapes and
  functions
• Some are hair receptors

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TOUCH (CONTD)

• Hair receptors
• Free nerve endings wrapped around the base of
  each hair follicle
• Hair follicles fire with a burst of activity when
  first bent
• If hair remains bent for a period of time, the
  receptors will cease firing
• Sensory adaptation
• Example wearing a watch

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TOUCH (CONTD)

• Free nerve endings
• Near bottom of the outer layer of skin
• Have nothing protecting or surrounding them
• Pacinian corpuscle
• In fatty layer of skin
• Largest touch sensor
• Highly sensitive to touch
• Responds to vibration and adapts very quickly

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TOUCH (CONTD)

• Brain areas
• Somatosensory cortex
• Located in the parietal lobe
• Transforms nerve impulses into sensations of
  touch, temperature, and pain

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PAIN

• What causes pain?
• Pain unpleasant sensory and emotional experience
  that may result from tissue damage, ones
  thoughts or beliefs, or environmental stressors
• Pain results from many different stimuli

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PAIN (CONTD)
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PAIN (CONTD)

• How does the mind stop pain?
• Gate control theory of pain
• Nonpainful nerve impulses compete with pain
  impulses in trying to reach the brain
• Creates a bottleneck or neutral gate
• Shifting attention or rubbing an injured area
  decreases the passage of painful impulses
• Result pain is dulled

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PAIN (CONTD)

• Endorphins
• Chemicals produced by the brain and secreted in
  response to injury or severe physical or
  psychological stress
• Pain-reducing properties of endorphins are
  similar to those of morphine
• Brain produces endorphins in situations that
  evoke great fear, anxiety, stress, or bodily
  injury as well as intense aerobic activity

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PAIN (CONTD)

• Dread
• Connected to pain centers in brain
• Not the act itself that people fear
• Time waiting before event causes dread
• Acupuncture
• Trained practitioners insert thin needles into
  various points on the bodys surface and then
  manually twirl or electrically stimulate the
  needles
• After 10 to 20 minutes of stimulation, patients
  often report a reduction in various kinds of pain