EXPLORING PSYCHOLOGY (7th Edition in Modules) David Myers

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Warm Up In your notes, briefly answer the
following questions 1. How do you think you did
on this test compared to the first test? 2. If
you think you did better, what do you think
helped you this time? 3. If you think you did
worse, what do you think was the reason?
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Scores 39, 40, 40, 46, 47, 50, 52, 53, 54, 63,
64, 70, 75, 76, 77, 82, 82, 85, 90, 91, 96 Last
tests mean 54 This tests mean 65 11
points!! Last tests median45 This tests
median 64 19 points!! Curve 90s 4 60s 7 30s
10 80s 5 50s 8 70s 6 40s 9 This makes the
highest grade 100, and passes the lowest 60.
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Sensation Perceptionbasic terminology
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Scientific Names for the Six Senses (You Should
Know These)

• Related to
• Sight Visual (like vision)
• Hearing Auditory (like audio)
• Taste Gustatory (you eat with gusto!)
• Smell Olfactory (when you drive past
• an ol factory it often smells bad)
• Touch Tactile (sounds like texture)
• Balance Vestibular

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• Sensation
• Information coming into our brain from our
  sensory receivers. (What comes in.)
• Perception
• The way the brain organizes and interprets the
  data received by our senses (How we understand
  it.)
• Stimulus
• Something that triggers a response.

Can you have sensation without perception?
Prosopagnosia (agnosia ignorance, or not
knowing) Inability to recognize faces. Sensation
is fine,perception just doesnt work. Example of
Prosopagnosia FACE BLINDNESS
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Bottom-up Processing

• Start at the bottom with the sense receptors
  and individual stimuli, work up to the brain to
  form meaning.
• processing that begins with the sense receptors
  and works up to the brains integration of
  sensory information

Letter A is really a set of black lines that
the brain puts together to perceive as an A.
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Top-Down Processing

• Starting from experiences and expectations (the
  top) and working down to create perception
  (what we think we see.)
• information processing guided by higher-level
  mental processes
• as when we construct perceptions drawing on our
  experience and expectations
• How do you read the words below?
• Is it because of what you are actually sensing?
  Or because of what you expect to see?

THE CHT
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Bottom Up Vs. Top Down

• What do you see?

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Bottom Up vs. Top DownWhat do You See?
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Top-Down Processing

• Aoccdrnig to rscheearch at Cmabrigde Uinervtisy,
  it deosn't mttaer in waht oredr the ltteers in a
  wrod are, the olny iprmoetnt tihng is taht the
  frist and lsat ltteer be at the rghit pclae. The
  rset can be a total mses and you can sitll raed
  it wouthit a porbelm. Tihs is bcuseae the huamn
  mnid deos not raed ervey lteter by istlef, but
  the wrod as a wlohe.

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Sensation vs. PerceptionWhat do you see?
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Sensation vs. PerceptionWhat do you see?
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Psychophysics

• Psychophysics study of the relationship between
  physical characteristics of stimuli and our
  psychological experience of them
• Stimulus We experience
• light brightness
• sound volume
• pressure weight
• taste sweetness
• (Why do dogs hear a dogwhistle, but we dont?)

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Thresholds

• Absolute Threshold
• Minimum stimulation needed to detect a particular
  stimulus 50 of the time.

Subliminal Messages Messages presented below
absolute thresholds (subbelow,
liminalthreshold). Not consciously
perceived. (Technically, a subliminal message
can be something you DO perceive, just less than
50 of the time.)
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• subliminal message- stimulus that lies below
  ones absolute threshold for conscious awareness
• We can detect some subliminal messages
• How is that?
• because absolute thresholds involve
• detecting the stimulus 50 of the time
• Does this mean we can be subliminally persuaded?
  

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Subliminal Messages

• Some have argued that humans still pick up
  these messages that influence our unconscious.
  Do these messages have suggestive powers?
• Why do people who buy subliminal message tapes
  that promise to make them more confident, or more
  relaxed, say they work?

Mr. Subliminal
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Subliminal Message In The Lion King?
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Difference Threshold Amount of change needed to
notice that a change has occurred.
Webers Law The greater or stronger the
stimulus, the greater the change required to
notice a difference. Two stimuli must differ by a
constant minimum percentage (rather than a
constant amount), to be perceived as
different. JND just noticeable difference
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Sensation Thresholds

• Signal Detection Theory predicts how and when we
  detect the presence of a faint stimulus (signal)
  amid background stimulation (noise)
• Assumes that there is no single absolute
  threshold - it varies by person, and by
  situation.
• What might a persons detection of a stimulus
  depend on?

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Sensory Adaptation

• Diminished sensitivity as a consequence of
  constant stimulation. Your sensory receptors get
  tired.

Put a band aid on your arm and after a while you
dont sense it.
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Sensory Adaptation

• Quick Write What function does sensory
  adaptation serve? How might it help us? (Think
  evolution and survivaland present day)

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Now you see, now you dont
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The EYE vision
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Feature Detection
Different nerve cells in the visual cortex
respond to specific features, such as edges,
angles, and movement.
Ross Kinnaird/ Allsport/ Getty Images
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The Eye
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Pathways from the eyes to the visual cortex
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Biology of Vision Know the Steps

1. Light enters the eye through the cornea
   (transparent covering), and passes through the
   pupil (the black hole in your eye).
2. The size of the opening (pupil) is controlled by
   the iris (the colored part of your eye) which is
   a muscle that opens or closes the pupil, (dilates
   or constricts), causing either more or less light
   to get in.

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Biology of Vision Know the Steps

1. Behind the pupil, the lens, a transparent
   structure, changes its curvature in a process
   called accommodation, and focuses the light rays
   into an image on the light-sensitive back surface
   called the retina, where image is focused.

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Biology of Vision Know the Steps

1. Image coming through activates photoreceptors in
   the retina called rods (dark/light) and cones
   (color/detail).
2. As rods and cones set off chemical reactions they
   form a synapse with bipolar cells which
   transducts (changes) light energy into neural
   impulses (electrical messages/action potentials).
3. Neural impulse travels along the ganglion cells
   which send information up the optic nerve
   (bundle of neurons that take information from
   retina to the brain).

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Biology of Vision Know the Steps

• The Optic Nerve carries neural information to the
  Thalamus (sensory switchboard).
• Thalamus sends information to the visual cortex,
  in the occipital lobe.
• The brain then constructs what you are seeing and
  turns image right side up.