Transcript Document 7146907

Perception
The process of organizing and interpreting
information, enabling us to recognize
meaningful objects and events.
Perception
• The active process of selecting,
organizing, and interpreting the
information brought to the
brain by the senses
• Perception is the way we
interpret sensations and
therefore make sense of
everything around us
• Example:
– 7’9” vs. 6’9”
Top Down Processing
• Processing information from the
senses with higher level mental
processes using our experiences
and expectations
• Using your background
knowledge to fill in the gaps
• Examples:
– Grouping
Gestalt Psychology
• Gestalt - focused on
how we GROUP
objects together as an
organized whole.
• Whole exceeds the sum of
the parts
• Example: Necker cube – Do
you see circles with white
lines or a cube? Do you see
the x in the center in the
front edge or the back?
Figure Ground Relationship
Figure –ground - Our first perceptual decision
is what in the image is the figure and what is
the background.
Example: At an assembly, Ms short speaking is
the figure, ground is people, curtain etc. on
stage behind her
Grouping
Grouping – tendency to organize
stimuli into coherent groups and not
isolated elements.
•Examples
closure
Grouping
• Proximity - group objects that are close together as being part
of same group
• Example – three girls standing in the hallway next to each other
• Similarity - objects similar in appearance are perceived as
being part of same group
• Example – black toy poodles and red toy poodles are seen as two
different groups of dogs
• Continuity - objects that form a continuous form are perceived
as same group
• Example – Geese flying south form a “V”
• Connectedness – objects that are uniform and linked are
perceived as a single unit
• Example – beads on a necklace
• Closure - like top-down processing…we fill gaps in if we can
recognize it
• Example – IBM Logo
Who emphasized that the whole
may exceed the sum of its parts?
1. Evolutionary
Psychologists
2. Parapsychologists
3. Behaviorists
4. Gestalt
Psychologists
5. Humanistic
Psychologists
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The perceptual tendency to group together
stimuli that are near each other is called
Interposition
Proximity
Similarity
Closure
Retinal Disparity
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A floating sea vessel is to the ocean water
as ____________ is to _____________.
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Lig
1. Light and shadow;
relative height
2. Closure; continuity
3. Proximity; similarity
4. Top down; bottoms
up
5. Figure; ground
Depth Cues
• Depth Perception
– visual ability to see the world in 3-D
even though images strike retina in two
dimensions and
– Ability to perceive the distance to an
object
• Visual Cliff Experiment - Eleanor
Gibson
– Crawling experience helps with depth
perception
– Depth perception is partially innate
• See depth by using two cues
• Examples
– Monocular Cues
– Binocular Cues
Binocular Cues
• Binocular cues – depth cues
that depend on the use of
two eyes.
• Used to judge distance of
object up close.
• Examples:
• Retinal Disparity - as an
object comes closer to us,
the differences in images
between our eyes becomes
greater.
• 3-D Movies – simulate retinal
disparity
• Convergence - as an object
comes closer our eyes have
to come together to keep
focused on the object.
Monocular Cues
• Monocular cues – depth
cues used with one eye
• Used to judge distance
of object far away
from you
• Examples:
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Linear Perspective
Interposition
Relative size
Relative height
Texture gradient
Shadowing
Interposition
closer objects cut off the view of
part or all of a more distant one
Relative Size
the smaller of two objects is
perceived as farther away
Relative Height
objects higher in our field of vision
furthest away
Horizontal vertical
illusion
Linear Perspective
provides a cue to distance when
parallel lines seem to converge in the
distance
Relative Motion
objects beyond the fixation point
appear to move with you, objects in
front of the fixation point appear to
move backward
Light and Shadow
brighter ones seems closer and
dimmer one seems further away
Texture Gradient
closer objects have a more distinct
texture and farther away objects
appear more densely packed and smooth
Which of the following is a binocular
cue for the perception of distance?
Interposition
Size Constancy
Linear Perspective
Relative Height
Convergence
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Which of the following is most helpful in
perceiving the distance of objects far away
from you?
Retinal Disparity
Phi phenomenon
Binocular Cues
Continuity
Monocular Cues
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Which of the following is a
monocular cue?
1. Retinal Disparity
2. Perceptual Set
3. Perceptual
Adaptation
4. Interposition
5. Convergence
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How many monocular cues can you
find?
Perceived Motion
• Stroboscopic effect – continuous
movement in a rapid series of
slightly varying images
– Example: animated film
• Phi phenomenon – an allusion
created when two or more adjacent
lights blink on and off in quick
succession
• Example: Blinking Christmas Lights
Constancy
• Perpetual constancy –
perceiving objects as
unchanging even as
illumination and retinal
images change
• Objects change in our
retina constantly as we or
they move….but we are
able to maintain content
perception
• Examples
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Shape Constancy
Size Constancy
Brightness Constancy
Color Constancy
Perceptual Constancy
• Shape constancy – perceive objects
as having a constant shape
Perceptual Constancy
• Shape Constancy illusion– some times
we perceive the shape of something
to change with the angle of our view
Perceptual Constancy
• Size constancy – perceive objects
as having a constant size
Perceptual Constancy
• Size constancy illusion–
sometimes we perceive
objects as having a
changing size because of
the interplay between
perceived size and
distance
• Moon
illusion
• Ponzo
illusion
Ames Room
Ames Room
Lightness Constancy
• Lightness constancy aka
Brightness constancy –
perceiving an object as
having constant
lightness even while its
illumination varies.
• Depends on…
– Relative luminance –
the amount of light an
object reflects
relative to its
surroundings
Color Constancy
• Color constancy – familiar
objects are perceived to be
the same color even if the
light they reflect changes.
• Depends on what we’re
comparing it to…
– Surrounding context –
perceived color is influenced by
its surrounding context
– Surrounding objects – perceived
color is influenced by its
surrounding objects
Example: color of these blue
circles are identical . Because
the brain computes the color of
an object relative to its context,
the perceived color changes
Apple in a bowl of fruit appears
to be red even if the light
changes because the brain
perceives (expects) it to be red.
Light Constancy refers to the fact
that
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The frequency of light waves has
a fixed relationship to the
brightness of the light
objects are perceived to have
consistent lightness even if the
amount of light they reflect
changes.
light waves reflected by an
object remain constant despite
changes in illumination levels.
the perceived whiteness of an
object has a constant relation to
its lightness.
one of the depth cues involves
perceiving dimmer objects as
being farther away.
Th
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Although the image of a car on our retina becomes
smaller as the car moves farther away, we perceive the
car to as able to still hold 4 passengers. Which of the
following best describes this phenomenon
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Perceptual Set
Context Effect
Lightness Constancy
Size Constancy
Context Effects
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On a cloudy day, you are likely to perceive
a yellow flower as ______________on a
clear sunny day
57%
Less colorful than
Less yellow than
Equally as yellow as
More whiter than
More yellow than
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Sensory Deprivation and Restored
Vision
• Experiments on sensory
deprivation
– Brains cortical cells don’t
develop normal connections to
interpret visual stimuli
– Critical period - specific time
during which an organism has to
experience stimuli in order to
progress through
developmental stages properly.
• There is a critical period for
normal perceptual development
Perceptual Adaptation
Perceptual adaptation – the
ability to adjust to artificially
displaced or inverted visual
field
• Demonstrates the impact of
experience on perception
Example:
– Displacement goggles
Perceptual Set
Perceptual set (aka mental predisposition) –
mental predisposition to perceive one thing
and not another
– Schemas – concepts that organize and interpret
unfamiliar info/ambiguous situations
Examples: Do we see a saxophonist or woman’s face
Do we see a Lochness Monster, or a log
Does pilot hear “Cheer up” or “Gear up”
Perceptual Set
Context Effects
• Context effects – perceptual
set can be influenced by the
context (expectations and
emotions, and motivations)
• Examples:
– eel of orange or eel of wagon
– Sun Ming 7’9”vs. “little guy” at 6’9”
Humans born blind or kittens raised under restricted conditions
do not have the cortical regions needed to interpret visual
stimuli. Sensory restriction does not appear to do damage if it
occurs later in life. This suggests that
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1. a critical period exists for normal
perceptual development.
2. perceptual adaptation to changed
visual input can be dramatic.
3. a given stimulus may trigger widely
different perceptions.
4. detecting a stimulus depends on the
signal's strength and our
psychological state.
5. much of our information processing
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Although Chris sees his teacher in school everyday, he
didn’t recognize her when he saw her at Menchies.
This best illustrates the importance of
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Monocular Cues
Perceptual Set
Context Effects
Proximity
Perceptual
Adaptation
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The tendency to perceive a moving light in the
night sky as belonging to an airplane rather than
a satellite best illustrates the impact of
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1. Perceptual
Constancy
2. Relative Height
3. Context Effects
4. Perceptual Set
5. Feature detection
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Perception is a Biopsychosocial
Phenomenon
Is There Extrasensory
Perception?
Parapsychology
Claims of ESP
• Parapsychology – study of paranormal phenomena
including ESP and psychokinesis
• Extrasensory Perception – claim that perception can
occur apart from sensory input
Examples:
– Telepathy – mind to mind communication
• I can read your mind…you want AP Psych to be over
– Clairvoyance – perceiving remote events
• I know exact location of the homework you lost
– Precognition – perceiving future events
• I know who will win the next Presidential election
• Psychokinesis (PK) – mind over
matter (levitation)
– Girl in movie Matilda could make things “fly”
After learning that her new school friend had experienced
several episodes of depression during junior high, Erin
incorrectly perceived her friend's laughter as artificial and phony.
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Interposition
Perceptual Set
Clairvoyance
Phi Phenomenon
Clairvoyance
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This best illustrates the impact
Knowing about the effects of the perceived
distance of objects on their perceived size
helps us to understand
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Moon Illusion
McGurk Effect
Prosopagnosia
Phantom Limb
Sensations
5. Color Constancy