Title: Chapter 6 Perceiving the World
1Chapter 6Perceiving the World
- AP Psychology 2009-2010
- Mrs. Guerin T-9
2Chapter 6 Perceiving the World
- Textbook pages 212-248
- Study Guide pages 102-119
- Theme Perception is an active process
perceptual impressions are not always accurate
representations of events.
3Key Questions
- What are perceptual constancies, and what is
their role in perception? - What basic principles do we use to group
sensations into meaningful patterns? - How is it possible to see depth and judge
distance? - What effect does learning have on perception?
4Key Questions (continued)
- How is perception altered by attention, motives,
values, and expectations? - How reliable are eyewitness reports?
- Is extrasensory perception possible?
5Sensation vs. Perception
- Whats the difference?
- Sensation is the process of bringing information
into the nervous system (Ch 5) - Perception is the mental process of organizing
sensations into meaningful patterns (Ch 6)
6Perceptual ConstanciesTaming an Unruly World
- size constancy the perceived size of an object
remains the same, even though the size of its
image on the retina changes - EX
- Hold your left hand close to nose
- Hold your right hand at arms length
Hands look totally different sizes but we know
theyre the same
7Perceptual Constancies (continued)
- shape constancy the perceived shape of an
object remains stable, even though the shape of
its retinal image changes - EX
8Perceptual Constancies (continued)
- brightness constancy the brightness of objects
appears to stay the same as lighting conditions
change - EX
- White shirt still a white shirt whether in
- sun or shade
9Perceptual Constancies (continued)
- native vs. empirical
- inborn vs. learned
- (both affect perception)
10Perceptual OrganizationGetting It All Together
- Shhh.dont say it out loud - what do you see?
11Perceptual Organization (continued)
- figure-ground organization tend to see an
object (figure) against a background (ground) - reversible figures background and figure can
switch
12Perceptual Organization (continued)
13Perceptual Organization (continued)
14Perceptual Organization (continued)
- GESTALT PRINCIPLES
- nearness (aka proximity)
- similarity
- continuation (aka continuity)
- closure
- contiguity
- common region
15Perceptual Organization (continued)
- Gestalt Principle of
- nearness (aka proximity) stimuli that are near
each other are grouped together
16Perceptual Organization (continued)
- Gestalt Principle of
- similarity stimuli similar in size, shape,
color, or form are grouped together
17Perceptual Organization (continued)
- Gestalt Principle of
- continuation (or continuity) perceptions tend
toward simplicity and continuity
18Perceptual Organization (continued)
- Gestalt Principle of
- closure tendency to complete a figure so that
it has a consistent overall form
19Perceptual Organization (continued)
- Gestalt Principle of
- contiguity nearness in time and space
perception that one thing caused another - EX
- knocking on your head at the same time as you
(secretly) knock on a table sounds like your
head is made out of wood
knock!
knock!
20Perceptual Organization (continued)
- Gestalt Principle of
- common region stimuli found within a common
area tend to be seen as a group
21Designing for Human Use p217
- Engineering Psychologist
- Adapts machines for human use by making them
compatible with our sensory and motor capacities - http//www.edudecisions.com/articles/psychology/ps
ychology-jobs/engineering-psychologist.php
22Perceptual Organization (continued)
- Camouflage patterns or designs that break up
figure-ground organization - EX
- Military uniforms (in battle), animals, insects.
23Perceptual Organization (continued)
- perceptual hypothesis an initial guess about
how to organize sensations - (We all do this to figure out what we see, but
were not always correct) - EX
- You see a friend in the distance only to realize
when they get closer that its someone else
24Perceptual Organization (continued)
- ambiguous stimuli patterns that allow more than
one interpretation - EX
- Neckers cube
25Perceptual Organization (continued)
- impossible figure patterns that cannot be
organized into stable, consistent, or meaningful
perceptions - EX three pronged widget
-
26Depth PerceptionWhat If the World Were Flat?
- depth perception the ability to see in 3D and
judge distances - Q Is depth perception learned or innate?
- A BOTH!
27Depth Perception (continued)
- Visual cliff a glass-topped table made to look
like a cliff
28Depth Perception (continued)
- Depth cues features of the environment and
messages from the body that supply information
about distance and space - Monocular cues work with just one eye
- Binocular cues require two eyes
29Depth Perception (continued)
- muscular cues come from the body
- accommodation (monocular cue) the bending of
the lens to focus on nearby objects (sensations
from muscles attached to each lens flow back to
the brain - convergence (binocular cue) the turning inward
of both eyes to see something at a distance under
50ft
30Depth Perception (continued)
- retinal disparity a discrepancy (difference) in
the images that reach the right and left eyes - stereoscopic vision perception of space and
depth (3D) caused by the fact that the eyes
receive different images
31random dot stereogram
32Depth Perception (continued)
- A Birds Eye View
- P223 in textbook
33Pictorial Cues for DepthA Deep Topic
- pictorial depth cues (all are monocular)
features found in paintings, drawings, and
photographs that impart information about space,
depth, and distance
34Pictorial Cues for Depth (continued)
- Linear perspective
- Relative size
- Height in the picture plane
- Light and shadow
- Overlap (or interposition)
- Texture gradients
- Aerial perspective
- Relative motion (or motion parallax)
35Pictorial Cues for Depth (continued)
- Linear perspective convergence of parallel
lines in the environment
36Pictorial Cues for Depth (continued)
- Relative size to depict two objects at
different distances, the more distant object is
smaller
37Pictorial Cues for Depth (continued)
- Height in the picture plane objects that are
placed higher (closer to the horizon line) in a
drawing tend to be perceived as more distant
38Pictorial Cues for Depth (continued)
- Light and shadow copying natural light patterns
to create the appearance of a 3D picture
39Pictorial Cues for Depth (continued)
- Overlap (or interposition) when one object
partially blocks another
40Pictorial Cues for Depth (continued)
- Texture gradients changes in texture also
contribute to depth perception (texture gets
smaller and finer in the distance)
41Pictorial Cues for Depth (continued)
- Aerial perspective smog, fog, dust, and daze
add to the apparent distance of an object
(distant objects tend to be hazy)
42Pictorial Cues for Depth (continued)
- Relative motion (or motion parallax) when
looking out a window, closer objects seem to move
more than objects that are farther away
43Pictorial Cues for Depth (continued)
- The Moon Illusion perceiving the moon as larger
when it is low in the sky - Apparent-distance hypothesis the horizon seems
more distant than the night sky
44Pictorial Cues for Depth (continued)
- Ponzo Illusion the upper bar is the same length
as the lower bar, but because the upper bar
appears to be farther away than the lower bar, we
perceive it as longer
45Perceptual LearningWhat If the World Were
Upside Down?
- Perceptual learning changes in the brain that
alter how we process sensory information
attributed to prior experience
46Perceptual Learning (continued)
- Perceptual habits well-established patterns of
perceptual organization and attention that affect
our daily experience
47(No Transcript)
48Perceptual Learning (continued)
49Perceptual Learning (continued)
50Perceptual Learning (continued)
- Perceptual features lines, shapes, edges,
spots, and colors (elements that the brain is
especially sensitive to) - Other-race effect the tendency to be better at
recognizing faces from ones own racial group
than faces from other racial or ethnic groups
51Perceptual Learning (continued)
- Active movement self-generated action
(accelerates perceptual adaptation) - EX Two groups wore goggles that distorted vision
- some walked on their own
- others were pushed around in wheelchairs
- those that walked adapted more quickly
52Perceptual Learning (continued)
- Context information surrounding a stimulus
53Perceptual Learning (continued)
- Frames of reference internal standards for
judging stimuli - Adaptation level the medium point of your
personal frame of reference - EX If asked to lift a 10 lb weight would you
label it light, medium, or heavy?
54Perceptual Learning (continued)
- Illusion length, position, motion, curvature,
or direction is consistently misjudged (but
stimuli is real) - http//dragon.uml.edu/psych/illusion.html
- Hallucination people perceive objects or events
that have no external reality
55Perceptual Learning (continued)
- Stroboscopic movement motion perceived when
objects are shown in rapidly changing positions - strobe light on dance floor has the opposite
effect freezes movement
56Perceptual Learning (continued)
57Perceptual Learning (continued)
- Size-distance invariance the strict
relationship between the distance an object lies
from the eyes and the size of its image
58Motives and PerceptionMay I Have YourAttention!
- Pages 234 236
- Selective attention giving priority to a
particular incoming sensory message - Divided attention when you divide your mental
effort among tasks, each of which requires more
or less attention (limited capacity for storing
thinking about info)
59Motives and Perception
- ATTENTION IS ALSO FREQUENTLY RELATED TO contrast
OR change IN STIMULATION
60Motives and Perception
- Inattentional blindness failure to perceive a
stimulus that is in plain view, but not the focus
of attention - Habituation a decrease in perceptual response
to a repeated stimulus - EX dripping faucet vs. ticking clock
61Motives and Perception
- Orientation response (OR) prepares us to
receive information from a stimulus - EX
- Pupils enlarge, brain-wave patterns shift,
breathing stops briefly, blood flow to head
increases, we turn toward stimulus, etc.
62Motives and Perception
- Boiled Frog Syndrome not being able to notice
gradual changes in stimuli
63Perceptual ExpectanciesOn Your Mark, Get Set
- Bottom-up processing analyze info starting at
the bottom with small sensory units (features)
and build upward to a complete perception - Top-down processing preexisting knowledge is
used to rapidly organize features into a
meaningful whole
64Perceptual Expectancies
65Perceptual Expectancies
- Perceptual expectancy (or set) a readiness to
perceive in a particular manner, induced by
strong expectations - (past experience, motives, context, etc.)
- perceptual sets often lead us to see what we
expect to see - Perceptual category classes, types, groups
66Psychology in ActionPerception and Objectivity
Believing is Seeing
- (pages 239 242)
- Perceptual reconstruction
- Eyewitness
- Weapon focus
- Reality Testing
- Perceptual Awareness
- Attention
-
67A Step BeyondExtrasensory Perception Do You
Believe in Magic?
- (pages 243 246)
- ESP
- Parapsychology
- Psi Phenomena
- Clairvoyance
- Telepathy
- Precognition
- Psychokinesis
- Coincidence
- Zener Cards
- Fraud
- Skepticism
- Statistics and Chance
- Research Methods
- Replicate
- Ganzfield
- Stage ESP