NAME:
HOUR:
PERCEPTUAL INTERPRETATION & ILLUSIONS
Where Is It Going? - Motion Perception
 Neural pathways in the brain combine information about eyechanging
activity, the
image, and the contrast of the moving object to the
background.
 Brain views larger objects as moving more
than smaller objects
 Brain assumes shrinking objects are
and enlarging objects are
Stroboscopic Motion:
 The illusion of motion by the rapid projection of slightly
 The concept a
images
uses
Phi Phenomenon:
 An illusion of movement created when two or more adjacent
blink on
and off in succession.
Induced Motion:
 Karl Duncker studied this with the dot and moving rectangle. Rectangle moved but people
thought it was the
 This because of
moving.
processing (people expected the dot to move) and our
assumption that the background is
. (parked car example pg. 123)
Spiral Motion Detectors:
 Research shows that different neural pathways in the
process information about the depth of objects, movement, form, and color.
 As you view the spiral motion your spiral motion
When you look at a stationary object, they are
causing the illusion.
are being used.
for a brief instant
Motion Blindness:
 Look steadily at one stationary point, such as one of the white discs. Don’t blink as blinks
and sudden eye movements destroy the illusion. Notice that one, two or all of the white
discs will
and
 Deals with your
.
attention.
Perceptual Constancy:
 Perceiving objects as
(having consistent lightness, color, shape, and
size) even as illumination and retinal images change.
 Example:
Size Constancy:
 A person’s understanding that as an object moves further or closer to them its actual size
stays the
 As an object appears to become larger we realize it is getting
, not bigger.
 As an object appears to become smaller we realize it is moving
, not
getting smaller.
P
 Perceptions of the world depend on our
- Colin Turnbull’s
o
experiment with Kenge
P i
n
 To perceive the size of objects accurately we must also perceive their
accurately o
t
i
 Thus, many visual illusions occur simply because a particular image lacks sufficient
n
cues
t B
Shape Constancy:
 The understanding that an object’s shape remains the same even though the
A
of view makes the shape appear changed
Lightness/Brightness Constancy:
 The ability to see an object as having a constant level of brightness no matter how the
conditions change
 If you look at a sheet of paper in bright sunlight it looks blazingly
View the same sheet in a dimly lit room, and it appears
 Perceived lightness stays roughly constant as long as the
same.
.
.
stay the
 When the
changes you may perceive the
as changing.
Sensory Deprivation: Restored Vision:
 Early visual
can have a profound effect on perception.
Blakemore & Cooper’s restricted environment with kittens.
 Do the kittens ever fully regain normal sensitivity to horizontal or vertical lines?
 This illustrates the “
” phenomenon
 These experiments show that
stimulation, the cortical cells had not
developed normal connections making them functionally
to shape.
 A sensory restriction does no permanent damage if it occurs
This suggests that visual experiences during
in life.
are a critical period for
normal sensory and perceptual development.
 Experience guides the
of the brain’s neural connections.
 If deafness or blindness is corrected as an infant, it
area. Nurture
the pertinent brain
what nature has
Perceptual Set:
 A mental
to perceive something one way and not another
 If we believe we are going to see or hear something, we
 Example of
processing
 Influence of the “power of

Guided by
” (subliminal perception)
: concepts or mental frameworks that organize and interpret
information
Context & Culture:
 The
in which we interpret sensory stimuli
 Culture can also influence how we
information.
 Nativist Position – people throughout the world view the world the
way
because they share the same perceptual rules.
 Empiricist Position – People actively construct their perceptions by drawing on their prior
experiences.

Carpentered-World Hypothesis – People living in urban and industrialized environments
where there are more
will be
more susceptible to the Muller-Lyer Illusion than people in non-carpentered natural
environments.
Illusions:
 When we

the true characteristics of an object or image.
Help researchers understand how sensation and perception
works
Müller-Lyer Illusion:
 The
the
pointing arrows signify that the line is closest to you, and
pointing arrows signify the opposite case
Ponzo Illusion:
 Converging lines indicate that
line is farther away than
line
 Experience tells us that a more distant object can create the same-sized image as a nearer
one only if it is actually
. As a result, we perceive the bar/monster that
seems farther away as
.
Moon Illusion:
 Moon appears larger when it is on the
than when it is directly
.
 Objects on the horizon are perceived as

The moon appears to be
away than those above us
those objects on the horizon. Since it is
bigger than those object it is perceived as
!
Ames Room Illusion:
We perceive the room to be as we are used to, a perfect
fact it is a
!
. When in