Transcript No Slide Title

PERCEPTION OF OBJECTS
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Problems for Perception
Gestalt Heuristics
Intelligent Perception
Figure-Ground Separation
Problems for Perception
• We are remarkably good at correctly
perceiving the environment
• To do this, our brains must overcome
problems with the input from sense organs
Ambiguous Information
• Any particular pattern of stimulation on the
retinas could be caused by many different
patterns in the environment
• This is called the inverse projection problem
Viewpoint Invariance
• Ability to recognize an object even when seen
from different viewpoints
Gestalt Heuristics
• Heuristics are problem-solving strategies that
are based on previous knowledge
• The Gestalt approach emphasizes perceiving
whole patterns, not individual parts
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Law of Pragnanz
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• Perceive the simplest
possible object, given
ILARITY
(C) CONTINUITY
the sensory information received
XTURE
(F) SIMPLICITY
Law of Similarity
• Objects that look similar are grouped into
the same pattern
IMITY
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(B) SIMILARITY
(C) CON
Law of Good Continuation
• Points are grouped together when they
form smooth, continuous lines or curves
B) SIMILARITY
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(C) CONTINUITY
Law of Proximity
3_19
• Objects that are close together tend to be
grouped into the same pattern
(A) PROXIMITY
(B) SIMILA
Law of Common Fate
• Objects that are move together are
grouped into the same pattern
Law of Familiarity
• Objects are more likely to be grouped into
patterns that are familiar
Law of Common Region
• Objects in the same region of space tend to
be grouped together
LOSURE
(E) TEXTURE
(G) COMMON REGION
(F) SIM
Law of Uniform Connectedness
• Uniform areas that are connected appear to
be part of the same object
Law of Synchrony
• Events that occur at the same time are
grouped together
Intelligent Perception
• Top-down processing allows us to correctly
interpret sensory information
• We are typically unaware of the top-down
strategies that we use: unconscious inference
Figure and Ground
• Accurate perception requires segregating the
object we are perceiving (figure) from its
background (ground)
Figure
Seen as in front
Thing-like
More memorable
Meaningful
Owns the border
Ground
Seen as behind
Unformed
Less memorable
Less meaningful
Not grouped with border