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ation about depth as an
individual moves because objects that are close appear to move more
than objects that are farther away
H. Perceptual Constancies
1. Perceptual constancy refers to the tendency to see the world as invariant,
constant, and stable, despite changes in the stimulation of sensory
receptors
2. Size and shape constancy
a) Size constancy refers to the ability to perceive the true size of an
object despite variations in the size of its retinal image
b) Shape constancy refers to the ability to perceive correctly an
object’s actual shape, even when the object is slanted away
from the viewer, making the shape of the retinal image
substantially different from that of the object itself
c) Orientation constancy refers to the ability to recognize the true
orientation of the figure in the real world, even though its
orientation in the retinal image is changed
d) Lightness constancy is your tendency to perceive the whiteness,
grayness, or blackness of objects as constant across changing
levels of illumination
IV. Identification and Recognition Processes
A. Bottom-Up and Top-Down Processes
1. Bottom-up processing is taking sensory data into the system and
sending it upward for extraction and analysis of relevant information.
It is anchored in empirical reality and deals with bits of information
and the transformation of concrete, physical features of stimuli into
abstract representations. Also called data-driven processing.
2. Top-down processing is when past experiences, knowledge,
motivations, cultural background, and expectations affect perception,
as higher mental functioning influences how objects and events are
understood. Also called hypothesis-driven processing.
3. Phonemic restoration occurs when there are gaps in physical signals
and perception replaces part of a word that was obscured by noise in
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PSYCHOLOGY AND LIFE
a very loud environment
B. Object Recognition
1. Irving Biederman has proposed that all objects can be assembled from
a set of geometrical ions, or geons. From a set of 36 geons, Biederman
believes that perception can make a strong guess at the nature of an
object.
C. The Influence of Contexts and Expectations
1. Expectations can influence hypotheses about what is out there in the
world and can influence what is actually perceived
2. It takes longer to recognize an object when it is seen in the wrong
context, not in a familiar place
3. Object identification is a constructive, interpretive process
4. Set is a temporary readiness to perceive or react to a stimulus in a
particular way. There are three types of sets: motor, mental, and
perceptual.
a) A motor set is a readiness to make a quick, prepared response
b) A mental set is a readiness to deal with a situation, such as a
problem-solving task or game, in a way determined by learned
rules, instructions, expectations, or habitual tendencies.
Mental sets can actually prevent problem-solving when old
rules do not fit new situations.
c) A perceptual set is a readiness to detect a particular stimulus
in a given context
D. Creatively Playful Perception
1. Perceptual creativity involves experiencing the world in ways that are
imaginative, personally enriching, and fun
E. Final Lessons
1. A perceptual experience in response to a stimulus event is determined
not only by the stimulus but also by the person experiencing it. In
addition to sensation, final perception depends on past experience,
expectations, wants, goals, values, and imagination.
2. A proper balance of top-down and bottom-up processing achieves the
basic goal of perception: to experience what is out there in a way that
maximally serves your needs as a biological and social being, moving
about and adapting to your physical and social environment.
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CHAPTER 5: PERCEPTION
DISCUSSION QUESTIONS
1. Why are there separate chapters on sensation and perception?