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PerceptionPerception

Chapter 6Chapter 6

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PerceptionPerception

The process of selecting, organizing, and The process of selecting, organizing, and interpreting sensory information, which enables interpreting sensory information, which enables us to recognize meaningful objects and events.us to recognize meaningful objects and events.

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Selective AttentionSelective Attention

Perceptions about objects change from moment to Perceptions about objects change from moment to moment. We can only focus on limited aspects of moment. We can only focus on limited aspects of

sensory input at any given timesensory input at any given time

e.g. : “Cocktail Party Effect” e.g. : “Cocktail Party Effect”

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Perceptual IllusionsPerceptual Illusions

Illusions provide good examples in Illusions provide good examples in understanding how perception is understanding how perception is

organized. Studying faulty perception is as organized. Studying faulty perception is as important as studying other perceptual important as studying other perceptual

phenomena.phenomena.

Line AB is longer than line BC.

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Tall ArchTall Arch

In this picture, the In this picture, the vertical dimension of vertical dimension of the arch looks longer the arch looks longer than the horizontal than the horizontal

dimension. dimension. However, both are However, both are

equal.equal.

Rick F

riedman/ B

lack Star

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Perceptual OrganizationPerceptual Organization

How do we form meaningful How do we form meaningful perceptions from sensory information?perceptions from sensory information?

We organize it. Gestalt psychologists We organize it. Gestalt psychologists showed that a figure formed a “whole” showed that a figure formed a “whole”

different than its surroundings.different than its surroundings.

called a called a “gestalt”“gestalt”

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Organization of the visual field into objects Organization of the visual field into objects (figures) that stand out from their (figures) that stand out from their

surroundings (ground).surroundings (ground).

Form PerceptionForm Perception

Tim

e Savings S

uggestion, © 2003 R

oger Sheperd.

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GroupingGrouping

After distinguishing the figure from the ground, After distinguishing the figure from the ground, our perception needs to organize the figure into our perception needs to organize the figure into

a meaningful form using grouping rules.a meaningful form using grouping rules.

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Perceptual InterpretationPerceptual Interpretation

Immanuel Kant (1724-1804) maintained that Immanuel Kant (1724-1804) maintained that knowledge comes from our inborn ways of knowledge comes from our inborn ways of

organizing sensory experiences.organizing sensory experiences.

John Locke (1632-1704) argued that we learn John Locke (1632-1704) argued that we learn to perceive the world through our to perceive the world through our

experiences.experiences.

How important is experience in shaping ourperceptual interpretation?

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Kittens raised Kittens raised without exposure without exposure to horizontal lines to horizontal lines later had difficulty later had difficulty

perceiving perceiving horizontal bars.horizontal bars.

Blakemore & Cooper (1970)

Sensory DeprivationSensory Deprivation

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(a) Loch ness monster or a tree trunk; (b) Flying

saucers or clouds?

Perceptual SetPerceptual Set

Other examples of perceptual set.Other examples of perceptual set.

Frank Searle, photo Adam

s/ Corbis-Sygm

a

Dick R

uhl

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To an East African, the woman sitting is balancing a metal box on her head, while the family is sitting

under a tree.

Cultural ContextCultural Context

Context instilled by culture also alters Context instilled by culture also alters perception. perception.

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Perception RevisitedPerception Revisited

Is perception innate or acquired? Is perception innate or acquired?

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Human Factors & Human Factors & MisperceptionsMisperceptions

Understanding human factors enables us to Understanding human factors enables us to design equipment to prevent disasters.design equipment to prevent disasters.

Two-thirds of airline crashes caused by human error are largely due to errors of perception.