*Chapter 6Perception

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

*Selective AttentionPerceptions about objects change from moment to moment. We can perceive different forms of the Necker cube; however, we can only pay attention to one aspect of the object at a time. Ex: Cocktail Party PhenomenonNecker CubeExperiment - Video

*Inattentional BlindnessInattentional blindness refers to the inability to see an object or a person in our midst. Simmons & Chabris (1999) showed that half of the observers failed to see the gorilla-suited assistant in a ball passing game. Daniel Simons, University of Illinois

*Change BlindnessChange blindness is a form of inattentional blindness in which a majority of individuals giving directions failed to notice a change in the individual asking for directions.

1998 Psychonomic Society Inc. Image provided courtesy of Daniel J. Simmons.Experiment - Video

*Perceptual IllusionsIllusions provide good examples in understanding how perception is organized. Studying faulty perception is as important as studying other perceptual phenomena.Line AB is longer than line BC.

IllusionsPhysicalParadoxical/Perceptual *

*Perceptual OrganizationVisual CaptureVision vs. other senses? Vision usually winsGESTALT PSYCHOLOGY-A movement formed in Germany in the 1920s and 30s -The study of how people organize the world visually into meaningful units and patterns. - The whole is more important than the sum of the parts - In other words, when we perceive something, properties emerge from the object that are not found in any particular component.

Gestalt: Form PerceptionPeople ALWAYS organize the visual field into 2 parts___________: stands out from the rest of the environment ___________: the background

SOMETIMES

Your eyes have trouble distinguishing FIGURE and GROUND

GESTALT PRINCIPLES1. _______________

Things that are near each other, tend to be grouped together

For Example

GESTALT PRINCIPLES2. ConnectednessIn order to complete forms, the brain FILLS IN THE GAPS

For Example

GESTALT PRINCIPLES3. _______________

Things that are alike in some way (e.g. color, shape, size) tend to be perceived as belonging together

For example

GESTALT PRINCIPLES4. _________________

Lines and patterns tend to be perceived as continuing in time or space

For Example

*Depth PerceptionVisual CliffDepth perception enables us to judge distances. Gibson and Walk (1960) suggested that human infants (crawling age) have depth perception. Even newborn animals show depth perception.Innervisions

*Binocular CuesRetinal disparity: Images from the two eyes differ. Try looking at your two index fingers when pointing them towards each other half an inch apart and about 5 inches directly in front of your eyes. You will see a finger sausage as shown in the inset.

*Binocular CuesConvergence: Neuromuscular cues. When two eyes move inward (towards the nose) to see near objects and outward (away from the nose) to see faraway objects.

*Monocular CuesSee Characteristics of Perception assignment we did in library and/or homework.

*Apparent MotionPhi Phenomenon: When lights flash at a certain speed they tend to present illusions of motion. Neon signs use this principle to create motion perception.Two lights flashing one after the other.One light jumping from one point to another: Illusion of motion.

*Perceptual ConstancyPerceiving objects as unchanging even as illumination and retinal images change. Perceptual constancies include constancies of shape and size.Shape Constancy

*Size ConstancyStable size perception amid changing size of the stimuli.Size Constancy

*Size-Distance RelationshipThe distant monster (below, left) and the top red bar (below, right) appear bigger because of distance cues.From Shepard, 1990Alan Choisnet/ The Image Bank

*Size-Distance RelationshipBoth girls in the room are of similar height. However, we perceive them to be of different heights as they stand in the two corners of the room.Both photos from S. Schwartzenberg/ The Exploratorium

*Ames RoomThe Ames room is designed to demonstrate the size-distance illusion.

What is your perception of

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*Perception: Nature or Nurture?Perceptual Interpretation: Restored VisionBlind adults w/ restored vision:could differentiate figure and ground relationships, but had difficulty distinguishing a circle and a triangle (Von Senden, 1932). Others struggled w/ facial recognition & expressions.Perceptual Interpretation: Sensory DeprivationKittens raised without exposure to horizontal lines later had difficulty perceiving horizontal bars.

*Perception: Nature or Nurture?Perceptual AdaptationVisual ability to adjust to an artificially displaced visual field, e.g., prism glasses.Courtesy of Hubert Dolezal

*Perception: Nature or Nurture?Perceptual SetA mental predisposition to perceive one thing and not another. What you see in the center picture is influenced by flanking pictures.From Shepard, 1990.

*(a) Loch ness monster or a tree trunk; (b) Flying saucers or clouds?Perception: Nature or Nurture?Perceptual SetOther examples of perceptual set.Frank Searle, photo Adams/ Corbis-SygmaDick Ruhl

FILL IN THE FOLLOWING WORDS?1. Goose4. Wager7. Bonnet Swan Gamble Derby D_ck B_t _at

2. Bear5. Sinful8. Shoot Wolf Evil Kill _ox B_d H_nt

3. Artist6. Courage9. Tractor Brush Brave Crops P_int _old _arm

FILL IN THE FOLLOWING WORDS1. Sam4. Base7. Cat Pete Ball Mouse M_ke B_t _at

2. Package5. Pillow8. Help Carton Sheet Suggest _ox B_d H_nt 3. Needle6. Bend9. Hurt Sharp Crease Punish P_int _old _arm

*Children's schemas represent reality as well as their abilities to represent what they see.Perception: Nature or Nurture?SchemasSchemas are concepts that organize and interpret unfamiliar information.Courtesy of Anna Elizabeth Voskuil

Schemas: Recognizing a Face*

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*Students recognized a caricature of Arnold Schwarzenegger faster than his actual photo.Features on a FaceFace schemas are accentuated by specific features on the face.Kieran Lee/ FaceLab, Department of Psychology, University of Western Australia

*Eye & MouthEyes and mouth play a dominant role in face recognition.Courtesy of Christopher Tyler

*To an East African, the woman sitting is balancing a metal box on her head, while the family is sitting under a tree.Perception: Nature or Nurture?Cultural & Context EffectsContext instilled by culture alters perception. What do you see in this picture?

*Perception: Nature or Nurture?Perception = Biopsychosocial

*Perception & Human FactorsHuman Factor Psychologists design machines that assist our natural perceptions.The knobs for the stove burners on the right are easier to understand than those on the left.Photodisc/ PunchstockCourtesy of General Electric

*Is There Extrasensory Perception?Perception without sensory input is called extrasensory perception (ESP). A large percentage of scientists do not believe in ESP.Telepathy: Mind-to-mind communication. One person sending thoughts and the other receiving them. Clairvoyance: Perception of remote events, such as sensing a friends house on fire.Precognition: Perceiving future events, such as a political leaders death.

*Putting ESP to Experimental TestIn an experiment with 28,000 individuals, Wiseman attempted to prove whether or not one can psychically influence or predict a coin toss. People were able to correctly influence or predict a coin toss 49.8% of the time.

*Premonitions or Pretensions?Can psychics see the future? Can psychics aid police in identifying locations of dead bodies? What about psychic predictions of the famous Nostradamus?

The answers to these questions are NO! Nostradamus predictions are retrofitted to events that took place after his predictions.

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*OBJECTIVE 1| Describe the interplay between attention and perception.***OBJECTIVE 2| Explain how illusions help us understand some of the ways we organize stimuli into meaningful perceptions.*OBJECTIVE 3| Describe Gestalt psychology's contribution to our understanding of perception.***************OBJECTIVE 5| Explain the importance of depth perception, and discuss the contribution of visual cliff research to our understanding of this ability.

**OBJECTIVE 6| Describe two binocular cues for perceiving depth, and explain how they help the brain to compute distance.***OBJECTIVE 9| Explain the importance of perceptual constancy.*OBJECTIVE 10| Describe the shape and size constancy, and explain how our expectations about perceived size and distance to some visual illusions.****OBJECTIVE 12| Describe the contribution of restored-vision and sensory deprivation research in our understanding of the nature-nurture interplay in our perceptions.*OBJECTIVE 13| Explain how the research on distorting goggles increases our understanding of the adaptability of perception.*OBJECTIVE 14| Define perceptual set, and explain how it influences what we do or do not perceive. Right half the class should close their eyes and the left half of the class should see the saxophonist for about 20 seconds. Then the left half of the class should close the eyes and the right half should see the womans face. All of them should then write their responses while watching the middle picture. Responses are compared to show perceptual set.****All what we perceive not only comes from the environment but also from our minds. Schemas or concepts develop through experience.**Portrait artists understood the importance of this recognition and therefore centered an eye in their paintings.**********OBJECTIVE 16| Describe the role human factors psychologists play in creating user-friendly machines and work settings.

*OBJECTIVE 17| Identify the three most testable forms of ESP, and explain why most research psychologists remain, skeptical of ESP.**