Perception Schema Evaluate schema theory with reference to

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Perception: Schema Evaluate schema theory with reference to research studies

Perception: Schema Evaluate schema theory with reference to research studies

 • Definition: Concept – Idea about something that provides a means for understanding

• Definition: Concept – Idea about something that provides a means for understanding the world • Schema – Mental framework for organizing knowledge • Meaningful structure • Concepts are organized into categories – Apple concept – Fruit category

Schema • Characteristics – Can include other schemas – Encompasses typical, general facts which

Schema • Characteristics – Can include other schemas – Encompasses typical, general facts which can vary – Can vary in degree of abstraction • Justice vs. apple

Problems with Schemas • Stereotypes – Meaningful organization of a group of people –

Problems with Schemas • Stereotypes – Meaningful organization of a group of people – But…. you lump them all together • Distortions and Mistakes – Settings are unfamiliar • Require a novel approach – Wrong schemas become activated

Different Types of Schema • Scripts – Provide information about the sequence of events

Different Types of Schema • Scripts – Provide information about the sequence of events • Going to a restaurant, dentist • Self-Schemas – Information about ourselves • Memory about our strengths and weaknesses and how we feel about them • Social Schemas – Stereotypes – Represent information about groups of people

Early concepts of Schema • Bartlett, 1932 (schema & culture) • Piaget, 1950 s

Early concepts of Schema • Bartlett, 1932 (schema & culture) • Piaget, 1950 s (development of perception)

Sir Frederich Bartlett, 1932

Sir Frederich Bartlett, 1932

Bartlett, 1932 • Theory: Schema impacts how we recall information – Our own culture,

Bartlett, 1932 • Theory: Schema impacts how we recall information – Our own culture, language and experience – Rationalization • Process of making information or a story conform to the cultural expectations of the participants • Implications: – Memory is an active reconstructive process, not a passive one.

"The War of Ghosts" One night two young men from Egulac went down to

"The War of Ghosts" One night two young men from Egulac went down to the river to hunt seals and while they were there it became foggy and calm. Then they heard war-cries, and they thought: "Maybe this is a war-party". They escaped to the shore, and hid behind a log. Now canoes came up, and they heard the noise of paddles, and saw one canoe coming up to them. There were five men in the canoe, and they said: "What do you think? We wish to take you along. We are going up the river to make war on the people. " One of the young men said, "I have no arrows. " "Arrows are in the canoe, " they said. "I will not go along. I might be killed. My relatives do not know where I have gone. But you, " he said, turning to the other, "may go with them. " So one of the young men went, but the other returned home. And the warriors went on up the river to a town on the other side of Kalama. The people came down to the water and they began to fight, and many were killed. But presently the young man heard one of the warriors say, "Quick, let us go home: that Indian has been hit. " Now he thought: "Oh, they are ghosts. " He did not feel sick, but they said he had been shot. So the canoes went back to Egulac and the young man went ashore to his house and made a fire. And he told everybody and said: "Behold I accompanied the ghosts, and we went to fight. Many of our fellows were killed, and many of those who attacked us were killed. They said I was hit, and I did not feel sick. " He told it all, and then he became quiet. When the sun rose he fell down. Something black came out of his mouth. His face became contorted. The people jumped up and cried. He was dead.

Results 1. Bartlett found that different subjects recalled the passage in their own characteristic

Results 1. Bartlett found that different subjects recalled the passage in their own characteristic way. 2. He also detected a number of consistent tendencies. (Schema) • short and tended to become more coherent, and fit in more closely to the subjects own viewpoint. • select certain feature of the passage and uses these to anchor the whole story. • detail is often changed so as to become more familiar. 3. subject tends to recall is his attitude towards it

Jean Piaget (1896 -1980)

Jean Piaget (1896 -1980)

Conservation Experiment Subject -age of 6 -9 Method -geometrical experiment called "cows on a

Conservation Experiment Subject -age of 6 -9 Method -geometrical experiment called "cows on a farm“ -green card board to represent farmland -Two identical green farms were established, each had a little wooden cow placed upon it, subjects were asked whether the cows had the same amount of grass to feed upon. -proceed to equally add little cubic farmhouses to the models. -In one farmyard the houses where all arranged in a tidy row, on the other farmland the houses were all scattered about.

Results -6 -7 years of age: The average that a child can conserve number

Results -6 -7 years of age: The average that a child can conserve number -7 -8 years of age: a child can conserve substance -Until the ages of 8 -9, children are irresistibly inclined to think there is less grazing land on the farmland which contains the scattered houses. ***Schema and Conservation

Piaget Experiment

Piaget Experiment

Basics of Perception

Basics of Perception

Appearance and Reality • Physical Environment (Reality/Stimuli) • Psychological Field (Appearance/Perception) – Psychology’s Task:

Appearance and Reality • Physical Environment (Reality/Stimuli) • Psychological Field (Appearance/Perception) – Psychology’s Task: “the study of behaviour in its causal connection with the psychophysical field. ” -- Koffka (1935)

Constancies 1. Size 2. Shape 3. Brightness • Bring stability to our visual perceptions,

Constancies 1. Size 2. Shape 3. Brightness • Bring stability to our visual perceptions, which would otherwise seem distorted and erratic

Size Constancy

Size Constancy

Perceptual Constancies • Size constancy – Perceived size of an object remains constant, despite

Perceptual Constancies • Size constancy – Perceived size of an object remains constant, despite changes in its retinal image – Example: hold your left hand close to your face, and extend your right hand out. Did your right hand shrink? • Native or empirical? – Native: some perceptions are so basic they seem to be inborn – Empirical: based on prior experience

Perceptual Constancies • Shape constancy – Perceived shape of an object is unaffected by

Perceptual Constancies • Shape constancy – Perceived shape of an object is unaffected by changes in its retinal image – Examples • Book, look at it from the side, from the top – Does the shape change? • Sitting in different locations in the movie theater • Alcohol impairs size and shape constancies

Perceptual Constancies • Brightness Constancy – The apparent brightness of objects remains the same

Perceptual Constancies • Brightness Constancy – The apparent brightness of objects remains the same as long as they are illuminated by the same amount of light – Only if the objects are surrounded by the same light Constancies rescue us from confusion

Learned or Innate • Constancies seem to be learned • Developmental Changes – Young

Learned or Innate • Constancies seem to be learned • Developmental Changes – Young children do not seem to have constancies. • Example: They will ask why the truck next to the car is getting larger and smaller as it moves closer to your car or farther away – Children are also less accurate at the extremes of the constancy conditions • Example: children are as accurate as adults with size constancy up to 10 feet – Then they become less accurate as the distance increases

Perceptual Hypothesis • We always seek meaningful pattern – Meaningful pattern represents a perceptual

Perceptual Hypothesis • We always seek meaningful pattern – Meaningful pattern represents a perceptual hypothesis • Preexisting ideas and expectations guide our interpretation • Racism?

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Ambiguous Stimuli • Allowing for more than one interpretation • We construct meaningful perceptions

Ambiguous Stimuli • Allowing for more than one interpretation • We construct meaningful perceptions – We do not just record events and stimuli

Impossible Figures • Stimuli offers conflicting information so perceptual organization becomes impossible • Such

Impossible Figures • Stimuli offers conflicting information so perceptual organization becomes impossible • Such figures cannot be organized into stable, consistent, or meaningful perceptions

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Impossible Figures

Impossible Figures

M. C. Escher’s Impossible Waterfall

M. C. Escher’s Impossible Waterfall

Is the ability to understand drawings learned? • Kennedy, 1983 – Edges of surfaces?

Is the ability to understand drawings learned? • Kennedy, 1983 – Edges of surfaces? – Parallel edges? – Lines showing color boundaries? • Page 206, Figure 7. 8 – Tribe in Papua New Guinea thought the parrot had been cut many times

Depth Perception • Ability to see the relation of objects in space • Virtual

Depth Perception • Ability to see the relation of objects in space • Virtual Cliff Experiment – Age: 6 -14 months – Table and “created” cliff – Results • Babies would not walk over edge • Touch glass with hands

Perceptual Learning • Learning has a powerful impact on our perception – Stepping off

Perceptual Learning • Learning has a powerful impact on our perception – Stepping off a curb in England • Perceptual Learning: – Any change in perception that is based on past experiences – Lasting changes in the brain that alter the way we process sensory information

How does learning affect perception? • Amount of attention give to various stimuli –

How does learning affect perception? • Amount of attention give to various stimuli – Using a computer, you must learn to look for certain icons, commands, signals • Distinguish between stimuli that may have seemed identical at first – Telling the difference between certain spices when you are cooking • Learn to focus on one part of a group of stimuli instead of each one individually – Example?

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Perceptual Habits • Definition: ingrained patterns of organization and attention – Connected with schemas

Perceptual Habits • Definition: ingrained patterns of organization and attention – Connected with schemas • Shows how schemas impact behavior • Brain sensitive to lines, shapes, edges, spots and colors – Sensitivity appears learned

Perceptual Habits • Ames Room

Perceptual Habits • Ames Room

 • Grobstein & Chow, 1975 – Cats and University – “Vertical Cats” •

• Grobstein & Chow, 1975 – Cats and University – “Vertical Cats” • Easily avoided chair legs, but missed when trying to jump – “Horizontal Cats” • Easily jump onto a chair, but would bump into chairs – Actual decrease in brain cells tuned to the missing features

The Stroop Effect

The Stroop Effect

Adaptation Level • External context in which a stimulus is judged as an important

Adaptation Level • External context in which a stimulus is judged as an important factor affecting perception – Context: information surrounding stimulus • Personal Frames of reference – Internal standards for judging stimuli • Depends on adaptation level the “medium” point of your frame of reference • Constantly modified by experience

Psychophysical Field

Psychophysical Field

Psychophysical Field

Psychophysical Field

Perceptual Grouping • How are sensations organized into meaningful perceptions? – Figure-ground organization •

Perceptual Grouping • How are sensations organized into meaningful perceptions? – Figure-ground organization • Inborn • Brain responds more actively to figures than to background • Example: Reversible Figures – Figure and ground can be switched

Gestalt Psychology • Main Question – What causes the formation of a figure? –

Gestalt Psychology • Main Question – What causes the formation of a figure? – What brings order to our perception? 1. 2. 3. 4. 5. 6. Nearness Similarity Continuity Closure Contiguity Common Region

1. Nearness • Stimuli near each other tend to be grouped together • Example

1. Nearness • Stimuli near each other tend to be grouped together • Example – Three people standing by each other and another 10 feet away… the individual seen as an outsider

How many different colors?

How many different colors?

Principle of Proximity

Principle of Proximity

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Similarity • “birds of a feather flock together” • Stimuli that are similar in

Similarity • “birds of a feather flock together” • Stimuli that are similar in size, shape, color and form tend to be grouped together. • Example – Two bands marching next to each other with different color uniforms…seen as two groups not one

Principle of Similarity

Principle of Similarity

OXXXXX XOXXXXX XXOXXXX XXXOXXXXXXXOXXXXXXOXXXXXXOXXXXXXXOXXX XXXXOXX XXXXXOX XXXXXO

OXXXXX XOXXXXX XXOXXXX XXXOXXXXXXXOXXXXXXOXXXXXXOXXXXXXXOXXX XXXXOXX XXXXXOX XXXXXO

Continuity • Perceptions tend toward simplicity and continuity • See page 203, 7. 3

Continuity • Perceptions tend toward simplicity and continuity • See page 203, 7. 3 c

Principle of Continuity

Principle of Continuity

Closure • Tendency to complete a figure • Very strong • Example – See

Closure • Tendency to complete a figure • Very strong • Example – See page 203 7. 3 d

Principle of Closure

Principle of Closure

Contiguity • Nearness in time and space • Perception that one thing has caused

Contiguity • Nearness in time and space • Perception that one thing has caused another • Example – Knocking on head and desk

Common Region • Stimuli found within a common region or area tend to be

Common Region • Stimuli found within a common region or area tend to be seen as a group • Example – Group individuals together from the same country or state

Designing perception for humans • Page 204 • Definitions – Engineering psychologists – Natural

Designing perception for humans • Page 204 • Definitions – Engineering psychologists – Natural design – Feedback • Describe all four examples

Camouflage • Learning and past experience also affect our perception • Designed to break-up

Camouflage • Learning and past experience also affect our perception • Designed to break-up figure-ground organization • See page 205, 7. 5

Illusions • Perceptual learning is responsible for illusions – Length, position, motion, curvature or

Illusions • Perceptual learning is responsible for illusions – Length, position, motion, curvature or direction is consistently misjudged – Hallucination: people perceive objects that have no external reality • Can all illusions be explained? – Not in all cases

Illusions • Muller-Lyer illusion – Line test – Looks like a distant corner, not

Illusions • Muller-Lyer illusion – Line test – Looks like a distant corner, not a nearer one. • Corner of a building or corner in a room

Research: Gregory, 1990 • Participants: Zulus, a group of people in South Africa who

Research: Gregory, 1990 • Participants: Zulus, a group of people in South Africa who live in a “round culture” • Results: The typical Zulu villager does not experience the Müller-Lyer illusion. At most, he/she sees the V-shaped line as slightly longer than the other. – Confirms the importance of past experience and perceptual habits in determining our view of the world.

Cultural Significance (Gregory, 1990) • Past Experiences – We would have to test someone

Cultural Significance (Gregory, 1990) • Past Experiences – We would have to test someone who never sees a straight line. • Zulus (S. Africa) – Round houses, no straight roads or square houses, tools and toys are round • They see the line as slightly larger – Confirms past experience and perceptual habits in determining our view of the world – BUT, it may be just misperception

Sensation vs. Perception • A somewhat artificial distinction • Sensation: Analysis – Extraction of

Sensation vs. Perception • A somewhat artificial distinction • Sensation: Analysis – Extraction of basic perceptual features • Perception: Synthesis – Identifying meaningful units • Early vs. Late stages in the processing of perceptual information

Perceptual Expectancies

Perceptual Expectancies

Top-down and Bottom-up Processing • Bottom-up: Stimulus driven; the default • Top-down: Context-driven or

Top-down and Bottom-up Processing • Bottom-up: Stimulus driven; the default • Top-down: Context-driven or expectationdriven.

Problem… c • All of these theories are basically “bottomup” • None can account

Problem… c • All of these theories are basically “bottomup” • None can account very well for context effects (top-down)

Perceptual Set • What is a perceptual expectancy (set)? • Induced by strong expectations

Perceptual Set • What is a perceptual expectancy (set)? • Induced by strong expectations – Readiness to perceive in a particular manner – Created by suggestion • “Fuel Ahead” Low on Gas – Actually say “Food Ahead”

Gibson’s Ecological Optics: an alternative view • Constructivist models vs. direct perception • Constructivist

Gibson’s Ecological Optics: an alternative view • Constructivist models vs. direct perception • Constructivist models – Stimulus information underdetermines perceptual experience (e. g. , depth perception) – Rules (unconscious inferences) must be applied to the stimulus information to achieve perception – Top-down processes compensate for the poverty of the stimulus

Turnbull and the Pygmies 1961

Turnbull and the Pygmies 1961

Research: Turnbull, 1961 • Method – Naturalistic observation • Subject/ Participant – Kenge, a

Research: Turnbull, 1961 • Method – Naturalistic observation • Subject/ Participant – Kenge, a member of Ba. Mbuti, a local Pygmy village in Africa • Results – Heard of buffalo in the distance • swarm of insects. – fishing boat two or three miles out on a lake

Implications • Implications – There were no long-range views in the jungle where Kenge

Implications • Implications – There were no long-range views in the jungle where Kenge had lived his entire life • Vision was usually limited to about 100 feet • No need for the Ba. Mbuti to develop size constancy. – Perception • Innate ability to DEVELOP perceptual habits/constancies

Follow-up Research • Supportive Research – Blackmore and Cooper (1970) • Vertical and horizontal

Follow-up Research • Supportive Research – Blackmore and Cooper (1970) • Vertical and horizontal Cats – Adams (1987) • Infants exposed to primary color squares and grey squares • Contradictory Research – Gibson and Walk (1960) • BUT…Campos ( et al 1978) contradicts Gibson and Walk and supports Turnbull

Boiled Frog Syndrome

Boiled Frog Syndrome

Research: Piaget, 1954 • Subjects: Children (started on his own) • Method: Naturalistic observation

Research: Piaget, 1954 • Subjects: Children (started on his own) • Method: Naturalistic observation • Procedure: interacted with his children, Lucienne, Jacqueline, and Laurent from when they were born to when they were 19 months old – BUT…. follow-up research in a structured format

Results • Stages of Perceptual (Cognitive Development) • 1 st stage – She apparently

Results • Stages of Perceptual (Cognitive Development) • 1 st stage – She apparently believed that her own actions created the world, • 2 nd stage – She realizes that people and objects are independent of her actions. • Object Permanence – child’s realization that an object exists even when he or she cannot see or touch it

 • Representational thought – the intellectual ability of a child to picture something

• Representational thought – the intellectual ability of a child to picture something in his or her mind • The child’s intelligence is no longer one of action only • Ages of 5 and 7, – Conservation • the principle that a given quantity does not change when its appearance is changed.