Feature Integration Theory
Psychology 355: Cognitive Psychology
Instructor: John Miyamoto
04/16/2015: Lecture 03-4
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Outline
• Treisman’s Feature Integration Theory
♦
Role of Attention in Binding Features to Objects
• Automatic and Controlled Processes
• Briefly discuss Midterm 1 (Monday April 20)
Psych 355, Miyamoto, Spr '15
Feature Integration Theory
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Feature Integration Theory (FIT): Figure 4.32
• Anne Treisman hypothesized that attention plays a critical role
in combining features into objects (binding features to objects).
• Preattentive stage
♦
Automatic; effortless; unaware of process; object analyzed into features
• Focused attention stage
♦
Attention plays key role; features are associated with (bound to) objects
Psych 355, Miyamoto, Spr '15
Same as This Slide But Without the Emphasis Red Rectangles
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Feature Integration Theory (FIT): Figure 4.32
• Anne Treisman hypothesized that attention plays a critical role
in combining features into objects (binding features to objects).
• Preattentive stage
♦
Automatic; effortless; unaware of process; object analyzed into features
• Focused attention stage
♦
Attention plays key role; features are associated with (bound to) objects
Psych 355, Miyamoto, Spr '15
Describe Task in Schmidt & Treisman Experiment
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Treisman & Schmidt Experiment
• Next you will see 2 numbers and 4 objects.
The numbers are next to the objects.
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1
YOUR TASK
• Make sure that you notice and remember the numbers.
• Then try to remember as much as you can about the objects.
• When the display is gone, write down the numbers, and
describe the objects as best you can.
Psych 355, Miyamoto, Spr '15
“Prepare to Respond” Slide
5
Prepare for the First Trial (a Slow Trial)
The stimulus will appear
about here.
The trial will start when I say “go”.
When I say “go” (click), a display will appear and then disappear.
Psych 355, Miyamoto, Spr '15
Actual Trial Begins on Click – The First Trial is Slow
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Example of Treisman Display
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Psych 355, Miyamoto, Spr '15
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7
Pattern Mask
Psych 355, Miyamoto, Spr '15
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Dependent Variables
• What were the numbers in the display? Write them down.
• What did the objects in the middle look like?
Write down some notes about them.
Actual Display:
• The next display is presented much faster so be ready.
Psych 355, Miyamoto, Spr '15
“Prepare to Respond” Slide
9
Prepare for the Second Trial (a faster trial)
The stimulus will appear
about here.
The trial will start when I say “go”.
When I say “go” (click), a display will appear and then disappear.
Psych 355, Miyamoto, Spr '15
Similar Trial But Display Duration is Much Shorter
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Treisman Display
Psych 355, Miyamoto, Spr '15
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Pattern Mask
Psych 355, Miyamoto, Spr '15
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Dependent Variables
• What were the numbers in the display? Write them down.
• What did the objects in the middle look like? Write down some
notes about them.
Actual Display:
• Did any of you see the correct features but have them associated
with the wrong object? This illustrates feature migration and
illusory conjunctions (of features).
Psych 355, Miyamoto, Spr '15
Illusory Conjunctions & Feature Integration Theory
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Illusory Conjunctions and the Binding Problem
•
Features occasionally "migrate" from one object to another.
Illusory conjunctions – people see the right features but attach
them to the wrong objects.
•
Feature Integration Theory (FIT – due to Anne Treisman):
♦
There is a stage in perceptual processing where features are represented
independently from "binding" to objects. Features can still float from
one object to another. (Preattentive Stage)
♦
It takes attention to bind features together into objects.
(Focused Attention Stage)
Psych 355, Miyamoto, Spr '15
Conclusions re Feature-Integration Theory
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Conclusion re Feature Integration Theory (FIT)
• Main Hypothesis:
Focused attention helps bind features to objects.
• Comment: Much easier to create illusory conjunctions
with abstract objects like
objects like
or
◘
or ▲ than with familiar
.
• Comment: Why did I ask subjects
to identify the numbers on either side
of the display?
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1
• Example of Balint's syndrome:
♦
Patient with Balint's syndrome has difficulty focusing on individual objects.
♦
Patient with Balint's syndrome is especially prone to seeing
illusory conjunctions.
Psych 355, Miyamoto, Spr '15
Automatic and Controlled Processes
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Automatic versus Controlled Processes
• Automatic processes are processes that occur without conscious
control; automatic processes do not interfere with other concurrent
mental activities.
• Controlled processes are processes that require conscious attention in
order to carry them out.
• Examples:
♦
♦
Learning to touch type at a keyboard. Initially requires controlled processing,
then become automatized with lots of practice.
Stroop effect – reading word meaning is an automatic process.
book rock bird hair knot
blue
Psych 355, Miyamoto, Spr '15
green red
blue green
Characteristics of Automatic and Controlled Processes
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Characteristics of Automatic and Controlled Processing
Characteristics of Automatic Processes:
Examples: reading, comprehending spoken language, identifying a friend
----------------------------------♦
... can be initiated without intention;
♦
... operate very rapidly;
♦
... operate without conscious control of the process
Characteristics of Controlled Processes:
Examples: Writing a letter, solving a problem (usually), making a big decision
----------------------------------♦
... usually initiated intentionally;
♦
... often occurs slowly;
♦
... operate with conscious control (usually); require attention to execute them;
Psych 355, Miyamoto, Spr '15
Schneider & Shiffrin – Some tasks are/are not automatic
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Some Tasks Can Be Automated; Others Cannot
Schneider & Shiffrin (1977): Search for a target letters in displays
that contain distractors (non-targets).
• Consistent mapping condition: Letters that are used as targets are
never used as distractors.
• Varied mapping condition: Letters that are used as targets are also
used as distractors on other trials.
Psych 355 students: You can ignore this slide. I won't ask you
for the details of the Schneider & Shiffrin (1977) study.
Psych 355, Miyamoto, Spr '15
Schneider & Shiffrin - Findings
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Some Tasks Can Be Automated; Others Cannot (cont.)
• Consistent Mapping Condition: After many thousands of trials
(thorough training), accuracy was just as good when searching 4
positions as when searching 1 or 2 positions.
• Varied Mapping Condition: After many thousands of trials (thorough
training), accuracy still got worse and worse as the number of
positions to search increased from 1 to 2 to 4.
• Interpretation: The search became automatic in the consistent
mapping condition, but could not be automatized in the varied
mapping condition.
Psych 355 students: You can ignore this slide. I won't ask you
for the details of the Schneider & Shiffrin (1977) study.
Psych 355, Miyamoto, Spr '15
Summary re Automatic & Controlled Processes
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Summary re Automatic and Controlled Processes
• Divided attention (task sharing) becomes easier and performance
improves as tasks become automatized.
• Obviously practice promotes automatization.
• Some tasks cannot be automatized.
• This distinction has many important applications
Psych 355 students: These two
points are the only things that I
want you to know about the
Schneider & Shiffrin (1977)
study.
♦
Effects of practice on skill learning
♦
Automatic social responses, e.g., prejudiced responses (racial/gender/ethnic)
that are masked by more acceptable responses.
Psych 355, Miyamoto, Spr '15
Info re Midterm 1 - END
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Midterm Exam: Monday April 20
• Format: Multiple choice, true/false, short answer
• Time allowed: whole class period (50 minutes)
• ** Bring a scantron form and #2 pencil to the exam **
What will be on the test?
• Textbook, chapters 1-4, lectures, sections, CogLab assignments
• The main Psych 355 webpage has a link to a document that is titled
"What will be covered on Midterm 1?".
♦
The url for this document is
https://faculty.washington.edu/jmiyamot/p355/mid1.topics.htm,
but it is probably easier to find the link on the Psych 355 webpage.
Psych 355, Miyamoto, Spr '15
Continue This Slide - END
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Midterm Exam: Monday April 20
Study materials (on the Psych 355 website)
• Download pdf's of the study guides for Chapters 1 – 4 from
the Psych 355 website.
• See Midterm 1 from Spring 2014.
First, study the version without an answer key.
Later, use the answer key to check your thinking.
• See quizzes 1 and 2 from Spring 2014.
• The document "What will be covered on Midterm 1?" (see link on preceding
slide) contains suggestions regarding the most effective way to study
for this exam.
Psych 355, Miyamoto, Spr '15
END
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