V. Thought and Behavior: Do we control our own minds?
Brain, Mind, and Belief: The Quest for Truth
... the brain creates a picture -- a simulation that we mistake for reality. George Johnson
Today’s Agenda
Traveling the brain's pathways Thinking with categories Unconscious influences on behavior
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Operations in neurocognitive networks
Activation moves along lines and through nodes (along the pathways of the brain)
• Integration • Broadcasting
Connection strengths are variable• A connection becomes stronger with repeated
successful use• A stronger connection can carry greater activation
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REVIEW
Some nodes of the cortical net for fork
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Each node in this diagramrepresents a cortical column
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C — conceptualM — motorT — tactileV — visual
REVIEW
Some nodes of the cortical net for fork
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Some nodes of the cortical net for fork
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A word network with two subnets partly shown
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Visual features
C – Cardinal concept nodeM – MemoriesPA – Primary auditoryPP – Phonological productionPR – Phonological recognitionT – TactileV – Visual
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Ignition of a word network from visual input
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Speaking as a response to ignition of a net
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Speaking as a response to ignition of a net
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Speaking as a response to ignition of a net
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From here (via subcortical structures) to the muscles that control the organs of speech articulation
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An MEG study from Max Planck Institute
Levelt, Praamstra, Meyer, Helenius & Salmelin, J.Cog.Neuroscience 199824
Thinking: Traveling the pathways of the brain
Starting a trip through the brain’s pathways• Often induced by sensory input
Hearing the telephone ring Seeing your cat scratching a favorite chair
• Often initiated internally Using information already present in the mind
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Internally induced mental processing
Operates with previously acquired information Deduction, induction, reasoning, figuring things out,
connecting the dots, … Examples: thinking about ..
• The story that Santa comes down the chimney• The story of Noah’s ark and the great flood
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Today’s Agenda
Traveling the brain's pathways Thinking with categories Unconscious influences on behavior
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Categories and reality
• Categories are in the mind, not in the real world • In the world, everything
is unique lacks clear boundaries changes from day to day
• (even moment to moment)• Whorf: “kaleidoscopic flux”
Types of Conceptual Categories
Discrete – clear boundaries• Even integers• Towns in MA
Radial – membership comes in degrees• Birds• Vehicles
Family resemblance• Games• Furniture
Ill-defined, vague• Thought• Mind
Properties of radial categories
1. No small set of defining features • Example: CUP
• What’s the difference between a cup and glass?2. Fuzzy boundaries
• Example: VEHICLE Car, truck, bus Airplane? Boat? Toy car, model airplane? Raft? Roller skate? Snowboard?
3. Prototypicality• Prototypical vehicles: CAR, TRUCK, BUS• Peripheral vehicles: AIRPLANE, TOY CAR, RAFT, ROLLER SKATE, etc
How do radial categories work?
We can understand how they work by understanding how they are represented in the cortex
Different connections have different strengths (weights) More important properties have stronger connections For CUP,
• Important properties: Short (as compared with a glass) Ceramic Having a handle
• These properties are not necessary • But cups with these properties are more prototypical
The properties of a category have different weights
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CUP
MADE OF GLASS
CERAMIC
SHORT
HAS HANDLE
The properties are represented by nodes, which are connected to lower-level nodes
The cardinal node
The threshold
More important properties have greater weights, represented by greater thicknesses of lines
Activation of a category node
The node will be activated by any of many different combinations of properties
The key word is enough – it takes enough activation from enough properties to satisfy the threshold
The node will be activated to different degrees by different combinations of properties• When strongly activated, it transmits stronger
activation to its downstream nodes.
Radial categories and inference
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CUP
MADE OF GLASS
CERAMIC
SHORT
HANDLE
These connections are bidirectional
Separate fibers for the two directions; shown as one line in the notation
An important finding from neuroanatomy
Cortico-cortical connections are generally reciprocal• If there is a connection from A to B there is also a
connection from B to A Consequence: Bidirectional processing
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Bidirectional processing and inference
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CUP
SHORT
HANDLE
Thought process: 1. The cardinal concept node is activated by a subset of its property nodes 2. Feed-backward processing activates other property nodes
Consequence: We “apprehend” properties that are not actually perceived
Category Structure and Inference
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Category
Properties
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B F
E
Consequence:
If A and B, then E and F
C D
Examples
Dark clouds, thunder• It’s going to rain
Ceramic, cup-shaped, handle• Probably holds coffee (without breaking)
ATM• Probably has money
Afro-American trying to break into house• Must be a burglar
Categories and cognitive malfunction
Underdifferentiation• Assuming that members of a category are alike
Illusory properties• Assuming that a category has one defining feature• Assuming that members of a category share some
properties that are lacking in those outside the category
Illusory category boundaries• Or: failure to recognize ‘fuzziness’
Categories and cognitive malfunction
Underdifferentiation• Assuming that members of a category are alike
Illusory properties• Assuming that a category has one defining feature• Assuming that members of a category share some
properties that are lacking in those outside the category
Illusory category boundaries• Or: failure to recognize ‘fuzziness’
Category errors with consequences Example: Dietary fats
Original report: JAMA, 8 Feb 2006 Big news: Front page of NY Times. Etc. “Landmark Study”
• 48,835 women• Eight years• $415 million
Study finds that reducing fat intake does not confer health benefits
Co-author: JoAnn Manson, chief of preventive medicine at Harvard’s Brigham and Women’s Hospital• MSNBC: “…respected nutrition authority”
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Category errors with consequences Example: Dietary Fats
MSNBC: 8 Feb 2006: Study: Low-fat diet fails to decrease cancer, heart risks in older women“Eating less fat late in life failed to lower the risk of cancer and heart disease among older women, disappointing news for those who expected greater benefits from a healthy diet.” …“The eight-year study showed no difference in the rate of breast cancer, colon cancer, and heart disease among those who ate low-fat diets and those who didn’t.”…“The study, appearing in Wednesday’s Journal of the American Medical Association, is part of … a landmark government project involving tens of thousands of … U.S. women.”
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Exercise: What is wrong with this study?And with the press report on this study?
Answer: They didn’t consider the differences between different kinds of fat
A category error• All members of the category treated as alike
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There are different kinds of FAT
From the web site of the FDA
Polyunsaturated Canola oil Good
Monousaturated Olive oil Very good
Saturated Butter A little is OK
Transfat Margarine Really bad
Type of Fat Example Good/Bad
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Categories and cognitive malfunction
Underdifferentiation• Assuming that members of a category are alike
Illusory properties• Assuming that a category has one defining feature• Assuming that members of a category share some
properties that are lacking in those outside the category
Illusory category boundaries• Or: failure to recognize ‘fuzziness’
Illusory properties
• Assuming that a category has one defining feature• Example: MAN
What is it that distinguishes humans from other animals?
Proposal: “tool-making animal” (Caution: TOOL is a category)
• Assuming that members of a category share some properties that are lacking in those outside the category White supremacy
Categories and cognitive malfunction
Underdifferentiation• Assuming that members of a category are alike
Illusory properties• Assuming that a category has one defining feature• Assuming that members of a category share some
properties that are lacking in those outside the category
Illusory category boundaries• Or: failure to recognize ‘fuzziness’• Example: BEARD
Today’s Agenda
Traveling the brain's pathways Thinking with categories Unconscious influences on behavior
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Unconscious influence of language on behavior:Experiments with “scrambled sentence test”
Experiments by John Bargh and colleagues• Bargh, Chen, and Burrows, 1996
Scrambled sentence test• “The purpose of the study is to investigate
language proficiency”• Task: Write down a grammatically correct
sentence using only four of the five words given
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Sample “scrambled sentence” data
him was worried she always shoes give replace old the sky the seamless gray is should now withdraw forgetful we us bingo sing play let sunlight makes temperature wrinkle raisins from are Florida oranges temperature be will sweat lonely they
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Two sets of scrambled sentence data
Experimental group• worried, old, gray, forgetful, bingo,
wrinkle, selfishly, careful, sentimental, wise, stubborn, courteous, withdraw, retired, rigid, traditional, bitter, obedient, conservative, knits, dependent, ancient, helpless, gullible, cautious, alone
Control group• Neutral words
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“Elderly priming condition”
Trigger words in the “scrambled sentence” data
him was worried she always shoes give replace old the sky the seamless gray is should now withdraw forgetful we us bingo sing play let sunlight makes temperature wrinkle
raisins from are Florida oranges temperature he will sweat lonely they
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Trigger words in the “scrambled sentence” data
him was worried she always shoes give replace old the sky the seamless gray is should now withdraw forgetful we us bingo sing play let sunlight makes temperature wrinkle
raisins from are Florida oranges temperature he will sweat lonely they
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After the subject finished..
Experimenter partially debriefed subject• “… how people use words in various flexible ways”
Experimenter tells subject that elevator is down the hall Subject leaves, walks down the hall: 32 feet Confederate uses stopwatch to measure time taken to
walk the 32 feet Then experimenter gives complete debriefing
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Results
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(9.75 meters is about 32 feet)
Second experiment (for replication) , with first
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Another experiment (Bargh, Chen & Burrows, 1996)
Scrambled sentence test – 30 items• E.g., “he it finds instantly”
34 subjects (NYU psych students) Three versions of test given to 3 subgroups
1 Words associated with concept RUDE 1 aggressively, bold, rude, bother, disturb, intrude,
annoyingly, interrupt, audaciously, brazen, impolitely, …
2 Words associated with concept POLITE1 respect, honor, considerate, appreciate, patiently, cordially,
yield, polite, cautiously, courteous …
3 Neutral words1 exercising, flawlessly, occasionally, rapidly, practiced…
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Experimental procedure
Neither the experimenter nor the confederate knew which priming condition was being used with each subject
After finishing, subject was to go to see the experimenter in another room down the hall
Confederate posed as a subject who was having trouble understanding directions, kept asking questions of the experimenter
Test measure: How long did the subject wait before interrupting the experimenter?
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Experimental procedure (cont’d)
Ten minute limit Debriefing, including question: subject was asked
how the scrambled sentence test might have influenced them during the rest of the procedure• None of the subjects showed any suspicion of
influence of the scrambled sentence test Further debriefing: subjects were asked whether
experimenter had been polite• Scale from –3 to +3
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Results: Mean time before interrupting
RUDE priming condition• 326 sec
Neutral condition• 519 sec
POLITE priming condition• 558 sec• N.B.: almost 10 minutes• But 21 of the 34 did not interrupt at all
during the ten-minute time period!
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Percentage of subjects who interrupted
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Polite Neutral Rude
Percent
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Unconscious influences of language on behavior
The experiments show a clear influence of language on behavior
The influence is unconscious How does it work?
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Explanation in terms of brain structure
Bidirectional connections• A hypothesis verified by neuroanatomy
Consequence: reverberating activation The activation levels increase with repeated
activation
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AB
Consequences of repeated activation
Links become stronger• A lasting effect• A primary factor in the learning process
Nodes become more highly activated• Short-term effect• When more highly activated, sends out
stronger activation
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Priming and reverberating activation
worriedold
gray
forgetful
bingo
wrinkle
careful wise
retired
traditional
helplesscautious
alone Florida
SLOW
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This word was NOT in the data presented
Unconscious influence of language on behavior:Mars
In 1997 the first Mars Rover landed on Mars• Propelled on a U.S. Pathfinder rocket
Results• Sales of Mars Rover toys increased dramatically
No surprise• Sales of Mars candy bars increased dramatically
(named for company founder Franklin Mars)
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Functional layout of the gray matter
Primary areas: • Visual (occipital)• Auditory (temporal)• Somatosensory (parietal)• Motor (frontal)
Secondary areas Association areas Executive area, in prefrontal lobe
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Primary motor and somatosensory areas
Central Sulcus
Sylvian fissure
Primary Motor Area
Primary Somato-sensory Area
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Divisions of Primary Motor and Somatic Areas
Primary Somato-sensory Area
Primary Motor Area
Primary AuditoryArea
PrimaryVisual Area
Mouth
HandFingers
Arm
Trunk
Leg
Higher level motor areas
Primary Somato-sensory Area
Actions performedby hand
Primary AuditoryArea
PrimaryVisual Area
Mouth
HandFingers
Arm
Trunk
Leg
Actions per-Formed by leg
Actions performedby mouth
Primary Somato-sensory Area
Primary Motor Area
Primary AuditoryArea
PrimaryVisual Area 71
Conceptual structure: in higher-level cortical areas
Verbal concepts
NominalConcepts
Verbal concepts (the meanings of verbs)
They get reinforced, hence strengthened, by repeated activation• And activation spreads automatically among related
concepts, because they are interconnected If they were not interconnected, they wouldn’t be
related
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Observations from Bargh 2009
Related cognitive neuroscience research has shown an automatic connection between behavioral concept representations and their corresponding motor representations
Merely hearing action verbs pronounced out loud activates the same brain region (Brodman 45) as does witnessing a meaningful action (Jeannerod, 1999)• Both activate implicit motor representations needed to
carry out that type of behavior (Perani et al., 1999)• Motor programs thus appear to be part of the very
meaning of action-related verbs (Grezes & Decety, 2001; Pulvermuller, 2005)
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Concepts associated with rudeness
DISTURB BRAZEN
BOTHER BOLD RUDE
INTRUDE
IMPOLITELY INTERRUPTAGGRESSIVELY
AUDACIOUSLY ANNOYINGLY
As these concepts are all activity-related, they are all presumably located in the frontal/prefrontal lobes. In the experiment they were triggered by visual linguistic input.
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Percentage of subjects who interrupted
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Polite Neutral Rude
Percent
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Another experiment (Harris, Pierce, & Bargh, 2013):Anti-smoking PSAs and smoking behavior
56 smokers watched a short television segment that included a commercial break that showed a public service announcement
Randomly placed in one of three groups acc. to type of PSA• Group 1: a Philip Morris “Quit-Assist” PSA• Group 2: a Legacy “Truth” anti-smoking PSA• Group 3: a control PSA (not about smoking at all)
Subjects were given a brief break after TV viewing• They were left alone during this break• They had the option of going outside for a smoke
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Anti-smoking PSAs and smoking behavior: Results
Subjects were given a brief break after TV viewing• They were left alone during this break• They had the option of going outside for a smoke
Group 1: a Philip Morris “Quit-Assist” PSA• 42% smoked during the break
Group 2: a Legacy “Truth” anst-smoking PSA• 33% smoked during the break
Group 3: a control PSA (not about smoking at all)• 11% smoked during the break
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Results
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Percentage of participants who smoked following exposure to public service announcement
T h a t ‘ s i t f o r t o d a y !
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