psy 239 401 chapter 8 slides

The Personality PuzzleSixth Editionby David C. Funder

© 2013 W. W. Norton & Company, Inc.

Chapter 8: The Anatomy and Physiology of

Personality

Slides created byTera D. LetzringIdaho State University 1

Objectives

• Discuss what the structure, or anatomy, of the brain can tell us about personality

• Discuss the degree to which personality is a matter of chemistry

• Discuss how this knowledge can be used to improve quality of life

2© 2013 W. W. Norton & Company, Inc.

Two Aspects of the Brain That Can be Examined with Technology

• Anatomy: functions of parts of brain• Biochemistry: effects of neurotransmitters and

hormones on brain processes• Both are related to personality and behavior


The Brain and Personality: Parts and Types of Nerves

• Dendrites• Axons• Afferent nerves• Efferent nerves• Interneurons


Personality and the Brain


The Brain and Personality: Research Methods for Studying the Brain

• Brain damage– Phineas Gage– Lesions

• Brain stimulation– Mostly animals, but also people while conscious– Transcranial magnetic stimulation (TMS) and

transcranial direct current stimulation (tDCS)


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Depression and Recovery From Brain Stimulation

© 2013 W. W. Norton & Company, Inc.


• Brain activity and imaging– Used to observe functioning directly– Detect when the brain is working

• Electroencephalography (EEG) • Magnetoencephalography (MEG)



• Brain activity and imaging– Detect what parts of the brain are working

• CT scans• Positron emission tomography (PET) • Functional Magnetic Resistance Imaging (fMRI)



• Difficulties with imaging techniques– May indicate inhibitory activity– All parts of the brain are always active to some

degree• Blood oxygenation level dependent (BOLD)

imaging signals and perfusion imaging– Brain activity in response to a stimulus does not

mean the same psychological process occurs every time that area is active



• Difficulties with imaging techniques– Most researchers only look at small areas

• Difficult to detect the neural context effect– The technology is difficult to use


fMRI Data


The Brain and Personality: Ascending Reticular Activating System (ARAS)

• Connected to cerebral cortex and rest of brain• Regulation of balance between arousal and

calming by allowing information into the brain– Believed to be the basis for the distinction

between extraversion and introversion– Supporting evidence: the lemon juice test– More recent research is contradictory


The Brain and Personality: The Amygdala

• Links perceptions and thoughts with emotional meaning

• Role is assessing whether a stimulus is threatening or rewarding

• Relevant traits: anxiety, fearfulness, sociability, sexuality, optimism

• Relevant for motivation– Whitman murders at University of Texas in 1966


The Brain and Personality: Frontal Lobes and Neocortex

• Higher cognitive functions• Pleasant emotions (left) and unpleasant

emotions (right) • Approach (left) and withdrawal (right)• Inhibition of reactions to unpleasant stimuli

(left)• Brain asymmetry



• Social understanding and self-control– Phineas Gage (1848)– Others with brain damage

• Somatic marker hypothesis


Phineas Gage



• Social understanding and self-control – Negative emotions and cooperativeness– Role in self-enhancement

• Cognition and emotion– Capgras syndrome– Both are needed for each to function fully


The Brain and Personality: The Anterior Cingulate

• Important for experiencing emotion• Controlling emotional responses and behavior

impulses– Charles Whitman

• Possible implications for extraversion and neuroticism


The Brain and Personality: The Lessons of Psychosurgery

• Prefrontal leucotomy (by 1937)• Prefrontal lobotomy—more drastic• Observations of patients consistent with brain

damage• Replaced with drugs


The Brain and Personality: Brain Systems

• “Nearly everything in the brain is connected to everything else” (p. 269)

• Neural context effect• Persistence• C-system


Biochemistry and Personality

• Galen (Rome, A.D. 130–200) proposed that personality depended on the balance of humors (blood, black bile, yellow bile, phlegm)

• The chemistry of the mind– Neurons communicate with neurotransmitters– Hormones stimulate or inhibit neural activity– About 60 chemicals transmit information in the

brain and body– People differ in average levels


Communications Among Neurons


Biochemistry and Personality: Neurotransmitters

• Dopamine– Involved in responding to reward and approaching

attractive objects and people– Related to sociability, general activity level, and

novelty-seeking– Reward-deficiency syndrome: related to problems

with processing dopamine


Biochemistry and Personality: Neurotransmitters

• Dopamine– Possible relation with bipolar disorder,

extraversion, and impulsivity– Activates the behavioral activation system (BAS)– Individual differences in development of nerve

cells that produce and are responsive to dopamine– Related to plasticity


Biochemistry and Personality: Serotonin (and Prozac)

• Role in inhibition of behavioral impulses, particularly emotional impulses

• Serotonin depletion syndrome– Dangerous criminals, arsonists, and violent,

suicidal individuals– Irrational anger, hypersensitivity to rejection,

chronic pessimism, obsessive worry, and fear of risk taking


Biochemistry and Personality: Serotonin (and Prozac)

• Prozac: a selective serotonin reuptake inhibitor (SSRI) – Physical effect: increases serotonin levels– Psychological effects: controversial

• Positive effects• Makes negative emotions less severe and

doesn’t affect positive emotions


Biochemistry and Personality: Hormones

• Hormone definition• Epinephrine and norepinephrine

– Released in respond to stress; create the fight-or-flight response

– Anxiety, neuroticism


Biochemistry and Personality: Epinephrine and Norepinephrine

• Females might respond differently to stress– Tend-and-befriend – Importance of oxytocin

• Only the initial response to stress


Biochemistry and Personality: Testosterone

• About 10 times higher concentration in men• Link with aggression is complex• Related to many other behaviors in men and

women• Role in control and inhibition of aggression

and sexuality• Unknown causal direction


Biochemistry and Personality: Cortisol

• Released in response to stress• Chronically high levels in people with severe

stress, anxiety, and depression• Low levels related to post-traumatic stress

disorder (PTSD) and sensation seeking


Biochemistry and Personality: Oxytocin

• Role in mother-child bonding, romantic attachment, and sexual response

• Decreases fearfulness


Cosmetic Psychopharmacology

• Definition• But personality is not based specifically on

chemicals and cannot be precisely adjusted with medications

• What do you think of cosmetic psychopharmacology? Is this a good or bad idea? How else might people improve their personalities?

• If you could take a pill to improve your personality, would you do it? Would you still be the same person?


Putting It All Together: The Big Five and Personality


Biology: Cause and Effect

• “The relationship between the brain and its environment works in both directions” (p. 289)

• Understanding the brain can help us understand behavior, but understanding behavior can also help us understand the brain


Clicker Question #1The research methods used to study the brain:a) are essentially unchanged from methods that were used when people first started studying the brain.b) provide completely reliable, objective, and indisputable evidence about how the brain is related to behavior.c) make it possible to observe which parts of the brain are most active.d) only work with animals.


Clicker Question #2

The frontal lobes and neocortex seem to play a role in:a) social understanding and self-control.b) emotions and decision making.c) how people respond to pleasant and unpleasant stimuli.d) All of the above.


Clicker Question #3

The chemical that is released in response to stress and prepares the body for fight-or-flight is: a) epinephrine.b) dopamine.c) testosterone.d) serotonin.


psy 239 401 chapter 8 slides

Technology

brain brain activity

brain difficulties

brain biochemistry

brain asymmetry

brain processes

brain systems

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personality puzzle