Physiological Approaches to Personality PDF

Physiological Approaches to Personality Chapter 7 Dr. Linden-Andersen PSY 206 © 2023 McGraw Hill Limited 1 Learning Objectives 1. Explain the types of questions asked by psychologists regarding the role of human physiology in personality. 2. Identify and describe the physiological mea...

Physiological Approaches to Personality Chapter 7 Dr. Linden-Andersen PSY 206 © 2023 McGraw Hill Limited 1 Learning Objectives 1. Explain the types of questions asked by psychologists regarding the role of human physiology in personality. 2. Identify and describe the physiological measures commonly used in personality research. 3. Examine physiologically based theories of personality and describe related research findings. © 2023 McGraw Hill Limited 2  The Biological Domain Brain imaging techniques have enabled researchers to learn more about the brain’s role in behaviour and personality than previously thought @CGinspiration/Getty Images possible © 2023 McGraw Hill Limited 3  A Closer Look The Brain Injuries of Phineas Gage While working in construction, dynamite accidentally ignited and the explosion shot an iron rod out of the hole like a bullet It shot up through Gage’s left cheek, just below the cheek bone, passed behind his left eye, and exited the top of his skull © 2023 McGraw Hill Limited 4  A Closer Look The Brain Injuries of Phineas Gage 2 The iron rod destroyed a large portion of the front part of his brain Remarkably he survived! Prior to his accident, he was a highly agreeable and conscientious, after his personality changed dramatically –and became obstinate and capricious © 2023 McGraw Hill Limited 5  A Physiological Approach to Personality Advantage: Physiological characteristics can be measured mechanically and reliably Physiological characteristics refers to the functioning of organ systems within the body E.g., nervous system, cardiac system, musculoskeletal system Physiology is important as differences in physiology create, contribute to, or indicate differences in psychological functioning Simplicity and parsimony © 2023 McGraw Hill Limited 6  A Physiological Approach to Personality 2 Connections among environmental conditions, personality traits, and responses build a theoretical bridge that links personality to specific situations in terms of Evoking a certain psychological response Which can be identified and measured using specific physiological measures © 2023 McGraw Hill Limited 7 Physiological Measures Commonly Used in Personality Research Electrodermal Activity (Skin Conductance) Cardiovascular activity Brain Activity Other measures: Biochemical analyses of blood and saliva © 2023 McGraw Hill Limited 8 Electrodermal Activity (EDA): Skin Conductance Most obtained by electrodes or sensors placed on the skin surface Sweat glands directly influences by sympathetic nervous system (branch of autonomic nervous system) Advantage: Noninvasive, no discomfort Disadvantage: Movement constrained © 2023 McGraw Hill Limited 9 Electrodermal Activity (EDA): Skin Conductance 2 Electrodermal activity: Due to increased sweat with arousal, skin conductance of electricity increases Can measure responses to various stimuli, including sudden noises, emotionally charged pictures, pain, anxiety, fear, guilt Some people display EDA in the absence of external stimuli—associated with anxiety and neuroticism © 2023 McGraw Hill Limited 10 Cardiovascular Activity Blood pressure Can measure stress reactivity Heart rate (beats-per-minute) Increases with anxiety, fear, arousal, cognitive effort © 2023 McGraw Hill Limited 11 Cardiovascular Activity 2 Cardiac reactivity Greater than normal increase in blood pressure and heart rate when performing task such as backward serial subtraction Cardiac reactivity (and Type A) associated with coronary heart disease Associated with Type A personality— impatience, competitiveness, hostility © 2023 McGraw Hill Limited 12 The Brain Neuroscience – scientific study of nervous system Brain function – Positron emission tomography (PET) or functional magnetic resonance imaging (fMRI) Brain structure – magnetic resonance imaging Brain connections – focus on functional connectivity between brain regions Brain electrical activity – Can be measured by electrodes on the scalp—electroencephalograph (EEG) or evoked potential technique—uses EEG, but the participant is given a stimulus and the researcher assess specific brain response to stimulus © 2023 McGraw Hill Limited 13 Other Measures Biochemical analyses of blood and saliva Hormones (e.g., testosterone or cortisol) Monoamine oxidase (MAO) © 2023 McGraw Hill Limited 14 Physiologically Based Theories of Personality Extraversion-Introversion Sensitivity to Reward and Punishment Sensation Seeking Neurotransmitters and Personality Morningness-Eveningness Brain Asymmetry and Affective Style © 2023 McGraw Hill Limited 15 Extraversion-Introversion Measured by Eysenck Personality Questionnaire (EPQ) High extraversion: Talkative, outgoing, likes meeting new people and going to new places, active, bored easily, hates routine Low extraversion: Quiet, withdrawn, prefers being alone or with a few friends to large crowds, prefers routines, prefers familiar to unexpected © 2023 McGraw Hill Limited 16 Extraversion-Introversion 2 Eysenck’s theory Introverts have a higher level than extraverts of activity in the brain’s ascending reticular activating system (ARAS) People strive to keep ARAS activity at optimal level—introverts work to decrease and avoid stimulation; extraverts work to increase and seek out stimulation © 2023 McGraw Hill Limited 17 Extraversion-Introversion 3 Eysenck’s theory Research indicates that introverts and extraverts are NOT at different resting levels, but introverts ARE more reactive to moderate levels of stimulation than extraverts This work led Eysenck to revise his theory— the difference between introverts and extraverts lies in arousability, not in baseline arousal © 2023 McGraw Hill Limited 18 Extraversion-Introversion 4 Eysenck’s theory When given a choice, extraverts prefer higher levels of stimulation than introverts Geen (1984): Introverts and extraverts choose different levels of stimulation, but equivalent in arousal under chosen stimulation Introverts and extraverts perform task best under their chosen stimulation level, poor when performing under a stimulation level chosen by other group © 2023 McGraw Hill Limited 19 Sensitivity to Reward and Punishment Reinforcement sensitivity theory Impulsivity and anxiety Personality based on two hypothesized brain systems Behavioural Activation System (BAS): Responsive to incentives (cues to reward) and regulates approach behaviour Fight-Flight-Freeze system (FFS): Responsive to conditioned and unconditioned aversive stimuli that are immediately threatening or punshing Behavioural Inhibition System (BIS): Responsive to cues to punishment, frustration, uncertainty, and motivates ceasing, inhibiting, or avoidance behaviour Active BIS produces anxiety, active BAS produces impulsivity © 2023 McGraw Hill Limited 20  Sensitivity to Reward and Punishment 2 Relation between Eysenck’s dimensions of extraversion and neuroticism, and Gray’s dimensions of impulsivity a anxiety © 2023 McGraw Hill Limited 21  Sensation Seeking Tendency to seek out thrilling, exciting activities, take risks, avoid boredom Early sensory deprivation @Purestock/SuperStock research Hebb’s theory of optimal level of arousal © 2023 McGraw Hill Limited 22 Sensation Seeking 2 Zuckerman: High sensation seekers are less tolerant of sensory deprivation Require much stimulation to get to optimal level of arousal Zuckerman’s Sensation Seeking Scale Moderate positive correlation between extraversion and sensation seeking © 2023 McGraw Hill Limited 23 Sensation Seeking 3 Physiological basis for sensation seeking Neurotransmitters: Chemicals in nerve cells are responsible for the transmission of nerve impulse from one cell to another Monoamine Oxidase (MAO): Enzyme that maintains a proper level of neurotransmitters © 2023 McGraw Hill Limited 24 © 2023 McGraw Hill Limited 25 Sensation Seeking 4 Physiological basis for sensation seeking Too little MAO = too much neurotransmitter Too much MAO = too little neurotransmitter High sensation seekers have low levels of MAO, Producing a need for stimulation to reach the optimal level of arousal © 2023 McGraw Hill Limited 26 Neurotransmitters and Personality Dopamine: Associated with pleasure Serotonin: Associated with depression and other mood disorders Norepinepherine: Associated with fight or flight response © 2023 McGraw Hill Limited 27 Neurotransmitters and Personality 2 Cloninger’s Tridimensional Personality Model Novelty seeking Low levels of dopamine Harm avoidance Low levels of serotonin Reward dependence Low levels of norephinepherine © 2023 McGraw Hill Limited 28 Neurotransmitters and Personality 3 Focus on genes involved in regulating our neurotransmitter systems DRD4  novelty seeking Needle in a haystack Clonginger’s model has much in common with Gray’s, Eysenck’s, and Zuckerman’s © 2023 McGraw Hill Limited 29 Morningness-Eveningness Being a “morning-type” or “evening-type” of person is a stable characteristic Due to differences in underlying biological rhythms Many biological processes fluctuate around a 24-25 hour cycle—circadian rhythm; e.g., body temperature, endocrine secretion rates But wide individual differences are in the circadian rhythm Identified through temporal isolation studies © 2023 McGraw Hill Limited 30 Morningness-Eveningness 2 Individuals with shorter circadian rhythms: Hit peak body temperature and alertness earlier in day Get sleepy earlier, than individuals with longer rhythm Tend to be morning persons Individuals with longer rhythms Tend to be evening persons © 2023 McGraw Hill Limited 31 Morningness-Eveningness 3 Circadian rhythm in body temperature. Morningness-Eveningness Questionnaire Cross-cultural replication and documentation of stability of characteristic © 2023 McGraw Hill Limited 32  Brain Asymmetry and Affective Style Left and right sides of the brain are specialized, with asymmetry in control of psychological functions A EEG, can measure brain waves, such as alpha wave—an inverse indicator of brain activity Left frontal hemisphere More active than the right when a person is experiencing pleasant emotions Right hemisphere More active than left with unpleasant emotions Patterns replicated in adults, children, and infants © 2023 McGraw Hill Limited 33 Brain Asymmetry and Affective Style 2 Research indicates that the tendency to exhibit asymmetry (favouring left over right, or right over left activation) is a stable individual characteristic Dispositionally positive persons show greater left frontal EEG activity Dispositionally negative persons show greater right frontal EEG activity Conclusion: Affective lifestyle may have origins in, or be predicted by a pattern of asymmetry in frontal brain activation © 2023 McGraw Hill Limited 34 Summary and Evaluation Study of personality can be approached biologically Two ways to think about how physiological variables are useful in personality theory and research: 1. Use physiological measures as variables that may be correlated with personality traits 2. View physiological events as providing causal substrate for personality trait © 2023 McGraw Hill Limited 35