Physiological approaches to personality

skin conductance

advantages = noninvasive & no discomfort

• measures responses to stimuli

Cardiovascular activity

• Blood pressure-increase,in responses to stress

• Heart rate= increases with anxiety, fear, arousal & cognitive effort

Cardiac reactivity

• Greater than normal increase in BP and heart rate

• Impatience, competitiveness, and hostility

Electroencephalograph (EEG)

• Researcher assesses specific brain response to stimulus

• Electrodes placed on the scalp

Functional magnetic resonance imaging (fMRI)

• Maps the structure and function of the brain

Brain activity & personality

• Extraversion= increased frontal brain activation to positive images

• Neuroticism= increased frontal brain activation to negative images

Extroversion & the brain

• Regions involved in processing reward info

Neuroticism & the brain

• Regions associated with threat, punishment & negative effect

Agreeableness & the brain

- regions process info about intentions & mental states of other individuals

Conscientiousness & the brain

• Regions involved in planning & voluntary control of behavior

Testosterone

• Competitiveness, aggression & risk-taking

Cortisol

• Stress & anxiety

MAO

• Sensation seeking

Zuckerman'S research (sensation seeking)

• High sensation seekers = less tolerant to sensory deprivation

Zuckerman'S sensation-seeking scale

• Moderate positive correlation between extroversion & sensation seeking

Monoamine oxidase(MAO)

• Too little MAO = excessive amount of neurotransmitter left in synapse

• Too much MAO = amount of neurotransmitter left in synapse would be less

• High sensation seekers - low levels of MAO

Eyseneck’s theory of extraversion

• Low extraversion = work to decrease & avoid stimulation & higher levels of activity in brain's ascending reticular activating system(ARAS)

• High extroversion = work to increase & seek stimulation

Circadian rhythm

• Biological processes fluctuate around 24-25 hour cycle

• An average body temp shows a peak round mid-evening & though in early morning

Morning people

• Snorter rhythms are morning people

Night person

• Longer rhythms are evening people