ch 7: physiological approaches to personality

explain building a theoretical bridge

how is personality physiologically measured?

• electrodermal activity

• cardiovascular activity

• brain activity

what is electrodermal activity?

provides a measure of sympathetic nervous system activity

• skin conductance

what is emotional reactivity (Nock & Mendes)?

intensity and persistence of emotion in response to stimuli

• elevated among people with lived experience of self-injury—especially in response to negative/stressful contexts

explain the stress induction task (Nock & Mendes)

matching game in which failure feedback is given (even when a response is correct)

→ determine how long people stay in the game and tolerate distress from negative (failure) feedback

• induced stress in 2 groups (with/without history of self-injury) & measured skin conductance

what were the main findings and implications of Nock & Mendes?

main findings:

• individuals with a history of self-injury had elevated skin conductance & more negative emotional reactivity stress

• individuals who self-injured also quit the game sooner which might indicate lower distress tolerance

implication:

• emotional reactivity & distress tolerance may be key to understanding self-injury—they are also parts of personality & individual differences

what is blood pressure (BP) - cardiovascular activity

• pressure exerted by blood in the artery walls

• common measure of stress response

what is heart rate - cardiovascular activity

expressed in BPM → good indicator of stress/anxiety, cognitive effort

what is cardiac reactivity?

• increases in BP and heart rate in times of stress

• chronic cardiac reactivity linked with Type A personality (hostility)

what is electroencephalogram (EEG) - brain activity?

measure brain activity (electricity) via electrodes to determine areas of brain activity

what in functional magnetic resonance imaging (fMRI) - brain activity?

shows images of areas of brain activity

what is psychopathy?

decreased limbic activation when viewing violent images for those high in psychopathy vs. a control group (who had more activity)

what are other MRI findings in personality psychology?

• neuroticism: increased frontal brain activation to negative images

• extraversion: increased frontal brain activation to positive images

what is eysenck’s ORIGINAL theory?

• ascending reticular activating system → ‘gateway‘ for nervous stimulation of cortex

original theory:

• introversion → higher resting cortical arousal (ARAS lets in too much)

• extraverson → lower resting cortical arousal (ARAS lets in too little)

what is eysenck’s REVISED theory?

those high in introversion or extraversion do not have different resting states of arousal → the difference lies in degree of arousability (supported by significant research)

what is sensitivity to reward and punishment?

• behavioural activation system (BAS): responsive to rewards AND regulates approach behaviour

  • active BAS → impulsivity

• fight-flight-freeze (FFFS): responsive to immediate threats aversive stimuli—plays a role in our FEAR response (correlated with fear proneness/avoidance)

• behavioural inhibition system (BIS): resolves conflict between the BAS and FFFS

  • active BIS → anxiety & rumination (linked with neuroticism)

what is sensation-seeking?

tendency to seek out thrills, seek experience, take risks & avoid boredom → less tolerant of sensory deprivation

what is teh physiological basis of sensation-seeking?

monoamine oxidase (MOA): regulates neurotransmitter level by breaking them down

• too little MOA → too much neurotransmitter

• too much MOA → too little neurotransmitter

  • high levels of sensation-seeking → low MOA

describe problem gambling & personality

high sensation seeking and impulsivity

• 3 year longitudinal study (18-21):

  • sensation seeking and impulsivity predicted problem gambling

what is the cloninger’s tridimensional personaluty model?

• low levels of dopamine in novelty seeking

• *low levels of serotonin in harm avoidance

• low levels of norepinephrine in reward dependence

what is the circadian rhythms?

biological processes fluctuating on a 24-25 hour cycle

• shorter circadian rhythms → hot peaks earlier; sleep earlier at night

• longer circadian rhythms → hit peaks later; sleep later at night

explain morningness-eveningness and depressive symptoms

main findings: higher eveningness correlated with higher depressive symptoms

implication:

• eveningness may help understand some of the biological mechanisms involved in depression

• morningness mas help understand protective factors

what is brain asymmetry?

• hemispheres of brain are specialized & involved in specific functions

• EEG measures brain activity (alpha wave - an inverse indicator of brain activity)

• emotions often measured by activation in the frontal brain

explain brain asymmetry & affective style

• left frontal hemisphere → more active when experiencing pleasant emotions

• right frontal hemisphere → more active when experiencing negative emotions

this response is stable a affective style considered trait-like