Biology, Personality, and Psychopharmacology

neuroscience

the study of the nervous system; neuropsychology is the study of the relationship between brain function and behavior

cerebral cortex

has 16 billion neurons (all of which impact our behavior, emotions, cognition, etc. and therefore affect our personality)

neuropsychologists use EEG, fMRI, CT, etc to study the brain

certain brain structures are associated with behavior, cognition, emotion, that explain individual differences (i.e., personality), brain function is interdependent, frontal lobes function associated with differences in people’s tendency to procrastinate, respond to reward/punishment, make decisions, (etc.)

what does the brain and biology interact with

environment to make us who we are

neurotransmitters

work to regulate behavior and psychological functioning (including propensity to depression, anxiety, delinquency)

traits and effects of brain/biology on the expression of various traits or characteristics

sensation seeking, extraversion, neuroticism

sensation seeking

a trait defined by the need for varied, novel, and complex sensations and experiences and the willingness to take physical and social risks for the sake of such experience

high sensation seeking

more likely to use drugs, gamble, make financially risky decisions

brain activity in sensation seeking

more brain activity (vs low sensation seekers) when seeing or experiencing something novel (creates a reward network of sorts), become bored more quickly and develop a tolerance to novel stimuli

the brain and sensation seeking

negatively correlated with MAO levels, dopamine and serotonin levels, testosterone levels, sensation seeking scale (zuckerman)

the brain and extraversion

extraversion is considered a foundational personality feature

arousal hypothesis

role of RAS (introvert have a higher baseline arousal), lemon test (extra vs intro)

MAO in extraversion

lower

dopamine receptors in extraversion (extroverts)

extraverts need more dopamine to feel happy because they’re less sensitive to it (socializing increases dopamine activating those multiple receptors and creating a reward loop toward socializing)

dopamine receptors to extraversion (introverts)

introverts are more sensitive to dopamine so all the things that excite extroverts feel overwhelming and anxiety provoking

EEG

extraverts have less brain wave activity than introverts when stimulated

compared to introverts

extraverts respond less strongly to moderately intense stimuli; introvers’ arousal levels increases more quickly than extraverts

extroversion and positive emotions

are linked

introverts habe a thicker prefrontal cortex (processing center)

extraverts brains are more geared toward rewards seeking, thicker prefrontal cortex can limit spontaneity

individual differences in extraversion

may be result of difference in subcortical/white matter regions of the brain

brains of extraverts

may release more dopamine than introverts when rewards

introverts require less

of a drug than do extraverts to feel its effects

MRI data on neuroticism as a trait

neuroticism due to the interaction of various regions of the brain

amygdala in neuroticism

vastly different amygdala from extraverts

activation of neuroticism

increased activation of frontal regions for emotion processing and regulated, heightened level of cortical arousal, tendency to experience negative emotions

ECT

induce seizure activity that may adjust chemical (neurotransmitter) and hormonal balances

Tx

therapeutic interventions, Psychopharmacology (SSRI, MAO-I, Buspirone, Beta blockers)

most effective treatment

tx in combination, ie medication and therapy