TASK 4 - BIOLOGICAL BASES Flashcards
four humours (galen)
- personality/temperament depends on strength of fluids/humours
1. blood = sanguine; cheerful
2. black bile = melancholic; depressive
3. yellow bile = choleric; angry
4. phlegm = phlegmatic; calm
temperament in dogs (pavlov)
- strong balanced mobile = sanguine –> lively, fast, eager
- weak = melancholic –> inhibited, anxious, easily upset
- strong unbalanced = choleric –> excitable, hyperactive, irritable
- strong balanced slow = phlegmatic –> calm, consistent
cloninger’s theory
= tridimensional personality model
= relations between neurotransmitters and personality dimensions
A. dopamine (cloninger)
= facilitates response to pleasurable, exciting stimuli; transmission of signals of reward
- active = high levels of novelty seeking (= tendency to seek pleasure and excitement) –> exploratory, excitability, impulsiveness
- inactive = low in novelty seeking –> not motivated to find fun and variety
B. serotonin (cloninger)
= inhibits response to harmful, unpleasant stimuli; transmission of signals of punishment
- inactive = high levels of harm avoidance (= tendency to avoid pain and anxiety) –> worry, pessimism, fear of uncertainty
- active = low in harm avoidance –> not motivated to avoid pain and anxiety (risk-taking)
C. noradrenaline (cloninger)
= inhibits response to stimuli that have previously been associated with pleasure; transmission of signals of conditioned reward
- inactive = high levels of reward dependence (= tendency to develop strong sentimental attachments; related to one’s response to people/things that have tended to be associated with pleasure) –> sentimentality, warm communication, dependence
- active = low levels in reward dependence –> not develop strong sentimental attachments
gray’s theory
= reinforcement sensitivity theory
= certain regions of the brain work together as mechanisms or systems that underlie personality
- differences among people in activity of these systems are basis of important personality dimensions
A. behavioural activation system (gray)
= regions of brain receiving signals indicating that rewards are being experienced
- ‘GO’ system = encourages pursuit of rewards –> signals to communicate pleasurable and exciting nature of rewards
- differences in tendency to be impulsive, seek pleasure and excitement –> the stronger, the more one tends to pursue rewards
- -> cloninger’s novelty seeking
B. behavioural inhibition system (gray)
= regions of brain receiving signals indicating that punishments are being experienced
- ‘STOP’ system = encourages the avoidance of punishments –> signals to communicate the painful and frightening nature of punishments
- differences in tendency to be anxious and to avoid pain –> the stronger, the more one tends to avoid punishments
- -> cloninger’s harm avoidance
C. fight-or-flight system (gray)
= regions of the brain motivating extreme reactions (fight or flight) in response to extremely threatening situations
- differences in tendency to show extreme reactions, (responding aggressively, leaving hurriedly) –> the stronger, the more ready one is to fight or to flee when an emergency situation arises
- -> cloninger’s reward dependency
eyseneck’s theory
= theory of personality
A. extraversion vs. introversion
B. neuroticism vs. emotional stability
C. psychoticism
A. extraversion vs. introversion
= strength of reactions to stimulation (difference in arousability of people’s brains)
- extraversion: seek stimulation, bored by low level of stimulation (enjoy loud noises, bright colours, meeting people)
- introversion: avoid stimulation, prefer low level of stimulation (prefer quieter surroundings, enjoy being alone)
ARAS (ascending reticular activating system):
- brain stem
- regulates amount of stimulation that is admitted to brain from NS which receives stimulation
- little stimulation in ARAS: under-aroused = seek stimulation = extraversion
B. neuroticism vs. emotional stability
= strength of reactions to stressful stimuli (difference in sensitivity to stress)
- neurotic: great deal of stress, sensitive to stress (nervousness, anxiety, fear)
- emotionally stable: less sensitive to stress (little negative emotions caused by stresses)
limbic system:
- regulate responses to stress
- overwhelmed by stressful stimuli = neurotic
C. psychoticism
- high levels: aggressiveness, manipulation, tough mindedness, risk taking, impulsivity (criminal behaviour, mental illnesses, creativity)
- low levels: opposite
high levels of testosterone +low levels of monoamine oxidase (MAO)
zuckerman’s model
= five factors representing basic dimensions of personality/temperament
- activity, 2. sociability, 3. impulsive sensation seeking, 4. aggression, 5. neuroticism-anxiety
- each dimensions is caused by its own set of interactions among brain structures, neurotransmitters + hormones
o-RST
= original reinforcement sensitivity theory (gray)
= focused on motivational systems
- BAS = approach system
- BIS = defined avoidance orientation.
r-RST
= revised reinforcement sensitivity theory
= sees BIS as comparator that evaluates whether to approach/avoid stimulus
- better definitions (BIS, BAS, FFFS).
√ strong basic personality model, grounded in neuroscience and animal learning
x under-utilised in literature, not have breadth in research
- most modern models under-represent systems of the r-RST (biologically-based) –> despite processing other qualities
hybrid model of learning in personality (HMLP)
- comparison to gray
= concept of BAS; sensation seeking is potentially dysfunctional if directly expressed, but likely to be functional if expressed through socio-cognitive mediators (e.g. rationality/ conscientiousness)
- sensation seeking concerns exploratory behaviour that is not necessarily associated with reinforcement
√ clear differentiation between biological basis of sensation seeking and socio-cognitive mediators
√ sensation seeking consistent with BAS in r-RST
x only concerns BAS & mediators
x under-utilised in literature, no measure of punishment sensitivity
approach & avoidance temperament model (AATM)
- comparison to gray
= behaviour distally predicted by temperament & proximally predicted by goals
–> approach temperament vs. avoidance temperament
- biologically based, makes predictions from BAS & BIS through socio-cognitive mechanisms of goals
√ clear differentiation between biological basis and socio-cognitive goals
x under-utilised in literature
x outdated (based on o-RST)
psychobiological model of temperament & character (PMTC)
- comparison to gray
= character (socio-cognitive) is thought to predict outcomes independently from temperament (biological)
- incorporates genes & environment
- character dimensions: self-directedness, cooperativeness, self-transcendence
√ biological, includes amount of literature
x outdated (based on o-RST)
hormones
= biological chemicals that are produced in glands of one part of the body, transmitted to other parts of body where they have their effects
testosterone
- hormones
= responsible for many physical characteristics of men (development of male reproductive organs, hair growth, voice, muscle mass)
- situationally influenced (increase after victory, sex; decline after defeat)
- influence individual’s behaviour during early development
- higher levels: being wilder, more unruly
- lower levels: better behaved, more socially responsible, better academic achievement, more friendly
cortisol
- hormones
= released by adrenal cortex (perimeter of adrenal glands) which are located above the kidneys; triggered by physical or psychological stress
- prepare body for action in response to stress (increase in blood pressure, blood sugar, suppression of immune system)
- little cortisol release = emotionally insensitive/reactive
- low cortisol = high sensation-seeking levels/risk-taking (men)
oxytocin
- hormones
= produced in hypothalamus, released by pituitary gland
- release promotes close attachment with others = emotional bonding (giving birth, breastfeeding, orgasm)
- contribute to cooperative relationships by being trusting + trustworthy
- higher levels = more trusting + trustworthy
mechanisms of action
- oxytocin
= neuropeptides can influence neurotransmission, not in same way as classical neurotransmitters (GABA, serotonin, dopamine)
- slower degradation –> no effect over longer distances and thus no temporal specificity
1. dynamic concept: different areas of the brain use different modes of communication - exposure to certain stimuli can lead from one form of peptide release to another
- emphasises task dependency, context + individual differences
2. volume transmission: three-dimensional diffusion into extracellular fluid + lack of obvious structural extracellular communication pathways - source of release may be distant from target cells
3. priming hypothesis: peptidergic oxytocin signal can trigger dendritic peptide release that is independent of electrical activity
interaction with other systems
- oxytocin
= social affiliative behaviour (modulated by oxytocin) is accompanied by modulation of dopaminergic reward pathways
- oxytocin can effectively modulate reward-related brain regions + elevate serotonin levels
behaviour modulation
- oxytocin
= oxytocin modulates social behaviour
- by increasing trust, empathy & pair bonding or by reducing social stress & anxiety
- precise outcome mediated by context + individual variation
- fear + emotion regulation: oxytocin reduces amygdala activation in response to fear
- -> strongest effect when strong or socially relevant stimuli
- anxiety: oxytocin reduces heightened anxiety
functional connectivity
- ocytocin
= prolonged priming effect of oxytocin can elicit functional rewiring of neural networks
- rewiring = temporary alteration (strengthening/weakening) of the way the network is configured and how it responds
social regulation of stress
= social interaction and oxytocin are linked through feedback loop (specific social contexts promote OT release) –> regulates social cognition and behaviour
- oxytocin reduces cortisol release in stressful situations (especially in interaction with social support)
oxytocin receptor gene (OXTR)
= responsible for encoding oxytocin receptor protein
- variations influence strength of oxytocin signal by affecting the number/ distribution/ efficiency of receptors
- variants seem relevant to understanding individual differences in social behaviour and stress regulation
two most widely studied OXTR SNPs
- Rs53576 = associated with responses to social support
- A allele: reduced responsiveness to social support received in anticipation of stress –> more stressed, lower tendency to seek social support = more oxytocin
- G allele: less cortisol secretion, more oxytocin in response to social support –> less stressed, higher tendency to seek social support - Rs2254298 = associated with attachment status
- A allele: secure attachment = more oxytocin
- G allele: insecure attachment = lower levels of oxytocin
theoretical model for development of individual differences in social regulation of stress
= genetic variants of OXTR are relevant during at least 2 stages of the psychological feedback loop –> connects stable cognitive representations of relationships in context of acute stress
- role for oxytocin in individual differences, in responses to social support following stress
- role for oxytocin in early development of stable cognitive representations of relationships –> influence how individuals use social support to regulate their stress
personality neuroscience
= use of neuroscience methods to study individual differences in behaviour, motivation, emotion and cognition
- three levels at which personality can be analysed:
1) traits: relatively stable patterns of behaviour, motivation, emotion
2) characteristic adaptations: individual’s specific responses to particular life circumstances
3) life stories
- meta-traits
- big five
- aspects
- facets
1a. stability: tendency to regulate/restrain potentially disruptive emotion & behaviour
- serotonin: regulatory/inhibiting effect on mood, behaviour & cognition
2a. neuroticism
3. withdrawal, volatility
2b. agreeableness
3. compassion, politeness
2c. conscientiousness
3. industriousness, orderliness
1b. plasticity: tendency to explore + engage with possibilities
- dopamine: 2 branches
2d. extraversion
3. enthusiasm, assertiveness
- -> 1 to brain regions involved in motivation, emotion & reward (nucleus accumbens, amygdala) = extraversion
2e. openness to experience
3. openness, intellect
- -> 1 to structures for higher cognition (prefrontal cortex) = openness to experience
- number and identity of facets is unclear
2a. neuroticism
= sensitivity to punishment and negative affect; tendency to experience negative emotions and cognitions that accompany experiences of threat and punishment
- brain activity at rest or in response to aversive or novel stimuli in amygdala, insula and anterior cingulate
- neural activity in medial prefrontal cortex (= poor emotion regulation) + reduced volume
- BIS: passive avoidance in situations where goals are in conflict –> hippocampus and amygdala
- FFFS: responses to proximal threat or punishment –> amygdala, hypothalamus, periaqueductal gray.
- lower serotonin levels (modulates BIS and FFFS)
2b. agreeableness
= tendency toward altruism & opposed to exploitation of others
- volume in brain regions associated with social information processing (superior temporal gyrus, posterior cingulate cortex, fusiform gyrus)
- ability to suppress aggressive impulses & other socially disruptive emotions
- -> left DLPFC (emotion regulation)
2c. conscientiousness
= top-down control of behaviour and impulses in order to follow rules and pursue non-immediate goals
- prefrontal cortex: greater volume in regions involved in maintaining goal-relevant info in WM + execution of planned action based on abstract rules.
- low serotonin levels: linked to absence of control
2d. extraversion
= sensitivity to reward and positive affect
- dopamine (component of BAS) : sensitivity to reward, drives behaviour that involves approaching potential rewards
3. enthusiasm (= sociability & positive emotionality): linked to liking –> relates to opioid system
3. assertiveness: linked to wanting
2e. openness/intellect
= tendency to explore, detect, appreciate and use patterns in abstract sensory information
- intellect: intelligence and working-memory
- dopamine influence on prefrontal cortex
