lecture 3 Flashcards
PSYC 2130 lecture 3 material
What does biology have to do with personality?
- many personality characteristics are genetically determined
- behavioural tendencies derive from out evolutionary history
- human behaviour is produced by a complex biological system
- brain structures, hormones, neurotransmitters
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anatomy
- functions of parts of the brain
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biochemistry
- effects of neurotransmitters and hormones on brain
What are some cases of brain damage?
chronic traumatic encephalopathy (CTE)
- observed in athletes in high impact games (memory loss, depression, suicidal tendencies)
- dave dveson is an example of CTE
- committed suicide and requested his brain be studied (had mood swings, and aggression that he had no control over)
treatment
- deep brain stimulation (DBS)
- stimulates structure in brain that reduces obsessions and repettitive behaviours
What are some ways to image brain functions?
detects when brain is working
Electroencephalography (EEG)
- electrodes on the scalp picks up electrical signals generated by brain
Magnetoencephalography (MEG)
- detects magnetic indications of brain activity
-
detects what parts of the brain are working
computed tomography (CT) scan
- create representations of very thin slices of brain; exam small structures
positron emission tomography (PET)
- map brain activity based on blood flow
functional magnetic resistance imaging (fMRI)
- map brain activity based on magnetic impulses generated by oxygen in blood
Difficulties with brain imaging techniques
- all parts of brain always active
- brain activity in response to stimulus does not mean the same psychological process occurs every time it is active
- same portion may light up while experiencing anxiety, excitement, problem solving
- neural context effect
- nearly everything in brain is connected to everything
- knowledge of functions may not be very informative in absence of information about what other areas are doing
- technology is very hard and expensive to use
what does the Amygdala do?
- activated by emotionally arousing stimuli
- role in assessing whether a stimulus is a threat or a reward
- once assessed, activates relevant emotional centres
- activates hypothalamus to release cortisol
- links perceptions and thoughts with emotional meaning
- anxiety, fear, sociability, sexuality
which side of the brain is associated with positive/negative emotions
left of brain
- pleasant emotions
- promotes good feelings/ inhibits bad
- anger
right of brain
- unpleasant emotions
- associated with neuroticsm
Who was Phineas Gage, and what happened to him?
he got impaled through the brain/cheek at work with a rod
- stayed conscious
effects
- caused emotional flatness
- frontal lobe was damaged
- basically a lobotomy
what is the insula?
- small region of cerebral cortex
- mentalizing, empathy
- larger insula = higher agreeableness
- conscientiousness, neutralized distractions generated by insula
differences between prefrontal leucotomy, and prefrontal lobotomy
Prefrontal lecuotomy
- control pathalogical levels of arousal
- less brain damage
Prefrontal lobotomy
- drastic measures, more brain damage
- replaces with drugs, chemical lobotomy
What is the function of the frontol lobe?
- converging evidence
- emotional control center and home of personality
- functions
- recieves informtion from limbic system and mediating between cognitions and emotions through executive functioning
- anticipate and plan future
- organizing and problem solving
- reasoning, memory
Biologically-based personality theory; name the 3 seperate systems that influence behavioural tendencies
Behavioural approach system (BAS), fight-flight-freeze system (FFFS), and Behavioural inhibition system (BIS)
What is Behavioural approach system (BAS)?
- approach
- high = extraversion
- regulates approach motivation and goal directed behaviours to attain rewards
- activities ‘hope’ and ‘happiness’ that encourage approach behaviours
- characterized by optimism, sensation seeking, and impulsivity
- high BAS sensitivity = substance use and aggression
- mesolimbic dopaminergic pathway
What is fight-flight-freeze system (FFFS)?
- avoidance
- responds to immediate punishment or threats
- activates panic, fear, rage
- initiates escape, fight/flight
- high FFFS sensitivity is associated with phobias and panic disorders
- hypothalamic-pituitary-adrenal (HPA) axis
What is Behavioural inhibition system (BIS)?
- cautious approach
- assess thread and respond accordingly
- too little = psychopathy
- responsible for resolving goal conflicts
- between or within BAS and FFFS
- conflict detected
- elicits anxiety to inhibit ongoing behaviours (focus and asses conflict)
- assessed as strong, produces high anxiety
- inhibits BAS mediated behaviour, and facilitate FFFS mediated behaviour
- hippocampus and amygdala
How does chemistry relate with the brain?
- neurons communicate with neurotransmitters
- hormones stimulate or inhibit neural activity
- about 60 chemicals transmit information in brain and body
- people differ in average levels of neurotransmitters and hormones, these differences produce personality differences
What are neurotrasmitters and what do they effect?
dopamine
- the nueromodulator of explorations
- unifying theory of role of dopamine in personality
- overarching function exploration
- cognitive exploration
- openness/intellect, impulsivity
- behavioural exploration
- extraversion, reward seeking
- extraversion associate with dopaminergic systems
too much : schizophrenia, stress
too little : depression, parkinsons
how does serotonin affect the body?
- modulates all behavioural processes
- mood, perception, reward, anger, aggression, appetite, memory, sexuality, and attention
- low serotonin = depression + irritability + aggression
- high serotonin = constructive social interactions; decrease aggression and increase dominance
- reduce amygdala activation
- too high = irritability, restlessness, and anxiety
- selective serotonin reuptake inhibitors (SSRI)
- reduces neuroticism (depression and anxiety)
- makes people less irritable rather than less anxious
- does not make you happier; make negative emotions less severe
- affects personality
- helps organize behavour (coscientiousness)
- helps people get along with others (agreeableness)
- helps people avoid mood swings/overreactions (neuroticsm)
Should people use medication for enhancement, rather than treatment?
- use of psychoactive medications by normal individuals for enhancement, rather than treatment
- are ordinary problems inappropriately medicalized?
- is it appropriate to use drugs to change negative personality?
- is personality based on chemicals?
Hormones that affect behaviour
- epinephrine + norepinephrine
- released in response to stress to create fight/flight
- females respond differently to stress
- tend and befriend
- calm others down; get people to work together
- tend and befriend
- oxytocin
- promotes nurturant and sociable behaviours, relaxation, and reduction of fear
- decrease anxiety and increase attachment between mothers and children
- simple acts of touch release oxytocin
- hugs, massages, hugs
How does testosterone affect behaviour?
- 10x higher concentration in men
- high levels = aggression, violent behaviour, increased sexual motivation
- control/inhibits aggression or sexuality
- fatherhood
- decreases testosterone and aggression
- interacts with personality traits, facilitates already inclidned behaviours
- big five: higher levels of testosterone = low agreeableness
what is cortisol and how does it affect behaviour?
- released in response to stress
- speeds up metabolism
- preps body for action
- high levels = stress, anxiety, depression
- low levels = related to PTSD
- sensation seeking, impulsivity, not following societal rules, abnormal response to danger
Cause and effect; brain and enviornment
- relationship between brain and its environment works in both directions
- brain → environment
- environment → brain
- understanding brain = understanding behaviour
- mind-body debate
- are we products of our physical bodies
