7: PHYSIOLOGICAL APPROACHES TO PERSONALITY

Question 1

Advantages of Physiological Approach

Answer 1

An advantage of the physiological approach is that physiological characteristics can be measured mechanically and reliably.
1. Physiology is important to the extent that the differences in the biology create contribute to or indicate differences in psychological functioning
eg: people differ from one another in how sensitive our nervous systems are to stimulation
2. Simplicity & parsimony. Physiological differences result in a given personality difference or a difference in an important behaviour pattern. However, it is not the only cause
eg: people with risk-taking behaviours do so because of a possible deficiency of chemicals or activity in the amygdala

Question 2

Body Liquids as Physiological Measures

Answer 2

1. Body liquids
   - Black bile means Melancholia (melancholy)
   - Yellow bile means Choleric (easily angered)
   - Blood means Sanguine (cheerful, optimistic)
   - Phlegm means Phlegmatic (dull)

Question 3

Body type measures of physiology

Answer 3

> Endomorphy (obesity), Mesomorphy (muscularity), Ectomorphy (thinness), 1-7 scale
- Visceratonia (relaxation, sociability)
- Somatotonia (courage, energy)
- Cerebrotonia (inhibition, shyness)

Question 4

Electrodermal Activity (skin conductance)

Answer 4

> Before any visible sweat, electricity can be conducted through it
1. Two electrodes are placed on each palm, one is put through low voltage.
2. They measure how must electricity is present at the other electrode.
3. The difference in the amount of electricity that’s passed into the skin at one, and the amount detected at the other electrode tells us how well the skin is conducting electricity ( SNS activity increases → more water produced → better conduction )
Electrodermal responses can be elicited by stimuli like sudden noises, emotional pictures, mental effort, pain, emotional reactions like anxiety, fear and guilt.

Question 5

nonspecific electrodermal responding

Answer 5

Without stimuli, associated with anxiety and neuroticism

Question 6

Cardiovascular Activity

Answer 6

1. Blood Pressure: Diastolic & Systolic pressure
   Diastolic: Smaller #, the resting pressure in the system between contractions
   Systolic: Larger #, the max pressure in the system when the heart contracts
2. Heart Rate: BPM
   - Measuring the time interval between successive beats
   Cardiac Reactivity: Phenomenon where heart rate & blood pressure goes up in times of stress. Associated with Type A personality: characterized by impatience, competitiveness and hostility

Question 7

The Brain

Answer 7

• Because personality is the study of differences between people, large sample sizes are needed
• The Decade of the Brain: Intensive research of the last century became a priority
• Resulted in major advances to make brain imaging tech more user-friendly and more widely available due to lower costs, while improving the efficiency of the data
  Personality Neuroscience was created to serve as an outlet for the increasing amount of research on personality & the brain.
  Measures of The Brain
  1. Function
  2. Structure
  3. Connections
  4. Electrical Activity

Question 8

Brain Function

Answer 8

Refers to the changes (increase or decrease) in the activation of various regions of the brain in response to specific cognitive activity (working memory) & environmental events. Working memory is in the prefrontal cortex; long-term memory is in the hippocampus.
PET (Positron Emission Tomography) & fMRI
- fMRIs measure glucose consumption: more = more active neurons
- fMRIs can pinpoint specific areas associated with specific task

Question 9

Canli et al.

Answer 9

> Used an fMRI to scan brains of people as they looked at 20 negative images & 20 neutral images
Found that neuroticism was correlated with increased frontal brain activation in response to negative images
Those high in neuroticism produce more brain activation from tasks provoking anxiety or fear.

Question 10

Izuma, Saito & Sadato

Answer 10

Persons with higher self-esteem showed more activation in their brain rewad centers while looking at themselves than persons lower in self-esteem

Question 11

Brain Structure

Answer 11

Instead of measuring how active a region is, MRIs can be used to measure the volume or thickness of various brain areas
DeYoung et al.
> Used the Big 5 Model for predictions for which areas of the brain would be responsible for making behaviours relavant to each trait
> Evidence for certain brain regions being associated with certain traits
eg: Extraversion & the medial orbitofrontal cortex (processing reward info). Neuroticism & regions associated with threat & punishment. Conscientiousness correlated with having a thicker cortex across several regions.

Question 12

Brain Connections

Answer 12

> Personality correlates may be found in the strength of connections between brain areas
eg: some may have more of a connection between reason and emotion
Openness to Experience show more total connectivity & communication among all regions (creative, imaginative
Conscientiousness is correlated to more connectivity (planning, prioritizing)
**Correlation does not mean causation: Does not prove that the stronger connections cause the trait, or that the trait causes more connections

Question 13

Brain Electrical Activity

Answer 13

EEG (electroencephalogram) measures electricity in the brain via electrodes
> People with a predisposition for positivity and up-beat display more left brain activation, and negativity and pessimistic display more right brain
The Evoked Potential Technique: EEG is measured and the participant is given a stimulus, like a flash of light, and they must measure the brain’s responsiveness to that stimulus
> Extraversion and Sensation Seeking are related to diminished reactivity and diminished evoked potentials

Question 14

Saliva

Answer 14

an indicator of the functionality of the immune system (the immune system’s quality of functioning goes up & down with stress & emotions; therefore may relate to personality)

Question 15

Hormones

Answer 15

testosterone (aggressive, risk-taking patterns), cortisol (from noradrenaline, MAO (regulate neurotransmitters)

Question 16

Eysenck’s Theory

Answer 16

> Introverts have higher levels of activity in the brain’s ARAS; ascending reticular activating system than Extraverts

> Introverts and Extraverts are just maintaining their optimal level of arousal

ARAS: Structure in the brain stem thought to control overall cortical arousal: what Eysenck originally thought was responsible for differences between I & Es.

• Thought of as a gateway through which nervous stimulation entered the cortex
• If the gate was somewhat closed, resting arousal of the cortex would be lower
  > Introverts have higher resting levels of cortical arousal because their ARAS lets in too much stimulation.
  They engage in introverted behaviours because they need to keep their already heightened levels in check. Conversely, extraverts engage in more extraverted behaviours because they need to increase their level of arousal.
  > Eysenck also incorporated Hebb’s notion of “optimal level of arousal”, meaning a level that is just right for any given task (eg. going to a final exam tired is not optimal)
  If introverts have a higher baseline (at rest) of arousal than extraverts, then introverts are above their optimal level of arousal more often than extraverts.

Question 17

Eysenck’s Revised Theory

Answer 17

> The fact that extroverts are not different at resting levels but ARE under different moderate levels of stimulation led him to revise his arousal theory.
Evidence now suggests the difference between them lie in their arousability (arousal response), not their baseline arousal level.
They don’t differ in brain activity when sleeping for example, but when presented with stimulation, introverts show enhanced physiological reactivity

Question 18

Research Surrounding Eysenck’s Theory

Answer 18

> Extraverts push a button at a higher rate when the button produces changes in visual environments
Studying in a noisy room scored as more extroverted than quieter rooms
Extraverts choose a louder level than introverts
Performance declined if in the wrong environments (supports optimal stimulation and its differences

Question 19

Reinforcement Sensitivity Theory (Gray)

Answer 19

> People differ in the relative sensitivity of the responsive to reward and responsive to punishment systems of the brain
Being more sensitive to reward means being more vulnerable to positive emotions approaching stimuli. **Responsible for impulsivity.*
Being more sensitive to punishment or frustration are vulnerable to unpleasant emotions. Responsible for anxiety.
There should be varying degrees of sensitivity to punishment and reward.
- There is some evidence that two forms of learning are under separate neural control, and it appears likely that different brain mechanisms may be involved when a person or an animal learns through reinforcement or punishment
Thus, there should be people with varying degrees of sensitivity to punishment and reward
Impulsive people have a stronger approach than avoidance and are less able to stop approach behaviour especially when met with desirable reward
Impulsive people do not learn well from punishment because they have a weak behavioural inhibition system

Question 20

Behavioural Activation System

Answer 20

1. (dopamine): when recognizing stimulus as rewarding, triggers approach-oriented behaviour.
   - Also for creating pleasurable emotions, optimism and impulsiveness

Question 21

Behavioural Inhibition System

Answer 21

(serotonin): resolves conflict between BAS and FFFS. activation is anxiety and rumination to assess the risk

Question 22

Hebb’s Theory of Optimal Level of Arousal

Answer 22

> People are motivated to reach the optimal level
Controversial because researchers thought tension reduction was the goal of all motives yet he says we are motivated to seek out tension

Question 23

Sensation Seeking

Answer 23

1. Thrill and adventure seeking, physical risk
2. Experience Seeking: unusual experiences, travel, wild parties, unusual friends
3. Disinhibition: Drinking, rec. drug use, sexual experimentation, gambling
4. Susceptibility to boredom: low tolerance for routine, repetition

Question 24

Zuckerman’s Research

Answer 24

> Some were not as distressed as others by sensory deprivation
Sensation-Seeking Scale Findings
Low sensation seekers were able to tolerate it for longer
Notice Eysenck offered a similar explanation for extraversion: showing a correlation between extraversion and sensation seeking.
Neurotransmitters
- High sensation seekers have low MAO (breaks it down), could be maintained by having high levels of neurotransmitters in the system
Personality & Neurotransmitters
Dopamine: pleasure, like a reward system
Serotonin: SSRI inhibit the reuptake of it leaving it in the synapse longer. Low serotonin is associated with irritable behaviour
Norepinephrine: Activates fight or flight

Question 25

Tridimensional Personality Model

Answer 25

Novelty seeking → low dopamine
Harm avoidance → serotonin
- low levels associated with risk of depression
- SSRIs lead to decreased vulnerability to overreact to stress by down-regulating sensitivity to serotonin
Reward dependence → low norepinephrine

Question 26

Brain Asymmetry and Affective Style

Answer 26

• Left hemisphere is more active when experiencing pleasant emotions
• Crying kids separated from parents have more right-brain activation with stability over time
  Individual differences in frontal brain asymmetry exhibit enough stability and consistency to be considered as indicative of an underlying biological disposition
  > Monkeys with greater right-sided activation had higher levels of cortisol. Identical results have been found with 6-month-old children. These researchers induced fear in the infants by having a male stranger enter the room, slowly approach the infant, and stare at the infant for two minutes. Those infants who had greater right-sided activation at baseline showed increased cortisol responses to the stranger. Also, those infants who showed the most right-sided activation during the stranger approach phase also displayed more crying and facial expressions of fear, and tried to escape more, compared to infants with less right-sided activation

Question 27

High T Males:

Answer 27

Less likely to marry, more divorce, less friendly smiles, more dominant gazes

Question 28

The Addicted Brain

Answer 28

1. Endorphins are natural opiates that regulate pain and produce euphoria
2. The leader vernets have 2 times the amount of serotonin but if removed as leader can decrease by half. If promoted, can develop 2x the amount. UCLA dominant students show similar findings
3. OCD is characterized by low serotonin
4. Beta-Phenylethylamine is responsible for romantic rushes in new relationships
5. MAO causes more thrill seeking. Cells in the brain can be operantly conditioned by drugs. Drugs trigger highs, they don’t contain them