Eysencks PEN model and Greys

Question 1

Biological basis extraversion

Answer 1

• The Ascending Reticular Activating System (ARAS) is a structure at the top of the brainstem that is connected to the thalamus, the hypothalamus and the cortex
  The ARAS acts as a gate and controls the overall level of arousal in the cortex
• People low in extraversion (i.e., introverts) display higher levels of activity in the ARAS (i.e., too much arousal is let in), which causes them to seek situations with low stimulation
  People high in extraversion, on the other hand, display lower levels of activity in the ARAS (i.e., too little arousal is let in), which causes them to seek situations with high stimulation

Question 2

Support for Extraversion

Answer 2

• Although Eysenck originally predicted differences at base level, he later revised his theory and predicted differences in reactivity

Introverts showed greater cortical arousal than extraverts in 22 out of 33 EEG studies (Gale, 1983).

Question 3

Neurotics opposite

Answer 3

Emotionally stable

Question 4

Biological basis of Neuroticism

Answer 4

According to Eysenck, some people have a more responsive sympathetic nervous system

The Autonomic Nervous System (ANS), of which the sympathetic nervous system is a part, controls emotional responsiveness to emergencies and prepares us to either flight or fight when there is a threatening situation

These responses are (more or less) involuntary
People high in neuroticism display hypersensitivity in the ANS

Question 5

Support for Neuroticism

Answer 5

• Eysenck predicted that neurotics would react more strongly to potentially threatening situations

Neurotics also display more cardiovascular reactivity after recalling an event from the last six months in which a person had made them very angry than after doing mental arithmetic task (Jonassaint et al., 2009)

Question 6

Psychopaths opposite

Answer 6

Sociable

Question 7

Psychoticism skew

Answer 7

positively skewed distribution (i.e., most people low psychoticism, few people medium or high psychoticism) - quite rare

Question 8

Support for Psychoticism

Answer 8

• Miskovic and Schmidt (2010) examined how much attention participants paid to happy, neutral and angry faces and found that people who were high in Psychoticism were less likely to look at angry faces than people who were low in Psychoticism - look at neutral faces. - shows not good with social cues
  Surprisingly, no effects of Extraversion and Neuroticism

Question 9

Scale’s internal consistency

Answer 9

• To what extent do all items of one scale measure the same construct?
  
  • The answer on N1 should be similar to the answers on N2 and N3
• Eysenck et al. (1985) reported “good” internal consistency for Extraversion (α = .84 and .88) and Neuroticism (α = .80 and .84)

but “questionable” internal consistency for Psychoticism (α = .61 and .62)

* Lying had “acceptable” internal consistency (α = .73 and .77)

Question 10

Measurement of the P-E-N model

Answer 10

The Short-Scale EPQ-R consists of 48 questions that have to be answered with simple yes-or-no responses (Eysenck, Eysenck & Barrett, 1985)

• Besides 12 items for each domain, the questionnaire also has a scale (called Lie) with 12 items which measure whether the questionnaire has been answered truthfully (i.e., social desirability)

Question 11

Negatives for PEN model

Answer 11

• There was less support for the existence of Psychoticism as a trait
  
  • Psychoticism might be two traits: Agreeableness and Conscientiousness
• findings from structural neuroimaging studies did not support the P-E-N model
• These studies reported structural differences in brain areas outside the ARAS or the limbic system

Question 12

Grey’s model overall meaning

Answer 12

• Some people might be more sensitive to positive reinforcements and tend to seek rewards and positive experiences
  
  • They will learn faster when they are offered pleasant stimuli

Other people might be more sensitive to negative reinforcements and tend to avoid punishment and negative experiences
* They will learn faster when there are aversive stimuli

However, these processes are not opposites, they are independent
* Orthogonal
* Some people might be sensitive to both rewards and punishments

Question 13

Gray’s original RST (Gray, 1982)

Answer 13

1. Behavioural Activation System (BAS)
   * Sensitivity to rewards and pleasant stimuli
   * Approach and Impulsivity
   * Dopamine
   
   2. Behavioural Inhibition System (BIS)
      
      • Sensitivity to punishment and aversive stimuli
      • Avoidance and Anxiety
      • Norandrenaline and serotonin
   3. Fight-Flight System (FFS) – (added later and role revised over time)
      
      • Unconditioned Responses and Fear
        Sympathetic nervous system

Question 14

Gray’s revised RST (Gray & McNaughton, 2000)

Answer 14

• Gray proposed three independent systems:
  
  1. Behavioural Activation System (BAS)
     
     • Largely unchanged from original model
     • Sensitive to conditioned and unconditioned responses to reward
  2. Fight-Flight-Freeze System (FFFS)
     
     • Sensitive to conditioned and unconditioned stimuli
     • Emotion – fear
  3. Behavioural Inhibition System (BIS)
     
     • Conflict resolution between FFFS and BAS
     • Emotion - worry
• modulates anxiety, weighs up risks in reasonable way to decide best course of action

Question 15

Relationship between the two traits

Answer 15

High BAS - high impulsivity, high E & little high in N
High BIS - high anxiety, high N & Low E

High susceptibility to punishment - introverted
High susceptibility to reward - extraverted

Question 16

Greys measurement

Answer 16

• BAS – Impulsivity (three subscales)
• Reward Responsiveness (α = .73):
  “When I get something I want, I feel excited and energized”
• Drive (α = .76):
  
  • “I go out of my way to get things I want”
• Fun Seeking (α = .66):
  
  • “I crave excitement and new sensations”
• BIS – Anxiety (α = .74)
  “If I think something unpleasant is going to happen, I usually get pretty worked up”

No separate FFFS scale, but some items from BIS seem to tap also into fear rather than only anxiety

Question 17

1. Hereditary or genetic contributions

Answer 17

Plomin et al. (1994): Heritability was 51% for Extraversion and 46% for Neuroticism, but Psychoticism was not measured

Eaves et al. (1999): Heritability was around 40% for Extraversion and around 30% for Neuroticism but only around 20% for Psychoticism

Keller et al. (2005): Heritability for Extraversion and Neuroticism was around 50% but for Psychoticism only around 40%

Whisman et al. (2011) found that people with one or two copies of the short allele (S’S’ or S’L’) had higher BIS scores (but not higher BAS scores) than people with two copies of the long allele (L’L’)

Question 18

2. Physiological substrates: Extraversion

Answer 18

Extraversion is negatively correlated with cortical thickness in the lateral prefrontal cortex (Wright, 2006)

Neuroticism is negatively correlated with cortical thickness in the orbitofrontal cortex (OFC), but this did not remain significant after controlling for gender (Wright et al, 2006)

• Extraversion is correlated with greater volume in the medial orbitofrontal cortex (DeYoung et al., 2010)
• Fuentes et al. (2012)
• Correlations between BIS scores and reductions in the volume of the right and medial orbitofrontal cortex and the precuneus
  No correlations between BIS scores and the volumes of the amygdala and the hippocampus

Question 19

Temporal stability

Answer 19

• Costa and McCrae (1994) conducted a meta-analysis regarding the temporal stability of personality traits

Extraversion was stable median correlation .64

Neuroticism was also stable median correlation .64

Time periods ranging from 6 to 30 years

Costa and McCrae did not examine Psychoticism, but less stability generally reported trait

• Carver and White (1994) found that the test-retest reliability of the BAS-BIS questionnaires after eight weeks ranged between .59 and .69, which is “acceptable” (but not “good”)

Question 20

Cross-cultural evidence

Answer 20

• Barrett, Petrides, Eysenck and Eysenck (1998) examined the EPQ-R in 34 countries and calculated whether the distribution of the items across the four domains (P-E-N-L) was similar

Question 21

RST Critiques

Answer 21

Lack of theoretical integration of the two motivational sensitivities with relevant cognitive mechanisms, such as attention and memory.

The independence of the two BIS and BAS systems – unlikely in humans that one system completely inhibits the other (Corr, 2001).

Does not explain the sociability element that is captured by extraversion.