PEN model RST model Flashcards
Eysenck’s theory assumes that there are three personality domains:
Psychoticism (P)
Extraversion (E)
Neuroticism (N)
Describe the entire population (not just clinical)
Domains are orthogonal (statistical independence)
Being highly extraverted does not make you more or less neurotic
What did Eysenck argue is the 4 sources of support for Eysenck’s Psychoticism-Extraversion-Neuroticism
(P-E-N)theory?
Psychometric evidence
Biological basis
Theoretically plausible
Predictive of social issues
Which trait prefers to spend time alone and predictable contexts and are quiet and well-ordered?
Introvert
Which trait prefers excitement and stimulation, the company of others, are talkative, outgoing and externally driven, and like parties and friends?
Extraversion
Introduce two theories of personality:
What are the main theories
Eysenck’s Psychoticism-Extraversion-Neuroticism (P-E-N)
Gray’s Reinforcement-Sensitivity Theory (RST)
Which trait is emotionally unstable, anxious, fearful, tense, moody, irritable, depressed, poor sleep, slow to return to ‘even keel’ after stressful event?
Neurotic
Which trait is considered even-tempered, quick to return to equilibrium after stressful event, calm, slow to react emotionally?
Emotionally stable
Which trait is seen as aggressive, cold, and lack empathy (all negative facets, except creativity)?
Psychotic
Which trait is seen to be selfish, sympathetic, cooperative, and conventional?
Sociable
According to Eysenck, people high in neuroticism display hypersensitivity in the what?
Hypersensitivity in the SNS, which causes them to react more strongly to potentially threatening situations.
Biological basis of P-E-N: Neuroticism:
Limbic System: Neuroticism
Role of the Limbic System?
Regulates the sympathetic nervous system (SNS)
part of the autonomic nervous system (ANS)
produces involuntary responses
“Fight or Flight” response to threatening situations
remains constantly active at a basic level to maintain homeostasis
Which part of the brain has networks of nuclei located in the brainstem? Includes ascending pathways to the cortex (ARAS) and descending pathways to the spinal chord?
Reticular Formation & ARAS
Which area is the outmost layer of the brain, contains sensory, motor, and association areas?
Cortex
True or False:
Personality traits reflect individual differences in brain structure / function
True
Which region in the brain is a deep brain structure
eg. hippocampus/ amygdala.
Involved in emotional processing and homeostasis?
Limbic System
Biological basis of P-E-N: Systems:
Mapping brain circuits to traits
What are the 2 arousal systems?
Reticulo–cortical circuit: Extraversion
(how we encounter stimuli)
Limbic system: Neuroticism
(how we react to them)
Name the key regions of the brain involved in personality
Reticular Formation & ARAS
Cortex
Limbic system
Arousal system:
Reticulo–cortical circuit: Extraversion
Controls the cortical arousal generated by incoming stimuli.
Which arousal system is typically more aroused in introverts than extroverts?
Arousal system:
Reticulo–cortical circuit: Extraversion
Arousal system:
Limbic system: Neuroticism
Controls response to emotional stimuli.
Which arousal system is more aroused in neurotic individuals when facing emotion-inducing stimulation?
Limbic system: Neuroticism
Biological basis of P-E-N :
Describe the process of the Reticulo–cortical circuit: Extraversion
The Ascending Reticular Activating System (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.
Biological basis of P-E-N: Extraversion
Reticulo–cortical circuit: Extraversion
Performance and Arousal
Relationship = inverted U-shape:
Performance improves as arousal increases,
but it deteriorates when arousal levels become too high
Arousal = this optimal level,
can be different for different tasks and for different people
Increased activation of the limbic system is then needed to?
Regulate their response
Biological basis of P-E-N: Psychoticism
In the original model: Underspecified biological basis, possibly related to regulation of serotonin or dopamine. Might also be related to sex hormones
In recent decades…
The amygdala as a key component in predominant models of psychopathy.
The amygdala is “the brain’s fear centre”, and psychopathy, thought to be characterised by extremely low fear, is mainly due to amygdala dysfunction.
So some dysfunction to the amydgala could = psychoticism
Measurement of P-E-N: Questionnaires
Eysenck developed a questionnaire to measure the three domains
Several versions have appeared: EPI, EPQ, EPQ-R, Short-Scale EPQ-R
What does this involve?
The Short-Scale EPQ-R consists of 48 questions that have to be answered with simple yes-or-no responses:
Does your mood often go up and down? (N)
Do you take much notice of what people think? (P)
Are you a talkative person? (E)
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)
If you say you will do something, do you always keep your promise no matter how inconvenient it might be? (L)
Measurement of P-E-N: Evaluation
What would you expect?
Reliability across repetition
High similarity within scales
(Internal consistency; Cronbach’s alpha) :
To what extent do all items of one scale measure the same construct?
The answer for N1 should be similar to the answers for N2 and N3
Low similarity between scales (orthogonal)
ie - low between neuroticism and extraversion
To what extent do the scales correlate with each other?
The answer for N1 should be different from E1
Measurement of P-E-N: Evaluation
What would you find?
Within scales: Eysenck reported “good” internal consistency
for Extraversion and Neuroticism (.85)
but “questionable” internal consistency for
Psychoticism
(α = ~.6).
Between scales: The three scales were orthogonal:
did not correlate with each other (rs ≤ .14)
Which theory argued differences in personality rely on the extent to which people respond to rewards and punishment?
Gray’s Reinforcement Sensitivity Theory (RST)
Gray’s Reinforcement Sensitivity Theory (RST)
What are the key principles?
Some people are highly sensitive to positive reinforcements and tend to seek rewards and positive experiences
They will learn faster when they are offered pleasant stimuli
Some people are highly sensitive to negative reinforcements and tend to avoid punishment and negative experiences
They will learn faster when there are aversive stimuli
What is special about Gray’s Reinforcement Sensitivity Theory (RST) processes of responding to positive and negative reinforcement?
However, these processes are not opposites, they are independent
Orthogonal
Some people might be sensitive to both rewards and punishments
Gray’s RST (Gray, 1982): Gray proposed three independent systems
What are the 3 different components?
Components:
Behavioural Activation System (BAS)
Behavioural Inhibition System (BIS)
Fight-Flight System (FFS) – (added later and role revised over time)
Unconditioned Responses and Fear
Biological Bases
For BAS: Dopamine (but generally under-specified)
For BIS: Septo-hippocampal pathway
For FFS: Sympathetic nervous system (SNS)
Gray’s RST (Gray, 1982):
Which system is sensitive to rewards and pleasant stimuli
Produces behaviours like approach and Impulsivity
Mediated by dopamine
Behavioural Activation System (BAS)
Gray’s RST (Gray, 1982):
Which system is sensitive to punishment and aversive stimuli
Produces behaviours like Avoidance and Anxiety
Mediated by norandrenaline and serotonin
Behavioural Inhibition System (BIS)
Gray’s RST (Gray, 1982):
Which system
Unconditioned Responses and Fear
Fight-Flight System (FFS) – (added later and role revised over time)
Gray proposed impulsivity / anxiety as alternative to E and N at 30-degree rotation:
The more anxious someone is (introverted neurotic),
the more they will respond/ learn better to punishment
The more impulsive someone is (extroverted neurotic)
the more they will respond/ learn better to reward
Carver & White (1994): BAS/BIS questionnaire
What were the 3 subscales?
BAS/BIS= completely orthogonal ( - correlation that measures completely different things)
1) Reward Responsiveness:
“When I get something I want, I feel excited and energized”
“When good things happen to me, it affects me strongly”
2) Drive:
“I go out of my way to get things I want”
“When I see an opportunity for something I like, I get excited right away”
3) Fun Seeking:
“I crave excitement and new sensations”
“I often act on the spur of the moment”
The 3 Systems Revision by Gray & McNaughton (2000) was modified:
Behavioural Activation System (BAS)
Largely unchanged from original model
Sensitive to conditioned and unconditioned responses to reward
Fight-Flight-Freeze System (FFFS)
freeze response in addition to f/ f
Global avoidance and escape system in threatening situations
Sensitive to conditioned and unconditioned stimuli
Associated with fear
Behavioural Inhibition System (BIS)
Conflict resolution between FFFS and BAS
Emotion – worry
Do the traits described by the models have a biological basis?
Name the 4 types of evidence:
Temporal stability
Similarity across species
Cross-cultural evidence
Hereditary or genetic contributions
Evaluation: Similarity across species (P-E-N)
A review of 19 studies that had examined the presence of Extraversion and Neuroticism (and other domains) in 12 animal species
Based on the Big 5 Theory
=
Many but not all species displayed extravert and neurotic behaviour
Gray (1970) showed that rats have separate systems controlling their behaviour in reaction to the presence of rewarding and punishing stimuli
Evaluation: Similarity across species (P-E-N)
To improve the quality of research into personality traits among non-human animals, one can examine?
Inter-rater reliability:
Does Rater A agree with Rater B that Animal A is an extravert and Animal B is an introvert?
Test-retest reliability: Does Animal A display extrovert behaviour and does Animal B display introvert behaviour at Time 1 and Time 2?
However, some concerns remain due to some personality traits/ animals being harder to observe. If a trait is suspected to have a biological basis, then we can expect to see it across all cultures/ species
Evaluation: Heredity/Genetics
D. Hereditary or genetic contributions: Behavioral genetics
Identify genetic influences by comparing traits in biologically and nonbiologically related family members
Evidence for:
Plomin et al. (1994): Heritability accounts for
51% for Extraversion and 46% for Neuroticism,
but Psychoticism was not measured
Which type of study involves associations between genetic variation within genes of interest selected a-priori and specific traits?
Candidate Gene Studies
Candidate Gene Studies
Genes are selected based on known (or hypothesised) relevance to the trait in question.
What were the early findings?
Variation in the serotonin transporter gene 5HTT, which is responsible for re-uptake of 5-HT from synapses, was associated with neuroticism (Schinka et al. 2004; Sen et al. 2004) and with BIS scores (Whisman, Richardson and Smolen, 2011)
Candidate Gene Studies
Genes are selected based on known (or hypothesised) relevance to the trait in question.
What association was found?
Found associations between DNA blocks (called “SNPs”)
in the D4 dopamine receptor (DRD4) gene
and extraversion seeking
Candidate Gene Studies
Genes are selected based on known (or hypothesised) relevance to the trait in question.
Variation in the serotonin transporter gene 5HTT, which is responsible for re-uptake of 5-HT from synapses, was associated with
neuroticism and with BIS scores
Candidate Gene Studies
Genes are selected based on known (or hypothesised) relevance to the trait in question.
Which interaction was related to the BAS Scores?
Interactions between two gene loci that are related to the activity of the dopamine system were related to BAS scores
Hereditary or genetic contributions: Molecular genetics:
What is a problem for the Candidate Gene Studies which showed support of genes influencing personality?
Many of these finding were not replicated
Most traits are polygenic, i.e., influenced by multiple genes
Hereditary or genetic contributions: Molecular genetics
Identify genes that are associated with specific traits
What are Genome-wide association studies?
Interrogate hundreds of thousands to millions of SNPs across the entire genome not just one gene.
(eg. allows investigation of polygenic genes)
Without assuming any prior knowledge about the underlying biology associated with the trait.
- You get a manhattan plot
Name an issue with the Manhatten Plot concerning
Genome-wide association studies:
Because the method entails MANY comparisons
(across all DNA blocks), a correction to avoid type I error is applied (eg. Bonferroni correction)
This sets a very high threshold for significant results.
Therefore, significant results can only be obtained in very large samples (N>5000) and often only across multiple cohorts (with Meta-analysis)
What trait is the most well studied in Psychology?
Neuroticism
Which personality trait is highly expressed in post-mortem brains of complete suicides?
Neuroticism
Which personality trait is suggested to regulate release of cortisol and is involved in anxiety-like behaviours?
Neuroticism
Evaluation: Physiological/ Neural substrates
Structural brain measures (MRI, PET)
Measuring and analysing the anatomical properties of the brain.
Volume: also includes the surface area.
Gyrification: the folding of the cortex.
These structural measures then can be linked to specific traits/ behaviours
When measuring cortical thickness to look at the neuroanatomical correlates of extraversion and neuroticism, they found…
(Cortical thickness: gray matter between the pial and white surface.)
Evaluation: Neural substrates
Wright et al. (2006) in the context of P-E-N:
The findings suggest that variation in regional cortical thickness may have behavioural significance for the expression of extraversion.
But:
But:
The hypothesised relations between neuroticism and the limbic system were not confirmed.
Decreased thickness (or volume) is not necessarily related to reduced activation in a particular region.
Additional “general” caveats: sample size, reliability of measures, gender distribution
Evaluation: Physiological \ Neural substrates
Functional brain measures (fMRI, EEG, MEG…)
Measuring and analysing the functional properties of the brain.
During rest – while the participants are not engaged in any particular task
During task – while the participants perform a task that is relevant to the trait that is being evaluated.
Barrós-Loscertales et al. (2010) used fMRI to look at the association between BAS scores and brain activation during tasks. What were the materials used?
Letter discrimination task: is the letter a vowel?
Letters are superimposed on a background image that is either neutral, appetitive (erotic), or aversive (murdered people, human threat, etc.)
Sensitivity to Reward scale (SR): measures individual differences in attraction to positive stimuli
Barrós-Loscertales et al. (2010) used fMRI to look at the association between BAS scores and brain activation during tasks.
What were the Hypotheses (based on original RST theory, but also on previous findings)?
Appetitive pictures would activate BAS-related regions
(i.e. the striatum, the OFC and the mPFC),
and regions known to modulate the action of the BAS
(i.e. the lateral prefrontal and occipital cortices).
These activations would correlate positively with SR scores.
Aversive pictures would activate the BIS-FFFS structures
(i.e. hippocampal formation and the amygdala),
as well as regions known to modulate the action of the BIS-FFFS (i.e. the lateral prefrontal and occipital cortices).
These activations would correlate negatively with SR scores.
Barrós-Loscertales et al. (2010) used fMRI to look at the association between BAS scores and brain activation during tasks.
What were the findings?
The erotic picture condition activated regions related to the BAS (substantia nigra, caudate, putamen, nucleus accumbens, MPFC, and OFC). In some of these regions (MPFC), activation positively correlated with SR scores.
The aversive picture condition activated regions within the limbic system related to BIS (amygdala, hippocampus, and posterior and anterior cingulates). Activation in these regions did not correlate with SR scores.
Regions in the frontal lobes were activated during both the erotic and aversive picture conditions.
Functional brain measures
Barrós-Loscertales et al. (2010) used fMRI to look at the association between BAS scores and brain activation.
In the context of RST / previous findings
are the findings consistent?
In the context of RST / previous findings:
Findings are consistent with previous results (showing activation in similar brain regions), but not necessarily with the original theory.
For aversive stimuli, lack of correlation between activations and SR scores might indicate “state” rather than “trait”.
General/methodological evaluation:
Male only sample
Incidental task
Eysenck proposed a theory which attempted to explain how differences in personality can be caused by differences in physiology
Some findings (measurement, validity) offer support for the existence of Extraversion and Neuroticism as traits
Other findings (temporal stability, animal behaviour, cross cultural comparisons) offer support for the biological basis of Extraversion and Neuroticism
However, these findings do not necessarily support the P-E-N model
Different neural mechanisms than those proposed by the theory.
Other theories, such as the Five-Factor and the Big-Five model, also include Extraversion and Neuroticism and might explain the findings better.
There was less support for the existence of Psychoticism as a trait
Psychoticism might be two traits: Agreeableness and Conscientiousness
What is this an evaluation summary for?
Evaluation: Summary (P-E-N)
Good empirical support demonstrating the biological basis of the RST.
Different neural mechanisms than those proposed by the theory
Although the revised version of the RST (Gray & McNaughton, 2000) has addressed some earlier criticism (Matthews & Gilliland, 1999), the theory is still criticised for
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.
What is this an evaluation summary for?
Evaluation: Summary (RST)
keep going babe
you can do it lmao
