Extraversion and Neuroticism (2)

The Reward Hypothesis (Depue & Collins, 1999)

Follow on from Gray’s Reinforcement Sensitivity Theory (RST)

• Explicitly forwarded the reward-processing view of extraversion

Localisation of RST and the Reward Hypothesis

Midbrain dopamine system

• DeYoung (2010)

FFM: Facets of Agreeableness

• Straightforwardness

• Trust

• Altruism

• Modesty

• Tendermindedness

• Compliance

Intercorrelations of Agreeableness and Extraversion

Relation to sociable and outgoing behaviours

• Agreeableness is indirectly linked to reward

The Biological Root of Reward - Intra-Cranial self-stimulation

• Rats in an operant chamber with lever

• Study the effects of reinforcing electrical brain stimulation

• Dopamine release correlates with brain stimulation

Di Ciano et al. (1995)

• Intravenous cocaine and amphetamines

• Learnt to press lever to release

• Spike in dopamine when anticipating drug release

(Remember Bio Psych module)

Mesolimbic dopamine pathway

Connects:

• Ventral Tegmental Area (VTA; midbrain area) - primary dopamine producing area

To:

• Nucleus Accumbens - processing

Mesocortical dopamine pathway

Ventral Tegmental Area (VTA) - primary dopamine-producing area

Prefrontal cortex (PFC) - processing

Reward or pleasure?

• Dopamine does not correlate directly with pleasure

• Released before the reward

• Increases by reward seeking

Knutson et al. (2001)

Ps put in a scanner and shown small or big rewards (£5 vs £20)

• Nucleus Accumbens was more active for large rewards

• Ps reported feeling more happy following large reward cue

Individual differences in self-reported happiness correlated with the size of the response observed in the mid-brain reward areas

Wu et al. (2014) Extraversion - Method

Monetary GAIN trials

1. Cue

2. Anticipation

3. Target

4. Fixation

5. Outcome

Arousal → questionnaire

Wu et al. (2014) Extraversion - Findings

• Anticipation of large monetary gains:

  • Left Nucleus Accumbens (NAcc) activity correlated significantly with the trait of Positive Arousal (~E)

• No correlation between negative arousal

Extraversion & Neuroticism - Double Dissocation Evidence

Wu et al (2014)

Two distinct/independent systems

• Positive arousal (E) → Nucleus Accumbens

• Negative arousal (N) → Anterior Insular

 

Cremers et al. (2011)

Normal Variation in Extraversion: The Medial Orbitofrontal Cortex (mOFC)

• Structural MRI

• OFC volume positively correlated with extraversion

DeYoung Cybernetic Big Five Theory’s Explanation of Extraversion

1. More motivated by the possibility of attaining a reward

2. Get more enjoyment out of a reward when attained.

Hence, he argues that:

1. The wanting of the reward (i.e. motivation) → dopaminergic activity

2. The liking (i.e. enjoyment) → the opioid system.

 

Biopsychological Mechanisms of Extraversion

Responsiveness of mid-brain (dopamine) reward systems

Wu et al. (2014) Neuroticism - Method

Monetary LOSS trials

1. Cue

2. Anticipation

3. Target

4. Fixation

5. Outcome

Arousal → questionnaire

Wu et al. (2014) Neuroticism - Findings

Anticipation of large monetary losses:

• Right Anterior Insula (rAI) correlated significantly with the trait of Negative Arousal (~N).

No correlation with positive arousal (~E)

Neuroticism - Structures of Defensive Distress System

• Amygdala

• Anterior Cingulate Cortex

• Insula

Eysenck’s Theory of Neuroticism (1967)

N is determined by the interaction of the Ascending Reticular Activating System (ARAS) with the limbic system.

The limbic system:

• Involved in the initiation of emotional activity

• Affects the sympathetic branch of the autonomic nervous system

  • Fight or flight mechanism

Activation of Sympathetic Nervous System (SNS)

• Faster heart rate

• Increased respiration

• Increased blood flow to the limbs

• Increased sweating

• Closing down of the blood supply to organs that are not involved in urgent physical activity

• Experience of unpleasant emotional feelings (fear, anxiety, anger).

Neuroticism and “Emotionality” - Eysenck

High N → tendency to extreme emotional responses to life events

Low N → appear more stoic or emotionally unmoved by the same life events

N reflects individual differences in the sensitivity of some brain system that controls the extent of these emotional reactions

Structures of the Limbic System

• Hypothalamus

• Autonomic Nervous System (ANS)

  • Sympathetic (fight or flight)

  • Parasympathetic (Amygdala)

Parasympathetic Nervous System (PNS)

1. Experience a stressful event

2. The amygdala interprets the incoming emotional information

3. The amygdala sends distress signal to the hypothalamus

Hypothalamus

Command centre

• Communicates with the rest of the body by sending/receiving signals to/from ANS

Amygdala

• Two almond-shaped regions in the brain, typically associated with the experience of fear, anxiety and aggression and emotion.

• Important for functions such as the processing of memory (particularly emotional memories) and decision-making.

• It’s the primary structure in the brain responsible for the fight-or-flight response.

Patient S.M. – “the woman with no fear”

• Reported in the literature in 1994.

• A female patient who suffers from an extremely rare genetic condition, Urbach–Wiethe disease

• Resulted in the complete bilateral amygdala destruction since late childhood.

• She is reported not to experience fear

Adolphs et al. (1994)

Patient S.M. had impaired recognition of emotional facial expression

Phan et al. (2002) & Kober et al. (2008)

Amygdala = a core structure of emotional processing

Drevets et al. (1992) & Victor et al. (2010)

Depression = exaggerated amygdala response to emotional material

Niedtfeld et el. (2010)

Borderline Personality Disorder = exaggerated amygdala response to emotional material

Goossens et al. (2007)

Phobias = exaggerated amygdala response to emotional material

Simmons et al. (2011)

PTSD = exaggerated amygdala response to emotional material

Fredrikson & Furmark (2003)

Self-reported anxiety = exaggerated amygdala response to emotional material

Triggers of Amygdala Hyper-responsivity in PTSD

• Personalised traumatic narratives and material (Shin et al., 2004; Driessen et al., 2004)

• Combat sounds and photographs (Pissiota et al., 2002; Hendler et al., 2003)

• Trauma-related words and affective material (Protopopescu et al., 2005; Shin et al., 2005)

Holmes et al. (2012)

• Neuroticism and negative affect in non-clinical populations

  • 1050 young adults, aged 18-35 years

  • ~18% reported a family history of psychiatric disorders

• Found:

  • Positive correlation between LAmygdala volume and negative affect score.

Positive and Negative Affect Schedule (PANAS-SF)

• Measures emotional traits

• Widely used instrument

• “How much does X adjective describe you”

• Derived from the lexical theory of individual differences

PANAS-SF - Extraversion

Very high correlation between positive affect (0.483)

PANAS-SF - Neuroticism

Very high correlation between negative affect (0.565)

Types of personality measures

• Explicit self-rating

• Behavioural

• Performance

• Implicit

Types of personality measures - Explicit self-rating

Self-description using personality questionnaire

Types of personality measures - Behavioural

• Spontaneous behaviour in a particular situation.

• e.g. How did you and your peers interact with one another today? Does this relate to your individual personalities?

Types of personality measures - Performance

Balloon Analogue Risk Task (BART)

• E.g. How long can you sit with a spider crawling up your arm (as a measure of Neuroticism)

Types of personality measures - Implicit

IAT (Implicit Associations Test)

Balloon Analogue Risk Task (BART) - Procedure

• Pump up 30 balloons (virtually)

• Each pump earns $0.05

• If the balloon pops, lose the money

• To keep money, collect before it pops

Ju and Wallraven (2023) - Method

Split participants into 2 groups (high and low BART scorers)

• Found that the high-score BART group included more:

  • Male participants

  • Higher sensation-seeking scorers

  • More risky decision-makers (in an emergency situation)

Ju and Wallraven (2023) - Findings

Higher risk-taking (i.e. higher BART score) significantly correlated with both sensation-seeking and risky driving behaviour.

Explicit self-rating measures - Sensation Seeking Scale (SSS-V)

Four primary scales:

• Disinhibition,

• Boredom Susceptibility,

• Thrill and Adventure Seeking,

• Experience Seeking,

(Total score)

Zuckerman’s alternative to the Five-Factor Model (2006)

Trait → Correlates with FFM traits

Sociability → Agreeableness

Neuroticism-Anxiety → Neuroticism

Impulsive Sensation Seeking → Openness to experience

Aggression-Hostility → like Psychoticism (Eysenck)

Activity → Extraversion

Friedman et al.

qIAT - Questionnaire-Based Implicit Association Task

• Reliable and valid measures of extraversion, conscientiousness