bio basis Flashcards
structural imaging studies 1 damage to dorsolateral pre frontal cortex Forbes 2014
Damage to the left DLPFC
associated with high neuroticism
and low conscientiousness
* Findings suggest that neuroticism
and conscientiousness (although
psychometrically independent
personality dimensions)
potentially rely on a common
neural structure
structural brain image 2 high neuroticism in DLPFC
High levels of
neuroticism
associated with low
cortical folding of the
left DLPFC (Schultz et
al., 2017)
Structural brain image 3 117 ppl and cortico limbic brain diff.
Structural brain images of 117 participants (Eijndhoven et al., 2017)
* Neuroticism is accompanied by cortico-limbic brain differences
* Higher neuroticism scores were predicted by thinning of the left OFC and a
smaller volume of the right amygdala
trait (Hans)
extraversion, neuroticism, psychoticism added later. Hans Eyesenck
Bio basis for traits
Effects of having high low 2 dimensions Extra and Neuroticism
High N, high E = Choleric type
High N, low E = Melancholic type
Low N, high E = Sanguine type
Low N, low E = Phlegmatic type
Position of e & N
- Position on Extraversion spectrum dependent
on cortical arousal - Position on Neuroticism spectrum dependent
on limbic system activity
extraversion and Neuroticsim and their bio effects.
- Balance of “inhibition” and “excitation” in the brain - extraversion
- Dimension that ranges from calm to nervous
- Since every individual tested fits on the dimension of normalityto-neuroticism dimension, it is a genetically-based,
physiologically-supported dimension of personality
There are individual differences in sympathetic nervous system
(fight or flight) responsivity - Individuals with sympathetic hyperactivity are candidates for
the various ‘neurotic’ disorders e.g., panic attacks - neuroticism
A03 +imaging studies
- Some sugges brain structure / function different for Extravert vs Inrovert
+ 3 behavioural studies
- introverts choose a lower level of noise than do extraverts
- extraverts take more pauses during
- repetitive tasks due to boredom
introverts require more depressant drugs
- arousal unclear
- Fear does not = sweating, trembling, have increased heart rates, increased
pupil size universally (very few show all, Kreibig, 2010)
five factor model
resting state fmri data from 810 young adults. measured activation patterns and if they can predict OCEAN;
YES: Openness, Agreeableness, Conscientiousness, Neuroticism
NO: (not Extraversion) in new participants.
Gray 1981 RST
proposed three
neurological systems as underlying
personality
* behavioral approach system (BAS)
* behavioral inhibition system (BIS)
+ instinctive Fight-Flight-Freeze (FFS)
BAS
Behavioral Approach System (BAS)
* underlying system for impulsivity
* Signals impending reward
* Triggers approach behaviour
* People with high impulsivity are highly sensitive to reward
BIS
- underlying neurological system for anxiety
- Signals punishment
- Triggers inhibition and withdrawal from threat
- people with high anxiety are highly sensitive to signals of
punishment
FFS
- underlying neurological system for response to threat
- Escape behaviour
- When is defensive behaviour triggered?
A03 Ravelle cafeine study
Revelle, moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task. - affected by time of day, early morning. Pattern reversed in evening, groups differed in the phase of their diurnal arousal rhythms. Low impulses aroused in morning and less in eve - grays theory.
Contributions to one trait
Genetics
Shared environment
Non shred environments
Types of genetic variance; additive
total effect of a trait stemming from one or more gene loci, each locus contributes to the trait in a measurable way
Types of genetic variance; dominant
some genes arent expressed but some are
Types of genetic variance; epistatic
genes and environment can interact and particular genes are expressed in certain circumstances
adoption studies
non random environment of mz twins adopted away, Mz twins raised together treated atypically, Mz twins raised together behave atypically.
pre natal environment
Separate placentas = 19% Mz and 58% DZ. fused 13% MZ 42% DZ and single is 68% MZ.
DrD4 genetic
DrD4 gene linked to dopamine and novelty seeking, impulsivity but not extraversion. Dopamine genes work in concert to explain 6.6% of variation in sensation seeking behaviours.
