personality and the brain (the big 5)

Question 1

Neural correlations of extraversion (the brain and extraversion)

Answer 1

Fmri studies found extraversion associated with neural activation in response to pleasant stimuli in dopaminergic neurons and other brain regions in the reward network

Effects of manipulating dopamine pharmacologically are moderated by extraversion, such that extraverts responded with more positive affect in response to stimuli previously paired with dopamine drug experience

Extraversion was also found to be positively related to volume of medial OFC (mOFC; a cortical region involved in monitoring the reward value of stimuli), as well as glucose metabolism in mOFC while at rest

Question 2

Neural correlations of neuroticism (the brain and neuroticism)

Answer 2

The brain structure most frequently linked to neuroticism is the amygdala, which modulates attention and arouses the sympathetic nervous system in response to danger signal

All the systems implicated in neuroticism are modulated by serotonin, and pharmacologically modulating serotonin level was found to result in decline in neuroticism. However, the actual relationship between serotonin and neuroticism seems complex

Question 3

Neural correlations of openness (the brain and openness)

Answer 3

Openness is linked to individual differences in dopamine function

Research has found that – whereas extraversion is associated with encoding of stimulus value, and functional connectivity between dopaminergic neurons and the nucleus accumbens and caudate nucleus – openness was correlated with encoding of stimulus salience, and functional connectivity between dopaminergic neurons and dlPFC

In addition, openness is linked to the default network, is a set of brain regions that are more active during rest and is thought to be responsible for self-generate thoughts

Question 4

Neural correlations of conscientiousness

Answer 4

Structural MRI studies have found positive associations of conscientiousness with the volume of regions in dlPFC

It can be attributed to the fact that dlPFC is one of the regions of the goal priority network, which is thought to play a role in determining the priority of goals and reorienting attention away from distractors and toward goal-relevant stimuli

And conscientiousness was positively associated with functional connectivity in this goal priority network

Conscientiousness may be linked to serotonin, but extant evidence is inconclusive

Question 5

Neural correlations and agreeableness

Answer 5

Much of the relevant neuroscience research comes from the study of empathy, which involves mentalizing (understanding others’ perspectives) and mirroring (feeling others’ emotions)

Mentalizing was found to primarily involve the default network, whereas mirroring for emotion primarily involves the insula and regions of midcingulate cortex.

In an fMRI study, agreeable participants showed increased neural activities in the reward circuits knowing that a charity received a payment compared with that they received payment themselves

Agreeableness is related negatively to testosterone, & positively with serotonin