Canli et al. ( 2001) used fMRI to study response to emotional stimuli and correlated them with personality. They found positive correlation between extraversion and increased activation to positive stimuli in the frontal and temporal lobes, and parts of the caudate, putamen, and amygdala. Similar results were found by Canli et al. (2002) where the degree of activation in the amygdala during presentation of happy stimuli correlated with extraversion.

Let us look at the boarder picture. Behaviour of an individual is under the control of executive functions. Our reaction to any stimuli involves planning, spatiotemporal segmentation and execution. It also entails self-regulation. Any given situation demands certain degree of attention, regulation of emotion and behaviour, and performance of psychomotor activity. All this are linked to the prefrontal cortex. Hence, it can be inferred that our executive functions are controlled by the prefrontal cortex. The amount of dopamine in the prefrontal cortex increases in response to stress. This, in turn, intensifies our attention towards the stressor. It is important to note that chronic stress might lead to extra amount of dopamine in the prefrontal cortex than what is functionally needed. This increase might impair the functions of the prefrontal cortex, thus leading to decreased attention, hypervigilance, and certain psychotic symptoms.

Deprivation and its psychological consequences has been a topic of interest for many psychologists. Studies of baby rats and monkeys confirm impaired executive function in those experiencing maternal deprivation. Now that we know the outcome of executive functions, we can infer the social and behavioural cost of maternal deprivation.

Adjustment of an individual is also appraised by their ability to understand and interpret behaviours of others in terms of deciphering other person's intentions and thoughts. The brain structures supposed to constitute the neural basis of this ability are amygdala and its projections to the superior temporal gyrus, thalamus, and prefrontal cortex. fMRI studies show that the superior temporal gyrus, amygdala and prefrontal cortex are involved in processing social information. Thus, they can be considered to constitute the neural basis of social intelligence.