PET brain scans reveal that introverts have more activity in the frontal lobes of the brain and anterior, or front, thalamus.
Extroverts exhibit more activity in the anterior cingulate gyrus, temporal lobes and posterior thalamus.
The differences in cognitive style and sensory-processing relate to the qualities associated with introversion and extroversion. True introverts are quiet, inwardly focused and reclusive. Extroverts are gregarious, socially active and sensation seeking.
"Introverts get more of their stimulation internally, whereas extroverts seek outside sources," Johnson said. "Extremely introverted and extroverted personalities are two ends of a continuum, with most people falling somewhere in between.
There is no case for this after Eysenck it is better to classify as E ... I ... and normal.
E cannot be I and viceversa. Again after Eysenck; I manages sodium amytal and alcohol better: E does not
Notice the effect of anxiety: E reacts at once and has it out ; I takes it's time and hides away.
Ina phase of Affective illness, poor old E will present as 'hysteric' where as I will be agitated and slowed down.
E-mail reaction is welcome