REGIONAL CEREBRAL BLOOD-FLOW AND EXTROVERSION

Regional cerebral blood flow (rCBF) was examined in a group, of 17 sub jects (8 men, 9 women, ages 22-35 years) at rest and during three ment al activations, inducing perceptual and spatial processing. The subjec ts completed two personality questionnaires, the Eysenck Personality I nventory and the Karolinska Scales of Personality (KSP). The aim of th e study was to examine the relation between rCBF and the extraversion- introversion dimension. Earlier studies of rCBF at rest have found hig her blood flow in the temporal lobes for introverts than for extravert s, and a negative correlation between extraversion and global CBF amon g women. Both findings were confirmed in this group. The importance of related personality dimensions, such as impulsivity and anxiety, for rCBF differences between extraverts and introverts were examined, usin g scales from the KSP questionnaire. It was found that anxiety-pronene ss aspects of introversion were more important in determining high tem poral blood flow than low-impulsivity aspects. Global CBF in women, as a measure of general arousal, was mainly related to the sensation-see king aspects of extraversion. Results from the spatial processing task s showed more right-hemispheric activation for introverts than extrave rts in a mental rotation task.