To investigate the neuro-biological bases of introversion-extraversion personality traits, the concentration of four neurochemicals (Cho, mI, α-Glx and NAA) in anterior cigulate gyrus between normal extroverts and introverts were examined using non-invasive 1H MRS technique. Our study revealed that introverts have significantly higher level of α-Glx, Cho and mI in the anterior cingulate gyrus than extroverts. This result provides new evidence that the anterior cingulate gyrus is related to personality traits partly in support of Eysenck's supposition that introverts have higher arousal level than extroverts. Moreover, this result offers neurochemical data for psychobiological theories of personality.
- H MRS