P300 and Introverted/Extraverted Personality Types


  • This paper was based on the first author's undergraduate Honor's Thesis at the Department of Psychology, University of California, San Diego. We thank Dr. Ben Williams for his administrative support and Drs. Don MacLeod and Jeff Miller for comments. The constructive comments of the reviewers are gratefully acknowledged. This work was supported by NIAAA grant AA06420 and is publication 6024NP from the Research Institute of Scripps Clinic. G. DiTraglia is now at the Department of Psychology, University of Arizona, Tucson, Arizona.

Address requests for reprints to: J. Polich, Department of Neuropharmacology (BCR1), Scripps Clinic and Research Foundation, 10666 N. Torrey Pines Road, LaJolla, California 92037.


The P300 component of the event-related potential elicited with a two-tone auditory discrimination task and two-trial block replication procedure was obtained from 16 introverted and 16 extraverted undergraduate students. P300 demonstrated no overall significant effects for either the personality variable or the block variable. However, P300 amplitude to the target stimuli declined significantly between Block 1 and Block 2 for the extraverted subjects, but did not change across trial blocks for the introverted group. Female subjects tended to have larger P3 amplitudes than male subjects, but this factor did not interact with either the personality variable or the trial block variable. The results suggest that P3 amplitude habituates more rapidly for extraverts than for introverts.