Changes in N1 and P3 components of the auditory event-related potentials in extroverts and introverts depending on the type of the task.
OBJECTIVE
The aim of the study was to examine the interconnection between N1 and P3 components of event-related potentials (ERP) and the personality type extraversion/introversion in two tasks with different conditions: mental and sensomotor. The hypothesis to test was that the difference in the information processing by extraverts and introverts depends on the task type.


METHODS
Twenty-six healthy middle-aged volunteers (13 extroverts, 13 introverts) were studied. The two groups were matched in gender, age and education. Electroencephalograms were recorded from Fz, Cz and Pz (10/20 system). Each subject participated in three series of 100 sound stimuli each (75 high--1200 Hz and 25 low--800 Hz, randomly presented)--a passive series, a series with a sensomotor task and a series with a mental task (counting of high tones).


RESULTS
We found differences in the stimulus information processing between extraverts and introverts, most prominent in the series with tasks. The introverts showed shorter latency and lower amplitudes of N1 in the counting task and longer latency and higher amplitudes in sensomotor tasks than did the extraverts. The extroverts had higher P3 amplitudes in the series with tasks.


CONCLUSIONS
The present study confirms the hypothesis that the personality type has an electrophysiological substrate, the type characteristics--extraversion/introversion influence the parameters of N1 and P3 components. The interconnection between the personality type and the processes of cortical activation depend on the type and requirements of the task.
Philipova
Dolja T
DT
Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
D000161:Acoustic Stimulation; D000328:Adult; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005120:Extraversion, Psychological; D005260:Female; D006801:Humans; D007439:Introversion, Psychological; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*