[Augmenting-reducing construct in evoked brain potentials: dynamic test of Eysenck's dimensions]

Eysenck's personality dimensions (neuroticism N, and extraversion, E) are formulated on the basis of levels of activity within the Central Nervous System. These can be explored by means of electroencephalographic techniques, such as the cerebral evoked potential (CEP). The augmenting-reducing construct allows the prediction of individual differences according to the tendency of subjects to augment or reduce sensory experience and CEP amplitude. The present work explores auditory CEP at increasing intensities in order to develop a stimulus-response function. A negative correlation between N score and the slope of the stimulus-response function for some CEP components was found. Together with the positive correlation between N score - CEP amplitude at minimum intensity, such data suggest a higher nervous system reactivity in subjects with high N score. For E dimension, a positive correlation between E score and latency of CEP components was found (inhibition effect). These findings support to some extent Eysenck's theory. The augmenting-reducing construct is discussed in terms of its contribution as a dynamic test of Eysenck's dimensions.