Trends in the psychophysiology of individual differences.

Pavlov's typology of higher nervous activity was the first systematic approach to the psychophysiology of individual differences. Pavlov's theory has been further developed by Teplov, Nebylitsyn and their pupils in the Institute of Psychology in Moscow. In particular, Nebylitsyn has delineated a new property of the nervous system and has shown that it is different from strength of nervous system. In the Western research context we can compare the relationship between these two parameters to that between arousal and conditioning level. Eysenck's theory of the physiological bases of extraversion/introversion is discussed in relation to Nebylitsyn's theses and Gray's conception of arousability. Finally, it is suggested that future work in the psychophysiology of individual differences should stress the study of the ontogenetic development of the physiological variables.