Some relationships between personality, arousal and the strength of the excitatory process

Abstract

The primary object of the present investigation was to test the inverted 'U' model developed by investigators of 'arousal' in the west and of the 'strength of the excitatory process' in the Soviet Union to explain the relationship between a variety of factors and measures of behavioural, subjective and physiological response. In the present project adult human subjects took part in four experiments. The following factors were investigated in one or more of them: introversion, neuroticism, 'strength of the excitatory process', stimulus intensity, stimulus duration, signal frequency, signal probability, accessory stimulation, time on task, task repetition and time of cay. Measures of psychoticism were also taken. The response indices included: gustatory measures, reaction time, signal detection theory measures, vigilance scores, autonomic indices and measures of subjective state.

Support for the model emerged most strongly in the form of certain lower order interactions between the factors, for example between introversion and neuroticism for simple auditory reaction time, and between neuroticism and time of day for the speed of response to signals in a vigilance task. Support from higher order interactions was less forthcoming.

Compared to low N subjects, high N subjects scored relatively low on the 'strength of the excitatory process' as measured by Nebylitsyn's index of the slope of the simple visual reaction time / stimulus intensity function. It was suggested, furthermore, that previously discrepant findings with respect-to introversion using this measure nay have been due to response bias effects, though experimental test of this idea yielded non-significant results.

Though only partial support for the model was obtained it was considered to remain a useful conceptual tool, and possible practical implications were discussed.