The effect of a low rate of regular signals upon the reaction times of introverts and extraverts

In an RT (reaction time) task involving responding to infrequent, regular signals, extraverts produced higher proportions of missed signals and lengthened RT's than introverts did. This result was only obtained after some time on task and is evidence that inhibitory states are formed more rapidly in extraverted subjects under low stimulation conditions. In a more extended version of the task, mean RT was found to be longer in extraverted than introverted subjects in the second half of the experiment though there was no significant difference between the groups in the first half. These findings are complementary to data from previous studies showing that extraverts generate stronger inhibitory potential in continuous responding tasks, or that their characteristic arousal level may be lower than that of introverted subjects. The need to distinguish between the different explanatory constructs is discussed and a simple model amalgamating the major theoretical positions is outlined.