Fast reducers, slow augmenters: a psychophysiological analysis of temperament-related differences in reaction time.

Augmenting-reducing theory describes temperament-related differences in the modulation of stimulation. Reducers are supposed to need more stimulation than augmenters because of a cortical attenuation of incoming stimuli. The study investigated differences between augmenters and reducers (classified by questionnaire) in performance and information processing strategies in a simple reaction time task. Fifty-two subjects (27 augmenters, 25 reducers) took part in a visual reaction time task with go- and catch-trials (30%). Reaction times, commission errors, and psychophysiological indicators of information processing (N1, P300, EMG) were recorded. Reducers were faster and exhibited more commission errors than augmenters. Moreover, reducers exhibited higher N1-amplitudes, faster EMG-onsets and higher EMG-amplitudes than augmenters. An additional pain tolerance test revealed that male reducers were more pain tolerant than the other participants. These results are consistent with the proposition that reducers have a higher need for stimulation than augmenters. Probably, they utilize locomotor activity in order to compensate for their attenuated arousal. Copyright 2003 Elsevier B.V.