Stimulus analysis and response organization in the CNV-paradigm: ERP studies about extraversion, cognitive information processing, and motor preparation

The extraversion model of Brebner and Cooper explains behavioral differences between extraverts and introverts by differences in excitatory and inhibitory processes connected to the demands of stimulus analysis and response organization in a specific situation. The aim of the present work was to test this model with the biphasic Contingent Negative Variation, which is known to be functionally related to processes of stimulus analysis (initial CNV) and response organization (terminal CNV). In study 1, aspects of stimulus analysis were varied via four tasks differing in cognitive processing demands. According to the model, extraverts were expected to show increasing S-Inhibition with increasing task difficulty leading to lower amplitudes in the initial CNV. Introverts were expected to react with increasing S-excitation leading to higher CNV amplitudes. Statistical analyses revealed no interaction of task and extraversion on the initial CNV. In study 2 the complexity of motor responses was varied. Extraverts were expected to show increasing R-excitation with increasing motor complexity leading to higher amplitudes in the terminal CNV. Introverts should show decreasing amplitudes due to increasing R-inhibition. No differential effects of movement complexity were found on the amplitudes of the terminal CNV. Results will be discussed in terms of the Brebner-Cooper model and their consequences for psychophysiological personality research. (C) 2003 Elsevier Ltd. All rights reserved.