Cognitive Psychophysiology and Preparatory Processes: A Case Study
Emanuel Donchin Michael G. H. Coles Gabriele Gratton Cognitive Psychophysiology Laboratory University of Illinois Champaign
Event-Related Brain Potentials (ERPS) can be used in the study of cognitive function in general and preparatory activities in particular. This is illustrated by reference to a study of the effect of warning stimuli on ERPs and on the performance of a simulated driving task. The ERPs are viewed as scalp manifestations of intracranial activities that execute specific functional tasks in the information processing sequence. They are particularly well suited for the study of preparation because they allow the analysis of covert aspects of behavior. In the experiment described in this chapter, the subjects were warned by a series of digits displayed on their "vehicle" that they were about to encounter a packet of obstacles. The regularity of these warning digits and the length of the warning series served as independent variables. The ERPs elicited by the various warning stimuli were analyzed and several components, such as the CNV and the Slow Wave, were observed. The amplitude and scalp distribution of the components were affected by the experimental manipulations and, in turn, were correlated with the pattern of activities the subject used to avoid the obstacles. These data demonstrate that ERP measures can complement traditional behavioral measures to provide a more comprehensive picture of cognitive function than is available from the behavioral measures alone.
Cognitive psychophysiology, as its name implies, is a marriage of cognitive psychology and psychophysiology. The basic premise of this union is that the understanding of cognitive processes can be enhanced by augmenting the traditional tools of the cognitive psychologist by adding tools based on the measurement of physiological functions ( Donchin, in press). The psychophysiological data are, of course, useful only to the extent that they complement and expand