Probe evoked potentials: theory, method and applications.

The probe evoked potentials method which involves recording brain responses to irrelevant stimuli during performance of a wide range of cognitive tasks, is used with increasing frequency to assess patterns of regional cerebral activation mediating distinct cognitive operations. This paper delineates the evolution of the method, describes its procedural and theoretical features, reviews its applications with normal adults, infants and children, and with neuropsychologically compromised individuals. The outcome of these studies points to the advantages of this method over traditional evoked potential procedures in the assessment of regional cerebral engagement in cognitive operations, free of confoundings due to stimulus and response-specific activity, in ecologically valid experimental situations.