High Quality Content by WIKIPEDIA articles! The contingent negative variation (CNV) was one of the first event-related potential (ERP) components to be described. The CNV component was first described by Dr. W. Grey Walter and colleagues in an article published in Nature in 1964. The importance of this finding was that it was one of the first studies which showed that consistent patterns of the amplitude of electric responses could be obtained from the large background noise which occurs in electroencephalography (EEG) recordings and that this activity could be related to a cognitive process such as expectancy.