The contingent negative variation (CNV): timing isn't everything

When participants time intervals ranging from several hundred milliseconds to several seconds a negative polarity waveform, known as the contingent negative variation (CNV), manifests in the ongoing electroencephalogram (EEG). The perceptual and cognitive functions underlying this component are subject to ongoing debate. Moreover, recent evidence suggests that the link between the CNV and behavioral performance is non-linear and changes depending on the cognitive context. We suggest that the CNV reflects a common core preparatory process related to brain system optimization, and other cognitive processes that depend on the specific timing task employed.