Contingent Negative Variation (CNV) is an event-related potential (ERP) that is generated in response to a warning signal prior to the presentation of a stimulus. CNV was first reported by Grey Walter in the 1950s, and has been extensively studied since then. CNV is thought to reflect the preparation for an upcoming task or stimulus, and is used to study a variety of cognitive processes, such as anticipation, expectancy, and decision-making.
The CNV is a negative potential that is usually observed over fronto-central scalp sites following the presentation of a warning signal. The CNV is typically maximal in amplitude within the first 200–300 ms after the warning signal, and has a duration of approximately 500–900 ms. It is thought to reflect the process of task preparation and its magnitude is related to the degree of expectancy for the upcoming event.
The CNV is thought to reflect a variety of cognitive processes, such as anticipation, expectancy, and decision-making. For instance, CNV may be used to measure the degree of expectancy for an event. A larger CNV amplitude may indicate a higher level of anticipation for the upcoming task. Furthermore, the CNV can be used to study decision-making processes, as the CNV amplitude may be modulated by the degree of uncertainty associated with the upcoming task.
In summary, the Contingent Negative Variation (CNV) is an event-related potential (ERP) that is generated in response to a warning signal prior to the presentation of a stimulus. The CNV is thought to reflect the process of task preparation and its magnitude is related to the degree of expectancy for the upcoming event. Furthermore, the CNV can be used to study a variety of cognitive processes, such as anticipation, expectancy, and decision-making.
References
Dien, J., & Van Selst, M. F. (2009). Contingent negative variation: A review. International Journal of Psychophysiology, 73(1), 4–13. https://doi.org/10.1016/j.ijpsycho.2008.10.007
Walter, W. G. (1953). The contingent negative variation. An electric sign of sensory-motor association and expectancy in the human brain. Electroencephalography and Clinical Neurophysiology, 5(4), 455–473. https://doi.org/10.1016/0013-4694(53)90011-3
Weissman, D. H., Roberts, K. C., Visscher, K. M., & Woldorff, M. G. (2006). The neural dynamics of preparatory processes: An event-related potential study of temporal preparation with and without forewarning. Journal of Cognitive Neuroscience, 18(2), 251–268. https://doi.org/10.1162/jocn.2006.18.2.251