Contingent negative variation CNV

Another electric signal recorded from the surface of the skull is termed contingent negative variation (CNV). This is a very late potential fluctuation in the parietal region that arises when a subject participating in a reaction time experiment is advised, through a warning stimulus, of the imminence of another stimulus to which he or she has to respond. 

A technique known as contingent negative variation (CNV) measures brain-wave reaction to olfaction. These types of studies have shown the eftect of materials such as lavender and nutmeg in reducing stress or anxiety, and the ability of oils such as peppermint to stimulate brainwave activity. CNV research was incorporated into the development of the fragrance for a consumer personal care product launched in the late 1980s. 

Trimmel, M. (1987). Contingent negative variation (CNV) influenced by preceding slow potential shifts. Electroencephalography and Clinical Neurophysiology,... 

Aoki, H. 1996. Effect of odors from coniferous woods on contingent negative variation (CNV). Zairyo 45(4) 397-402. 

Torii, S., Fukada, H., Kanemoto, H. et al. 1988. Contingent negative variation (CNV) and the psychological effects of odour. In Perfumery—The Psychology and Biology of Fragrance, edited by S. Van Toller and G. H. Dodd. London, U.K. Chapman and Hall. 

A three-arousal model for engineering psychophysiology. CNV = contingent negative variation EEG = electroencephalogram EDA = electrodermal activity ERP = event-related potentials HR = heart rate HRV = heart rate variability. 

---