Pre- and Postimperative Negative Variation (CNV and PINV) under different Conditions of Controllability in Depressed Patients and Healthy Controls

Abstract

Publisher Summary This chapter discusses pre- and postimperative negative variation (CNV and PINV) under different conditions of controllability in depressed patients and healthy controls. In a variety of psychophysiological investigations, depressed patients have been shown to be hyporesponsive to neutral stimuli, as measured by the magnitude of the habituation of the orienting response in different physiological systems, especially in the sudo-motor system. It is known from the literature as well as from experiments that in depressed patients the CNV is also generally smaller, and the reaction time longer than in healthy controls. The amplitude of the CNV seems to be positively correlated to the subject's (S) motivation to react upon the imperative stimulus. CNV and reaction time of both groups did not differ in a statistically significant way. On the other hand, there are large differences in both measures of post imperative negative variation (PINV), patients showing the larger PINVs. It is difficult to interpret the statistically most significant finding of study—namely, the large differences in PINV between the groups in C1, which vanishes in C2 and reappears in C3.