[Modifications of contingent negative variation (CNV) induced by oxytocin infusion]

The central effects of an intravenous infusion of oxytocin (OT), 3,680 mIU in 45 min, were investigated in 20 male volunteers in a double-blind study combining an electrophysiological and a psychometrical approach. The electrophysiological approach consisted in the simultaneous recording of the CNV (Fz-A1 and Cz-A1) and the spontaneous EEG (bipolar P3-P4) recording on which was carried out an FFT analysis. On the other hand, various psychometric tests allowed to assess memory (Rey's tests), attention (K-T test) processes and mood changes (visual analogue scales). Within the hour following the infusion, OT induced a significant decrease of CNV amplitude and an increase of the post-imperative positive component at Cz-A1. A similar effect was still observed one week later, but was more marked at Fz-A1. Neither mood nor attention tests evidenced any significant effect of OT. Only one item of the memory test PRM (item 4) revealed a significant impairment after OT infusion. There were no subjective effects reported. These observations provide new electrophysiological arguments supporting a central action of peripheral OT administration in man. This action, which may be characterized as an acceleration of CNV "habituation" is the opposite of the one described with vasopressin.