ABSTRACT
In this study, we examined changes in the amplitude of differential digital photoplethysmogram (ΔDPG) and the power spectral changes of EEG at rest during cold water immersion of the contralateral fingers (2°C), and after alcohol intake (0.3 g/kg) in 8 male subjects. This experiment showed that the ΔDPG amplitude decreased at rest and finger blood pressure was increased during the cold water stimulation, but there was no signifincant change in heart rate and EEG power spectrum. On chronological measurements for 30 minutes after alcohol intake, ΔDPG amplitude decreased slightly and finger blood pressure increased. Heart rate also tended to increase, and the alpha 1 power (8.0-9.8 Hz) on EEG gradually increased. The ODPG and finger blood pressure responses to cold water stimulation every 10 minutes was decreased after alcohol intake, whereas heart rate was not affected. However, a decrease in the alphal power after stimulation was revealed. From these results, it may be concluded that during 5-10 s of cold water stimulation, increased skin sympathetic nerve activity was one of the factors that raises blood pressure.
