The heart rate response as an indicator of changes in activation induced by alcohol.

This experiment was conducted in order to examine different alcohol-induced states of activation as indicated by the acoustic evoked heart rate response (HRR). Twelve healthy male subjects received 0.7 g/kg alcohol in one session of a cross-over designed experiment. In the control session no alcohol was given. The measurements of three parameters of the heart rate response as well as the self-assessments of mood were repeated five times along the course of the venous blood alcohol concentration. Significant depressant alcohol effects were reflected in a decrease in the HRR acceleration as well as in a decrease in vitality, vigilance, and self-estimated startle reaction. Stimulating effects could be observed in an increase of the mean heart rate and the second HRR deceleration. We conclude that different alcohol-induced states of activiation represent different patterns of inhibitory and facilitatory processes, each manifesting itself in different parameters. The results suggest three major components of alcohol action: 1) an inhibition release with immediate onset,2) a slower processing inhitition,3) attention focussing as a compensatory response to inhibition.