Facial electromyographic (EMG) responses to emotionally significant visual images: differences between light and...

Fifty participants took part in an experiment designed to investigate individual differences in the effects of alcohol on facial EMG responses to emotionally significant stimuli. Participants took part in two experimental sessions during which they viewed emotionally negative and emotionally positive visual images. In one session they consumed alcohol (0.5 g/kg bodyweight) whilst in the other they consumed soft drink. We classified each participant as a light or heavy drinker on the basis of their self-reported alcohol consumption. Negatively valenced images elicited increases in both frontalis and corrugator activity but alcohol did not moderate this effect either in light or heavy drinkers. Nevertheless, heavy drinkers did respond more strongly to the negatively valenced images and this supports the view that responses to negative emotional stimuli may play a part in the development of heavy drinking as a result of negative reinforcement processes.