EFFECTS OF DIFFERENT PSYCHOPHYSIOLOGICAL STRESSORS ON THE CUTANEOUS ELECTROGASTROGRAM IN HEALTHY-SUBJECTS

To evaluate the effect of psychophysiological stress on the gastric el ectrical activity, the cutaneous electrogastrography (EGG), a non-inva sive technique, was performed in ten healthy subjects. Three different stressful (cold pressor test, arithmetic task, and Stroop color-word test) tests and a non-stressful (reading a booklet) task were administ ered, and EGG parameters (dominant frequency, coefficient of variation of dominant frequency, and gastric power) were recorded during baseli ne, task and rest periods. Neutral task did not affect EGG parameters. During stressful stimulations, a slight decrease in the dominant freq uency and an increase in the coefficient of variation of the dominant frequency were found. During arithmetic task, the gastric power signif icantly increased (baseline vs stimulus P=0.008; stimulus vs rest P=0. 015; baseline vs rest P=0.011), and a statistically significant differ ence beween gastric power during arithmetic and neutral task was obser ved (P=0.007). During Stroop test, the gastric power showed only a tre nd toward significance (baseline vs stimulus P=0.018; stimulus vs rest P=0.018). A wide interindividual variability was recorded during the stress period. Therefore, the individual susceptibility to psychologic al stress may influence he EGG response and gastric electrical activit y. In conclusion, cutaneous electrogastrography may be used as a non-i nvasive technique to study the effects of acute stressors on the gastr ic electrical activity.