Effects of different psychophysiological stressors on the cutaneous electrogastrogram in healthy subjects

To evaluate the effect of psychophysiological stress on the gastric electrical activity, the cutaneous electrogastrography (EGG), a non-invasive 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 administered, and EGG parameters (dominant frequency, coefficient of variation of dominant frequency, and gastric power) were recorded during baseline, task and rest periods. Neutral task did not affect EGG parameters. During stressful stimulations, a slight decrease in the dominant frequency and an increase in the coefficient of variation of the dominant frequency were found. During arithmetic task, the gastric power significantly increased (baseline vs stimulus P=0.008; stimulus vs rest P=0.015; baseline vs rest P=0.011), and a statistically significant difference beween gastric power during arithmetic and neutral task was observed (P=0.007). During Stroop test, the gastric power showed only a trend 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 psychological stress may influence the EGG response and gastric electrical activity. In conclusion, cutaneous electrogastrography may be used as a non-invasive technique to study the effects of acute stressors on the gastric electrical activity.