[Effect of adaptive biofeedback on the severity of vestibulo-autonomic symptoms of experimental motion sickness]

The effect of biofeedback control on motion sickness symptoms was investigated in 27 test subjects with different susceptibility who had been trained to regulate their skin resistance and skin temperature. The efficacy of two schemes was compared: scheme 1 - transfer of controlling abilities, and scheme 2 - application of biofeedback during vestibular stimulation. Use of either scheme inhibited significantly the severity of motion sickness symptoms in moderate susceptibility individuals; in other words, this decreased respiratory arrhythmia, skin galvanic response, heart rate and objective motion sickness manifestations, i.e. nausea, paleness, perspiration. This caused vestibular tolerance to increase by 50% to 150% as compared to the baseline. Biofeedback control proved ineffective in high susceptibility individuals. Scheme 2 was found to be more effective than scheme 1. Biofeedback control of skin resistance had a stronger inhibitory effect than that of skin temperature. These results suggest that the prophylactic effect of biofeedback control is associated with the regulation of a component of the complex autonomic reaction triggered as a single program during motion sickness.