Some neurophysiological mechanisms of the perception of interoceptive signals.

The principal objective of this study consisted in the identification of some basic mechanisms of the perception of the interoceptive signal. The EEG activation reaction through mechanoreceptive stimulation of the stomach served as the indicator. A positive relationship was found between the intensity of the activation reaction and the intensity of the stimulus employed; the extinguishability of the reaction in response to repeatedly acting interoceptive stimuli was also found. The characteristic features of the EEG activation reaction during an interoceptive effect and the characteristic on- and off-responses (the development of the reaction at the beginning and ending of the action of the stimulus) were identified. The data presented are aimed at the disclosure of the interaction of the elements of the dual function of the interoceptive analyzer: as a feedback signal for the central apparatus subserving the control of visceral functions and as an important element of the nonspecific activation of the brain.