Late EEG after-effects following short-lasting ventilatory interoceptive influences (hyperventilation and breath holding) in man.

The application of two kinds of ventilatory interoceptive influences with opposite effects on the acid-base balance (hyperventilation and breath holding) results in appearance of late nonspecific after-effects in human EEG, which do not disappear until the 30th min after the stimulation. They consist in local and spatial synchronizing processes in the alpha and beta EEG spectrum, being most pronounced in the beta-2 range (23-36 Hz). These changes are considered as a sign of a development of readjustment in the functional state of the central nervous system in the direction of its improvement. The triggering of this readjustment is largely determined by the considerable changes in the internal medium, leading to intensified interoceptive signalization (mechanical, chemical and proprioceptive), as well as to the development of a brief cerebral hypoxy, followed by improved brain blood flow.