The power spectrum within the high-frequency component, corresponding to the respiratory frequency of the animal, primarily reflects vagal tone whereas low-frequency component, LF, is reported to be influenced by both sympathetic and vagal tones [21].
The power spectrumwithin the high-frequency component, corresponding to the respiratoryfrequency of the animal, primarily reflects vagal tone whereaslow-frequency component, LF, is reported to be influenced by bothsympathetic and vagal tones [21].