Does conscious intention to perform a motor act depend on slow cardiovascular rhythms?

Slow oscillations around 0.1 Hz are characteristic features of both the cardiovascular and central nervous systems. Such oscillation have been reported, e.g. in blood pressure, heart rate, EEG and brain oxygenation. Hence, conscious intention of a motor act may occur only as a result of brain activity changes in frontal and related brain areas, or might be entrained by slow oscillations in the blood pressure. Twenty-six subjects were asked to perform voluntary, self-paced (at free will) brisk finger movements. Some subjects performed self-paced movements in relatively periodic intervals of around 10 s at the decreasing slope of the slow 0.1-Hz blood pressure oscillation. Our study reveals the first time that self-paced movements, at least in some subjects, do not stem from “free will” based on brain activity alone, but are influenced by slow blood pressure oscillations.