Active neural coordination of motor behaviors with internal states

The brain must continuously coordinate skeletomuscular movements with
internal physiological states like arousal, but how is this coordination
achieved? One possibility is that brain simply reacts to changes in
external and/or internal signals. Another possibility is that it is
actively coordinating both external and internal activities. We used
functional ultrasound imaging to capture a large medial section of the
brain, including multiple cortical and subcortical areas, in marmoset
monkeys while monitoring their spontaneous movements and cardiac activity.
By analyzing the causal ordering of these different time-series, we found
that information flowing from the brain to movements and heart rate
fluctuations were significantly greater than in the opposite direction.
The brain areas involved in this external versus internal coordination
were spatially distinct but also extensively interconnected. Temporally,
the brain alternated between network states for this regulation. These
findings suggest that the brain’s dynamics actively and efficiently
coordinate motor behavior with internal physiology.