Imagined movement increases the segregation of brain-heart networks

Understanding the mechanisms of motor imagery, the mental simulation of movement without execution, is key for the development of neurotechnologies. For instance, for detecting covert motor intent in noncommunicative patients or refining motor commands through brain-computer interfaces. While motor imagery engages motor-related brain regions, its precise mechanisms remain unclear, particularly in relation to cardiac dynamics. Evidence suggests heart-rate variability features have potential to enhance tasks’ classifications, yet the brain-heart relationship is not well understood. In this study, we examined motor imagery learning using a task involving right-hand grasping imagery. We found that motor imagery is correlated with a cardiac sympathetic uncoupling with directed connectivity within the motor cortex. Additionally, cerebellar-supplementary motor area segregation, in relation to cardiac parasympathetic activity, indexed longitudinal motor learning. These results suggest that varying patterns of heart rhythmicity and brain connectivity within the motor network actively change during motor imagery, suggesting the brain-heart axis as influencer of sensorimotor function and associated neuroplasticity of learning.