Cardiac vagal tone and executive functions: Moderation by physical fitness and family support

Executive functions (EFs) are crucial for academic success and have recently been linked to the ability to self-regulate in terms of cardiac vagal tone. The current study used a sample of 131 first-and second graders to examine whether the expected association between cardiac vagal tone (indexed by rMSSD) and EFs (inhibitory control and cognitive flexibility) was moderated by children's physical fitness and perceived family support. Linear regression analyses revealed that the cardiac vagal tone-inhibitory control link was moderated by physical fitness. Specifically, children with low cardiac vagal tone performed worse on the inhibitory control task when their physical fitness was low. Furthermore, family support moderated the association between cardiac vagal tone and cognitive flexibility: children with high cardiac vagal tone performed better on the cognitive flexibility task when family support was high. Implications for theory and educational practice are discussed.