Context differences in delta beta coupling are associated with neuroendocrine reactivity in infants

Although evidence suggests that delta–beta coupling may provide a useful index of trait level cortico-subcortical cross talk in baseline contexts, there has been little work done to clarify the role of delta–beta coupling across contexts and in association with other physiological markers of emotion processing. We examined whether individual differences in coupling were visible across both positive and negative emotion-eliciting episodes during infancy (age 6 months). We also tested the convergence between measures of delta–beta coupling and neuroendocrine reactivity, which is also believed to index emotion processing. Patterns of coupling across emotion-eliciting episodes differed based on infants' levels of cortisol reactivity. Low cortisol-reactive infants largely did not show differences in coupling across emotion contexts while high cortisol-reactive infants showed greater coupling in non-fear contexts during baseline and fear episodes. Moreover, high cortisol-reactive infants showed greater coupling than low-reactive infants in non-positive episodes. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 406–418, 2016.