Psychobiological processes in the development of behavioral inhibition

Despite robust prediction from early behavioral inhibition to anxiety development, evidence is accumulating for heterogeneity among children identified as behaviorally inhibited. In this chapter, we examine how behavioral inhibition is associated with a range of psychophysiological markers to better understand this heterogeneity. We suggest that these measures are not just correlated with behavioral inhibition but are markers of underlying processes that help to characterize which children are at highest risk for anxiety, thereby reducing heterogeneity. We organize the literature by discussing physiological markers as indexing reactivity and regulation, consistent with a temperament framework, and cover a wide range of physiological measures linked to behavioral inhibition and risk for anxiety, including electrodermal activity, cortisol, and EEG asymmetry, respiratory sinus arrhythmia, EEG delta-beta coupling, and event-related potentials. The findings presented herein support the notion that these physiological markers index mechanisms that contribute to children's behavioral manifestation of behavioral inhibition and may exacerbate the risk for inhibited children to remain on the trajectory of developing anxiety symptoms.