Abstract
Communication apprehension (CA) is generally defined as a predisposition to avoid communication, if possible, or experience anxiety symptoms when forced to communicate with others. CA was conceptualized as a trait-like tendency to respond, meaning that the inclination to avoid communication or experience anxiety during social interaction was fairly stable across time. State anxiety, on the other hand, is transitory in nature, and while it often represents the manifestation of CA, it can be triggered by situational factors even in communicators low in the trait. Although the construct was initially conceptualized as a cognitively experienced trait, the psychological literature on anxiety symptoms usually includes physiological symptoms. Indeed, studies published since the initial development of the CA construct have indicated that state anxiety experienced during communication is correlated with physiological measures. More recent work indicates that trait CA, while not typically correlated with measures such as heart rate, is correlated with stable, individual differences in brain activity. This chapter focuses on the complex theoretical and empirical relationships among physiological responses, trait CA, and communication state anxiety.