Heart rate pattern and resting heart rate variability mediate individual differences in contextual anxiety and conditioned responses

Cardiac activity provides possible markers for the identification of those at risk for the development of anxiety disorders. Cardiac deceleration has been linked to impaired fear conditioning while low heart rate variability (HRV) has been associated with elevated contextual anxiety and enhanced startle potentiation to affective stimuli. In the current studywe examined individual differences in conditioned responses as a function of cardiac activity. In addition to classifying participants as decelerators and accelerators, we examined baseline fear responding and conditioned responses in participants with low and high resting state heart rate variability. We complemented well-established physiologicalmeasures (startle response and skin conductance) and online distress and retrospective expectancy ratings of fear conditioning with measures of heart rate (HR). In contrast to accelerators, decelerators did not show any sign of startle fear conditioning, but demonstrated increased differential conditioning of online distress. Only marginal differences in contextual anxiety and conditioned fear responding were observed for low and high HRV individuals. These results may contribute to the identification of individuals who are at risk for the development of anxiety disorders.