ABSTRACTIndividual differences in estimates of respiratory sinus arrhythmia (RSA) have been implicated in the ability to respond efficiently to challenges encountered in different environmental contexts. Studies have used resting RSA and the suppression of RSA to emotional or challenging cognitive tasks to assess parasympathetic contributions to emotional and attentional regulation. In the current study, estimates of resting RSA, and RSA suppression were used in conjunction with measures of attentional control and anxiety to predict self -rated measures of executive functions and task performance on a mental math exercise. The data suggest that resting RSA, in conjunction with good attentional control and low anxiety are better predictors of global measure of a participant's ability to employ executive processes compared to RSA suppression. Both resting RSA and RSA suppression predicted more efficient task performance on the mental math exercise. The suppression of RSA, however, was more predictive of better performance in participants with poor attentional control and high anxiety. Resting RSA may be a better predictor of the ability of an individual to respond to challenges encountered in the environment. The degree of RSA suppression may be task specific and related to the interpretation of the degree of challenge associated with the task requirements.KEYWORDS: executive function, attention, emotion, anxiety, heart rate variabilityThe ability to engage various executive processes has been shown to be directly related to the regulation of attention and negative affect (Healy, Treadwell, & Reagan, 2011). Initial work by Derryberry and Rothbart (1988) defined attentional control as the ability to sustain attention to aspects of the environment in addition to an ability to shift one's attentional focus as dictated by the demands of differing environmental events. This flexibility in attentional processing has been seen as representing the functioning of an anterior attentional system linked to frontal lobe function which would allow an individual to engage and disengage attention to aspects of the environment. At the other extreme, attentional rigidity has been linked to the prevalence of anxiety disorders whereby individuals have difficulty disengaging from aspects of the environment associated with threat (Derakshan & Eysenck, 2009; Wells & Matthews, 1994). Research suggests that the ability to allocate attention to different aspects of the environment is useful in situations that require a reduction in negative affect (Lonigan, Vasey, Phillips, & Hazen, 2004).From a physiological perspective, estimates of the parasympathetic contribution to the beat-to-beat variation in heart rate (i.e., respiratory sinus arrhythmia, or RSA) have been used as a marker of emotional self-regulation and attentional control (Applehans & Luekan, 2006). Initial research had placed an emphasis on resting measures of RSA as representing an individual's level of responsiveness with higher resting estimates predicting more positive outcomes and/or behaviors from infancy to adulthood. In this regard, there exits an extensive literature that points towards high resting levels of RSA as being related to approach behavior, and emotional self-regulation in infants and children (Calkins & Keene, 2004; Kagan, Resnick, & Snidman; 1987; Stifter & Fox, 1991), increased attentional control in infants and children (Richards & Casey, 1992), positive emotional expressiveness in children (Calkins, 1997), modulation of negative affect, ratings of lower anxiety in adults, and increases in positive mood (Greaves-Lord, Ferdinand, Sondeijker, Dietrich, Oldehinkel, Rosmalen, Ormel, & Verhulst, 2007; Gyurak & Ayduk, 2008; Thayer, Friedman, & Borkovec, 1996). In contrast, lower resting RSA has been linked to chronic anxiety and the prevalence of anxiety disorders such as generalized anxiety disorder and post-traumatic stress disorder in adults (Friedman, 2007). …