reciprocal control of the autonomic

reciprocal control of the autonomic branches. Rather, higher level systems engage in highly sophisticated “banter” with the autonomic nervous system. In contrast to the reciprocal control characteristic of autonomic reflexes, higher level brain circuits exert more flexible control over the autonomic nervous system. This can include the classic reciprocal control pattern, but can also include an independent control pattern in which only the sympathetic branch or only the parasympathetic branch of the autonomic nervous system is activated, and a coactive control pattern in which both branches are activated. This greater flexibility in control may have behavioral and health significance. Beliefs about One’s Relationship with God and Autonomic Functioning Recently, we used a population- based sample of 50-68-year-old adults in the Chicago Health, Aging and Social Relations Study to examine risk factors for heart attack, a health outcome known to be influenced the autonomic nervous system. We were particularly interested in whether spirituality influenced risk for heart attack. With very few exceptions, everyone in our sample expressed a belief in God. However, individuals differed in how they perceived the quality of their relationship with God, much as individuals differ in how they perceive the quality of their relationships with other people. We defined spirituality as the degree to which a personal relationship with God was believed to offer safety, security, contentment, and love. One observation that emerged from this study was that spirituality was associated with a lower incidence of heart attack (7). This remained true after ruling out the effects Page |54 of demographics, health behaviors, body mass index, blood pressure, and other potential explanatory factors. Short of divine intervention, was there a rational explanation for this relationship? We certainly know that psychological factors can impact autonomic control, among other aspects of physiology. As considered above, when extreme or prolonged, sympathetic activation may have harmful consequences. Heightened sympathetic activation is known, for example, to predict a poorer outcome after heart attack. In contrast, parasympathetic activity may have beneficial or protective effects. From the perspective of a reciprocal model of autonomic control, high parasympathetic/low sympathetic control would be optimal whereas high sympathetic/low parasympathetic control would be considered a risk. But we also know that higher level neurobehavioral systems may not be constrained to reciprocal autonomic controls. Moreover, it has been argued that more autonomic control is better than little control, in that if affords greater capacity for adjustment of visceral functions. Could high levels of parasympathetic control, for example, mitigate the negative effects of sympathetic activation and perhaps yield an even more advantageous health outcome? To examine these questions, we developed two quantitative measures of autonomic control (7). The first was a common metric of autonomic balance (Cardiac Autonomic Balance), which represents the relative dominance of the two branches along a single autonomic continuum that ranges from purely parasympathetic control to purely sympathetic control. This metric is consistent with the classical model of HOUSE_OVERSIGHT_021300