The central autonomic network (CAN) is a network comprised of structures from the brain’s cortex, limbic system and brainstem areas. The limbic system and cortex are involved in emotional regulation and the body’s ability to deal with stress. Information is sent to brainstem components that then influence the rhythmic activity of the heart and other organs throughout the body.
The autonomic nervous system (ANS) is divided into two branches, the sympathetic and parasympathetic nervous systems. The sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) influence the time between heartbeats in an individual. Heightened activity in the SNS, or reduced in activity in the PNS, have been shown to increase heart rates and vice versa. The measurement of the average time between consecutive heartbeats, and how much it varies, is called heart rate variability (HRV). It is a measurement that can be taken by measuring an individual’s pulse, making it non-invasive in nature.
HRV research shows that this measurement can be used to determine the productivity of the CAN from moment to moment. Because biological functions are largely controlled by the brainstem components, HRV allows a practitioner to see how an individual is able to regulate emotion. Empirical research has proven that patients who display lower HRV measures than controls present with poor attention, generalized anxiety disorder and depression. Whereas, an individual who exhibits higher HRV measures is likely to display effective coping mechanisms for stressors. This research substantiates the use of HRV training in a biofeedback practice in conjunction with other modalities used to help an individual with brain markers for such disorders.