The 7th is usually Kathryn Britton’s day. Her article will appear on the 9th this month.

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There are numerous studies linking positive emotions to improved health outcomes (Steptoe & Wardle, 2005). Several researchers are speculating that the pathway might be the autonomic nervous system (ANS) (Thayer & Ruiz-Padial, 2006). The ANS is responsible for managing homeostasis in the body. It consists of two major parts – the sympathetic nervous system (SNS) which generally increases the activity of organs within the body (eg increases the heart rate) and the parasympathetic nervous system (PNS) which has the opposite effects to the SNS (eg slows the heart rate ). A useful analogy is that the SNS acts like the accelerator on your car and the PNS like the brakes.

In healthy human beings the two parts of the autonomic nervous system work synergistically. The PNS is the most dynamic part of the ANS and tends to respond more quickly than the SNS (Porges, 2001). For example when confronted with a stressor, the PNS decreases in activity which allows the SNS to dominate. This activates the so called stress response (“fright, fight or flight”). When the stressor has passed the PNS increases in activity and calms the body restoring it to its normally balanced state. Consequently the PNS is commonly called the calming or relaxation response.

However for various reasons (eg aging, lack of sleep, chronic stress and lack of exercise) the activity of the PNS can decrease which results in SNS dominance. This impacts the body’s ability to function optimally, which can in turn result in physical illness (Masi et al, 2006).

PNS activity is also predictive of emotional health –in particularly the ability to regulate emotions in a healthy and appropriate manner (Appelhans & Luecken, 2006). Lower levels of PNS are associated with depression (Chambers & Allen, 2002), anxiety (Friedman & Thayer, 1993), aggression (Beauchaine et al, 2007) defensiveness (Movius & Allen, 2005), post traumatic stress disorder (Hopper et al, 2006) and hostility (Virtanen et al, 2003). Perhaps when we refer to a “nervous breakdown” we are literally referring to a breakdown (failure of the brakes) in the PNS.

Higher levels of PNS are associated with psychological resilience. For example children with higher levels of PNS are less likely to be effected by marital conflict (Katz & Gottman, 1997). Similarly a longitudinal study found that British Civil servants with higher levels of the PNS are more resilient to stress (A. Britton et al, 2008).

There is also evidence that positive emotions are associated with higher levels of PNS activity. Some of the earliest research by Barbara Fredrickson found that positive emotions resulted in quicker heart rate recovery after people had been exposed to film clips that aroused negative emotions (Fredrickson & Levenson, 1998). New research from Barbara’s Positive emotion and Psychophysiology (PEP) Lab has found that PNS is related to positivity and social connectedness (Kok & Fredrickson, no date). Not surprisingly asking people to recall an experience where they felt gratitude results in higher levels of PNS (McCraty et al, 1995). And higher levels of PNS are associated with spirituality (Berntson et al, 2008).

There are a number of interventions that increase PNS activity, especially effective stress management techniques such as exercise (Sandercock et al, 2005), tai chi (Lee et al, 2002), meditation (Takahashi et al, 2005), massage (Delaney et al, 2002) and yoga (Khattab et al, 2007) – as does consuming fish oil (Holguin et al, 2005). And for some reason walking a dog increases PNS more than walking by yourself (Mattok et al, 2006).

There is also PC based software that teaches you to breathe in an optimal way to increase PNS (Lehrer et al, 2003). The software has been effective in treating depression (Karavides et al, 2007), asthma (Lehrer et al, 2007), fibromyalgia (Hassett et al, 2007), anger and anxiety (Reiner, 2008).

The software also appears to be sensitive to a persons emotional state. The software is my preferred coaching tool as it takes all the guess work out of identifying what activates a persons positive emotions – particularly the most powerful positive emotion called contentment (Gilbert et al, 2008). This shouldn’t be surprising given that the software is measuring instantaneous levels of the calming response. I have also made the following empirical observations about factors that increase PNS (as measured by the software):

• Engaging in flow activities
• Resolving a problem
• Practicing mindfulness
• Reflecting on activities that align with values/strengths
• Engaging in an active constructive conversation

We all talk about living more balanced lives – beyond the metaphor perhaps we are referring to a balanced autonomic nervous system that allows us to respond to (and recover from) life’s inevitable challenges.

References
Appelhans, B.M., Luecken, L J. (2006). Heart rate variability as an index of regulated emotional responding. Review of General Psychology, 10(3), 229-240.

Beauchaine, T.P., Gatze-Kopp, L., & Mead, H.K. (2007). Polyvagal theory and developmental psychopathology: Emotion dysregulation and conduct problems from preschool to adolescence. Biological Psychology, 74, 174-184.

Berntson, G.G. , Norman, G.J. , Hawkley, L.C. (2008) Spirituality and autonomic cardiac control. Annals of Behavioural Medicine, 35(2), 198-208.

Britton, A., Singh-Manoux, A., Hnatkova, K., Malik, M., Marmot, M.G., & Shipley, M. (2008). The association between heart rate variability and cognitive impairment in middle-aged men and women: The Whitehall II cohort study. Neuroepidemiology 31 (2), 115-121.

Chambers A.S. & Allen, J.B. (2002). Vagal tone as an indicator of treatment response in major depression. Psychophysiology, 39, 861-864.

Delaney, J.P., Leong, K.S., Brodie, D. (2002). The short term effects of myofascial trigger point massage therapy on cardiac autonomic tone in healthy subjects. Journal of Advanced Nursing, 37(4), 364-71.

Fredrickson, B., Levenson, R. (1998). Positive emotions speed recovery from cardiovascular sequelae of negative emotions. Cognition and Emotion, 12, 191-220.

Gilbert, P., McEwan, K., Mitra, R., Franks, L., Richter, A., & Rockliff, H. (2008). Feeling safe and content: A specific affect regulation system? Relationship to depression, anxiety, stress, and self-criticism. Journal of Positive Psychology, 3(3), 182-191.

Hassett, A. L., Radvanski, D. C., Vaschillo, E. G., Vaschillo, B., Sigal, L. H., Karavidas, M. K., et al. (2007). A pilot study of the efficacy of heart rate variability (HRV) biofeedback in patients with fibromyalgia. Applied Psychophysiology and Biofeedback, 32, 1–10.

Holguin, F., Téllez-Rojo, M.M., Lazo, M., Mannino, D., Schwartz, J., Hernández, M., Romieu, I. (2005). Cardiac autonomic changes associated with fish oil vs soy oil supplementation in the elderly. Chest, 127 (4), 1102-1107.

Hopper, J.W., Spinazzola, J., Simpson, W.B., Van Der Lol., B.A. (2006), Preliminary evidence of parasympathetic influence on basal heart rate in post traumatic stress disorder. Journal of Psychosomatic Research, 60, 83-90.

Karavidas, M. K., Lehrer, P. M., Vaschillo, E., Vaschillo, B., Marin, H., Buyske, S., et al. (2007). Preliminary results of an open-label study of heart rate variability biofeedback for the treatment of major depression. Applied Psychophysiology and Biofeedback, 32, 19–30.

Katz, L.F. & Gottman, J.M. Buffering children from marital conflict and dissolution (1997). Journal of Consulting and Clinical Child Psychology, 26(2), 157-171.

Khattab, K., Khattab, A.A., Ortak, J., Richardt, G., Bonnemeier, H.(2007). Iyengar Yoga increases cardiac parasympathetic nervous modulation among healthy yoga practitioners. Evidence-based Complementary and Alternative Medicine 4(4), 511-517.

Kok, B. E. & Fredrickson, B. L. (no date). The process of other-focus: Evidence for a psychophysiological model. Retrieved October 3, 2008 from http://www.bethanykok.com/BEK_APS_5_23_08.pdf

Lee, M.S., Huh, H.J., Kim, B.G., Ryu, H., Lee, H.S., Kim, J.M., Chung, H.T. (2002). Effects of Qi-training on heart rate variability. American Journal of Chinese Medicine, 30(4), 463-70.

Lehrer, P. M., Vaschillo, E., Vaschillo, B., Lu, S.-E., Eckberg, D. L., Edelberg, R., et al. (2003). Heart rate variability biofeedback increases baroreflex gain and peak expiratory flow. Psychosomatic Medicine, 65, 796–805.

Lehrer P.M., Vaschillo E, Vaschillo B, et al. (2004) Biofeedback treatment for asthma. Chest, 126, 352 – 61.

Masi, C.M., Hawkley,L.C., Rickett, E.M., Cacioppo, J.C. (2006). Respiratory sinus arrhythmia and diseases of aging: Obesity, diabetes mellitus, and hypertension. Biological Psychology, 74 (2), 212-223.

Mattok, M., Koike. H., Yokoyama, T., Kennedy, N.L. (2006). Effect of walking a dog on autonomic nervous system activity in senior citizens. Medical Journal of Australia, 184(2), 60-62.

McCraty, R., Atkinson, M. Willer, W.A. Rein, G. Watkins, A.D. (1995), The effects of emotions on short-term power spectrum analysis of heart rate variability. American Journal of Cardiology, 76 (14), 1089-1092.

Movius, H.L., Allen, J.N. (2005). Cardiac vagal tone, defensiveness and motivational style. Biological Psychology, 68, 147-162.

Porges, S.W. (2001). The polyvagal theory: Phylogenetic substrates of a social nervous system. International Journal of Psychophysiology, 42, 123–146.

Reiner, R. (2008). Integrating a Portable Biofeedback Device into Clinical Practice for Patients with Anxiety Disorders: Results of a Pilot Study. Applied Psychophysiology Biofeedback 33, 55–61.

Sandercock, G.R., Bromley, P.D., Brodie, D.A. (2005). Effects of exercise on heart rate variability: Inferences from meta analysis. Medical Science Sports Exercise, 37(3), 433-439.

Steptoe, A. & Wardle, J. (2005). Positive affect and biological function in everyday life. Neurobiology of Aging, 26, S108-S112.

Takahashi, T., Murata, T., Hamad, T. Omoria, M. Koska, H, Kikuchi, M, Yoshida, H., Wada, Y. (2005). Changes in EEG and autonomic nervous system activity during meditation and their association with personality traits. International Journal of Psychophysiology, 55, 199-207.

Thayer, J.F. & Ruiz-Padial, E. (2006). Neurovisceral integration, emotions and health: An update. International Congress Series, 1287, 122-127.

Virtanen, R., et al. (2003). Anxiety and hostility are associated with reduced baroreflex sensitivity and increased beat-to-beat blood pressure variability. Psychosomatic Medicine, 65(5), 751–756.

Images
Autonomic nervous system

Pushing on the brake

Walking a dog