December 2016 Research Roundup: Viva las Vagus

Unfortunately there often seems to be a wide chasm between what happens in the research lab and what happens on the front lines of clinical work. On the one hand, researchers need to listen to clinicians and learn about their direct experiences with clients. On the other hand, clinicians can benefit from hearing about clinically relevant research. We hope these “research roundups” provide useful summaries of recent research that can improve your practice with highly shame prone and self-critical clients.

In this post, we highlight some important findings at the intersections of physiology, biology and psychology that have actual real-world implications for your clinical work. So, today, what happens in (research laboratories studying the) Vagus, will not stay in Vagus. ;-)

However, before ‘pumping’ through the summaries, we'll briefly describe a few important terms so you don’t ‘skip a beat.’

Heart Rate Variability: What it is, and why psychologists care about it

Activity in our autonomic nervous system, a system responsible for the regulation of unconscious bodily functions (e.g. breathing, digestion, and heartbeat), reflects fluctuations of our internal states. As a result of the operation of our autonomic nervous system, there is typically a slight speeding up of the heart on every in-breath and a slight slowing down of the heart on every out-breath. The change in the heart rate from in-breath to out-breath is known as heart rate variability (HRV) and provides an index of autonomic nervous system function. Researchers often assess HRV by measuring High-Frequency Heart Rate Variability (HR-HRV; see below for more info), or respiratory sinus arrhythmia (RSA; see below) These measures provide an approximation of activity in the parasympathetic nervous system (the branch of the autonomic nervous system involved in relaxation and energy conservation). Certain situations (e.g. cognitively engaging tasks) involve decreases in HRV, whereas other situations (e.g. relaxation) involve increases in HRV. Vagal flexibility refers to the degree to which HRV changes according to situational demands. Some researchers hypothesize that vagal flexibility is associated with psychological wellbeing (e.g. see Bazhenova and colleagues).

Key Terms:

  • Autonomic nervous system: a system responsible for the regulation of unconscious bodily functions
  • Parasympathetic nervous system: a branch of the autonomic nervous system involved in energy conservation (i.e. “rest and digest”)
  • Vagus nerve: the primary component of the parasympathetic nervous system that relays signals from the brain to the body and from the body back to the brain
  • Vagal tone: the activity of the vagus nerve at rest, typically inferred by assessing heart rate variability while resting. Vagal tone is typically measured a couple of ways:
      1. High Frequency-Heart Rate Variability (HR-HRV): a measure of the high frequency oscillations of the heart that estimates parasympathetic activity
      2. Respiratory Sinus Arrhythmia (RSA): a measure that combines HR with respiration data that estimates parasympathetic activity
  • Vagal flexibility: the degree to which HRV varies between rest and challenging situations
  • Polyvagal theory: the theory that the myelinated vagus is key to the mammalian social-engagement system. (Note: this theory isn’t mentioned in the below research summaries, but is a key theory underlying each paper)
  • Prosocial behavior: behaviors intended to help others
  • Altruism: prosocial behaviors motivated by the goal of increasing another’s welfare


Giving Comes from the Heart

Although researchers have previously found that altruistic feelings are associated with increases in vagal activity, this is the first study to explore whether altruism is related to the ability to intentionally increase your heart rate variability. In this study, 240 physically healthy adults (ages 20 - 55) completed behavioral tasks that measure prosociality, as well as a biofeedback task. In the biofeedback task, participants observed a red ball on a screen, and were instructed that its position represented an aspect of their mental-bodily state. Participants were unaware that the mental-bodily state represented was the power of their heart’s high frequency oscillations, a measure closely related to HR-HRV. Then, researchers simply asked participants to make the ball move upwards without moving their body. The researchers found that participants’ ability to move the ball upwards (i.e. voluntarily increase their HR-HRV) was related to prosociality motivated by altruism, but was unrelated to prosociality motivated by social norms or strategy. In summary, people’s ability to regulate their HRV is related to individual differences in altruistic giving.

Take-aways: Teaching clients strategies that can increase their sense of social safety and thereby increase their heart-rate variability may help facilitate more altruistic prosocial behaviors. For example, relaxation techniques or lovingkindness meditation have been shown to increase HRV and may offer benefits not just to the client directly, but through improving their relationships because people tend to like people who are altruistic and prosocial.

Read more:
Bornemann, B., Kok, B. E., Böckler, A., & Singer, T. (2016). Helping from the heart: Voluntary upregulation of heart rate variability predicts altruistic behavior. Biological Psychology, 119, 54–63.


Vagal Flexibility predicts Social Sensitivity

sample_stimuli_2.jpgThe authors hypothesized that people higher in vagal flexibility would more sensitively respond to social cues and social feedback. In Study 1, they confirmed that vagal flexibility (calculated by subtracting RSA scores at rest from RSA scores during an attentionally demanding task) was a consistent, trait-like measure. Study 2 confirmed that vagal flexibility (RSA during a task minus RSA at baseline) and vagal tone (RSA at baseline) reflect distinct experiences. Whereas vagal tone was negatively correlated with self-report measures of depression, anxiety and stress, vagal flexibility was negatively correlated loneliness, a self-report measure linked to social functioning. In Study 3, participants competed an emotion perception task in which they viewed images of eyes, and guessed what emotion each pair of eyes depicted. Participants with greater vagal flexibility, but not greater vagal tone, more accurately detected the emotion displayed by the eyes, further suggesting that those with higher vagal tone are more sensitive to social cues. In Study 4, participants were asked to give a speech about their ideal job, and then received either positive or negative feedback from evaluators in a "question-and-answer period". Researchers later coded the videotaped interviews for sociable behaviors (smiling and laughing, gesturing and animation, and engagement with evaluators). In the positive feedback condition, participants with higher levels of vagal flexibility responded to the feedback with lower blood pressure reactivity and appeared more sociable to raters. In the negative feedback condition, participants with higher vagal flexibility reported more shame, had higher blood pressure reactivity, and appeared less sociable to raters. In other words, compared to participants with lower levels of vagal flexibility, those with higher levels of vagal flexibility responded more intensely to social feedback. Vagal tone was not linked to participants' responses to feedback following the videotaped interview. Together, these results suggest vagal flexibility uniquely reflects an individual’s sensitivity to emotional information and responsivity to social feedback.

Take-away: The findings of this study are complex. What it does suggest is that helping clients find techniques that result in higher vagal flexibility might help them respond more sensitively to social cues, and more sensitively to positive social feedback. On the other hand, higher vagal flexibility may also result in clients being more sensitive to negative social feedback as well. For now, research is still unclear as to how exactly clinicians might influence vagal flexibility in a positive manner. However, it does appear that vagal flexibility is strongly associated with social behavior.

Read more:
Muhtadie, L., Koslov, K., Akinola, M., & Mendes, W. B. (2015). Vagal flexibility: A physiological predictor of social sensitivity. Journal of Personality and Social Psychology, 109(1), 106-120.


To Strengthen your Heart, Warm It 

conceptual_model.jpgA ‘heart’y amount of research suggests that positive emotions promote physical health, and physical health promotes positive emotions. Yet, it remains mysterious why this might be the case. The authors of the present study hypothesized that positive emotions lead to physical health (indexed by vagal tone at baseline) via perceptions of social connectedness. Participants (65 university employees) were randomly assigned to one of two conditions: (1) a lovingkindness meditation (LKM) condition aimed to increase positive feelings towards the self and others, or (2) a waitlist control. Each week, participants in the LKM condition attended an LKM training class, while participants in the control condition attended an unrelated university class. Participants in the LKM condition were encouraged to meditate daily, and could do so with the aid of recordings provided by the researchers. On a daily basis, for 2 months, participants in both conditions reported their emotions, the amount that they meditated, and the degree to which they felt connected during their social interactions. Researchers also assessed participants' vagal tone by assessing HF-HRV and RSA at both the beginning and end of the study. Compared to participants in the control condition, those in the LKM condition experienced more positive emotions by the end of the study, especially if they had more vagal tone at baseline. Increased vagal tone, in turn, led to increased positive emotions. This positively reinforcing relationship between vagal tone (an index of physical health, particularly cardiac health) and positive emotions occurred via perceptions of social connection. Namely, positive emotions led people to feel more socially connected in their interactions, which in turn led to increases in vagal tone. According to the authors, “[results] suggest that positive emotions, positive social connections, and physical health influence one another in a self-sustaining upward-spiral dynamic.”

Take-away: Teaching clients loving-kindness meditation (LKM) can increase their experience of positive emotions, which can also improve their perception of their relationships and improve vagal tone over time (a strong index of cardiac health). For more information about how to use LKM with highly self-critical clients, see our posts here and here.

Read more:
Kok, B. E., Coffey, K. A., Cohn, M. A., Catalino, L. I., Vacharkulksemsuk, T., Algoe, S. B., ... & Fredrickson, B. L. (2013). How positive emotions build physical health: Perceived positive social connections account for the upward spiral between positive emotions and vagal tone. Psychological Science, 24(7), 1123-1132.

Article written by Christina Chwyl and Jason Luoma

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