The Brain–Heart Connection

Regulation is not only about the heart. The fluctuation of the heartbeat (HRV) is also a window onto how the brain is regulating the body. This page explains the brain–heart connection, with sources.

A two-way loop

The brain and heart are not one-directional; they are in constant two-way dialogue. At the center of it is the vagus nerve (the main parasympathetic pathway), running from the brainstem to the viscera.

Figure: top = brain (prefrontal cortex, PFC; amygdala), bottom = heart. The green two-way arrows represent the exchange, largely via the vagus nerve.

A neural network spanning the brainstem, hypothalamus, amygdala, and insular cortex is called the central autonomic network, and it integrates the regulation of the viscera, including the heart (Benarroch, 1993).

The neurovisceral integration model

Thayer and Lane proposed the neurovisceral integration model, linking emotion regulation with autonomic and cardiac control (Thayer & Lane, 2000). In this model, a central pathway is one in which the prefrontal cortex restrains over-reaction in regions like the amygdala and calms the heart via the vagus nerve.

• The better this prefrontal–cardiac pathway works, the higher (vagally mediated) HRV tends to be (Thayer et al., 2009)
• A meta-analysis of neuroimaging studies also shows HRV relates to activity in the prefrontal cortex and amygdala (Thayer et al., 2012)
• The model has since been organized as a hierarchical framework integrating perception through action (Smith et al., 2017)

So we watch "regulation"

Through HRV, what we glimpse is not mere cardiac motion but the capacity of brain and body to coordinate and adapt — that is, regulation. That HRV tends to drop under stress and recover afterward has this brain–heart loop in its background (Thayer et al., 2009; Thayer et al., 2012).

How Feelmo handles it

Against the background of this brain–heart connection, Feelmo reads HRV as the Regulation Score. How metrics are integrated is the core of Lumo Core and is not disclosed, as a trade secret. Related: Understanding HRV · The Science of Regulation.

References

1. Benarroch EE. The central autonomic network: functional organization, dysfunction, and perspective. Mayo Clinic Proceedings. 1993;68(10):988–1001.
2. Thayer JF, Lane RD. A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders. 2000;61(3):201–216.
3. Thayer JF, Hansen AL, Saus-Rose E, Johnsen BH. Heart rate variability, prefrontal neural function, and cognitive performance: the neurovisceral integration perspective on self-regulation, adaptation, and health. Annals of Behavioral Medicine. 2009;37(2):141–153.
4. Thayer JF, Åhs F, Fredrikson M, Sollers JJ, Wager TD. A meta-analysis of heart rate variability and neuroimaging studies: implications for heart rate variability as a marker of stress and health. Neuroscience & Biobehavioral Reviews. 2012;36(2):747–756.
5. Smith R, Thayer JF, Khalsa SS, Lane RD. The hierarchical basis of neurovisceral integration. Neuroscience & Biobehavioral Reviews. 2017;75:274–296.