Yoga Nidra: A tool to develop interoceptive awareness
The human body is an amazing highway of neural, humoral, and hormonal connections that enable it to feel, perceive, interpret, and react to different sensations or emotions. Interoception is the bi-directional process by which the body and brain share this information and regulate internal signals to manage one’s internal landscape (Chen et al., 2021). Cultivating interoceptive awareness improves homeostatic balance, self-regulation, resilience, and develops discriminative wisdom (Sullivan & Robertson, 2020). From discriminative wisdom comes the ability to ease suffering by distinguishing between prakriti, the distractions of the body, mind, and environment, and purusha, true nature as pure awareness.
Yoga nidra is an excellent yoga therapy practice to develop interoception. Also called yogic sleep, yoga nidra is an active meditation technique that guides the practitioner into a profoundly relaxed hypnagogic state by setting an intention on a specific mind state and then systematically focusing on different parts of the body and/or the breath while resting in savasana or corpse pose (Pandi-Perumal et al., 2022). The relaxation and feeling of unity created by the practice helps to manage stress, inspire self-transformation, improve learning, and promote physiological and psychological well-being (Pandi-Perumal et al., 2022).
Considered a top-down neurocognitive process, yoga nidra influences the physiological state by activating the parasympathetic nervous system through the vagal cranial nerve or efferent pathway (Chen et al., 2021). This relaxation signal is received from the peripheral organs, which in turn decreases heart rate, blood pressure and the flow of stress hormones in the body, thus off-setting the effect of chronic sympathetic nervous system stimulation and allostatic load (Sullivan & Robertson, 2020). The communication cycle continues as the peripheral organs then send interoceptive sensory signals back to the brain via the vagal or parasympathetic afferent pathway (Chen et al., 2021). These signals are received and processed at the brainstem and thalamus and then will move to higher regions of the brain, like the hypothalamus, insula, and anterior cingulate cortex, for integration and interpretation and, potentially, generating regulatory signals back to the peripheral organs via the descending, efferent pathways (Chen et al., 2021). In humans, the insula is actually activated when individuals consciously tune into their interoceptive state, which is done during yoga nidra and other meditation or mindfulness practices, suggesting it has an important role in the integration, regulation, and balance of sensory signals and stimuli (Chen et al., 2021). Therefore, the more yoga nidra and other techniques that cultivate interoception are practiced, the more this balancing, regulatory part of the brain is stimulated, strengthened, and prepared to maintain homeostasis.
Top-down neurocognitive practices like mental focus, visualization, and intention setting, which are all components of yoga nidra, support overall health and wellness by regulating the body’s systems. But they also improve interpersonal relationships and behavior as practitioners are more inclined to pause, reflect, and respond to negative stimuli in a healthier, more thoughtful way. Developing interoceptive awareness with yoga nidra, as well as other meditation and mindfulness practices, strengthens connections between an individual’s body, mind, and spirit and fosters the discriminative wisdom needed to live peacefully, intentionally, and free from suffering.
Resources
Chen, W. G., Schloesser, D., Arensdorf, A. M., Simmons, J. M., Cui, C., Valentino, R., Gnadt, J. W., Nielsen, L., Hillaire-Clarke, C. S., Spruance, V., Horowitz, T. S., Vallejo, Y. F., & Langevin, H. M. (2021). The emerging science of interoception: Sensing, integrating, interpreting, and regulating signals within the self. Trends in Neurosciences, 44(1), 3–16.
Pandi-Perumal, S. R., Spence, D. W., Srivastava, N., Kanchibhotla, D., Kumar, K., Sharma, G. S., Gupta, R., & Batmanabane, G. (2022). The Origin and Clinical Relevance of Yoga Nidra. Sleep and vigilance, 6(1), 61–84.
Sullivan, M. & Robertson, L. C. H. (2020). Understanding yoga therapy: Applied philosophy and science for health and well-being. Routledge.