In B.K.S. Iyengar’s book, Yoga: The Path to Holistic Health1, he discusses the philosophy of yoga and its sacred eight limbs. We are all too familiar with the most esteemed limb in the Western hemisphere: asana, or physical postures. Of course, those of us dabbling in yoga have probably also come across pranayama or breath control. I won’t name all the limbs, but today I will be exploring the fifth limb: pratyahara. Pratyahara is understood as the practice of withdrawing the senses in order to bring our focus inwards. However, I am going to go out on a limb (ha!) and make a statement that many yogi purists might see at sacrilege: pratyahara is not akin to the withdrawal of the senses at all. In fact, pratyahara and the grander practice of yoga facilitate our relationship with another sense: interoception.
Me in shanmukhi-mudra practicing pratyahara
What is Interoception?
Interoception is the sense of our internal bodily states with an emphasis on the sensations arising from the visceral organs (e.g., the gut, heart, lungs)2. With this definition, it becomes clear (at least in my opinion) that I am only disagreeing with the gurus in linguistics alone. Specifically, Iyengar states that pratyahara allows “the mind [to] turn inward and is set free from the tyranny of the senses”1. There is much wisdom in this statement because, while interoception is a “sense”, it is unlike our other senses in that it is an acquired skill that takes much practice. This is because our default brain mode is one of mind wandering or engaging in a “stream of consciousness” 3,4 — anyone who has dabbled in meditation can attest to the difficulty in attending to the present moment without allowing the mind to latch on to this enticing default mode. Mindfulness practice encourages the practitioner to turn their attention towards the present moment, which includes the sensations arising in the body. It is therefore unsurprising that studies have found a relationship between the ability to be mindfully aware and the ability to use interoception5. As the authors from one study state, “being mindfully observant is connected with greater body awareness”5. Thus, mindfulness meditation can hone our interoception.
Interoception on the Brain
Studies have demonstrated that mindfulness training improves interoception by altering the neural (brain) networks that are thought to control present moment awareness and the perception of bodily sensations3,4. One study, for example, used functional magnetic resonance imaging (fMRI) to assess how a mindfulness based stress reduction course could alter the activity in two key brain areas: (1) the insula, which is thought to be involved in internal sensations (i.e., interoception) and (2) the dorsomedial prefrontal cortex (DMPFC), which is thought to contribute to mind-wandering (think: mindlessness)3,6. Specifically, they found that the participants practicing mindfulness had greater brain activity in the insula and decreased brain activity in the DMPFC3. In short, mindfulness practice improves our ability to use interoception by inducing plastic changes to the very brain areas involved in interoception and mind wandering.
Brief Historical Context
Researchers have traditionally marginalized the role of bodily sensations on cognition — the topic of the second part of this two-part blog series. Darwin’s lesser known book published in 1872, The Expression of Emotion in Man and Animals, theorized that the experience of an emotion is heightened when accompanied by bodily expressions (e.g., baring one’s teeth, smiling)7,8. William James, the father of American psychology expanded on this idea when he suggested that visceral/bodily signals inform the mind about its emotional state5. This theory was epitomized in his idea that “we do not shiver because we are scared of the lion, but we shiver, and this is what we feel as our fear”9. Thus, both Darwin and James believed that bottom-up processing* (i.e., how the body informs the brain) is integral to understanding the way we feel.
*The concept of bottom-up processing will be expanded upon in Part 2 of this series.
This view was since banished from the research community in the age of top-down processing, where the emphasis was placed on how the brain informs the body (and not vice versa). It wasn’t until Antonio Damasio’s somatic marker hypothesis (SMH), which he proposed in his book Descartes’s Error in 1994 that the idea resurfaced in a significant way. It is beyond the scope of this series to delve into Damasio’s SMH, perhaps the topic of a future blog post. It will suffice to understand that the SMH describes how sensations arising in the body (i.e., the somatic marker) bias our decision-making10. In any case, the last two decades have seen an emergence in our understanding of how bodily sensations guide our thoughts, feelings, and behaviours11.
While it has taken centuries for the research community to grasp how the body and mind work together to create our experiences, we can appreciate Patanjali’s wise inclusion of pratyahara in his revered eight-limbed path of yoga. This is why interoception matters: interoception is the window into the body that informs the mind. And as we hone our interoceptive skills, we become privy to the influential power that is our visceral sensations. In the next post in this two-part series, we will look deeper at how our bodily sensations influence our thoughts, feelings, and behaviours.
- Iyengar BKS. Yoga: The Path to Holistic Health. New York: Dorling Kindersley Limited; 2001.
- Garfinkel SN, Seth AK, Barrett AB, Suzuki K, Critchley HD. Knowing your own heart: Distinguishing interoceptive accuracy from interoceptive awareness. Biol Psychol. 2015;104:65-74. doi:10.1016/j.biopsycho.2014.11.004.
- Farb NAS, Segal Z V, Anderson AK. Mindfulness meditation training alters cortical representations of interoceptive attention. Soc Cogn Affect Neurosci. 2013;8(1):15-26. doi:10.1093/scan/nss066.
- Farb NAS, Segal Z V, Mayberg H, et al. Attending to the present: mindfulness meditation reveals distinct neural modes of self-reference. Soc Cogn Affect Neurosci. 2007;2(4):313-322. doi:10.1093/scan/nsm030.
- Hanley AW, Mehling WE, Garland EL. Holding the body in mind: Interoceptive awareness, dispositional mindfulness and psychological well-being. J Psychosom Res. 2017;99:13-20. doi:10.1016/j.jpsychores.2017.05.014.
- Hasenkamp W, Wilson-Mendenhall CD, Duncan E, Barsalou LW. Mind wandering and attention during focused meditation: A fine-grained temporal analysis of fluctuating cognitive states. Neuroimage. 2012;59(1):750-760. doi:10.1016/j.neuroimage.2011.07.008.
- Darwin C. The Expression of Emotions in Man and Animals. London: John Murray; 1872.
- Strack F, Martin LL, Stepper S. Inhibiting and facilitating conditions of the human smile: a nonobtrusive test of the facial feedback hypothesis. J Pers Soc Psychol. 1988;54(5):768-777. http://www.ncbi.nlm.nih.gov/pubmed/3379579. Accessed October 30, 2017.
- Fuchs T, Koch SC. Embodied affectivity: on moving and being moved. Front Psychol. 2014;5:508. doi:10.3389/fpsyg.2014.00508.
- Dunn BD, Dalgleish T, Lawrence AD. The somatic marker hypothesis: A critical evaluation. Neurosci Biobehav Rev. 2006;30(2):239-271. doi:10.1016/j.neubiorev.2005.07.001.
- Werner NS, Schweitzer N, Meindl T, Duschek S, Kambeitz J, Schandry R. Interoceptive awareness moderates neural activity during decision-making. Biol Psychol. 2013;94(3):498-506. doi:10.1016/j.biopsycho.2013.09.002.