The Body's Role in Emotional Balance
Carlos S., known as “the man who felt two hearts,” had a medical pump installed in his chest to support his failing heart. The implant helped, but he could feel its beat more strongly than his own. This gave him the illusion that his heart was pumping in his abdomen, and that the size of his chest had grown. These seemingly minor sensory disturbances had a dramatic impact: Carlos couldn’t connect with his intuitive decision-making ability. He felt less empathy in response to people’s pain. And he had trouble reading the intentions of others.
Why would these small sensory changes carry such large emotional and social consequences? Let’s take a closer look at the brain to see how sensations are linked with emotions, and what that means for us.
The Neuroscience of Interoception
In the column Interoception: Your Body’s Superpower, I talked about the way receptors in the body specialize in distinct sensations, like temperature, the feeling of the breath, hunger or fullness, and muscle soreness and tension. Here’s what happens after these receptors perceive what’s going on in the landscape of the body—the tissues, organs, and skin.
Sensory information then travels along distinct pathways to the brain using specially designated spinal pathways. Sensory information can also travel from the body to the brain via alternate methods, which include the vagus nerve, a main communicator that conveys body states—think gut, heart, nervous system—to the brain. (For enthusiasts of polyvagal theory, you can see the connection between the vagus system and interoception happening right here “in the flesh.”)
Messages from the body arrive at a receiving area in the brainstem. Some complete their journey here. This activates the loop which sends direct feedback to the body in return. At this level, we’re less aware of body-to-brain communication; it happens under the surface of our awareness.
If information is marked for further passage, it travels to a relay station just above the brainstem, which sends it to a special area deep in the brain known as the insula. Here, the insula processes sensations in three stages. The first stage occurs in the back part of the insula, where the brain interprets sensations objectively, say, as cold, thirst, or pain. (Think of these as “pure” sensations.)
From there, information travels to the middle of the insula. Here, it is reinterpreted in a way that adds a valence, such as pleasant or unpleasant. Scientists often refer to these newly interpreted sensations as “feelings.” In the middle part of the insula, other sensory information such as proprioceptive signals add to the mix. (This shows us in neural terms that interoception and proprioception aren’t exclusive but rather, overlap with one another.)
The third stage of interoceptive processing takes place in the anterior part of the insula. Another region, the anterior cingulate cortex, also adds emotional layers to our sensory experience. In the anterior insula (particularly the right side), body states are reinterpreted as simple and complex emotions, like anger, sadness, happiness, lust, disgust, or fear. This part of the insula also correlates with the empathic response we feel to the pain and emotions of others, and to the hurt we feel in response to social exclusion (or, in this pandemic age, social isolation).
But there’s more: The anterior insula and anterior cingulate cortex represent not only our emotions, but the awareness we have of ourselves, others, and the environment. (This is also referred to as metacognitive awareness, the kind that contemplative practices like mindfulness aim to instill.)
Interoception is a system, made up of neural and neurochemical) circuits rather than any singular brain structure. That said, the insula plays a vital role. Its importance is telegraphed both by what happens when it activates and when it quiets.
According to neuroanatomist Bud Craig, the anterior insula (particularly the right side) activates in virtually every scientific study of subjective feelings, including primary emotions like anger, sadness, happiness, surprise, lust, disgust, and fear, as well as empathic happiness or pain, and romantic and maternal love.
In contrast, the anterior insula’s rich neural networks degenerate in several kinds of conditions. These include diseases in which we lose self-awareness and self-consciousness, such as frontotemporal dementia.
What’s more, brain images of people with alcohol dependence show reduced gray matter volume in the insula, together with a loss of neurons that specialize in emotional and social intelligence. And traumatic childhood experiences correlate strongly with decreased insular volume, which highlights another mechanism through which trauma impacts the body.
The key takeaway here: The process of interoception reveals that sensations are the building blocks for emotions. (And why a disruption in heartbeat sensations led to compromised empathy for Carlos, who we met above.)
And this brings us to one of the coolest implications that interoception has for emotional health: By working with sensations, we get better at regulating emotions. Let’s dive into this insight a little deeper.
But first, a tiny (yet important) digression:
The Cultural Relevance of Interoception
You can also think of interoception as mindfulness of the body. Mindfulness is a several thousand-year-old practice that has always involved the body and even movement. The Satipatthana Sutta, one of the two central discourses of Buddhism, has mindfulness of the body as one of its four central components. And in Mindfulness-Based Stress Reduction (MBSR), pioneered by Jon Kabat-Zinn, a bodyscan, breath-centered movement, and relaxation are all based in the body and comprise three of the four elements. The same is true of Mindfulness-Based Cognitive Therapy (MBCT).
Interoception and Emotional Regulation
Many studies link interoception with emotional regulation. In general, people with low levels of interoception (seen particularly in depression and chronic pain) also experience difficulty in understanding and identifying emotions. There are hundreds of recent studies that explore these correlations. But let’s look to a study that tells us why this connection between interoception, depression, and chronic pain might exist.
My colleague and friend Cathy Kerr co-authored this study. (Just prior to her death in 2016 of multiple myeloma, Cathy’s research in contemplative science had begun to take exciting new directions, and I think of her often.)
The idea: Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT) have been shown to reduce the risk of relapse in depression, and to attenuate the distress associated with chronic pain. These two systems use a common set of mindfulness exercises that involve the body.
The first two weeks of the standard 8-week program consist of a meditative bodyscan practice which directs the focus of attention through a series of body parts. The bodyscan has two aims: The first is to help practitioners learn to move their focus of attention through the body at will, even when sensations are unpleasant or painful. The second is to give people the experience of the way sensations ebb, flow, and fluctuate from one moment to the next.
The remaining 6 weeks of the mindfulness training program focuses on the sensations of breathing, a primary focus of traditional mindfulness practice and an emerging area of interoception research. These body-based breath awareness practices help practitioners detect when focus has moved away from the body, and to become familiar with the fluctuations of breath sensations. They receive the instructions to regard these bodily fluctuations, and any distressing thoughts that occur, as passing states of awareness rather than central parts of who they are.
Research has found that the somatic focus in standard mindfulness practices elicit changes in the neural circuits that address what to pay attention to (the signal) and what to ignore (the noise). This interoceptive focus increases attentional control over the alpha wave rhythm, which plays a key role in regulating sensory input and honing the skill at determining signal-to-noise dynamics.
The repeated practice of the bodyscan, together with the instructions to view sensations and emotions as passing states of awareness, helps practitioners learn to be present with distressing sensations in the chest, throat, and stomach that take place during intense emotional experience without being overwhelmed by emotions or catastrophizing thoughts. (This is what happens in depression and chronic pain: We have a distressing sensation, and then layer over it a negative thought about ourselves or the integrity of our body.)
They learn to switch attentional focus across both aversive and non-aversive body sensations.; this reduces reactivity to the aversive sensations. (While this is happening, the brain uses the alpha state to learn to control the “volume” of sensations.)
The article mentions that mindfulness-based training in body-focused attention could exert an “upward” influence on cognitive and emotion regulation as well as meta-cognitive awareness. What this means in a nutshell: Learning to be present with difficult (or neutral) sensations helps us develop a sensory form of resilience. This in turn “trickles up” to the brain, where it is experienced as emotional resilience.
In this way, interoception (read: the body) becomes a training ground for emotional balance.
My take: There’s a quote from Heraclitus that reads, “No [wo]man ever steps in the same river twice, for it's not the same river and he's not the same [wo]man.”
Why does focusing on the body have such profound healing effects? It’s because our field of sensory awareness is like that river: It fluctuates from moment to moment. Even if we don’t quite recognize it, sensations are not permanent. They change from one moment to the next. The ebb and flow of sensations mirrors the ebb and flow of our mental and emotional experience.
When we learn to be present with sensations, we begin to note that they change from one moment to the next. You can think of this as sensory resilience. This ability to be present with changing bodily sensation fosters the ability to be present with changing emotions, even difficult ones, and to cultivate the ability to tolerate them, to view them as fluctuations in our perceptual field.
Sensations are the origins of emotions. And getting better at being with difficult or neutral sensations helps us get better at being with difficult or neutral emotions.
This makes attention to bodily sensation (without cognitive evaluation or even, description) a valuable therapeutic tool in contemplative practice, psychotherapy, and other approaches to well-being.
The Social Context of Interoception
This one’s perhaps a little obvious. The entire field of neuroscience is influenced by three factors that haven’t historically received enough attention: Who does the studying, who gets studied, and what gets studied? The demographics of neuroscientists in the United States alone (stats aren’t readily available in other areas) are alarming.
So, who does the studying? White neuroscientists comprise 56.4 percent of all neuroscientists. People of Asian ethnicity make up 27.9 percent, and Latin-X scientists make up 7.4%. Black neuroscientists make up 4.6 percent, and Native 0.2 percent. Perhaps more concerningly, BIPOC representation in neuroscience is not increasing at a steady pace.
Another social context issue in neuroscience is who gets studied. Many studies have participants who are college students. In part, students are a “captive” audience, and neuroscientists are often located in university laboratories. But this means that for the most part, research subjects tend to be WEIRD—that is to say, Western, Educated, Industrialized, Rich, and Democratic. (Let’s add young, mostly white, able-bodied, and more to the list, too.)
In fact, the field of contemplative science research has received well-deserved criticism for testing methodologies that are not adapted to non-WEIRD populations. That’s a concern, because if something works well in one population and context, that doesn’t mean it works well in another. So the results of a lot of this research don’t always apply to non-student populations. And that means that research related to well-being is focused—you guessed it—on people with social privilege.
And finally, there’s the what gets studied part. As I continue to work on this book about embodiment, I’ve noticed that few scientists conduct research on the social aspects of interoception, proprioception, body agency, etc. (There are a few exceptions, such as the study by Negar Fani, Ph.D., that I discussed in last week’s column.)
I’ve asked about this directly when interviewing scientists; they know it’s an issue. But it means that embodiment tends to be something that scientists study in a lab, and therefore in individuals rather than small or large groups. This means that studies often lack another aspect of its social context, which is the way our bodies are social, and affect one another. Neuroscience’s focus on the individual means that we have less research to pair with our valuable epistemic knowledge about how important social factors, such as systemic oppression, gender-based violence, and ableism, etc. impact our inner senses are our experience of embodiment.
I don’t think this means that the neuroscience of interoception is invalid, particularly because it has been replicated to a strong degree. But it’s important to acknowledge what’s missing. And to know that many of these practices can, and should, and already do, adapt to the people who practice them. I love the way Prentis Hemphill talked on their podcast (Season 1, Episode 5) about how BIPOC practices and traditions have always incorporated embodiment.
I also recommend the innovative work of neuroscientist, contemplative practitioner, and activist Dr. Sara King. She integrates the traditions of yoga, mindfulness, and meditation with neuroscience and embodied social justice, with an emphasis on bringing these traditions into real-world situations.
Summary:
This article explores the role of the body, particularly interoception, in building emotional balance. Although this is a well-studied area, one of the most exciting implications is that increasing our ability to tolerate difficult sensations and emotions builds emotional resilience. That’s radical! Here are the main points that underlie this revelation in the study of emotional health:
The insula processes sensations in three stages: In the first stage, the back part of the insula, the brain interprets sensations objectively, say, as cold, thirst, or pain.
The middle insula reinterprets sensations in a way that adds a valence, such as pleasant or unpleasant.
In the final stage, the anterior part of the insula reinterprets sensations as simple and complex emotions, like anger, sadness, happiness, lust, disgust, or fear.
In the brain, interoception includes not just our sensations, or even our emotions, but the thoughts we have about them and the awareness we have of ourselves, others, and the environment. (This is also referred to as metacognitive awareness, the kind that contemplative practices like mindfulness aim to instill.)
The anterior insula’s rich neural networks degenerate in several kinds of conditions. These include diseases in which we lose self-awareness and self-consciousness, such as frontotemporal dementia, and alcohol dependence'
Traumatic childhood experiences correlate strongly with decreased insular volume and interoceptive processing issues
The key takeaway of interoception: Sensations are the building blocks for emotions.
This means that by working with sensations, we get better at regulating emotions.
Learning to be present with difficult (or neutral) sensations helps us develop a sensory form of resilience. This in turn “trickles up” to the brain, where it is experienced as emotional resilience.
Many studies link interoception with emotional regulation. In general, people with low levels of interoception, such as depression, chronic pain, and eating disorders, also have difficulty in understanding and identifying emotions.
One of the most-studied ways to work with sensations is by practicing the bodyscan meditation from Mindfulness-Based Stress Reduction (or other forms of mindfulness)
Because sensations are constantly changing, you can focus on other nodes of interoception besides the body scan, including the sensations of breathing, tightness or dehydration (or suppleness and hydration) in your connective tissue, hunger or fullness, or inflammation
'“Everywhere in the world, self starts with body.” (Roy Baumeister)
PRACTICE SECTION.
It’s tempting to skip over this section and receive the information cerebrally, or feel like you’ve got it “covered.” But the world around us is cerebral, and rewards conceptual insight and processing. My recommendation is to take on these practices and make them your own, because they really do help build a sensory resilience that impacts our mind, brain, and emotional and social experience.
I’ve got two suggestions for this article’s “body practice.”
In last week’s practice, you chose a sensation to track over a period of several months. This week, you can take that sensation and become more intimate with it. You can go from tracking it to embodying it “close up” for several minutes (or more) at a time. You can choose the sensations of breathing—how, for example, the inhale and exhale feel as they travel through your nose, or affect your upper chest, or change the shape of your belly.
Each time you lose focus (totally normal!), practice bringing awareness back to the sensation without judgment. If the “volume” of sensation feels too loud, you can experiment with seeing that sensation as a passing state of awareness, and staying with it as long as you’re comfortable doing so. Consistency is key in the practice; even if you’re trying this for just a few minutes a day, try to do it daily, if possible.
The second: You can practice this bodyscan meditation with Jon Kabat-Zinn. Highly recommended!
Sources:
Carlos S., known as “the man who felt two hearts,” had a medical pump installed: Robson, D. (n.d.). The mind-bending effects of feeling two hearts. Retrieved November 20, 2021, from https://www.bbc.com/future/article/20141205-the-man-with-two-hearts
According to neuroanatomist Bud Craig: Craig, A. D. (2014). How Do You Feel?: An Interoceptive Moment with Your Neurobiological Self (Illustrated edition). Princeton University Press.
And brain images of people with alcohol dependence show reduced gray matter volume: Senatorov, V. V., Damadzic, R., Mann, C. L., Schwandt, M. L., George, D. T., Hommer, D. W., Heilig, M., & Momenan, R. (2015). Reduced anterior insula, enlarged amygdala in alcoholism and associated depleted von Economo neurons. Brain : a journal of neurology, 138(Pt 1), 69–79. https://doi.org/10.1093/brain/awu305
In preschool and school-age children, traumatic childhood experiences: Luby, J. L., Tillman, R., & Barch, D. M. (2019). Association of Timing of Adverse Childhood Experiences and Caregiver Support with Regionally Specific Brain Development in Adolescents. JAMA network open, 2(9), e1911426. https://doi.org/10.1001/jamanetworkopen.2019.11426
My colleague and friend Cathy Kerr co-authored this study: Kerr, C. E., Sacchet, M. D., Lazar, S. W., Moore, C. I., & Jones, S. R. (2013). Mindfulness starts with the body: somatosensory attention and top-down modulation of cortical alpha rhythms in mindfulness meditation. Frontiers in human neuroscience, 7, 12. https://doi.org/10.3389/fnhum.2013.00012
So, who does the studying? White neuroscientists comprise: https://www.zippia.com/neuroscientist-jobs/demographics/. Accessed February 15, 2023.
Hi Bo, wondered what you think about polyvagal theory and how that aligns with a body-oriented approach to mental wellbeing?