July 12

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How do you feel? Interoception- the new science of emotion

Feeling Alive

What happens when someone asks, “How do you feel?” Besides possibly uttering the rote response, “good, how are you”—what is the process of sensing how you’re really feeling in that moment? It seems to involve interoception—the sense of the physiological condition of the body. Interoception mediates many different sensations—pain, temperature, itch, hunger, sexual arousal, and sensual touch, to name a few. And by representing various sensations in the brain, it provides a grounded, biological basis for those fuzzy feelings we call emotions [1].

The interoceptive neural network (from Craig, 2003).

The science of interoception has an interesting history. At least since William James (1884) proposed his influential theory of emotion—insightfully claiming that “our feeling of [bodily] changes as they occur is the emotion”—scientists have pondered and produced experiments to test the role of bodily information in emotion. The 20th century psychological revolutions of Behaviorism and Cognitivism, though, saw the study of interoception go into (interim) hiding; researchers focused more on observable behavior and cognitive, conscious mechanisms. Credit, then, the neuroanatomist Bud Craig for bringing interoception back to the fore of affective science. Through delicate neurological studies in other mammals and primates, Craig demonstrated that the interoceptive network—from neurons sensing the status of all bodily tissues and sending signals up the spinal cord to the brain stem and thalamus that converge in the insular cortex—is conserved across mammalian species, and particularly developed and interconnected in humans. His is a triumphant story of basic, “low-level” neuroscience inspiring deep psychological questions that are truly interdisciplinary and inherently human—what are our feelings, why do they matter, and how can we better use them?

Interoception for sense of self

Contemporary research on interoception is beginning to reach not only feelings-focused psychologists (like me), but medical professionals, clinical psychologists, and mind-body therapists, Why? Because the relationship of interoception to health involves an important focus on well-being: what it means, physiologically and psychologically, to feel well. The biological goal of interoception is to monitor and regulate physiological systems for optimal functioning. Better understanding the function of interoception, therefore, may inspire novel mind-body therapies for many conditions—psychological disorders that reflect interoceptive dysregulation (such as autism spectrum conditions), as well as anyone open to learning from emotion for well-being.

Interoception—the evolved, elaborated human capacity to feel and know our feels—may actually offer an antidote to subjective and societal ills. Humanity, with its exponential growth of voices, ideas, and social-media-fueled social comparison, is undergoing unprecedented challenges to available natural resources and social attention—which may consistently seep perceived resources for intra- and inter-personal refuge. For example, the current Western influx of yoga, meditation, and “turning off” from the collective cacophony has roots in—and now scientific backup for—ancient Eastern contemplative traditions. Mindfulness meditation practices based in Buddhist traditions were recently shown to improve interoception, along with constructive boosts for emotional health [2]. Why might meditation help people through interoception? It may start with a biological basis of self.

But first, let’s review how interoception is measured. The most common method assesses interoceptive accuracy—how well can you sense what’s happening in your body? This usually involves hooking someone up to a heart rate monitor and asking them to simply sit and tune in attention to count their heartbeats, across multiple unspecified time intervals, without feeling their pulse. The reported counts are compared to the measured counts, and an objective score is calculated. Scores tend to vary widely across people, providing statistical potential for linking it to outcomes. This is the most common operationalization of interoception, and thus what reflects “better interoception” in this article.

Briefly, there are two other prominent ways to measure interoception. Interoceptive sensibility refer to self-report responses that assess different qualitative reflections on how the (potential) perception of sensations may be conscious, understood, and inform decision-making. Interoceptive awareness represents how well someone consciously knows their own level of interoceptive attunement–i.e., metacognitive awareness of interoceptive accuracy. This is usually calculated by the correspondence between interoceptive accuracy scores and rated confidence (e.g., on a scale from 1-10) during each trial, when making heartbeat count guesses.

The Rubber Hand Illusion

It appears interoception influences not only that mushy stuff we call feelings, but first, our sense of self. For example, researchers have found that people better at interoception may have stronger selfhood, as evidenced by resistance to the rubber hand illusion. This parlor trick, brought into the lab, involves covering someone’s real hand with a curtain and placing a fake rubber hand next to it. By having the participant look at the rubber hand, and gently stroking both the real and fake hand at the same time, people often report a psychological “flip” of feeling that the rubber hand is their own! 

But interoception, with its biological purpose of sensing and mapping our own physiological spatial parameters, makes the illusion less likely for those more interoceptively in-touch [3]. 

Interoception and Emotion for Self And Others

All organisms require apparatuses to sense the external environment, and basic emotional reactions amount simply to approach or avoid, even in unicellular organisms. Interoception is then the moment-by-moment updating of our brain about our body’s state, including its reaction to the perceived environment. In humans, our idiosyncratic conscious appraisal of bodily sensations constructs what we call emotions, and interoception fuels this fire, whether you like it or not. People better at interoception, for example, report feeling emotions more intensely, along with greater acuity in identifying their own feelings. Alexithymia—relative inability to define sensations and emotions—is predicted by worse interoception, and a common hallmark of many aberrant social-psychological conditions, including autism [4]. Once emotions are understood, interoception may also facilitate greater ability to regulate them, either by cognitive reappraisal or suppression [5]. 

All this poses the intriguing question: does better feeling me, help me to feel you? How interoception may shape social processing is, so far, an understudied but growing topic. We have some clues from the impact of interoception on empathy—the ability to sense, understand, and (perhaps) share the emotions of others. 

For example, interoception strengthening a sense of self may also facilitate the psychological faculty of self/other distinction [6]—a critical component for me not getting swept away by your sadness if I’m empathizing with you, such that I can better keep my head and help you. However, not all studies find that interoception facilitates empathy, suggesting a complex relationship and potential moderating factors. Future research on interoception should continue to demonstrate its importance for personal and collective well-being, and inform interventions for improving health in all of us.  

So next time someone asks, “How do you feel?”, you might first check in with your body.  And besides telling them what that burrito from lunch is doing to your stomach, you may discover something more insightful and useful. 

  1. (Bud) Craig, A. (2003). Interoception: The sense of the physiological condition of the body. Current Opinion in Neurobiology, 13(4), 500–505.
  2. Singer, T., & Engert, V. (2019). It matters what you practice: Differential training effects on subjective experience, behavior, brain and body in the ReSource Project. Current Opinion in Psychology, 28, 151–158.
  3. Tsakiris, M. (2017). The multisensory basis of the self: From body to identity to others. Quarterly Journal of Experimental Psychology, 70(4), 597–609.
  4. Brewer R, Cook R, & Bird G. (2016) Alexithymia: a general deficit of interoception. R. Soc. open sci. 3: 150664.
  5. Kever, A., Pollatos, O., Vermeulen, N., & Grynberg, D. (2015). Interoceptive sensitivity facilitates both antecedent- and response-focused emotion regulation strategies. Personality and Individual Differences, 87, 20–23.
  6. Palmer, C. E., & Tsakiris, M. (2018). Going at the heart of social cognition: Is there a role for interoception in self-other distinction? Current Opinion in Psychology, 24, 21–26.