A Breath of Thin Air
WINNER - SANDS COX CHARITY ESSAY PRIZE 2019
Figure 1. A bridge generously embellished in prayer flags.
“Om Mani Padme Hum” – on stretches the baritone voice of our guide Motup. You’re turn he eagerly says. “Om Mani…” I feebly manage, acutely aware of the thinness of the air in my lungs. Our current altitude of 4000m clearly has more of an effect on me than Motup, as you’d expect when comparing a native of Ladakh (3000m) to a lowlander from Newcastle (60m).
‘Om Mani Padme Hum’ roughly translates as “the jewel is in the lotus” and is one of the most prevalent Buddhist mantras repeated across Northern India, Nepal, and Tibet. Beyond the dutiful repetitions by monks and yogis, the mantra seems to have permeated the very structures of these mountainous civilisations: etched into prayer wheels, stone, and of course the prayer flags that brightly adorn the landscape (figure 1). Its repetition is thought to bring one closer to understanding true compassion and achieving enlightenment. In addition to faith, one also requires control of breathing to tirelessly repeat the mantra. A focus on breathing is something that appears to be ubiquitous across human societies around the world. At its most basic level, how many times have you told someone to “take a deep breath” to calm down? Through to the more formalised breathing practices of meditation, yoga, and more recently mindfulness. In fact, my curiosity about breathing was the very reason for my presence in the Himalayas.
In October 2019, I was fortunate enough to go on the Birmingham Medical Research Expeditionary Society trip to Green Lake in Northern Sikkim, in the Indian Himalaya. As part of the research agenda of the trip, I was working on a study of the effect of ascent to high altitude on breathing perception under the supervision of Professor Kyle Pattinson. In brief, the study was using ascent to high altitude to induce a ‘transient illness state’ in otherwise healthy participants, mimicking the effect of chronic disease on symptom perception. Whilst the trek at high altitude was to act as a form of exercise intervention, which could represent a form of ‘interoceptive training’ improving individuals’ subjective symptoms of breathlessness.
Interoception is the neuroscientific term describing one’s awareness of their internal bodily state, in this context we were interested in awareness of the breath – ‘respiratory interoception’. Current discussion of perception is based upon the Bayesian Brain hypothesis, which in short, is that to facilitate the interpretation of the multitude of noisy sensory inputs, the brain generates an internal model of the world, which it continuously assesses and updates with incoming sensory stimuli. As all sensations are essentially coming from the brain, our experiences can be greatly influenced by both our expectations and mood, which in turn affect our internal model of the surrounding environment. It is suspected that such differences in brain processing may explain the all too common conundrum in clinical medicine of a patient’s symptoms not correlating with objective peripheral measures of physiology or pathology. How can two patients with the same oxygen saturations have two polar experiences of breathlessness: one remaining housebound whilst the other works fulltime and cares for their grandchildren?
As outlined by Marlow et al (1), the classic optical illusion by Joseph Jastrow in 1899 illustrates this phenomenon surprisingly well (figure 2). Whether we see a duck or a rabbit is largely influenced by what we expect to see in this picture. This holds true for our interpretation of sensory stimuli, including subjective symptoms such as pain and breathlessness. Do you see a rabbit (remain asymptomatic) or see a duck (experience shortness of breath)? Our study used a breathing apparatus which allowed the experimenter to provide small increases in respiratory resistance to further study this concept.
Figure 2. Duck or rabbit? Regardless of the sensory modality, the brain is thought to rely heavily on predictions when interpreting ambiguous stimuli (1).
Now, having probably thought more about your breathing than usual over the course of this article, I’ll leave you with an adage from Terri Guillements…
“The wisest one-word sentence? Breathe.”
– Terri Guillements.
1. Marlow L, Faull O, Finnegan S, Pattinson K. Breathlessness and the brain: the role of expectation. Curr Opin Support Palliat Care. 2019;13(3):200–10.