Does my body need protection, right here, right now?   February 10th, 2024

Before delving into the topic of interest for this post, I would first like you to take a look at the image of the two tables. To most people, this image depicts two tables of which one appears longer and thinner than the other. However, the truth is that the two tables are of the exact same size, both in terms of length and width. For the sceptics out there, please take out a ruler and measure for yourselves. 

This visual illusion, specifically called the Shepard’s table illusion (1), is only one of many sensory illusions having been found distort the perception of reality (2). But how can the tables look so different? The simple answer is that what we see, hear, feel, smell, etc., is actually not pure reflections of reality. Rather, it all constitutes perceptions, which are influenced, not only by what is happening in the outside world and/or inside our own bodies at real time, but also what we expect to perceive (both consciously and unconsciously) based on our previous experiences, as well as which consequences a particular perception may lead to. In other words, our sense of reality is really an integrated perception of what is really happening now, what has already happened in the past, and what may potentially happen in the near and/or far future (see for example reference 3-5). 

Intriguingly, pain is no exception from this concept of thought. Lately, it has come to our sense that pain does not simply reflect the state of our tissues, such as the presence of actual or impending tissue damage. Rather, it has been suggested to reflect a perception of the need for tissue (or body) protection, or as formulated by Harvie and Moseley in their recent book, the answer “Most likely yes!” to the internally (unconsciously) asked question “Does my body need protection, right here, right now?” (5). It therefore makes sense that questions such as “when will pain be present and when will it not?”, “how intense will the painful experience be?”, and “how long will it last?”, cannot be answered by looking at an X-ray, a blood sample, or by performing a physical test. Rather, the answers to such questions will depend on the entire context around the pain, including both the past, present, and future aspects related to it.

A well-known example, which clearly demonstrates the importance of context for pain, is a case report from 1995 published in the British Medical Journal. This report tells us about a 29-year old builder who, by the end of his work day, jumped of a ladder and landed on a nail, which went straight through his boot. In excruciating pain, the builder was taken to the hospital. But when the boot was removed upon arrival, the doctors found that the nail had gone between his toes (6). In this example, the context of this man’s accident clearly implied severe tissue damage to his foot, but in reality, his foot was just fine. The pain the man felt was therefore completely unrelated to the actual state of his foot, but only the context around it.

Another much more common example of when the experience of pain does not necessarily reflect the actual state of the body region(s) at which pain is localized, is the state of chronic pain. Because when a person enters a state at which pain has become chronic, the pain experienced is often poorly associated with signs of actual or impending tissue damage (7). Therefore, many researchers (although not all) do agree with the notion that chronic pain may reflect an overprotective response of the body. In other words, the internal question “Does my body need protection, right here, right now?” is more often answered with “Most likely yes!” than “Most likely not”. 

So why is this good to know? Well, because by consciously asking yourself the same internal question as suggested by Harvie and Moseley whenever you experience pain, and especially if your pain has been with you for a long time, you may then realise that there is in fact no true danger, or threat of danger, to react upon. In other words, although your unconscious self may have answered “Most likely yes” to the question “Does my body need protection, right here, right now?”, your conscious response might be “Most likely not”. This may not make your pain disappear. However, research has shown that focusing on the positive aspects of pain, such as its non-harmful properties, can actually reduce both its intensity and unpleasantness (see for example reference 8 and 9). But maybe more importantly, doing so may give you the courage to live your life as you want, even when pain is there, because you know that what you do is not actually harmful. 

Elin Johansson

2024  Pain in Motion

References and further reading: 

  1. Shepard RN. Mind Sights: Original Visual Illusions, Ambiguities, and other Anomalies. New York: WH Freeman and Company; 1990.
  2. Purves D, Wojtach WT, Lotto B. Understanding vision in wholly empirical terms. Proc Natl Acad Sci USA. 2011;108(Suppl 3): 15588-95.
  3. Press C, Kok P, Yon D. The perceptual prediction paradox. Trends Cogn Sci. 2020;24(1): 13-24.
  4. Tabor A, Thacker MA, Moseley GL, Körding KP. Pain: A statistical account. PLoS Comput Biol. 2017;13(1): e1005142.
  5. Harvie DS, Moseley GL. Pain and perception: A closer look at why we hurt. 1st edition. Adelaide: Noigroup Publications; 2021.
  6. Fisher JP, Hassan DT, Connor NO. Minerva. BMJ. 1995;310: 70.
  7. Cohen SP, Vase L, Hooten WM. Chronic pain: an update on burden, best practices, and new advances. Lancet. 2021;397(10289): 2082-2097.
  8. Woo CW, Roy M, Buhle JT, Wager TD. Distinct brain systems mediate the effects of nociceptive input and self-regulation of pain. PLoS Biol. 2015;13(1): e1002036.
  9. Schulz E, Stankewitz E, Witkovský V, Winkler AM, Tracey I. Strategy-dependent modulation of cortical pain circuits for the attenuation of pain. Cortex. 2019;113: 255-66.