When discussing pain intensity and unpleasantness, one might wonder about masochists.
Philip Miller and Molly Devon describe a masochist as
One who derives sexual pleasure by receiving pain, domination, and/or humiliation, so-named for the genteel musings of the Austrian writer, Leopold von Sacher-Masoch. Contrary to popular opinion, the masochist still uses novocaine at the dentist and doesn’t proffer her body for vivisection. She will also decline PTA presidential nominations as readily as any non-masochist. It is only pain within the erotic context that she enjoys.
Within the scene, the term is often used to distinguish between those with a higher tolerance or enjoyment of punishment as opposed to those who prefer more sensual activities.
(Miller & Devon, 1995)
(Note that, while the use of the terms “pain” and “punishment” in this passage don’t reflect clinical use, the authors are not writing for a clinical audience.)
Tongue in cheek though it is, Miller and Devon’s emphasis on context is an important part of understanding how masochists can take nociceptive stimuli that often are related to actual tissue damage and experience them as something that is not, as the IASP definition of pain puts it, “always unpleasant” (“ IASP Terminology – IASP ,” 2017).
Within a sadomasochistic context, masochists have an expectation that tissue damage will be restricted to pre-negotiated, acceptable limits. While minor trauma, such as scrapes, bruises, and cuts, is not uncommon, practitioners of sadomasochism take significant precautions to avoid long-term harm. Miller and Devon’s work includes many pages of advice about inducing nociception without causing injury, and they quote Ms. Marie Constance saying, “Darling, I would never harm you , but there is a world of difference between hurt and harm, you know” (Miller & Devon, 1995).
Surprisingly little research has been done on exactly how a masochistic brain converts these nociceptive signals into something that is not pain. Kamping et al. used functional magnetic resonance imaging to compare the brains of healthy self-identified masochists to those of healthy non-masochistic controls while observing images that from the International Affective Picture System that were considered positive, negative, or neutral. In addition, they had a set of ten pictures that contained sadomasochistic content, and did ten trials with no picture at all (Kamping et al., 2016). They already knew, from previous research, that people in general tend to experience less pain when viewing pleasant images. Mathieu Roy et al. observed, “Emotions induced by pleasant or unpleasant pictures modulated the responses to painful electrical stimulations in the right insula, paracentral lobule, parahippocampal gyrus, thalamus, and amygdala” (Roy, Piche, Chen, Peretz, & Rainville, 2009).
When Kamping et al. compared the baseline pain tolerance of masochists and non-masochists, they found them similar. “As expected, masochists and controls showed no significant differences in pain threshold and tolerance. They did not significantly differ in pain intensity and pain unpleasantness ratings when painful stimuli were presented without an additional emotional context.” Both groups responded similarly to the positive and neutral images from the International Affective Picture System images, with some differences in neural function but not in pain perception between the two groups when viewing unpleasant pictures.
When viewing masochistic pictures, however, there were significant differences, with masochists reporting reduced pain intensity and unpleasantness to a degree normally associated with opioid drugs. The differential brain activation in masochists had little overlap with brain areas that other studies showed responding to sexual arousal, but were largely in areas that have been well documented as associated with pain. This neurologican and pain-reductions effects were related to the length of subjects’ interest in masochism, suggesting that the ability to modulate pain intensity and unpleasantness is learned rather than innate (Kamping et al., 2016).
While the nociception experienced by masochists while playing with “pain” lacks the unpleasantness required by the IASP definition, it is still referred to as pain by those who engage in it recreationally. More promisingly, there is some evidence that the “novel mechanisms of contextual pain modulation” are learned and, therefore, learnable; Kamping et al suggest that, with further research, this “might also be useful in treating clinical pain” (Kamping et al., 2016).