Fig. 1: Individual differences in the subjective experience of pain are further supported by differences between pain sensitivity classes in their ability to discriminate small differences in stimulus temperature via subjective reports.

Compared to participants from the High (red bars) and Moderate Pain Sensitivity classes (yellow bars), participants from the Low Pain Sensitivity class (green bars) needed a significantly greater increase in temperature from 43 °C to report changes in their perceived pain intensity and unpleasantness (p values: low – moderate: p_intensity = 0.017, p_{unpleasantness} = 0.003; low – high: p_intensity = 0.009, p_{unpleasantness} = 0.0005), as shown by post-hoc two-sided Dunn’s tests (A). Conversely, the highly sensitive class required a significantly larger decrease in temperature from 49 °C to report a change in perceived unpleasantness in relation to low or moderate sensitivity classes (p values: low – high: p_{unpleasantness} = 0.001; moderate – high: p_{unpleasantness} = 0.003), as shown by post-hoc two-sided Dunn’s tests (B). The smallest temperature changes to achieve discrimination in sensation from the sensation of a reference temperature, i.e., 43-ascending discrimination thresholds and 49-descending discrimination thresholds, are represented on the y axis. Error bars represent standard error of the mean. * represents p values < 0.05; ** represents p values < 0.01. Source data are provided as an xlsx Source Data file. n = 101 participants.