Pain dilates time perception

Abstract

We have all experienced that time seems stretched during unpleasant situations. While there is evidence of subjective time overestimation when perceiving external unpleasant stimuli, no study has measured the dilation of time when individuals experience an unpleasant situation in their own body. Here we measured the time dilation induced by a painful homeostatic deviance using temporal bisection task. We show that being in pain leads to an expansion of subjective time whereby a stronger increase in pain perception relative to non-painful stimulation leads to a stronger time-estimate distortion. Neurophysiological studies suggest that time estimation and the perception of self might share a common neural substrate. We propose that, along with bodily arousal and attentional capture, the enhancement of self-awareness may be critical to support dilated subjective time when experiencing pain. As other homeostatic deviances, pain may induce a focus on ourselves contributing to the impression that "time stands still".

Figure 1

Illustration of the procedure with the two training phases and the two test phases. In the training phases, participants learned to discriminate the ‘short’ (250 ms) and ‘long’ (750 ms) durations. In the test phases, participants were instructed to categorize a series of grey squares as ‘rather short’ or ‘rather long’ based on the two templates previously learned. The test phases were divided in two blocks: one block with the right hand in the water and one block with the left hand in the water. A trial in the test phase corresponded to: a fixation point for 500 ms, a grey square presented during 250, 300, 350, 400, 450, 500, 550, 600, 650, 700 or 750 ms and a blank screen until subject’s response. The stimulus duration was random and equiprobable. The Inter Stimulus Interval was 1000 ms. The pain and control conditions were counterbalanced as well as the hand immersed in the water (representing by the curved arrows). Pain intensity was assessed using a Visual Analogue Scale (VAS) at the end of each block.

Figure 2

(a) Mean proportion of long responses plotted against actual duration from 250 ms to 750 ms between the pain (solid line) and the control (broken line) conditions. (b) A focus on the bisection point (BP) in each condition, i.e. the duration giving rise to 50% of “long” and “short” responses. The bisection point shifted towards the left in the pain condition, consistent with a lengthening effect in the pain condition compared to the control condition. Errors bars represent standard errors corrected for within-subject design.