Pain-related and negative semantic priming enhances perceived pain intensity

Abstract

Background: Negative affective and pain-related cues, such as pictures or words, have been shown to act as primes and enhance the perceived intensity of subsequent painful events. For pain-related semantic primes, it remains unclear whether this effect depends on negative valence itself or, specifically, on the pain-relatedness of the words.

Objectives: To investigate the effect of pain-related, negative affective (pain-unrelated) and neutral semantic primes on the perception of subsequent noxious target stimuli.

Methods: Pain ratings in response to noxious electrical stimulation of light and moderate intensity were examined in 39 healthy subjects after subjects were exposed to semantic primes of different meaning and valence (pain-related, negative, positive and neutral adjectives) presented with different interstimulus intervals (0 ms, 500 ms and 1500 ms).

Results: Increased pain ratings of noxious stimuli were observed following pain-related and negative compared with neutral primes.

Discussion: The results support the motivational priming theory for semantic stimuli, indicating that affectively negative semantic primes increase subjective pain intensity. However, a specific pain-related priming effect was not reliably demonstrated. Additionally, it is shown that experimental parameters (ie, stimulus intensity and interstimulus interval) modify the extent of negative and pain-related semantic priming.

Conclusions: Verbal priming plays a role for the perception of noxious stimuli in a time-dependent manner.

Figures

Figure 1)

Design of experimental trials (example translated from German to English for illustration)

Figure 2)

Mean differences in pain ratings (Δ pain ratings) and standard errors to noxious stimuli in dependence of the primed adjectives (factor word Category) shown as differences to neutral adjectives

Figure 3)

Mean pain ratings and standard errors to noxious stimuli in dependence of the interstimulus interval (ISI) and the intensity of stimulation

Figure 4)

Mean differences in pain ratings (Δ pain ratings) and SEs to noxious stimuli primed by adjectives (factor word Category) with respect to the factors Intensity (Int) and interstimulus interval (ISI). Differences are shown in comparison with priming with neutral adjectives. Positive values indicate higher pain ratings for the priming with the particular category in comparison with neutral adjectives; asterisks indicate significant changes compared with neutral adjectives