(352) Sex Differences in Sensory Processing: The Role of Stimulus Modality ad Psychological Factors

Abstract

The experience of pain varies greatly from person to person. Many factors affect individual differences in pain, including sex and psychological factors. Previous studies have separately examined the effects of sex and psychological factors on pain, but most have not examined them in combination. The aim of this preliminary, exploratory analysis was to investigate sex differences in pain in a large sample to determine how pain responses and psychological measures of males compare to those of females using multiple quantitative sensory testing paradigms and multiple psychological measures. 141 participants (55 males, 86 females, mean age=29.1±6.8) were exposed to noxious heat, cold, and non-noxious audio stimuli. Participants were asked to rate their pain intensity and unpleasantness from thermal stimuli and the loudness of auditory stimuli. Psychological measures included the Barratt Impulsiveness Scale, Positive and Negative Affect Scale, PROMIS Anxiety, PROMIS Depression, PROMIS Pain Interference, and Pain Catastrophizing Scales. Univariate analyses and multiple linear models were constructed. Significant sex differences were found for cold and auditory stimuli but not heat. Females had lower cold tolerance during cold water hand immersion (means: males=76.2 seconds, females=59.7 seconds; p=.010). However, for 0.5°C cold phasic contact stimuli, males had greater pain intensity ratings (means: males=1.8, females=1.1; p=.030), and pain unpleasantness ratings (means: males=1.5, females= 0.9; p=0.040). Males had greater sensitivity to auditory stimuli as demonstrated by higher auditory unpleasantness ratings (means: males=4.1, females= 3.1; p=.049). Sex differences in psychological measures were found only for anxiety, which was greater in females (means: males=11.2, females=13.7; p=.006) and impulsivity, which was greater in males (means: males=56.0, females=51.7; p=.003). After adjusting for anxiety and impulsivity, the sex differences in cold pain tolerance, contact cold pain, and auditory sensitivity were not significantly different. Thus, sex differences in sensory processing are modality specific but may arise from sex differences in psychological factors.