Gender and laterality differences in thermosensation throughout the perceptible range

Area of Science:

• Thermosensory perception
• Pain research
• Sex differences in physiology

Background:

• Previous research indicates females may have higher sensitivity to experimentally induced thermal pain.
• Existing studies primarily focus on the sensory-discriminative aspects of pain, neglecting affective components.
• Gender differences in the affective perception of non-painful thermal sensations remain largely unexplored.

Purpose of the Study:

• To investigate sex differences in both sensory and affective dimensions across the entire thermosensory system, including warmth, coolness, heat pain, and cold pain.
• To explore potential laterality differences in these thermal perceptual dimensions.

Main Methods:

• Twenty healthy females and 20 healthy males participated.
• Participants immersed hands in water baths ranging from 10 to 47 degrees C.
• Ratings collected for thermal intensity, pleasantness/unpleasantness, and pain intensity.

Main Results:

• No sex differences were found in thermal intensity ratings.
• Females reported higher pain intensity for extreme temperatures (10, 15, 47°C) and greater unpleasantness for painful stimuli compared to males.
• Women perceived milder temperatures as more pleasant than men; significant sex x temperature interaction for affective ratings.
• Higher perceived pain intensity was reported for the left hand versus the right hand.

Conclusions:

• Sex differences in thermosensory perception are specific to the affective and painful components, not general intensity.
• Affective, but not intensive, ratings of innocuous temperatures reveal sex differences, indicating variations outside the nociceptive system.
• Laterality influences pain perception, with the left hand reporting higher pain intensity.