Influence of Cooling Rates and Contact Material on Illusory Wetness

Area of Science:

• Psychophysics
• Thermal Perception
• Sensory Science

Background:

• The perception of wetness can be triggered by cold, dry surfaces, a phenomenon known as illusory wetness.
• The rate of skin cooling is a critical factor in eliciting this illusory sensation.

Purpose of the Study:

• To investigate variables contributing to illusory wetness.
• To determine sensitivity to skin cooling rates.
• To examine the effect of thermal and material properties on perceived wetness.

Main Methods:

• Experiment 1: Method of constant stimuli to measure the difference threshold for skin cooling rate on the hand.
• Experiment 2: Participants rated perceived wetness of various materials at different surface temperatures.

Main Results:

• The difference threshold for cooling rate averaged 0.90°C/s at a reference of 0.5°C/s.
• Wetness was perceived at an average cooling rate of 1.09°C/s.
• Surface temperature was a more critical determinant of perceived wetness than material properties, which influenced heat transfer.

Conclusions:

• Skin cooling rate is crucial for illusory wetness.
• Surface temperature is the primary driver of illusory wetness perception.
• Material properties influence illusory wetness indirectly through their effect on heat transfer.