Studying the influence of contact force on thermal perception at the fingertip

This paper investigates the influence of contact force applied to the human’s fingertip on the perception of hot and cold temperatures, studying how variations in contact force may affect the sensitivity of cutaneous thermoreceptors or their interpretation. A psychophysical experiment involved 18 participants exposed to cold (20 °C) and hot (38 °C) thermal stimuli at varying contact forces, ranging from gentle (0.5 N) to firm (3.5 N) touch. Results show a tendency to overestimate hot temperatures (hot feels hotter than it really is) and underestimate cold temperatures (cold feels colder than it really is) as the contact force increases. This result might be linked to the increase in the fingertip contact area that occurs as the contact force between the fingertip and the plate delivering the stimuli grows.