Examine reveals how the mind differentiates cold and hot sensations

After we contact one thing scorching or chilly, the temperature is consciously sensed. Earlier research have proven that the cortex, the outermost layer of the mind, is liable for thermal sensations. Nonetheless, how the cortex determines whether or not one thing is scorching or chilly isn’t nicely understood. Thermal sensitivity is commonly subjective and individualistic; what’s a snug temperature for somebody may be too scorching or too chilly for another person.

In a brand new examine, Professor Kei Nagashima from the Physique Temperature and Fluid Laboratory, College of Human Sciences, Waseda College, Japan, and Dr. Hironori Watanabe from Waseda College, in collaboration with others, used electroencephalography (EEG) to map the mind’s response to cold and hot temperatures and make clear the exercise patterns. On this examine, 20 contributors have been uncovered to totally different temperature therapies on their proper index and center fingers. The temperature therapies got in pulses for 15 seconds with a 10-second intermittent temperature of 32 ˚C. Mind neural exercise in response to the 2 totally different temperatures, 40 ˚C and 24 ˚C, was recorded utilizing a wearable EEG gadget. The examine was revealed in Quantity 564 of Neuroscience on 09 January 2025.

The recordings have been analyzed to disclose region- and time-specific patterns of mind exercise. Clustered mind exercise was present in ten totally different areas inside the cortex. Curiously, each cold and hot temperatures invoked mind exercise in the identical ten areas. Nonetheless, the EEG differed in response to the 2 forms of thermal sensation. “Variations in these exercise patterns will enable temperature variations to be distinguished, resulting in totally different behaviors,” says Nagashima.

Various kinds of exercise patterns in the identical mind areas may very well be the underlying mechanism for distinguishing between cold and hot temperatures. It was additionally noticed that many of the mind exercise was concentrated in the best hemisphere, indicating that it has a higher function to play in thermal sensations than the left hemisphere.

The insights obtained on this examine may very well be utilized to creating extra goal strategies to guage thermal consolation. Nagashima states, “Thermal consolation is used as a regular for creating an optimum indoor atmosphere (air-con) by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, however it’s nonetheless based mostly on subjective reporting. We thought that it was important to guage it objectively and scientifically.” Well being dangers because of the ambiguity of subjective evaluations of thermal consolation may very well be circumvented with a greater understanding of the mind’s response.