Hot and cold sensations invoke unique activity in overlapping brain regions

Summary

A study by Professor Kei Nagashima and Dr. Hironori Watanabe from Waseda University explored how the brain distinguishes between hot and cold sensations using EEG. They tested 20 participants with hot (40 ˚C) and cold (24 ˚C) temperatures applied to their fingers.

When we touch something hot or cold, we consciously sense the temperature, but how the brain’s cortex distinguishes between the two is poorly understood. Temperature sensitivity varies from person to person.

In a study by Professor Kei Nagashima and Dr. Hironori Watanabe from Waseda University, EEG was used to map the brain’s response to hot and cold temperatures. They tested 20 participants by applying hot (40 ˚C) and cold (24 ˚C) temperatures to their fingers and recording the brain’s reaction.

The analysis revealed specific patterns of brain activity in different regions and over time. Both hot and cold temperatures triggered activity in the same ten areas of the cortex, but the EEG responses differed for each sensation.

Nagashima said, “Differences in these activity patterns will allow temperature differences to be distinguished, leading to different behaviors.”

Researchers reveal how brain transforms sensation into action

Different activity patterns in the same brain regions help distinguish between hot and cold temperatures. Most brain activity was concentrated in the right hemisphere, suggesting it plays a more significant role in thermal sensations.

The study’s findings could lead to more objective methods for evaluating thermal comfort. Professor Nagashima noted that current standards for indoor environments rely on subjective reports, but a scientific understanding of the brain’s response could reduce health risks associated with these subjective evaluations.

Journal Reference:

1. Hironori Watanabe, Satoshi Shibuya, Yuta Masuda, Taisuke Sugi, Kiyoshi Saito, and Kei Nagashima. Spatial and temporal patterns of brain neural activity mediating human thermal sensations. Neuroscience. DOI: 10.1016/j.neuroscience.2024.11.045