Feature and relationship between electroencephalogram power and salivary S-IgE concentration in healthy adults in different indoor temperatures

Abstract

Obtaining neural information about salivary secretory immunoglobulin E (S-IgE) is a starting point for investigating the mechanism of thermal environment regulation affecting human respiratory mucosal immunity. However, there is a scarcity of human-subjects research. To fill this void, we designed seven temperature conditions (15, 18, 21, 24, 27, 30, and 33 °C), collected electroencephalogram (EEG) and saliva from subjects, obtained thermal sensation and comfort votes, and detected S-IgE concentrations in saliva. Our results showed that the mean thermal sensation vote decreased by 2.31 units in the cold condition but increased by 2.25 units in the hot condition as compared to the thermal neutral condition (24 °C). Similarly, the absolute power of most channels in different frequency bands was the lowest at 24 °C within the thermally acceptable temperature range, including F8, F4, AF4, and T8 in α and β bands; at this temperature, the S-IgE concentration was the highest, increasing by 49.4 and 54.4%, respectively, compared to 21 and 27 °C. Furthermore, higher S-IgE concentration was associated with an increase in absolute power in the AF3 channel from the alpha band and the T8 channel from the theta band but a decrease in absolute power in the F7, T8, FC6, and F8 channels from the beta band (p < 0.05). Our findings suggest that EEG can be used to collect EEG signals associated to S-IgE concentration. Future research will concentrate on the effects of long-term temperature exposure on EEG signal and S-IgE concentration, as well as the link between them.