Investigating the relation between electroencephalogram, thermal comfort, and cognitive performance in neutral to hot indoor environment.

The relation between electroencephalogram signals, thermal comfort, and cognitive performance in neutral to hot indoor environment was investigated. The experiments were carried out at four temperatures: 26ºC, 30ºC, 33ºC, and 37ºC, and two relative humidity levels: 50% and 70%. Thirty-two subjects were exposed for 175 min. The electroencephalogram signals were measured for 30 min 25 min after the onset of exposure while the recruited subjects performed neurobehavioral tests and rated their thermal comfort. The relative power of electroencephalogram signals has a significant correlation with thermal comfort and performance of neurobehavioral tests. The ratings of acceptability of thermal environment and thermal comfort, the speed, accuracy, and PI of completing the tests are negatively correlated with the relative power of δ-band, but positively correlated with θ-band, α-band, and β-band. The ratings of thermal sensation have a better correlation with the above four bands, but the correlation trend is opposite. A linear relation was found between electroencephalogram signals and the speed. The results showed that the relative power of P7 channel located in the occipital lobe is the most suitable as a single electroencephalogram channel to reflect joint thermal comfort and cognitive performance at high temperatures, especially its α-band.