Experimental Procedure
The physiological parameters and EEG were recorded at four stages. The first test (Test 1) was performed at Xiamen (63 m) approximately one week before participants ascended to HA. After three days on train, all participants arrived in Lhasa (Altitudes: 3658 m) and stayed for two days. Subsequently, the participants stayed in Damxung County (Altitudes: 4300 m) for three weeks, then returned to Lhasa for three days and performed the second test (Test 2) in Lhasa. The third test (Test 3) was conducted within one week after the subjects returned to Xiamen. The last test (Test 4) was performed one month after participants returned to Xiamen (Figure 1).