Heterogeneous Effects of Eye-close and Eye-open on Electroencephalographic Microstates of Depressed Brain in Resting State

Previous studies have shown that the resting-state electroencephalogram (EEG) of depressed patients exhibits abnormal dynamic activation of large-scale networks in microstate analysis. However, the problem of heterogeneous results in microstate features as physiological markers for depressive disorders has not been addressed. An important factor contributing to this problem is that previous studies have overlooked the effects of eye-opening and eye-closing on resting-state EEG microstates in depression. To address this gap, the present study proposes a new microstate delineation method to accurately identify EEG microstates in both open-eye and closed-eye resting states, and further analyzes the differential performance of the depressed group and the control group in the two states. We validated our method on a dataset containing 64-channel EEG data (55 cases in the depressed group and 55 cases in the control group). The results showed that the classical seven microstate topographies were present in both open-eye and closed-eye conditions, which may explain why other studies have overlooked the impact of eye state on resting-state microstates in depression. In addition, the microstate characteristics of depression were differentially expressed in the open-eye and closed-eye conditions, with the depressed group showing more significant results in the closed-eye condition. Overall, our study demonstrates that eye state affects depression microstates and provides new insights to address the problem of heterogeneity in the results of EEG microstate studies of depression.