Test-retest reliability of EEG: A comparison across multiple resting-state and task-state experiments

Owing to its advantages in time resolution, electroencephalography (EEG) provides an important basis for studying the dynamic cognitive process of the human brain. To explore the electrophysiological mechanism of psychological processes, scalp EEG must have good test-retest reliability. Most studies explore the reliability of the resting-state EEG (rsEEG) or event-related potentials ( ERP), lacking a comprehensive comparison of multiple states. We comprehensively compared the test-retest reliability of the two rsEEG with eyes-open (EO) and eyes-close (EC) states, and the ERPs of PVT and oddball tasks, from frequency, time, and spatial domains to identify more widely applicable indicators. A total of 42 healthy adults (age range = 18-26 years old; mean = 19.5 +/- 1.4 years old; 14 males) underwent all three EEG recording sessions, including the present ( Session 1), 90 mins later (Session 2), and one month later (Session 3). During each EEG recording session, all the participants completed the same five states including two resting states (eyes- open, eyes-closed, each with 5 minutes) and two task states (PVT and oddball task). Intra-class correlation coefficients (ICC) were computed to assess the test-retest reproducibility of the five states. This study compares and analyses the test-retest reliability of two resting-state and three task-state EEG from the perspectives of time, frequency, and spatial domains. Results revealed the following: (1) The test-retest reliability of rsEEG was generally better than that of ERP. (2) For rsEEG, the test-retest reliability of the EC resting-state was higher than that of the EO, with the ICC median value of approximately 0.6. Furthermore, the test-retest reliability of the alpha band was the highest in all frequency bands. (3) For the two task-states ERP, the overall ICC of the PVT paradigm was higher than that of the oddball paradigm, and the test-retest reliability was highest at about 200 ms after the stimulus onsets. (4) In the spatial domain, the test-retest reliability is higher in the central region than in the peripheral region, which may be related to the signal-to-noise ratio (SNR). Our research involves multiple resting-state and task-state experiments. Based on the characteristics of frequency, time, and space domains, we comprehensively compared the optimal retest characteristics of multiple EEG and suggest the possible reasons. Some suggestions for the selection of appropriate experimental paradigms and indicators for the follow- up study of EEG test-retest reliability are provided and guide the application of EEG in the basic and clinical fields.