Frequency-specific resting-state EEG modulation during eyes-closed and eyes-open transitions in female soccer players

This study aimed to investigate differences in resting-state electroencephalographic (EEG) activity between female soccer players and female university students under eyes-open (EO) and eyes-closed (EC) conditions. A total of 25 female soccer players and 20 female university students participated in the study. Resting-state EEG signals were recorded using a 32-channel EEG system during 3 min of EO and 3 min of EC conditions. Absolute power in the delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz) frequency bands was calculated using Fast Fourier Transform (FFT). Electrodes were grouped into four regions of interest (ROIs): frontal, central, parietal, and occipital regions. A three-way repeated-measures analysis of variance (Group × Condition × ROI) and difference-score analysis (Δ = EC - EO) were conducted to examine group differences. The results revealed significant main effects of Condition and ROI across all frequency bands (all p < 0.01), indicating that the EC-EO transition reliably modulated resting-state EEG activity. No significant group-related effects were observed in the alpha or theta bands (all p > 0.05). In contrast, a significant Condition × ROI × Group interaction was found in the beta band (p < 0.05), whereas the delta band exhibited significant Condition × Group and Condition × ROI × Group interactions (both p < 0.05). Furthermore, difference-score analyses revealed exploratory differences in EC-EO modulation between groups in the beta and delta bands before correction for multiple comparisons; however, these effects did not remain significant after FDR correction. In conclusion, resting-state EEG modulation patterns differed between female soccer players and female university students in a frequency- and region-dependent manner, particularly involving the beta and delta bands. In contrast, alpha and theta activity mainly reflected fundamental physiological responses to EO and EC conditions and showed no apparent sport-specific differences. These findings suggest that long-term soccer participation may be associated with differences in resting-state neural regulatory patterns involving oscillatory processes previously implicated in visual information processing and sensorimotor regulation, although the functional significance of these patterns requires further validation. The present study provides new empirical evidence for understanding sport-related neural adaptations in open-skill sports.