ИСТИНА

The aim of this study was to investigate the EEG-correlates of subjective estimation of time spent. We have studied the dynamics of EEG power (10/20 standard electrode positions: O1, O2, P3, P4, C3, C4, F3, F4) during Go/No go task performance. Our participants performed four blocks of Go/No go task trials. They gave verbal time estimation of block duration. We divided all blocks into the three groups accordingly to quartiles of time estimation distribution: overestimation group (OG), accurate time judgments group (AG) and underestimation group (UG). We analyzed the averaged power spectra and averaged relative power spectra (% to whole power spectra 2-30 Hz) in 4-6 Hz, 6-13 Hz and 13-30 Hz frequency bands. We used ANOVA and Student’s t-test (with Bonferroni correction). Subjective interval estimation has EEG-correlates in beta-subband (13-30 Hz) (F3,35184=77.81, p<0.001). The shorter time estimation is accompanied by greater relative beta power (significant differences was observed in all electrode positions for groups UG and OG; in frontal, parietal and left central area (C3) for groups OG and AG; in parietal area, right central area (C4) and left occipital area (O1) for AG and UG). Asymmetry of relative beta-power is observed in frontal (28.4±0.4 vs 26.8±0.3, t=2.54, df=1819, p<0.05) and central (25.2±0.3 vs 26.8±0.3, t=-3.28, df=1847, p<0.001) cortical areas for AG and in parietal area (28.1±0.2 vs 27.3±0.2, t=2.51, df=4600, p<0.05) for UG, no inter-hemispheric differences of relative beta power was observed for OG. Thus, subjective time estimation of task duration has EEG-correlates in relative beta-power.