EEG Phase-Amplitude Coupling Strength and Phase Preference: Association with Age over the First Three Years after Birth

PAC+ clusters across all ages. Comodulograms of t scores, for each electrode, showing MI of each area. White lines outline clusters with significant MI (PAC+ clusters, p < 0.05, corrected for multiple comparisons). In some cases (e.g., Fp1, Fp2, O1, and O2), PAC+ clusters cover most of the comodulogram; therefore, in these cases, white lines outlining blue clusters mark the border of a small area that is not PAC+. Comodulograms indicate the level of coupling between phase frequencies (x-axis, 0–20 Hz), and amplitude frequencies (y-axis, 40–100 Hz). Each electrode is plotted at approximate electrode location on scalp. All analyzed EEGs were included (regardless of age at collection).

Phase preference across all ages. Comodulograms of phase max, for each electrode. Comodulograms indicate the average phase max value across all EEGs (regardless of age at collection). Here, only low-frequency, high-frequency, and channel combinations in PAC+ clusters are displayed. Each electrode is plotted at approximate electrode location on scalp.

Distribution of phase max across all ages and correlations with age. A, Circular plots display the mean proportion of low-frequency, high-frequency, and electrode combinations demonstrating phase max (radius of figure) at each phase bin (angles of figure) for each age (in months). Data are analyzed and plotted over all channels analyzed (left), anterior channels Fp1, Fp2, F3, F4, F7, F8, Fz (middle), and posterior channels P3, P4, P7, P8, Pz, O1, O2 (right). B, Correlation coefficients (ρ, radius of figure) of the Pearson correlation between the proportion of low-frequency, high-frequency, and electrode combinations demonstrating phase max at each phase bin (angles of figure), and age. *Indicates phase bins where the correlation is significant (p < 0.05, Bonferroni corrected for 18 tests).