Measure | Node | Uncorrected p-value | U statistic | z-score | Effect size | CI lower limit | CI upper limit |
---|---|---|---|---|---|---|---|

Relative low alpha power | O1 | 0.79 | 575 | −0.81 | −0.028 | −0.095 | 0.047 |

O2 | 0.74 | 582 | −0.65 | −0.013 | −0.089 | 0.049 | |

Relative alpha power | O1 | 0.86 | 562 | −1.10 | −0.078 | −0.13 | 0.049 |

O2 | 0.80 | 573 | −0.85 | −0.039 | −0.14 | 0.041 | |

Occipital connectivity | O1 | 0.94 | 543 | −1.52 | −0.76 | −2.18 | 0.48 |

O2 | 0.76 | 580 | −0.70 | −0.34 | −2.18 | 1.17 |

The relative power was computed following the methods of Vaudano et al. (2017). We considered the following two frequency bands: low alpha power (6–9 Hz) as in the main analysis; and alpha power (7.5–12.5 Hz) as in the study by Vaudano et al. (2017). The occipital connectivity corresponds to the connection strength of the electrodes (i.e., sum of in-strength and out-strength; Rubinov and Sporns, 2010). The

*p*-values,*U*statistics, and*z*-scores correspond to one-sided Mann–Whitney*U*tests assessing whether the relative power (or connectivity strength) is higher in the PPR group relative to the non-PPR group at a given occipital electrode. All*p*-values are not significant. The effect size (median difference) and confidence intervals further show that there are no statistical differences between the groups when using these measures.