Cases (n = 100) | Comparisons (n = 50) | P Value | Adjusted P Value^{a} | |
---|---|---|---|---|

P1, %^{b} | 21 | 48 | .001 | .003 |

N2, %^{b} | 38 | 60 | .011 | .011 |

P2, %^{b} | 89 | 98 | .106 | — |

N3, %^{b} | 87 | 84 | .621 | — |

P1 IT, ms^{c} | 133 (118–175) | 137 (114–157) | .936 | — |

P2 IT, ms^{c} | 207 (191–221) | 206 (191–228) | .690 | — |

N3 IT, ms^{c} | 296 (247–329) | 321 (250–357) | .262 | — |

Total amplitude, µV^{c} | 27 (17–42) | 39 (28–67) | <.001 | .001 |

Percentage responses were compared by using χ

^{2}tests; implicit times and amplitudes were compared by using Mann-Whitney tests. IT, implicit time; —, not significant.↵a Adjusted

*P*value is after correcting for occipitofrontal head circumference, maternal smoking, and excess maternal alcohol intake during pregnancy with a linear regression model for VEP amplitude and a binary logistic regression model for the prevalence of VEP components.↵b Percentage of VEPs containing the individual component.

↵c Median (interquartile range) for implicit times and amplitude.