Measure | Task | VLBW (n = 147), Mean ± SD | Term-born (n = 171), Mean ± SD | Difference, % (95% CI) | P | Cohen's d ES^{a} |
---|---|---|---|---|---|---|

Reaction time, ms^{b} | SRT | 285.00 ± 1.15 | 274.00 ± 1.13 | 4.0 (1.1–7.0)^{c} | .007 | 0.30 |

CRT | 468.00 ± 1.16 | 454.00 ± 1.12 | 3.2 (0.3–6.2)^{c} | .032 | 0.24 | |

WM | 655.00 ± 1.23 | 604.00 ± 1.22 | 8.4 (3.7–13.4)^{c} | <.001 | 0.40 | |

DA | 336.00 ± 1.22 | 314.00 ± 1.21 | 7.2 (2.7–11.9)^{c} | .002 | 0.36 | |

AL | 1299.00 ± 1.25 | 1220.00 ± 1.26 | 6.4 (1.3–11.9)^{c} | .014 | 0.28 | |

Accuracy, hit rate, %^{d} | AL | 80.20 ± 10.10 | 85.70 ± 7.50 | 5.5 (3.6–7.5)^{e} | <.001 | 0.63 |

↵a The group mean difference divided by the pooled SD of the group.

^{30}↵b

*T*test comparing logarithm (log 10) reaction times on CogState tasks. As a result of positively skewed distributions, geometric means ± SD are reported.↵c Group difference; a positive value indicates a longer reaction time for VLBW individuals.

↵d

*T*test comparing percentage of correct responses. The arithmetic mean ± SD is reported.↵e Mean difference; indicates the absolute percentage difference between groups.