Table 1. Results of linear mixed models (LMMs) to test whether proportion of time spent in vocal-postural-locomotor behaviors changes with postnatal day.
For each model, the proportion of vocal, postural, or locomotor time (per postnatal day) spent engaged in a behavior is the dependent variable, postnatal day is the fixed effect, and infant identity is the random effect. For each behavior category, a Bonferroni-Holmes correction was applied to adjust p-values.
| Behavior | β (SE) | T value | Adjusted P | Classification |
|---|---|---|---|---|
| Vocal behaviors (n = 192 observation days) | ||||
| Cry | −0.0128 (0.0019) | 6.88 | 0.0011 | immature |
| Phee | 0.0129 (0.0017) | 7.43 | 0.0004 | mature |
| Postural behaviors (n = 201 observation days) | ||||
| Forelimb support | −0.0010 (0.0020) | 0.51 | >0.05 | NA |
| Hanging | −0.0018 (0.0011) | 1.67 | >0.05 | NA |
| Hindlimb support | 0.0130 (0.0034) | 3.78 | 0.0373 | mature |
| Raising head | −0.0021 (0.0009) | 2.32 | >0.05 | NA |
| Righting reflex | −0.0081 (0.0015) | 5.54 | 0.0020 | immature |
| Locomotor behaviors (n = 191 observation days) | ||||
| Climbing | −0.0023 (0.0011) | 2.10 | >0.05 | NA |
| Crawling | −0.0160 (0.0019) | 8.35 | 0.0019 | immature |
| Digging | 0.0033 (0.0011) | 3.03 | >0.05 | NA |
| Jumping | 0.0005 (0.0002) | 2.37 | >0.05 | NA |
| Walking | 0.0147 (0.0012) | 11.95 | <0.0001 | mature |