Table 2.
Mother–infant interaction dimensions and brain volumes: whole group descriptive statistics and comparisons by infant sex
| Whole sample (N = 39) | Males (n = 20) | Females (n = 19) | Sex difference | ||
|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | t | p value | |
| Interaction dimensionsa | |||||
| Maternal dimensions | |||||
| Sensitivity | 3.48 (0.54) | 3.51 (0.52) | 3.45 (0.56) | −0.30 | 0.765 |
| Affect | 4.25 (0.53) | 4.26 (0.54) | 4.23 (0.52) | −0.21 | 0.836 |
| Infant dimensionsa | |||||
| Communication | 3.52 (0.91) | 3.76 (0.86) | 3.28 (0.91) | −1.70 | 0.098 |
| Fretfulness | 4.11 (0.69) | 4.06 (0.66) | 4.15 (0.74) | 0.40 | 0.695 |
| Brain volumes, cm3 | |||||
| Total grey and white matter | 586.12 (69.66) | 603.53 (69.35) | 567.80 (66.92) | 1.64 | 0.110 |
| Midbrain | 13.90 (1.91) | 14.42 (1.83) | 13.35 (1.89) | 1.79 | 0.082 |
| Subcortical grey | 34.65 (3.71) | 36.17 (4.16) | 33.05 (2.36) | 2.89 | 0.007 |
| Cerebellum | 74.83 (11.91) | 77.11 (12.51) | 72.43 (11.06) | 1.24 | 0.224 |
| Lateral ventricles | 14.27 (4.58) | 15.01 (4.54) | 13.49 (4.62) | 1.03 | 0.308 |
| Cerebrospinal fluid | 133.94 (40.70) | 142.36 (44.95) | 125.07 (34.68) | 1.34 | 0.189 |
| Intracranium | 857.71 (99.72) | 888.58 (88.54) | 825.20 (102.68) | 2.07 | 0.046 |
aLow scores indicate poor interactions (for example, lower levels of sensitivity, increased depressive affect, fewer communication attempts and increased infant fretfulness)