Table 3.
Mixed-effects models of nonverbal ability and executive functioning development.
| Scale | CI | NH | Difference | t |
|---|---|---|---|---|
| DAS-II Picture Similarities T-score | ||||
| Intercept | 53.7 (49.8, 57.6) | 63.1 (59.1, 67.0) | 9.4 (3.8, 14.9) | 3.33*** |
| Slope | 0.6 (−0.6, 1.8) | −1.8 (−3.3, −0.3) | −2.4 (−4.3, −0.5) | 2.45* |
| Leiter-R Attention Sustained scaled score | ||||
| Intercept | 9.7 (8.7, 10.7) | 12.7 (11.7, 13.8) | 3.0 (1.6, 4.5) | 4.14*** |
| Slope | 0.2 (−0.1, 0.5) | −0.2 (−0.6, 0.2) | −0.4 (−0.9, 0.1) | 1.53 |
| Leiter-R Forward Memory scaled score | ||||
| Intercept | 10.6 (9.4, 11.8) | 12.9 (11.7, 14) | 2.3 (0.6, 3.9) | 2.71** |
| Slope | 0.0 (−0.4, 0.3) | −0.3 (−0.7, 0.1) | −0.3 (−0.8, 0.2) | 1.08 |
| WISC-III Digit Span Forward raw score | ||||
| Intercept | 2.4 (1.8, 3.1) | 3.2 (2.6, 3.8) | 0.8 (−0.1, 1.6) | 1.85 a |
| Slope | 0.8 (0.6, 1.0) | 0.9 (0.7, 1.1) | 0.1 (−0.1, 0.4) | 0.99 |
| BRIEF Inhibit T-score | ||||
| Intercept | 58.8 (55.0, 62.6) | 50.0 (46.0, 53.9) | −8.8 (−14.3, −3.4) | 3.18** |
| Slope | −1.2 (−2.1, −0.2) | −0.4 (−1.7, 0.9) | 0.8 (−0.8, 2.4) | 0.95 |
| BRIEF Shift T-score | ||||
| Intercept | 48.9 (45.7, 52.1) | 50.7 (47.5, 54.0) | 1.8 (−2.7, 6.4) | 0.80 |
| Slope | 0.7 (−0.3, 1.6) | −1.7 (−2.9, −0.5) | −2.4 (−3.9, −0.9) | 3.08** |
| BRIEF Working Memory T-score | ||||
| Intercept | 59.7 (55.7, 63.7) | 51.7 (47.5, 55.9) | −8.0 (−13.8, −2.2) | 2.71** |
| Slope | −1.3 (−2.4, −0.2) | −1.1 (−2.5, 0.4) | 0.3 (−1.5, 2.1) | 0.28 |
Note. Values in parentheses are 95% confidence interval. Intercept is for the age of 3 years. Slope is the change in points per age-year. CI = cochlear implant; NH = normal hearing; DAS-II = Differential Ability Scales–Second Edition (T-scores); Leiter-R = International Performance Scale–Revised (scaled scores); WISC-III = Wechsler Intelligence Scale for Children–Third Edition (raw scores); BRIEF = Behavior Rating Inventory of Executive Function (T-scores).
a
p < .10.
*
p < .05.
**
p < .01.
***
p < .001.