Table A6.
Hierarchical Regressions Examining Contributions of Age to the Working Memory Composite Score in Experiment 2, Above and Beyond Processing Speed, Based on Increasingly Complex Processing Speed Measures
| 7- to 30-year-olds | ||||
|---|---|---|---|---|
|
| ||||
| Processing Speed Measure | ΔR2 | F for Δ | df | % Age Effects Not Mediated by Processing Speed |
| Age | .322** | 44.7 | 1,94 | |
|
| ||||
| Box Completion | .087** | 8.9 | 1,94 | |
| + Age | .237** | 32.7 | 1,93 | 73.6 |
|
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| Digit Copying | .258** | 32.7 | 1,94 | |
| + Age | .085** | 12.1 | 1,93 | 26.4 |
|
| ||||
| Digit-Symbol Substitution | .343** | 49.0 | 1,94 | |
| + Age | .039** | 5.9 | 1,93 | 12.1 |
|
| ||||
| Letter Comparison | .333** | 46.9 | 1,94 | |
| + Age | .080** | 12.7 | 1,93 | 24.8 |
Note—Estimates of age related change decreased as more complex processing speed measures were used. n = 96;
*
p < .05;
**
p < .01. Working Memory composite = average of paragraph recall, Rey-AVLT learning, card rotations (hits-FAs), backward digit span, and coordinative – sequential complexity z scores.