Table 1.
Descriptive statistics
| Task | Mean (SD) | Skew | Kurtosis | I.C. | Missing (%) | |
|---|---|---|---|---|---|---|
| Antisaccade | .81 (.12) | – 0.60 | – 0.65 | .87a | 5.7 | |
| VA – color | 2.5 (0.7) | – 0.41 | – 0.21 | .81b | 0.7 | |
| VA – concentric | 2.4 (0.7) | – 0.67 | – 0.01 | .79b | 0.7 | |
| SACT | .89 (.10) | – 1.15 | 0.92 | .87a | 4.0 | |
| Stroop DL | 1023 (484) | 1.63 | 2.53 | .87a | 3.0 | |
| Flanker DL | 659 (270) | 1.81 | 2.88 | .89a | 3.3 | |
| Symmetry span | 35.1 (8.8) | – 0.49 | – 0.09 | .74a | 3.0 | |
| Rotation span | 29.2 (8.5) | – 0.40 | – 0.01 | .76a | 3.0 | |
| Running span - digits | 66.9 (12.2) | – 0.33 | 1.11 | .83a | 2.3 | |
| Running span - letters | 51.6 (10.1) | – 0.08 | – 0.26 | .75a | 3.3 | |
| Raven’s advanced | 11.4 (2.8) | – 0.38 | – 0.26 | .77a | 1.3 | |
| Letter sets | 16.5 (4.4) | – 0.13 | – 0.66 | .85a | 2.0 | |
| Number series | 10.0 (3.0) | – 0.24 | – 0.70 | .73a | 1.0 | |
| Digit comparison | 29.9 (5.5) | – 0.49 | 0.08 | .88b | 0.0 | |
| Letter comparison | 20.6 (4.1) | 0.12 | 0.45 | .82b | 0.0 | |
| Pattern comparison | 39.1 (6.0) | – 0.09 | – 0.19 | .94b | 0.7 |
I.C. = Internal consistency, calculated before imputation. a = assessed using Cronbach’s alpha; b = assessed using split-half and stepped up with the Spearman–Brown prophecy formula. Missing % = total number of missing cases from the sample of N = 301, which were then imputed. Antisaccade and SACT scores are the proportion of correct responses; VA tasks are capacity (k) scores; Stroop DL and flanker DL scores are the average response time (ms) of the last four reversals in the adaptive procedure; symmetry span, rotation span, and running span tasks are edit distance scores for number of complete responses in the correct position (see Gonthier, 2022); all other tasks are total number of correct trials