Table 1. Between-group comparisons of error rates for verbal discrimination tasks per category and contrastive feature.
| Variable | Group | Test statistics | |||
|---|---|---|---|---|---|
| Category | Patients (N = 12) | Controls (N = 12) | Category effect | Group effects | |
| Patients | Controls | ||||
| Words (W) | 0.02 ± 0.02 | 0.01 ± 0.01 | χ2(2) = 10.86p = 0.003 | χ2(2) = 5.72p = 0.056 | U = 83, p = 0.276 |
| Pseudowords (PW) | 0.05 ± 0.05 | 0.02 ± 0.03 | U = 96, p = 0.089 | ||
| Phonemes (P) | 0.07 ± 0.09 | 0.04 ± 0.07 | U = 95, p = 0.099 | ||
| Feature | Patients (N = 12) | Controls (N = 12) | Feature effects | Group effects | |
| Patients | Controls | ||||
| Place (W) | 0.04 ± 0.08 | 0.01 ± 0.03 | Z = –1.34p = 0.250 | Z = –1p = 0.500 | U = 79, p = 0.366 |
| Manner (W) | 0.01 ± 0.02 | 0.01 ± 0.02 | U = 72, p = 0.500 | ||
| Place (PW) | 0.16 ± 0.22 | 0.03 ± 0.05 | Z = –2.38p = 0.008 | Z = –1.342p = 0.250 | U = 101.5, p = 0.045 |
| Manner (PW) | 0.02 ± 0.05 | 0.01 ± 0.02 | U = 78.5, p = 0.366 | ||
| Place (P) | 0.23 ± 0.23 | 0.08 ± 0.14 | χ2(2) = 18.31p = 0.00004 | χ2(2) = 7.0p = 0.065 | U = 99.5, p = 0.057 |
| Fricatives (P) | 0.03 ± 0.12 | 0.03 ± 0.12 | U = 72, p = 0.500 | ||
| Voice (P) | 0.07 ± 0.1 | 0.06 ± 0.08 | U = 70.5, p = 0.466 | ||
| Place and voice (P) | 0.05 ± 0.15 | 0.03 ± 0.08 | U = 72.5, p = 0.500 | ||
Mean relative error rates (± SD) and non-parametric test statistics for within- (Friedman χ2 and Wilcoxon signed-rank Z-statistics, Bonferroni-adjusted significance levels set at p < 0.017) and between-subject comparisons (Mann-Whitney U test, exact p-values [one-sided]) for each category and contrastive feature.