Table 2.
ANOVA results
| Brain area | Source of variation | df | F | Puncorrected | Multiple comparison | Remarks |
| (a) Oxy-Hb | ||||||
| PAAC (BA 41,42) | Language | 1, 352 | 3.190 | 0.075 | ||
| Word frequency | 1, 352 | 0.027 | 0.870 | |||
| Hemisphere | 1, 352 | 0.000 | 0.988 | |||
| Language × frequency | 1, 352 | 0.004 | 0.950 | |||
| Language × hemisphere | 1, 352 | 1.974 | 0.161 | |||
| Frequency × hemisphere | 1, 352 | 0.019 | 0.891 | |||
| Language × frequency × hemisphere | 1, 352 | 0.523 | 0.470 | |||
| SMTG (BA 21,22) | Language | 1, 376 | 11.658 | 0.001 | <0.005** | L1 > L2 |
| Word frequency | 1, 376 | 0.000 | 0.997 | |||
| Hemisphere | 1, 376 | 0.083 | 0.774 | |||
| Language × frequency | 1, 376 | 0.270 | 0.604 | |||
| Language × hemisphere | 1, 376 | 0.504 | 0.478 | |||
| Frequency × hemisphere | 1, 376 | 3.232 | 0.073 | |||
| Language × frequency × hemisphere | 1, 376 | 0.510 | 0.476 | |||
| AG (BA 39) | Language | 1, 389 | 23.660 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 389 | 0.004 | 0.951 | |||
| Hemisphere | 1, 389 | 10.003 | 0.002 | <0.01** | L > R | |
| Language × frequency | 1, 389 | 1.515 | 0.219 | |||
| Language × hemisphere | 1, 389 | 0.055 | 0.815 | |||
| Frequency × hemisphere | 1, 389 | 4.265 | 0.040 | cf. captiona | ||
| Language × frequency × hemisphere | 1, 389 | 0.202 | 0.654 | |||
| SMG (BA 40) | Language | 1, 383 | 35.164 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 383 | 0.069 | 0.793 | |||
| Hemisphere | 1, 383 | 8.483 | 0.004 | <0.05* | R > L | |
| Language × frequency | 1, 383 | 1.682 | 0.195 | |||
| Language × hemisphere | 1, 383 | 2.822 | 0.094 | |||
| Frequency × hemisphere | 1, 383 | 12.813 | 0.000 | <0.005** | R > L (LF word) | |
| Language × frequency × hemisphere | 1, 383 | 2.201 | 0.139 | |||
| POP (BA 44) | Language | 1, 380 | 3.732 | 0.054 | ||
| Word frequency | 1, 380 | 2.214 | 0.138 | |||
| Hemisphere | 1, 380 | 26.347 | 0.000 | <0.001*** | R > L | |
| Language × frequency | 1, 380 | 3.760 | 0.053 | |||
| Language × hemisphere | 1, 380 | 1.853 | 0.174 | |||
| Frequency × hemisphere | 1, 380 | 0.605 | 0.437 | |||
| Language × frequency × hemisphere | 1, 380 | 1.721 | 0.190 | |||
| PTR (BA 45) | Language | 1, 378 | 2.056 | 0.152 | ||
| Word frequency | 1, 378 | 0.358 | 0.550 | |||
| Hemisphere | 1, 378 | 60.631 | 0.000 | <0.001*** | R > L | |
| Language × frequency | 1, 378 | 0.082 | 0.774 | |||
| Language × hemisphere | 1, 378 | 5.691 | 0.018 | |||
| Frequency × hemisphere | 1, 378 | 0.513 | 0.474 | |||
| Language × frequency × hemisphere | 1, 378 | 0.042 | 0.839 | |||
| (b) Deoxy-Hb | ||||||
| PAAC (BA 41,42) | Language | 1, 342 | 28.500 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 342 | 4.267 | 0.040 | HF > LF | ||
| Hemisphere | 1, 342 | 0.318 | 0.573 | |||
| Language × frequency | 1, 342 | 0.466 | 0.495 | |||
| Language × hemisphere | 1, 342 | 1.778 | 0.183 | |||
| Frequency × hemisphere | 1, 342 | 3.431 | 0.065 | |||
| Language × frequency × hemisphere | 1, 342 | 0.260 | 0.610 | |||
| SMTG (BA 21,22) | Language | 1, 372 | 43.317 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 372 | 15.561 | 0.000 | <0.001*** | HF < LF | |
| Hemisphere | 1, 372 | 0.469 | 0.494 | |||
| Language × frequency | 1, 372 | 0.027 | 0.869 | |||
| Language × hemisphere | 1, 372 | 8.474 | 0.004 | <0.05* | ||
| Frequency × hemisphere | 1, 372 | 0.572 | 0.450 | |||
| Language × frequency × hemisphere | 1, 372 | 32.913 | 0.000 | <0.001*** | ||
| AG (BA 39) | Language | 1, 386 | 28.607 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 386 | 0.336 | 0.563 | |||
| Hemisphere | 1, 386 | 0.331 | 0.565 | |||
| Language × frequency | 1, 386 | 0.241 | 0.624 | |||
| Language × hemisphere | 1, 386 | 4.770 | 0.030 | |||
| Frequency × hemisphere | 1, 386 | 4.053 | 0.045 | cf. captiona | ||
| Language × frequency × hemisphere | 1, 386 | 2.196 | 0.139 | |||
| SMG (BA 40) | Language | 1, 377 | 53.687 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 377 | 2.250 | 0.134 | |||
| Hemisphere | 1, 377 | 1.597 | 0.207 | |||
| Language × frequency | 1, 377 | 1.700 | 0.193 | |||
| Language × hemisphere | 1, 377 | 0.020 | 0.887 | |||
| Frequency × hemisphere | 1, 377 | 3.323 | 0.069 | |||
| Language × frequency × hemisphere | 1, 377 | 1.950 | 0.163 | |||
| POP (BA44) | Language | 1, 374 | 9.146 | 0.003 | <0.05* | L1 > L2 |
| Word frequency | 1, 374 | 3.703 | 0.055 | HF > LF | ||
| Hemisphere | 1, 374 | 4.430 | 0.036 | R > L | ||
| Language × frequency | 1, 374 | 1.194 | 0.275 | |||
| Language × hemisphere | 1, 374 | 2.742 | 0.099 | |||
| Frequency × hemisphere | 1, 374 | 0.001 | 0.978 | |||
| Language × frequency × hemisphere | 1, 374 | 0.002 | 0.964 | |||
| PTR (BA 45) | Language | 1, 374 | 64.363 | 0.000 | <0.001*** | L1 > L2 |
| Word frequency | 1, 374 | 0.945 | 0.332 | |||
| Hemisphere | 1, 374 | 58.095 | 0.000 | <0.001*** | R > L | |
| Language × frequency | 1, 374 | 2.151 | 0.143 | |||
| Language × hemisphere | 1, 374 | 0.080 | 0.777 | |||
| Frequency × hemisphere | 1, 374 | 2.199 | 0.139 | |||
| Language × frequency × hemisphere | 1, 374 | 0.564 | 0.453 | |||
Note: Statistical analyses using a 3-way repeated-measure ANOVAs were conducted for 6 ROIs to evaluate the effects of 3 within-subject factors: the 2 languages (Japanese: L1 and English: L2), 2 word frequencies (high: HF and low: LF) and 2 hemispheres (left: L and right: R). df = degree of freedom, PAAC = primary and auditory association cortices, SMTG = superior/middle temporal gyri, AG = angular gyrus, SMG = supramarginal gyrus, POP = pars opercularis, part of Broca’s area, and PTR = pars triangularis, part of Broca’s area.
aCf., Compare the laterality (hemisphere effects) for the angylar gyrus with that for the supramarginal gyrus: Additional paired t-test analyses for the [oxy-Hb] signals showed LH > RH for the high-frequency L1 (corrected P < 0.01) and L2 (corrected P < 0.05) word tasks, and for the [deoxy-Hb] signals showed LH > RH for the high-frequency L1 word task (corrected P < 0.05).
P values were Bonferroni corrected for 6 tests with a significance level of P < 0.05 after correction for multiple testing. Asterisks indicate statistically significant results (*P < 0.05, **P < 0.01, ***P < 0.001).