Table 6 Summary of smooth terms for the model fitted to tongue sensor movements in the midsaggital plane during the production of [i]. The lexical predictor was whole-word frequency. TT = tongue tip, TB = tongue body, ver = vertical movements, hor = horizontal movements. Effective degrees of freedom (edf) substantially greater than 1 indicate a non-linear relationship between smooth and dependent variable

From: Paradigmatic enhancement of stem vowels in regular English inflected verb forms

smooth terms edf ref.df F-value p-value
s(time): TB hor [ɑ] 2.7721 2.9602 281.3910 < 0.0001
s(time): TB hor [i] 2.8188 2.9746 207.3173 < 0.0001
s(time): TB ver [ɑ] 2.8805 2.9888 347.3624 < 0.0001
s(time): TB ver [i] 2.9278 2.9959 281.6231 < 0.0001
s(time): TT hor [ɑ] 2.9160 2.9945 485.9599 < 0.0001
s(time): TT hor [i] 2.4159 2.7617 108.0798 < 0.0001
s(time): TT ver [ɑ] 2.9387 2.9970 611.4520 < 0.0001
s(time): TT ver [i] 2.8749 2.9878 217.0389 < 0.0001
s(word frequency): TB hor [ɑ] 1.8829 1.9850 6.9371 0.0261
s(word frequency): TB hor [i] 1.9379 1.9958 18.6328 0.0001
s(word frequency): TB ver [ɑ] 1.9361 1.9949 36.5984 < 0.0001
s(word frequency): TB ver [i] 1.9468 1.9968 19.0345 0.0001
s(word frequency): TT hor [ɑ] 1.7604 1.9405 2.9305 0.2095
s(word frequency): TT hor [i] 1.0011 1.0022 0.0986 0.7544
s(word frequency): TT ver [ɑ] 1.7777 1.9489 23.4363 < 0.0001
s(word frequency): TT ver [i] 1.9902 1.9998 105.0520 < 0.0001
s(Participant) 23.9066 24.0000 13106.4578 < 0.0001
s(Base) 53.0458 54.0000 7971.4828 < 0.0001