Extended Data Fig. 8: Comparison between decoding novel and repeated sentences.

a, b, Comparison metrics included spectral distortion (a) and the correlation between decoded and original spectral features (b). Decoder performance for these two types of sentences was compared and no significant difference was found (P = 0.36 (a) and P = 0.75 (b), n = 51 sentences, Wilcoxon signed-rank test). A novel sentence consists of words and/or a word sequence not present in the training data. A repeated sentence is a sentence that has at least one matching word sequence in the training data, although with a unique production. Comparison was performed on participant 1 and the evaluated sentences were the same across both cases with two decoders trained on differing datasets to either exclude or include unique repeats of sentences in the test set. ns, not significant; P > 0.05. Box plots as described in Fig. 2.