They do mention that the network is partially learning the words themselves: > "On the other hand, the network is not merely classifying sentences, since perfo

They do mention that the network is partially learning the words themselves: > "On the other hand, the network is not merely classifying sentences, since performance is improved by augmenting the training set even with sentences not contained in the testing set (Fig. 3a,b). This result is critical: it implies that the network has learned to identify words, not just sentences, from ECoG data, and therefore that generalization to decoding of novel sentences is possible."