The processing of derived and inflected suffixed words during reading

The encoding of suffixed words (both derivations and inflections) was asses sed by monitoring eye movements during reading English sentences in which t he target words were embedded. The target words were derived words in Exper iment 1 and inflected words in Experiment 2. In each experiment, whole-word frequency and root frequency were independently manipulated, where pairs o f words differing on one variable and matched on the other were inserted in to the same sentence frame. For derived words, root morpheme frequency affe cted processing earlier than did whole-word frequency: it affected the dura tion of the first fixation, whereas whole-word frequency affected processin g only beginning on the second fixation. In contrast, for (the regular) inf lected words, word frequency had significant effects beginning on the first fixation, whereas root frequency had significant effects beginning with th e first fixation duration only for plural nouns and not for inflected verbs . Subsequent regression analyses on the inflected words suggested that the usual part of speech for the stem may play a significant role in processing . The data thus indicate that in normal reading, both the whole word as a u nit and the root morpheme play a significant role in processing.