Word structure and decomposition effects in reading

Theories on the processing of compound words differ on the role attributed to access to individual constituents. These theories are mostly based on empirical evidence obtained in experimental settings that could induce artificial effects normally not occurring in natural processing. In this study we investigated the processing of compounds as compared to noncompound complex words in Italian through a reading task with eye movement recording. We included both head-initial and head-final compounds, in order to test whether the position of the head may influence the reading process. After ruling out the effects of length and frequency, we observed that pseudocompounds (i.e., words with a segment homograph to a real word in the leftmost part) elicited longer total reading times than all other types of complex words, including compounds. Furthermore, head-final compounds elicited longer total reading times than head-initial compounds. The results suggest that a word structure resembling a compound may induce longer processing, presumably related to unexpected morphological structures. The results also converge with previous evidence that in some cases there is a higher processing costs for head-final as opposed to head-initial compounds, possibly indexing a reanalysis of the stimulus in order to correctly assign the constituent properties. However, a deeper analysis restricted to compounds revealed a more complex scenario where several variables interact with headedness (namely, first and second constituent frequency, compound frequency, and compound length), and future studies are needed to discriminate among possible interpretations. Overall, our findings suggest that longer reading times are related to solving incongruities due to noncanonical structures, rather than to morphologically complexity per se.