What cross-morphemic letter transposition in derived nonwords tells us about lexical processing

According to an obligatory decomposition account of polymorphemic word recognition, a nonword that is composed of a real word plus derivational affix (e.g., teachen) should prime its stem (TEACH) to the same extent that a truly suffixed word does (e.g., teacher). The stem will be activated in both cases after the suffix is removed prior to the lexical status of the letter-string being of relevance. Importantly, disruption to the stem and suffix through letter transposition should have the same impact on the nonwords and words, with teacehn and teacehr equally priming TEACH. However, an experiment by Diependaele, Morris, Serota, Bertrand, and Grainger (2013) found that the equivalent priming for nonwords and words only occurred when they were intact. When letters were transposed, only the truly derived words showed priming. Since such a result cannot be handled by an obligatory decomposition account, it is important to replicate it. Therefore, the present study repeated the conditions of Diependaele et al. (2013), along with a nonword condition where the stem was followed by a non-suffix (e.g., teachin or teacihn). It was found that priming was maintained across all conditions regardless of letter transposition, hence maintaining obligatory decomposition as a viable account. However, the findings with the non-suffixed nonwords led to the conclusion that morphological structure does not control decomposition, but rather, has its impact after form-based components of the letter-string have been activated.