Morphosyntactic processing of complex nonwords in sentence context: An ERP study

The current study aimed to understand morphosyntactic processing of suffixes in sentence context. We employed Event-Related Potentials (ERPs) to assess how the morphosyntactic features carried by suffixes are integrated in the syntactic structure of the sentence during reading. Three types of sentences were tested: (1) sentences including non-stem+suffix nonwords embedded in syntactically congruent positions (She may selkify everybody by tomorrow); (2) sentences with non-stem+suffix nonwords in syntactically incongruent positions (She wore her selkify all day); and (3) sentences with the same syntactic structure as condition 1 and non-stem+non-suffix nonwords (She may selkert everybody by tomorrow). In addition, a control condition with the same syntactic structure as condition 2 and non-stem+non-suffix nonwords (She wore her selkert all day) was included to counterbalance the experimental stimuli. Participants silently read the sentences while the EEG signal was recorded. A significant effect of suffix status was detected in the 100-300 ms, 300-500 ms, 500-700 ms, and 700-900 ms time windows, with larger positive amplitudes for non-suffixes than suffixes. Moreover, a significantly larger P600 was found in the 500-700 ms time window for incongruent than congruent stimuli. The results demonstrate recognition of (non)word suffix in sentence context, in line with decompositional accounts of morphological processing, and highlight the importance of suffixes in morphosyntactic sentence analysis.